ANTH Final Exam Review
-Nutcracker man --> shows big jaw, teeth and muscles
Fossil for boisei
Homo habilis
Fossil sites found in East and South Africa Species of homo usually associated with stone tools
1) Phenetic 2) Biological 3) Recognition 4) Evolutionary
4 Main Species Concepts?
clade
A group of species that includes an ancestral species and all its descendants (group and common ancestor - with the node!).
obstretical dilemma
A hypothesis to explain why humans often require assistance from other humans during child birth to avoid complications is due to a biological tradeoff, whereas most non-human primates give birth alone with relatively little difficulty
behavioral isolation
Form of reproductive isolation in which two populations have differences in courtship rituals or other types of behavior that prevent them from interbreeding Example: indigobirds are parasitic birds that lay their eggs in the nests of host species; baby indigobirds raised by different species will not recognize each other as mates
-Learned that species aren't fixed -Fossils as remnants of extinct life forms -All living organisms came from a common ancestor -Processes of today are the same occurred in the past -These processes take lots of time
Darwin's Post Voyage Years
Descent with modification: Organisms within populations vary, and these variations are transferred from parent to offspring (heritable). Darwin didn't come up with the concept that evolution happened, but rather he and Wallace were the first to come up with a viable, testable explanation for how it happened
Darwin's hypothesis
Biological differences does exist between populations, but race is a cultural construct not a biological reality
Do biological differences exist between populations?
-No, because it's too late in life to affect reproduction -Light skinned people exposed to strong sunlight had abnormally low levels of the essential B vitamin folate in their blood (which is critical for pregnancy) -Folate deficiency related to increased neural tube defects (ie spina bifida) --> UVB radiation causes decomposition of folate -So too much sun takes away vitamin B reserve --> having darker ensures that not too much vitamin B is lost
Is skin color about avoiding skin cancer?
Brains: increases as body mass increases, primates bigger than predicted regression line, and humans are even bigger/extreme Longevity: increases as body mass increases, primates bigger than predicted regression line, apes more so and humans even more Fertility rate: goes down as body mass goes down, humans are still in line with other primates, primates a lot lower than nonprimates
Primates v. non-primates in brains, longevity, fertility
-Resources used for one activity cannot be used for another
Principle of allocation
Measuring amount of C14 decaying/decreasing after organism dies -Pro: Can tell age of organism -Con: must be organism; and only can go to around 50,000 years ago
Pro con of C14 and material/how it works and time point
-Volcanic ash has crystals that contain potassium and when a volcano erupts it resets the potassium to 100% -So K40 decays to Ar40 -Pro: Can be used back to 100000 years ago -Con: can only date in volcanic environments
Pro con of K40/Ar40 and material/how it works and time point
-Lake Systems -- Low-level energy: silts and clays SMALLER PARTICLES THAN RIVERS -Animal Fossils --Some float from the fluvial system --Killed near the lake --Hippos, crocodiles and fish
Lacustrine - Lake Deposits
Foot is more derived than Australopithecus and resembles resembles extant humans suggesting a more striding gait Hand bones are more robust than later Homo species Longer arms than legs
Post cranial characteristics of homo habilis?
-Gametic incompability -Zygotic mortality -Hybrid inviability -Hybrid sterility (mule or hinny) -Hybrid breakdown
Post-mating isolating mechanisms?
63 or so million years ago Primates likely originated from an ancestor that was: -Generalized (common/widespread) -Small -Arboreal -Frugivorous and/or insectivorous We still haven't found this ancestor.
Primates likely originated from an ancestor that was....and at what time....
-Analogous similarity between humans, dolphins, bats and horses --> open environment causes long, thin limbs -hypsodonty index (how crown height compares to width): correlation between hypsodonty and annual precipitation (if there's more precipitation, you have a higher crown height that allows the teeth to be worn down more and can eat grass/graze)
Taxon free approach examples?
True: humans have lowered the age of weaning...this allows women to ovulate and be fertile again
True or false: humans have lowered the age of weaning
False: Social behavior IS a type of adaptation to the environment
True or false: social behavior is not a type of adaptation to the environment
False: Wasn't the earliest era but was certainly when the archaeological record for tools kicked off
True or false: the Pleistocene was the earliest era in which tools were found
False. Theories are NOT hunches or ideas
True or false: theories are hunches or ideas
Phenetic species concept
WRONG concept -A set of organisms that look similar to each other and distinct from other sets -Do not have to be related under this definition, though it is implied NOT a biologically useful definition CON: Just because organisms look similar outward does not mean they're related (ex: Sloth and monkey)
Females are the investing sex: invest more time and energy in pregnancy and lactation because they have a lower reproductive potential than males
What do females invest more time and energy in?
1. Genotypic and phenotypic variation (molecular, microscopic, and macroscopic) 2. Human biological differences (by sex, age, geographic region, environment, chance) 3. Biocultural influences on variation (but why cultural differences ≠ "racial differences")
What do we mean by human variation?
Samples drawn from parts of the genome relevant to humans and see which is different between people
What do we mean by whole genome?
1. Tooth size and shape - selected to be effective for processing the main dietary components of an organism 2. Wear patterns on teeth - leave scratches and polish according to the abrasiveness and toughness of the foods they ate 3. Chemical analyses of fossils - tooth and body composition (stable isotopes) 4. Indirect evidence from other preserved materials
What do we use to see change in diet (particularly human)
Food goes in Goes towards Maintenance -Foraging -Defense Reproduction Growth
What does energy go out and get spent on?
-Reproductive isolation (mating with those similar to them to prevent infertile offspring) --Pre-mating isolating mechanisms --Post-mating isolating mechanisms
What does most species concepts require?
Selection acts on the PHENOTYPES of INDIVIDUAL organisms (what is expressed)
What does selection act on? Phenotype or genotype?
-Mating effort -Parental effort --Offspring quantity --Offspring quality
What falls under reproductive effort
OH24 v KNM-ER 1470 (latter Leakey found) -KNM-ER 1470 forehead and brain was taller than OH24, and some even reasoned it was a better candidate for Homo/looks more like humans and would be a good candidate for human ancestor -Differences too different to be the same species --> so they're a new species (Homo rudolfensis)
What fossil did Leakey find that caused there to be the naming of a new homo species and why was this split done?
grandmothering hypohtesis
alloparenting is essential in humans post-reproductive lifespan allows human females to contribute to the success of their progeny human males also contribute, and they also experience a decline in fertility
hypothesis
an idea of proposition that can be tested by observations or experiments. MUST be falsifiable, which means that they are worded in such a way that they can be shown to be incorrect
Paradigm
a fundamental change in approach or underlying assumptions; fundamental turnover in a perspective we know
health
a state of complete social, psychological, and physical well-being
modern synthesis
a synthesis of Mendel's and Darwin/Wallace's views that was not achieved until mid-1930s Evolution is defined as a two stage process -The production and redistribution of variation -Natural selection acting on this variation and affecting reproductive success
dominant
a trait governed by an allele that is expressed in the presence of another, different allele at the same locus
recessive
a trait that is not expressed in the presence of another allele at the same locus. There must be two alleles of the same recessive trait to express that trait.
plasticity
adaptation to a stressor; phenotypic adaptations WITHIN an individuals lifetime
Natural causality
all events in nature are due to natural causes. One of the assumptions of science
Common perception
all humans perceive events with the same suite of senses (there's no sixth sense). One of the assumptions of science
Ice cores
cylinders of ice drilled out from glaciers and polar ice sheets. Helpful for determining temperature on a global scale Con: doesn't look back far in time for old sites and gives only 2 locations More snow fall --> darker layers Summer --> lighter layers
-Frugivore -Folivore -Gummivore -Insectivore
diet characteristics of primates
primate biogeography
different forest structures, timing, and historical circumstances (other mammals present) produce different resources that have allowed difference in the adaptive radiations of primates on different continents
alleles
different forms of a gene
Mechanical isolation
different reproductive organs or other physiological differences make it impossible for a successful mating to occur
natural selection
differential reproductive success based on beneficial variants
natural selection operates on phenotype
does natural selection act on phenotype or genotype
It's more accurate aging children than in adults (because bones are in parts in children and bones have fused together in adults) Changes occur slowly through life, and at specific times in a sequence 1. Dental eruption 2. Epiphyseal fusion 3. Pubic symphysis bone is separated when younger and fuses later 4. Cranial sutures
Method to determine age at time of death?
O16 evaporates more readily than O18
O16 ______ more readily than O18
O18 precipitates more readily than O16 Will be more on the ground because heavier
O18 ______ more readily than O16
-Females have choice -Matrilineal kin group affect success -Sexually receptive signals - advertising *OBJECTIVE IS TO PASS ONES GENE ON
Other female reproductive strategies?
-Aggression towards other males -Establish dominance relationships with their buddies -Honest signaling (more colored and recognizable) -OBJECTIVE IS TO PASS ONES GENES ON
Other male reproductive strategies?
-Colder temperatures -Emergence and global spread of genus homo; a lot of evolution during this time
Other than temperature, what makes the Ice Ages (Pleistocene) different from all other epochs?
Broad Spectrum Revolution
Period where a wider range, or broader spectrum, of plant and animal life was hunted, gathered, collected, caught, and fished; revolutionary because it led to food production.
-Lucy (almost complete skeleton, the first, gives us a good representation of features and locomotion) -Kadanuumuu (which is big and most likely male) -Dikika Child/Selam (complete skeleton of a child, we can look at teeth to get age and compare to brain size to see how slow it grew and gain more insight on life history traits)
Fossils for afaranesis?
Fossils help us calibrate the rate of molecular change --> use dated fossils for the dates of last common ancestors and plot genetic distance against divergence dates and use the slope of the line to estimate rate of change
Fossils help us ______ the rate of molecular change
Little Foot, Mrs. Ples, Taung child
Fossils of africanus
-Through adaptations or traits that are shared between species -More difficult than it might seem (superficial similarity due to convergent evolution --> armadillos and pangolins look similar but are not closely related)
How do we place organisms into the groups which they belong
-Proxy data: taking indirect mines of data -Working on different scales (global, regional, or local/archeological sites) -Working on different time scales -Different kinds of proxies can be used together to create a full picture of past environments
How do we reconstruct past environments?
Most of DNA is non-coding (98%)
Is most of DNA coding or non-coding
Graduation reduction of responses to or perception of, repeated stimulation (diminution of normal neural responses) Ex: Ceasing to startle at loud sounds when they are common at you
explain habituation
adaptation
exquisitely constructed components that interact to help the organism survive + reproduce
Homo ergaster
first fully bipedal, large-brained hominid. African version/population of homo erectus. In AFRICA First Homo to be more human-like than ape-like and experience a huge increase in brain size
Founder effect
genetic drift that occurs after a small number of individuals colonize a new area Ex: part of island is torn apart from bigger island (random chance that the group that happens to be on the smaller land leaves)
Mode 2 tools
handaxes or the Acheulean. Most associated with Homo erectus
percussion scavenging
hominids needed only a hard rock to break open animal bones and reach the fat stored inside. What's this method called?
miocene is known as the time of ape evolution
miocene is known as the time of what evolution
Gene flow
mixing populations; the movement of alleles among populations through interbreeding
wild resource management
modifying the environment to encourage certain resources
co-evolution
most if not all species have significant evolutionary relationships with other species -ex: human parasites
Bad mutations
most mutations fall into this category
directional selection
moves frequency of alleles towards one direction
blending inheritance
parental traits blend such that their offspring have intermediate traits
core
piece that is broken up
Macrofossils
plants and animals (actual body part)
platyrrhines
prehensile tail (some) dental formula 2:1:3:3 (Extra premolar) Flat-nosed New World Monkeys South and Central America Ex: callitrichids, capuchins, howler monkeys, uakari
nocturnal
primates are traveling, foraging and eating after dark
dirunal
primates are traveling, foraging and eating in daylight hours
-Grooming (endorphin rush and prevention of lice and tick bites) -Access to mates (more mates to choose from and more opportunities to mate) -protection from predators (more eyes and ears; "selfish herd"; alarm calls and mobbing behavior) -better access to food (more eyes to find food; larger groups feed first; older members have experience)
pros of living in groups
structural genes
provide information to guide protein synthesis. Code for proteins Transcribed into mRNA Composed of sets of 3 bases
pastoralism
raising and managing domestic stock (animals)
agriculture/horticulture
raising and managing the domesticated plant products
genetic drift
random change in allele frequencies in small populations
punctuated equilibrium
the concept that evolutionary change proceeds through long periods of stasis punctuated by rapid periods of change
taxonomic uniformitarianism
the ecology of modern organisms is used to interpret the ecology of ancient and extinct closest relatives living species can be analogous to species in the past, so we can assume they live in the same habitat and we can detect species turnover patterns -Can be one or more species (environmental reconstruction based on single species or a group of species) -Absence of fossils: migration or extinction -Presence of fossils: immigration and evolution
mutagenesis
the failure of DNA repair mechanisms (rather than mutation because of random, rare events such as cosmic ray bombardment) -ex: simply copy errors can lead to point mutations...if the gametes, they're passed on
indicator taxon
the fossils found at a site can let us know type of environment it was and whether it was health or not; reveals status of environment
clines
the gradual changes in the frequency of an allele or trait over space --> change over distance
behavioral ecology
the relationship between an organism's behavior and its ecological/environmental conditions
genotype
the specific genetic makeup of trait; represented by letters in Mendelian genetics
biological anthropology
the study of human biology and behavior as product of evolution. Examines biology and behavior of humans from an evolutionary perspective
Anthropology
the study of humans
medical anthropology
the study of social patterns of ill-health and disease transmission, and experiences of and knowledge about health, illness and well-being Subfield of sociocultural anthropology Cross-disciplinary Often ethnographic Study of health and health-related issues in social context
Population genetics
the study of the effects of natural selection, gene flow and genetic drift on populations by looking at the distribution and change of certain alleles across populations
Developmental Evolutionary Biology
the timing of gene activation in the life-course is crucial to the development of the phenotype. Thus the simplistic mapping of gene --> protein --> phenotypic trait is a gross oversimplification because it doesn't include the dimension of time
-investments in growth/maintenance are investments in the future...but it's all pointless (in an evolutionary sense) if you die before you reproduce -What you put into one side you must take from the other
tradeoff between current and future reproduction
heredity
traits must be able to be passed on from parent to offspring
gene flow
transmission of alleles among populations
energy goes to reproduction
When extrinsic mortality is high
Energy goes to maintenance and growth
When extrinsic mortality is low
Arboreal Theory of Primate Origins
-1913-1916 We have primate features because we lived in trees. We have... -Grasping hands and feet to hold onto branches -Binocular vision to run and leap in an environment that requires depth perception and judging distances -Sophisticated brains to process the complex three dimensional space -Sense of sight heightened and sense of smell diminished due to shifting air of tree tops
Charles Darwin
-Challenged the conventional view -Had access to education and was at the right time and place -Son of upperclass English doctor -Medical school dropout, divinity student -Avid naturalist and collector -Recommended for position of ship's naturalist on HMS Beagle
Visual Predation Hypothesis
-Matt Cartmill -Opposite approach to arboreal -Animals that hunt and track prey items tend to have high degrees of optic convergence and prehension in their extremities (hunting carnivores, like felines, have closer eyes to see prey, as well as have hands to grab prey) -Stereoscopic vision needed to have a wide range of vision for depicting close ranges -The ancestral primate was an insect hunting specialist that hunted in fine branches in the forest canopy or undergrowth. -So, builds on arboreal features and came to rely on visually directed predation to capture prey
Angiosperm Hypothesis
-Robert Sussman noted that fruit bats have a primate-like vision system but only eat from angiosperms (which are relatively new/evolved after last of dinosaurs) -The new availability of rich and abundant fruits and flowers in the terminal branches of tropical forests provided a windfall of resources that were utilized by the earliest primate ancestors Ex: small-bodied grasping hand create grabs flowers -Allows sophisticated vision to spot colorful flowers and fruit at a distance -Grasping hands and feet were favored in fine terminal branches
Codons
3 bases. Codes for one of 20 amino acids (or signals "start" or "stop")
taxon free approach
-ecomorphology of a single species to reconstruct diet, locomotion or substrate use -groups of species in communities or guilds to reconstruct habitats using the ecological diversity patterns -Groups of species compared with living communities to find community structure differences "morphology reflects environment"* -Form follows functions (open environment produces organisms with long, thin limbs)
multimale/multifemale with fission-fusion communities
-large groups of adult males and females -often split into smaller foraging parties (that meet again and might actually recognize each other) Ex: chimpanzees
solitary foragers
-more nocturnal and more solitary -adults spend most time alone (or just with offspring) -dispersed food resources Pro: easier to live alone (they're huge --> too many isn't reproductively fit) Species: orangutan
monogamous or pair-bonded
-one adult male and female defend small territory together (liaison; work together --> don't overlap territory like orangutan) -small, clumped resources Ex: gibbons
bottleneck effect
A change in allele frequency following a dramatic reduction in the size of a population Common traits exist with little variation
DNA
A complex molecule containing the genetic information that makes up the chromosomes. deoxyribonucleic acid; stuff that genes are made of; particle of heredity
evolutionary species concept
A single lineage of ancestor/descent populations which maintains its identity from other such lineages with its own historical fate Advantages: -Acknowledges time depth -Lineages form discrete branches on an evolutionary tree -Applies to fossil record Cons: -Gaps in fossil record impose arbitrary boundaries -No way to confirm if species are actually related to fossil ancestors -Assumption that something is part of the same lineage.
-Adapted to high latitudes and cold climates -Light hair and skin pigmentation -They shared many genes with us for tasting, immune function, and even language
Adaptations of neanderthals?
-Nocturnal: Look for food at night (these usually have bigger eyes and eyes shine; smaller body size because easier to hide and get into spots of insects, as insects appear more at night) -Diurnal -Cathemeral: random
Activity patterns of primates?
-Sand and finer particles -Not common because erosion and fossils blown away can happen until they're lost -Animal Fossils --Natural deaths --Died in storms --Arid-adapted
Aeolian (Wind-Blown deposits)
-Long gestation and live birth -Heterodonty (different teeth) -Ability to regulate temperature -Body Hair -Sight and smell highly developed -Hearing as an extreme specialization -Hair follicles and sebaceous glands -Four-chambered heart -Skeleton highly ossified
All placental mammals have/share
Selection acts on the phenotypes of individual organisms (what is expressed), but results in changes in the frequencies of the underlying genotypes in a population
Although selection acts on the phenotypes...what is the result?
Refer to the pattern under which changes accumulate
Anagenesis v. Cladogenesis
What about non-primates who live in a similar environment?
Arboreal Theory of Primate Origins Cons
Genetic drift is NOT gene flow
Are genetic drift and gene flow the same thing?
evolution
genetic change in a biological population over time
Taung Child
Australopithecus africanus -had a small brain -walked upright -from Africa -was against Piltdown man and no one believed it was a true fossil/a human ancestor
oldowan
Basically when the stone tool record takes off (NOT the earliest). industry of stone tools, clearly hominid made. Hitting rock with other rock to intentionally make an edge. Still required manipulative skill and cognition beyond what apes do Core = piece that is broken up Flake = sharp piece that is broken off
Macrofossils preserve best where they are: -Quickly buried -Subjected to long periods of stability -In a slightly alkaline (not acidic) environment Can give morphology
Best preservation condition for macrofossils?
-Cranial capacity is larger than h. erectus -Brow ridges arches -Forebrains with steeper foreheads -Thinner cranial bones than H. erectus -Face is reduced in overall size -Occipital torus reduced (less football-shaped) -Prognathism reduced -Not a huge brow ridge that sticks out/can't hold a pencil -Found in Germany, France, Greece and Spain (Sima de los Huesos): Homeland in Africa, but really all features were seen all over -It was likely the ancestors of ourselves, and the Neandertals, it is also the very first hominin that we have DNA for. It was everywhere. -visual similarities: bigger brains, cranial bulb is bigger, taller forehead, cranial bones are thinner, and jaw gets smaller and more gracile. -Brow ridge is one of the most dominant features, makes up a lot of the face, despite it getting smaller
Characteristics of homo heidelbergensis
Small populations high mobility minimal manipulation of natural resources Consumption very close to time of harvesting
Characteristics of hunter-gatherers
Similar brain size but longer head shape Prominent brow ridges Massive nose Retromolar gap
Characteristics of neanderthals (Cranially)
Over long periods of time, natural selection leads to the accumulation of favored variations of traits (depending on the environment) which produce new forms of life from pre-existing forms (the origins of species) Individual organisms compete for resources, but it is the composition of the population that changes over time Natural selection can only act on existing variation - new variants do not arise in response to pressure
Bottom line of evolution?
cladogenesis
Branching evolution occurs when a new species branches out from a parent species; the formation of a new group of organisms or higher taxon by evolutionary divergence from an ancestral form. Splitting of an ancestral species into several, new species. involves evolution in a branching pattern, with many new species evolving from a single parent species. Increases biological diversity since it increases the number of species Occurs at the node; separation of a gene pool into two or more gene pools
-Extremely robust --Even fingers and toes are more heavily built than humans --Heavy muscle attachments -Short stature -Rib cage barrel shaped -Short forearms -Femora are bow-shaped front to back -Basically, below neck, they look like short muscular modern humans
Characteristics of neanderthals (post-cranially)
-Must have originated by splitting off and diverging from another mammalian species. -Hairy (because mammal) -Insectivore -Small -Arboreal -Might not have all or any primate characteristics like a larger brain or heightened smell or grasping hands (which is challenging because how can you be sure it was a common ancestor)
Characteristics of the primate common ancestor?
Yes! If you find old skeletal remains and want to know if they're an ancestor to a human, you can't conduct an experiment. But if you find earlier/intermediate fossils and notice similar morphology, you can be fine!
Can you still falsify a hypothesis without an experiment?
How do dinosaurs fit in Genesis? Fossils of animals they've never seen before?
Con to fixity of species?
1. Blunt force (baseball bats, lead pipes, tends to translate depression in bone) 2. Sharp force (knife, sword, resembles cuts) 3. Ballistic (bullet, clean entry and large exit wound)
Categories of trauma?
-Cave Systems --Chambers are filled with sediments and biota -Fossil Animals --Live there --Washed in --Fall in --Dragged in
Cave deposits
1) How do organisms come to resemble their parents? 2) What maintains this variation, when they don't exactly resemble parents? (ie, the blending problem: why aren't all dogs medium-sized?) 3) How can the range of variation be extended? (if dogs come from wolves, how can the smallest dogs be smaller than wolves)
Challenges to Darwin's theory?
life history traits
Characteristics and developmental stages that influence reproductive rates. Examples include longevity, age at sexual maturity, and length of time between births. *The series of changes undergone by an organism during its lifetime.* Tells reproductive potential and how organism population may increase due to difference in these strategies
Pleistocene - The Ice Ages!! -Icy only in Eurasia -Characterized by large climatic shifts (some warm parts/time periods, but overall colder), and some of the coldest global climates in over 450 million years Lasted from 2.6 mya - 10,000 years ago And tool record/sites kick off (although it was not the first time tools were found/the earliest part) --Important for archaeological record, as more tools and easier distribution and tools are better than body fossils as they preserve easier
Characteristics of Pleistocene and age?
-Despite being the best Homo erectus skeleton, he is still just an adolescent and we're basing off the way the species grows based off him --And we can't assume that our current growing processes/time period (for example time for teeth eruption) is the same as ours
Con of Turkana Boy
-needs to find more evidence for other claims aside grasping hands -How do you explain converging orbits? --Rasmussen said that insects that came with angiosperm (pollinators) drove selection for convergent orbits (to capture insects)
Con of angiosperm hypotheses
This suggests that the earliest primate did not depend on fruit, flowers or other plant matter (although lemurs do that!) We haven't found insectivore teeth in earliest primates
Con to Visual Predation Hypothesis
-Time averaging (most fossils have accumulated over hundreds, even thousands of years) -Collection bias (collecting fossils that are convenient or aren't hard to see) -Deposition --Autochthonous assemblage (no transport of fossils) --Allochthonous assemblage (fossils were transported from different habitats and accumulated together)
Cons of fossil proxies?
Gives the impression that we don't know anything
Cons of theories
-Extinction of species -Introduction of invasive species (pathogens, plants, animals, that easily grow and hurt other organisms because they might not have predators and the organisms they're attacking may not have resistance to these pathogens)
Consequences that human migrations have had on local ecosystems?
polygenic traits
Continuous variation of "complex traits" Gradual gradations; intergrading phenotypes traits controlled by more than one locus; multiple genes for one trait; includes most traits of the skeleton (height, skin color)
Homo habilis has a big brain but it's not huge yet and it also has features relating to an Australopith - some wonder if they should be lumped into homo
Controversy about naming homo habilis Homo?
1. Average cranial capacity increased 2. Vertical forehead larger 3. Minimal brow ridge 4. Mid-face does not stick out 5. Rounded skull 6. Face tucked below the brain (also smaller face) 7. Smaller teeth 8. Slender mandible 9. A chin
Cranial characteristics of Homo sapiens?
-Post-orbital bar (at minimum) or post-orbital closure (monkeys, apes, humans); probably to create stability around the eyes due to reliance on increased vision -Snout is reduced and more reliance on sight -Face located beneath the brain case -Primates have more upright posture -Foramen magnum rotated beneath the skull (the hole in the base of the skull through which the spinal cord passes)
Cranial features that characterize the Order Primates?
Favor woodlands, forests (suggests better adapted to forests) and tend to live in tropics (although expansive in Africa) New World Monkeys: South America Lorises, Old World monkeys and apes: Asia, Africa Fossil primates in North America, South America, Europe Nothing beyond the wallace line
Current primate distribution
These regulatory sequences/proteins control gene expression
DNA switches
1) Protein synthesis 2) Cellular replication (via mitosis or meiosis) 3) Regulation of other genes
DNA's three primary functions
Known as "Means of Natural Selection" 1) The ability of a population to expand is infinite, but the ability of the environment to support population is always finite (from Malthus) 2) Organisms within populations vary, and this variation affects ability of organisms to survive and reproduce (from his observations at Galapagos) 3) Variations are transmitted from parents to offspring (learned from dog and bird breeders)
Darwin's theory outline
Successful hunters Spears were simple and like javelins - not hafted (not like an axe) - Mode 3 technology, though Definite use of fire - could cooking food be the key to our success? No evidence of art or creativity but such things don't preserve well Possible belief in the afterlife (refer to Sima de los huesos) -A lot of diversity (and much clearer picture of life and evolution at this time, but this is mostly from Europe...)
Day to day life in H. heidelbergensis
It's incredibly diverse site Ancient carnivore dens preserve many H. erectus individuals (highly variable, showing how important it is to find more fossils rather than use 1 fossil to represent whole species) 1.75 mya Shows how homo erectus left Africa, as well as them possibly traveling together in a group and at various ages
Describe site at Dmanisi, Republic of Georgia
-Also known as pit of the bones -More than 4000 hominin fossils found at the bottom of a pit at the site -Recent dating (>500 kya) -Wonder if it's a refuse pit or part of a burial practice? H. heidelbergensis found here
Describe the Sima de los Huesos site
-manifested in many different ways in various parts of the world -different climate contexts and different cultural contexts -independently but similar consequences
Did food production start in just one region of the world, or was it independently invented?
Principle of Segregation
Different expressions of a trait are controlled by discrete units that occur in pairs: one from each parent Offspring inherit one discrete attribute from each parent - no blending!
1. Wild resource management 2. Pastoralism 3. Agriculture/Horticulture 4. Agro-pastoralism
Different modes of food production?
1) Reduces speed and agility 2) Sacrifice climbing 3) Sacrifice reaching tall things
Disadvantages of bipedalism?
Each primate species can be defined by its niche space such that we can say it is (for example) a diurnal, canopy-dwelling, frugivorous, medium-sized brachiator
Each primate species can be defined by...
Homo fossils found in East and South Africa
Early Homo localities?
P. boisei
Enormous teeth and chewing musculature Ruggedly built East Africa Fossil: Nutcracker man
Enrichment of O18 is greatest under hot, arid conditions
Enrichment of O18 is greatest under __________
A. afarensis
Ethiopia, Kenya, Tanzania Remains from more than 300 individuals Brain slightly larger than a chimp Long, strong arms Matured more quickly than modern humans (like an ape) Reduced canines and anterior teeth (like humans) Woodland, scrub, dry savanna Fossils: -Lucy (almost complete skeleton, the first, gives us a good representation of features and locomotion) -Kadanuumuu (which is big and most likely male) -Dikika Child/Selam (complete skeleton of a child, we can look at teeth to get age and compare to brain size to see how slow it grew and gain more insight on life history traits)
1) Found bones already in Africa before split (in Fayum) 2) Rafting: ocean currents from North America --> Europe --> Asia --> South America 3) Caviomorph rodents and a bird (Hoitzin) showed up at the same time as New World Primates and have the same African origins.
Evidence for African Origin of New World Primates
Evolution is not a line but a braided stream -Branching but sometimes even the parts of the stream connect again -Australopithecus -Homo habilis and Homo rudolfensis -Homo ergaster/erectus -Diverse forms of later homo
Evolution: Line, bush, or braided stream?
1) Everyone is always selfish (this is because selfishness is subjective) 2) Space and time exist (hard to support space exists through observation) 3) Describing how things came to be 4) Invisible gremlins live in my freezer 5) God exists
Example of non-falsifiable hypotheses
1. Lactase persistence -Positive selection of Multiple genes that favor lactase (which digests lactose) due to shift of pastoralism and dairying -People who don't have lactose tolerance experience cultural adaptation (convert fresh milk to yogurt, buttermilk, cheeses as fermenting bacteria consumes most/all lactose) 2. Amylase Copy -Amylase breaks down starches -Higher concentration in saliva of populations with historically high starch diets (so higher copies of amylase) 3. Malaria resistance (heterozygotes/carriers for sickle-cell disease)
Examples of human microevolution due to intensified agriculture?
-Shift in evolution from goal-directed change to natural selection -Shift in genetics (discovery of DNA and genetics) -Acceptance of plate tectonics -Geocentric model to heliocentric model -Fixity of species to evolution -Earth was very young to earth is actually old
Examples of paradigm shifts
1. Darwin's theory of evolution by natural selection 2. Savannah-based theory: hominins descended from the trees and adapted to life on the savanna by walking erect on two feet 3. Angiosperm radiation theory: the adaptive radiation primates occurred with the radiation of angiosperms that offered new opportunities and an unexplored niche 4.
Examples of theories?
Anubis baboon and Hamadryas baboon They look, act, and have different ecologies but they hybridize
Exception to species concept
-Linkage!! Genes that are the same chromosome
Exception to the law of independent assortment?
-Focused on traits that have 2 forms and are true breeding (appear every generation). Example: green/yellow seeds and smooth/wrinkled seeds -Cultivated true breeding lines and then studied results of crosses -Kept careful records 1) Made 14 trains of pure-breeding plants 2) Made monohybrid crosses (matings between plants that differed only in one trait, such as yellow seeded plant with green-seeded plant, F0). 3) Collected offspring and planted them to see their offspring (F1) (all plants yellow, yellow is dominant) 4) Continued growing, say a 3:1 yellow to green seed ratio (yellow is dominant, green recessive)
Explain Mendel's experiments
Flaked stone tools used to cut meat --> Meat offers a higher-quality diet (energy surplus) --> Homo emerges from Australopithecus with larger brain and smaller teeth (energy surplus lead to development of larger brain and you don't need large teeth if you have tools
Explain connection between tool-making, meat-eating and origin of homo
-River Systems --High energy deposits: sand and pebble sediments --Low energy deposits: smaller sands LARGER PARTICLES -Animal Fossils --Trapped in floods --Killed near the reiver --Hippos and crocodiles
Fluvial Deposits
Adapidae
Folivorous; diurnal; generalized arboreal quadrupeds with some leaping
-Infinitely large breeding population -Completely random mating -No migration or gene flow -No mutation -No natural selection
For a population to be in equilibrium, what are the conditions that must be in place?
Temporal Isolation
species are active at different times
niche
Full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions the limits, for all important environmental features, within which individuals of a series can survive, grow, and reproduce
-Structural protein (keratin and collagen) -Regulatory protein (Enzymes, antibodies, hormones, nutrients, mechanical)
Function of proteins
Like a swiss army knife (multiple purposes, due to being able to carry them/they're portable) -included the butchering and skinning of game, digging in soil, and cutting wood or other plant materials. Maybe even sexual selection and/or hurling big ones at prey like a discus. Also varied in size BUT DID NOT PUT IT ON LIKE SPEARS - ONLY CARRIED IN HANDS
Functions of the handaxe?
Different paces at which such changes can occur
Gradualism versus punctuated equilibrium
Chimps, organutans, gorillas, humans (pretty small group)
Great apes?
Residential schools -Familial attendance at RS associated with: --All five health and mental health outcomes --Lower self-perceived health and mental health --Higher risk for distress and suicidal behaviors War: Holocaust -Children of Holocaust survivors with PTSD --Lower rates of methylation in a stress-related receptor --Holocaust survivors and their children showed changes in the same location of the same gene, a stress-related gene linked to PTSD and depression (controls didn't exhibit methylation) War: Tutsi genocide in Rwanda -PTSD associated with NR3C1 epigenetic modifications in the mothers and offspring -Exposed mothers and offspring had higher methylation of NR3C1 -These may provide the possible mechanism of transmission of biological alternations of the HPA axis
Historical determinant examples?
-Extremely altricial (dependent) at birth -Long period of growth, including long childhood and adolescence stages -Early weaning -Late onset of reproduction -Long lifespan (especially the post-reproductive period, fossil record shows they lost teeth, so others helped them get food and these post-reproductive homo erectus must've had value in the group for them to get such help) -DECREASE in body dimorphism, which is similar to modern humans (suggesting pair-bonding, although NOT monogamy) -Larger social units (at the individuals live longer, but kids still grow up fast, and larger body sizes and larger groups of individuals would be better at driving away predators) -Possibly more alloparenting (and maybe more division along labor), as well as change in diet and provisioning behavior -increased reliance on tools (associated with reduction in arm as more sophisticated tools are made and the brain is re-organized)
Homo erectus and human life history traits?
Sima de los Huesos
Homo heidelbergensis, pit of bones, found in Spain,
Strepsirrhine - "turning in and wet nose" - lemurs, lorises, galagos Haplorhine - "dry nose" - tarsiers, monkeys, apes, humans --Catarrhine "down nose" - Old World (monkeys, apes, humans from Africa, Asia and Europe) --Platyrhine "flat nose" - New World monkeys (South and Central America
How are Haplorhine and Strepsirhine further divided
-Sea levels --Warm seas: a lot of O18 (since O16 evaporated a lot) --But when the glacier melts, the glacier (which had a lot of O16) then has oceans enriched with O16 --Colder regions: Have more O16 --Ice Age: A ton of O16 but more O18 in oceans
How can oxygen isotopes in glaciers and oceans show past sea level change
1. Superposition - gives us a dating method, as we can tell the age of the rocks deposited in the layers 2. Uniformitarianism - The processes that formed ancient deposits are the same as those that form modern deposits. (magma cooling and crystallizing, ocean basins filling up, rivers flooding and landmasses experiencing erosion) Can help us determine the depositional environment; past geologic events can be explained by phenomena and forces observable today
How can you use geological laws in an example?
-Big brain -Altricial offspring -Tool-making and tool-using -Fire use -Social cohesion and predator avoidance -Social status ("showing off") -Resource control and distribution ("meat for sex")
How did meat change human biology and behavior
Primates adapted to a variety of habitats and niches by differentiating: -Body size -Activity pattern -Diets -Substrates and locomotor behavior
How did primates adapt to a variety of habitats and niches?
Then Pan-African climate change results in drier, more seasonal habitats, so more open grasslands This coincides with the emergence of several species But by 1.2 ma, we're only left with homo erectus (due to climate change and tectonics)
How did species diversity change after about 1.2 million years ago?
Difficult to accumulate wealth Lethal raiding less common Social stratification less pronounced *exceptions are on coastlines, where resource productivity is very high)*
How do characteristics of living hunter-gatherers differ from living agriculturalists
Remember that Africa had always been the source for new hominin dispersals Fossil evidence: -Earliest modern fossils are from Africa (315k ago) -Hominin fossils outside Africa are not modern humans until 50k years ago Archaeology: -Earliest evidence for 'traditional' markers of modern human behavior -Shell beads and ochre use with symbolism -Technology very rapidly becomes more diverse and more complex: Mode 3 technology --> progression to Mode 4 and 5 at the same time Mode 3 is still in use --Overall more complex: bone tools, shell beads, ostrich eggshell containers, microliths, blades (M4), finely flaked points, arrows (M5), complex projectile objects -Deliberate burials (many of them), some with grave goods -Changes in diet (shellfishing and snaring) -Herbal plant lore (collecting plants), complex multi-step technologies (adhesives, composite tools, heat-treating of artifacts) -Rock art and cave painting (Europe from 30ka, rock art in Australia) Genetic evidence: -Modern human genetic diversity is very low (around 2%) implies recent common ancestry -Highest genetic diversity in Africa, been there longest and had largest long term effective population sizes -Certain groups in Africa - such as the KhoiSan have the highest genetic diversity of all = deepest lineages -Current genetic diversity is a subset of genetics in Africa -Compared to other migration waves, our genetic diversity was more homogenous compared to other earlier waves of hominins
How do each of the main kinds of evidence show that Africa is the ultimate source for modern humans?
Females are more interested in finding food
How do females maximize reproductive success
They are interested in finding females to mate with
How do males maximize reproductive success
niche space
How do primates use their different ecologies to live in the same ecosystems
Noting key adaptations in our lineage: -Locomotion -Cognition -Tool use -Culture -Changes in bodies -Genetics (Changes that are more difficult to see) -Changes in populations and how we maintain them (Out of Africa; domestication of plants and animals; demographic explosion)
How do we answer the question "How have we changed"
1) Reconstructing the human lineage (Ex: Ardi, 4.4 million years ago, skeletal remains show bipedalism) 2) Genotyping ancient DNA (although hard to get ancient DNA)
How do we answer the question "Where do we come from?"
-You can tell where skeletal remains were buried intentionally (usually they live next to each other and are complete skeletons) -Preserve where conditions are constant, and pH should be higher than neutral (less acidic) to preserve the bone) -Burial goods can influence what preserves and how (indicative of society and beliefs based on organization and function of goods) --Ex: bury precious things (could this indicate high status or good to help with the afterlife)
How do you use skeletal remains as part of the bioarchaeology toolkit? What are best preservation conditions?
Relies on human variation
How does forensic science work? What does it rely on
stabilizing selection: since it's only lethal when there are two copies of the allele, it'll persist since it can be advantageous against malaria if you have one copy
How does the sickle-cell trait persist?
Gametes (egg and sperm) have only 1 copy of each chromosome When gametes fuse (through sexual reproduction), they create a zygote with the full set
How gametes different than somatic cells?
1) Systematic 2) Explicit 3) Quantitive
How is data collection done?
-Body size -Activity pattern -Diet -Locomotion
How is niche separation achieved?
23
How many pair of chromosomes does a human have?
2
How many sets of the genome does a human cell have?
Body must be buried by sediment before decay, weathering, scavengers, etc., destroy the remains -The vast majority of living things wind up inside other living things (i.e., are eaten or decayed). Only a tiny fraction are buried. -Environment of deposition becomes important. High energy environments (like river channels) bury quickly, but are likely to destroy smaller bodies. -Low energy environments (lakes, lagoons, etc.) might preserve small corpses, but are not quick enough to bury large animals before they decay/are scavenged. -Larger bodies can be covered by rivers at flood stage:
How would fossils preserve or be modified in different energy regimes. How would different energy regimes affect the associations of fossils with one another and with other objects?
hominin
Humanlike primate that appears to be more closely related to present day humans than to present day chimpanzees. Humans and our upright-walking ancestors.
More O16 in glaciers but more O18 in oceans
Ice Age? Which type of O?
It's hard to do that, especially if you use one skull as a model for a population range/certain region (but the more skulls you collect of a certain population the more overlap of similarities you'll see between populations, so then you can see you can't determine who is "German" or "Inuit") People do vary by geographic region, not by race
If races aren't real, how can we tell groups from different places apart?
-Some chemicals like vitamin D are formed when UV radiation alters the structure of a compound (limited exposure is all you need) -Vitamin D leads to absorption of calcium in intestine and bone growth (lack of vitamin D leads to Rickets and Osetomalacia), and we can't produce vitamin D without UV exposure SO we're not all dark-skinned because we need vitamin D
If we need vitamin B why aren't we all dark skinned? Is selection working against light-skinned individuals?
-Raised the bottom line --Lower energy outlay (due to cooperation with group members, walking on two legs, using tools, simpler gut development, quicker metabolism)... ...and raises energy/calories revenue (due to finding new foods, using tools, and cooperating with group members)
Impact of human diet?
Microfossils are used to determine how old a piece of rock is and determine if there is gas or oil in the area. They are also used to see what kinds of major geological events took place such as earthquakes or major weather changes such as ice storms.
Importance of microfossils?
Ecological isolation
species are physically separate, such as eating different fruit, there's a river between them
omnivores, as meat doesn't contribute to many calories
In terms of diet, most primates are...
Hardy-Weinberg Equilibrium
In the absence of factors that alter them, the frequencies of genotypes (and phenotypes) remain constant generation after generation
metabolic dilemma
Infants at around 9-10 months post-conception become very metabolically expensive, more than the mother can support, so the baby must leave pre-maturely or else they'll be too big and pose metabolic issues on the mother
Modern humans are highly cooperate within groups - unique amongst animals Modern humans can create, store, and transfer information at an astounding rate across long distances This means humans were also better at systematic eradication of "others" We shouldn't think modern humans all evolved at the same across the whole area --> there was probably an equally complex series of replacements/introgressions within Africa. African Multiregionalism: homo sapiens didn't arise from a single point in space. The entire continent was our cradle and humans originated from several diverse populations that lived across Africa. But early humans were repeatedly drawn together and pulled apart, and whenever they mated and mingled, exchanging genes and ideas in a continent-wide melting pot that eventually coalesced into homo sapiens
Is there a reason we should believe that all humans arose simultaneously from across Africa, or is it likely there were small sub-populations that were all evolving and periodically meeting and interbreeding? What might cause populations to encounter one another after many thousands of years of isolation?
No! Hunter-gatherer diets vary! There is no one H-G diet, most likely due to different environments (which shows how the Paleo Diet shouldn't be generalized) Humans have evolved to eat a variety of diets, which is good because that means we can get a lot of nutrients
Is there one hunter gatherer diet?
-Outgroup (a related species that is clearly different) -Node: coalesce to a common ancestor (that may or may not be alive) -Root: base of a tree
Key parts of a phylogenetic tree?
1) Position of foramen magnum shifted; in bipedal, the position of the hole is directly under the skull 2) Shape of inner ear, which influences balance and locomotion 3) Curves of vertebral column (lordosis); humans have s-shaped curve near top of neck and near bottom of spine, while in other great apes it's more straight - cushions our head and balances us due to weight 4) Rib cage: in humans it's more barrel-shaped while in chimps and other apes it's funnel-shaped - barrel-shaped so we can swing our arms 5) Pelvis shape - in human it's bowl-shaped while in great apes it's tall/narrow; bowl-shaped so can carry organs on the top 6) Bigger glutes to support weight/give more strength 7) Sacral body is wider and broader than in apes - because needs to hold all the weight 8) Limb proportions - other apes have very long arms compared to their legs (in humans we have smaller arms) 9) valgus knee - knee is angled inward in humans --> this keeps balance because weight than goes to the midline 10) arch of foot appears in more modern hominins 11) in humans, toes are aligned while in other apes they have an opposed toe and it kinda looks like a hand
Know at least six ways to tell from a fossil if an organism was bipedal from its skeleton (three above the neck and three below the neck).
1. Fossils are accompanied by rich datasets about past environments = NEW EMPHASIS ON CONTEXT OF FOSSILS (context is very important) 2. Excavation and recovery methods are now more systematic (but also smaller-scale); questions are more refined and fieldwork more targeted 3. There have been advancements in techniques such as dating, DNA, and paleoenvironmental reconstruction
Know at least three "lessons learned" that are now common practice in modern paleoanthropology.
1. complex cognition 2. within-group cooperation 3. between-group cooperation (and conflict!) -Also we occupy all parts of the world, even remote islands constant shifting of the human genetic map caused extinction of species introduce invasive species
Know at least three possible aspects of human behavior that may have made humans successful at colonizing the globe. Why would we be the most invasive species?
Humans first in Africa, Australia, Europe, then New World and Polynesia 1. Australia -65000 years ago -"World's old continuous cultural traditions" 2. Europe -Relatively late colonization - only 55000 years ago -Explosion of material culture expression, and then rapid diversification 3. Americas -15000 years ago -Two models of who was there first --"Clovis First": big-game hunters who produced long "fluted" points or --"Pre-Clovis": were people here before then --Evidence points that there was an initial occupation earlier than Clovis (>11,500 years ago) --Genetic data shows populations held in Beringia, and that they eventually landed into the Americas. New site in northern Beringia has fluted points ("backflow" of cultural traditions towards Asia) 5. New Zealand Last (1000 years ago)
Know the order in which Homo Sapiens arrived in each place. What other hominin was already living in each place, and what happened to them?
1. Tooth size and shape -- selected to be effective for processing the main dietary components of an organism 2. Wear patterns on teeth -- scratches may indicate how tough the foods they ate were 3. Chemical analyses of fossils (using carbon stable isotopes and nitrogen isotopes) and seeing tooth and body composition 4. Indirect evidence from other preserved materials (cut marks on bones) -But it's difficult to reconstruct the diet of Lucy's species because nothing of their kind had existed before and they don't really exist today so it's hard to do an exact reconstruction when it's the middle
Know three main ways you can reconstruct ancient diet in hominins (hint: many of these you already know from the previous section on paleoenvironment). Why is it especially difficult to reconstruct the diet of Lucy's species?
New Zealand (1000 years ago) and Madagascar (10 ka)
Last two places where people spread?
Gibbons and siamangs
Lesser apes?
-Juvenile development (how developed an organism is at birth, how growth proceeds, when weaning happens) -Age of sexual maturity -Age of first reproduction -Number of offspring -Level of parental investment -Age and characteristics of senescence (deterioration of age) -Age at death
Life history traits examples
k-selected species
Life history traits sensitive to population density. Small number of large offspring, extensive parental care, repeated reproduction. Few offspring and a lot of investment in growth and child (which are more likely to survive) Human; elephant
Ability to produce eggs
Limiting factor of female reproductive success
Availability of females
Limiting factor of male reproductive success?
Germany, France, Spain (Europe)
Location of H. heidelbergensis
Artificial groups (analogous)
Look similar but not related
volcanoes, rivers, lakes
Main deposits in where hominin fossils have been found?
1. Inner ear bone shape 2. Foramen magnum placement 3. curvature of spine (lordosis) 4. barrel chest 5. relatively shorter arms
Major modifications for bipedalism above the waist?
1. broad, short pelvis 2. long femoral neck 3. valgus angle (knee) 4. convergent toe and arch 5. short, straight phalanges
Major modifications for bipedalism below the waist?
1. Congenital/developmental 2. Inflammation 3. Infection 4. Vascular or neoplastic 5. Metabolic 6. Degenerative
Medical causes/pathologies
Abscesses, nutritional stress, dental cavities Probably short life spans/not living very long, probably due to disease and... ...Warfare
Mortality and disease in H. heidelbergensis
Cladistics/cladograms
Most common method of using phylogeny?
Because primates are in their own niche, competition among primate species isn't so huge Competitive exclusion leads to niche separation
Niche and competition
Niche separation explains the diversity of fossil and living primates
Niche separation explains...
Catarrhines
No prehensile tail Dental formula: 2:1:2:3 Down-nosed Ex: baboons, macaques, velvet monkeys (Africa); langurs, snow monkeys, proboscis monkeys, golden snub-nosed monkeys (Asia); Apes
Successfully reproduce before you die
Objective of life?
1) Earth's position in the universe (thought to be at center, but it actually revolves around the sun) 2) Antiquity of the Earth (earth was thought to be very young but it's actually old) 3) Fixity of species (all species thought to be unchangeable but evolution falsified) 4) Humans are outside the natural order (hard to think this though, that humans must be considered separately from other organisms)
Obstacles of Evolutionary Thought and what has it changed to?
-Homo habilis -Homo rudolfensis *More fossils have to be recorded to expand on this thought or confirm it* They were alive at the same time
Of the fossils recovered that are early Homo, what are the two different species? Where they alive at the same time?
Us!!
Only primate to have passed the Wallace Line
proto-primates -> first primates -> first monkeys -> first apes -> first hominins -> hominin diversification
Order of human evolution?
Budget - finite Currency - calories
Organism's budget (infinite or finite) and currency?
-Bipedal, but still adept in trees (maybe to sleep in and defend themselves) -Teeth adapted for generalized diet (Australopithecus and Paranthropus had bigger teeth and jaw than Homo) -Small body size (<5 ft, <100 lbs) -Brains slightly larger than an ape (in order to solve complex situations and work with early tools) -Lived in mixed woodland, savanna habitats
Precursor to Homo was...
-North America to Europe and Asia -Africa to South America and Madagascar -South America to Africa again, and then to Europe and Asia again, and then back to Africa NEVER CROSSED WALLACE LINE
Primate Adaptive Radiations?
Common ancestor...diverges into... Lorises and Lemurs Tarsiers --> New World Monkeys --> Old World Monkeys --> Apes --> Humans (although some say that Humans are still apes)
Primate evolution tree?
-Grasping toes and fingers, number fingertips, fingernails (not claws) -Large forward-facing eyes, acute eyesight, stereoscopic vision -Reduced emphasis on smell, more on sight -Large brains relative to body size, which associates with -Low fertility, long gestation, slow growth, long maturation periods, long lifespans
Primate shared, derived characteristics
Method for measuring the last time silicate sediments were exposed to sunlight Electrons are trapped in the crystal lattice of some kind of silicate rock, like sand. They continue to be trapped, and accumulate, more or less at a set rate over time. Once they are exposed to light, heat, or some other pathway they glow, or luminesce. 100-350000 BP Pro: don't need an organism to date Con: You're dating the event/last exposure sand was to light, not the fossil buried in the sand
Pro con of Optically Stimulated Luminescence and material/how it works and time point
the branch of geology concerned with the order and relative position of strata and their relationship to the geological time scale. Pro: Can give a good time scale Con: Only an estimate of age, especially with fossils buried in layers
Pro con of Stratigraphy and material/how it works and time point
-Look at exposure in animals and see what fossils are contained within it -Refers to the use of animal bones to determine the age of sedimentary layers or objects -Observing evolutionary changes in animals Pro: if combined with stratigraphy it can help improve age accuracy Con: Relies on getting fossils or bones
Pro con of faunal dating/biochronology and material/how it works and time point
Earth's magnetic poles do not stay in the same position; sometimes they reverse, and it's recorded around the age of these reversals Check the magnetic orientation of grains and you have a sense of age (based on Law of Superposition) Pro: If there's ash in layers it increases precision, and Earth is pretty old so you have a broad range Con: Don't know real date
Pro con of paleomagnetic dating and material/how it works and time point
Pros: -Pays to grow larger (can produce quality offspring and transfer benefits to them) -Reproductive effort expended in the present may reduce reproduction in the future (reproducing too early is costly) Cons: -Takes time and energy -Every day you're alive is another day you die -Reduced fertility or increased probability of offspring mortality
Pros and cons of delaying reproduction
Trying to understand who the person was and their life and hoping it can represent population as whole
Purpose of bioarchaeology?
Genetic drift
RANDOM changes in allele frequency over time Most common in small populations
-Strepsirrhines (lemurs, lorises) -Haplorhines (tarsiers, monkeys, apes, humans)
Rather than prosimians and simians, what are the two major divided groups?
DNA is the template for making of RNA RNA is the template for making proteins
Relationship DNA, RNA and protein
Climate may have driven human migration out of Africa Evidence shows that drier climates may have driven migration out of Africa
Relationship between human dispersals and climate?
Science is -Cumulative -Evidence-based
Science is...
Science relies on... -Replication -Testing -Accountability
Science relies on...
Scientists are trying to falsify results, not prove them. In other words, reject/falsify the null hypothesis, not prove a hypothesis, as this is harder to do
Scientists are trying to....
"Skin color" controlled by different genes Huge variation across Africa not only in skin color but in the genetic basis for skin pigmentation
Skin color and genes?
At least one, possibly two or more species of early Homo -Homo habilis -Homo rudolfensis
So by 2.8-1.4 mya, how many species of early Homo were there?
Angiosperm and insect radiation
So what type of radiations influenced primate traits?
A. africanus
South Africa Found in Cradle of humankind Not likely living in caves, but victims of predators Some facial features different from East African Austrolopithecus Fossil: Little Foot, Mrs. Ples
biological species concept
Species are groups of interbreeding natural populations that are reproductively isolated from other such groups *must be in natural conditions and produce fertile offspring* Pros: -Fits well with population genetics Cons: -Assumes species must be at one time and one place (challenge are those baboons because they got together normally/naturally) -Excludes asexual species -Doesn't apply to the fossil record (dinosaurs are species!) -How come there are species even with a lot of gene flow?
Natural group (homologous)
Species look similar but are actually related (may look different due to selective pressures)
r-selected species
Species that reproduce early in their life span and produce large numbers of usually small and short-lived offspring in a short period. Life history traits maximize reproductive success in uncrowded environments. Many small offspring that mature quickly, little if any parental care. Rabbits
Uniformitarianism
The present is the key to the past. Explained that modern processes are the same as past processes, and that these processes are slow, and therefore Earth must be both dynamic and old.
pleiotropy
The ability of a single gene to have multiple effects. One gene influences more than one trait
Inheritance of Acquired Characteristics
The hypothesis that organisms' bodies change during their lifetimes by use and disuse and that these changes are inherited by their offspring (Ex: giraffe keeps stretching its neck until it can eat leaves, passes trait to offspring)
The imagined distribution of "racial" distribution: no overlap The actual distribution of "racial" variation: overlap; more overlap than ever (no real, hard boundaries)
The imagined distribution of "racial" distribution v the actual distribution of "racial" variation
specific mate recognition system species concept (SMRS)
The most inclusive population of individual bi-parental organisms which share a common fertilization system; have to recognize each other to mate Advantages: -Mate recognition is easier to determine than ability to breed -Fits with population genetics Cons: -Isolating mechanisms before fertilization difficult to quantify -Fossil records -Baboons again (some recognize as mates, others don't)
Fixity of species
The notion that species, once created, can never change; an idea diametrically opposed to theories of biological evolution. These facts corresponded to the organisms created in Genesis
Traditional taxonomy v cladistic taxonomy (phylogeny) Tarsiers are small and nocturnal (lemurs and lorises!), but they lack a tapetum lucidum (which is what lemurs have). They also move by vertical clinging and leaping (like lemur) and have unique teeth (so can't tell if related to lemurs) BUT they have shared, derived features with monkeys and apes
The tarsier is an example of what problem, and how?
1) Adapidae 2) Omomyidae
The two main groups of early primates?
Theories
These are built over a long time and accumulation of evidence. They're central to scientific thinking. A coherent explanation for a large number of facts and observations. Evidence based, internally consistent, well-tested explanation for a body of phenomena
1) Scientific revolution: during, the 1500-1700s, desire for greater exploration, coupled with a new view on nature, revealed an astonishing array of biodiversity and geologic diversity - led to new instruments for observation and measurement and accumulating "anomalies" 2) Fall of geocentric universe with Copernicus and Galileo 3) Carolus Linneaus had a classification system of plants and animals (humans were included in order primates) and binomial nomenclature, although he thought species were static 4) Lamarck challenged the fixity of species and one of the first to try to explain evolution by explaining the inheritance of acquired characteristics (somewhat ironically similar to epigenetics) 5) Uniformitarianism: learning that the same processes ruling the earth are still the same as before. Discovering the earth is super old (Hutton and Lyell) 6) Malthus: there will be competition for resources, which will limit the populations (that can grow infinitely if there are infinite resources)
Three (or more) scientific contributions that set the scene for the acceptance of the Darwin/Wallace theory of evolution by natural selection?
Three assumptions of science 1) Natural causality: all events in nature are due to natural causes 2) Uniformity in space and time: the laws of nature are the same no matter where you are in space in time. The same processes in the past should be happening now. 3) Common perception: all humans perceive events with the same suite of senses (there's no sixth sense)
Three assumptions of science
1. 40K/40Ar 2. 14Carbon 3. Optically Stimulated Luminescence
Three chronometric dating methods
1. The Arboreal Adaptation 2. The Visual Predation Hypothesis 3. The Angiosperm Hypothesis
Three hypotheses for the origin of the Primate order?
1) Variaton 2) Heredity 3) Differential Reproduction
Three keys for evolution by natural selection
-Disruptive selection -Directional -Stablizing
Three more specific types of natural selection?
1. Paleomagnetic 2. Biochronology 3. Stratigraphy
Three relative dating methods
1) Patterns of similarity between species 2) knowledge of ancestral forms (from fossils) 3) Genetics
Three sources of data for constructing phylogenies?
65 million years ago - present "Recent Life" -Age of mammals -Divided into 2 periods --Tertiary 65 Ma to 2.6 Ma: end of Dinosaurs to start of the Ice Ages --Quaternary 2.6 Ma to NOW...the Ice Ages and everything after
Time period of Cenozoic?
Ante-mortem: before death Post-mortem: after death Peri-mortem: around the time of death
Timing of death types?
Law of independent assortment
Traits governed by different systems of inheritance. SHOW NO PATTERN OF INTERDEPENDENCE. In other words, alleles for different traits sort independently in the F1 and subsequent generations.
True: Homo erectus/homo ergaster were all across the Old World between 1.9 and 1.4 Ma and evolved in Africa and spread rapidly, but they were probably not in Europe
True or false: Homo erectus/homo ergaster were all across the Old World between 1.9 and 1.4 Ma
False: Individual organisms compete for resources, but it is the composition of the population that changes over time
True or false: Individual organisms compete for resources, and they change over time
True: Natural selection can only act on existing variation - new variants do not arise in response to pressure
True or false: Natural selection can only act on existing variation - new variants do not arise in response to pressure
False: Over long periods of time, natural selection leads to the accumulation of favored variations of traits (depending on the environment) which produce new forms of life from pre-existing forms (the origins of species)
True or false: Over short periods of time, natural selection leads to the accumulation of favored variations of traits (depending on the environment) which produce new forms of life from pre-existing forms (the origins of species)
False: Theories are constantly evaluated and refined.
True or false: Theories stay the same
True: Theories ARE NOT truth
True or false: Theories ≠ truth
FALSE: a common trait doesn't always mean it's advantageous
True or false: a common trait is always advantageous
1. Law of Superposition 2. Uniformitarianism
Two geological laws?
East and South Africa
Two main parts of Africa were australopiths have been found?
1) Characteristics of organisms are determined jointly by "particles" (DNA) inherited from each parent 2) Particles from each parent are equally likely to be transmitted to offspring
Two rules Mendel induced from pattern of results in experiments
1) Absolute (Chronometric) - gives actual age 2) Relative dating - gives an estimate of age/not actual age
Types of dating methods and differences?
Fluvial Lacustrine Aeolian Volcanic Cave
Types of depositional environments?
-Macrofossils -Trace Fossils -Microfossils
Types of fossils?
1) Fossil proxies 2) Geological proxies 3) isotopes and cores
Types of proxies?
-Skeletonized -Heavily decomposed -Disarticulated -Fragmented Do this to determine the identity of the deceased and determine the circumstances around and since the time of death Typically trying to figure out who people are and trying to reconstruct the scene and see back in time to figure out what happened
Types of remains under the purview of forensic anthropology
if a population can lower "Extrinsic" mortality then stronger selection for longer life and to grow larger brain can occur: expensive tissue hypothesis
Under what conditions might a brain evolve
-Could see the goods buried in graves and compare with elite and non elite -Architecture between elite and non-elite -Differential male reproductive success: dip in diversity in male-inherited DNA but not female-inherited --Wherever agriculture occurs you see reduction in males reproducing (may be due to polygyny, male-biased warfare, wealthy men pass on their genes, changed in beliefs)
Visible evidence of social stratification
-Volcanic Systems --Ash --Lava - Basalt Flows -Animal Fossils --Trapped in the ash --Trapped underground --Footprints
Volcanic deposits
-Generation times -Mutation rates -Fossils -Ancient DNA
Ways to estimate rate of genetic change
1 yr
Weaning average of human industrialized populations?
No! They were not alone: -Later forms of Homo co-existed for a time with earlier forms of Homo (and with Paranthropus) -Earlier forms of Homo eventually went extinct, although they originally lived around the same time as erectus (and erectus was classified as a later homo because it persisted into later times, not because it appeared later) -Processes were not uniform nor simultaneous across Africa -Later forms of Homo not only survived extinction but went on to colonize the globe
Were there just homo species?
Some point it allowed social network --> lead to development of big brain, more sharing, pair-bonding Also the brain costs 20-25% of energy, so there had to be a net gain in calories to get a big brain.
What about the origin of meat-eating - why do we care?
1. We were all part of one big diverse evolving lineage (we're all one) 2. The other hominins were on their way out already, they weren't thriving when we came in (possible scenarios are climatic event, mad cow disease, cannibalism) 3. Homo sapiens had something to do with their demise (fought and we won)
What are three possible reasons that Neanderthals may have gone extinct?
1) Allows carriages of items in hands (which must've been essential for survival) 2) Heat efficiency (less surface area exposure to the sun) --Would especially make sense because humans sweat 3) Foraging efficiency --Foraging in open woodlands 4) Display (make yourself look bigger)
What are advantages to bipedalism?
-The ancestry of the initial Austronesian inhabitants of Vanuatu has been largely replaced by ancestry from Papuan peoples coming from the Bismarck Archipelago. -Europeans not truly Europeans but steppe people from the east -Can also mean cultural and biological assimilation - such as Indoeuropean languages or traditions
What are at least two piece of evidence that there have been recent large-scale replacements of human groups by other human groups?
-A higher skull due to a bigger brain -Shorter face that is more vertical (less overall prognathism, with prognathism reduced to the tooth roots) -Projecting supra-orbital torus (brow ridges) with a supra-orbital sulcus (what sits behind the ridge) --But no one knows what it's there -Football-shaped cranium (lump at the back of the skull/large torus at angular occipital) -Reduced arm length -Narrowed pelvis -Barrel-shaped ribcage
What are features of homo erectus that are unique to them?
-Temporal Isolation (species are active at different times) -Ecological isolation (species are physically separate, such as eating different fruit, there's a river between them) -Behavioral isolation (Form of reproductive isolation in which two populations have differences in courtship rituals or other types of behavior that prevent them from interbreeding) -Mechanical isolation (different reproductive organs or other physiological differences make it impossible for a successful mating to occur)
What are pre-mating isolating mechanisms?
Features of apes that preserve as fossils -No tail -Broad nose -Fewer lumbar vertebrae -Simple molars -Enlarged brain -Y-5 molar pattern
What are some of the main features of the apes (that can be found in skeletons)?
A. anamensis - East Africa A. afarensis - East Africa A. africanus - South Africa
What are the 3 australopithecus species we have to know and where they came from?
1) Random gene flow (flood) 2) One way movement from a large population to a small one 3) Each group receives migrants only from neighboring populations (most likely because of geography --> get genes from those closest to you) --Clines (gradation from one geographic area to another)
What are the different parts of gene flow?
1) Natural selection (directional, stabilizing, disruptive) 2) Sexual selection 3) Mutation 4) Gene flow 5) Genetic drift
What are the forces or mechanisms of evolution? In other words, the major drives in changes in allele frequency?
1) Cultural or sociocultural 2) Linguistics 3) Archaeology 4) Biological
What are the four major areas of anthropology?
-DID NOT HAVE ALL HUMAN BIPEDAL ADAPTATIONS (such as flat foot and funnel-shaped ribs) -From East, South, and North-Central Africa -Had 'gracile' and 'robust' forms --Gracile earlier (likely ancestral to homo) --Robust forms were not likely ancestral to homo Two teeth features (which are overall intermediate between apes and later hominids): 1. Palate shape is between u-shapes (which are apes) and parabolic (humans) 2. Tiny diastema present 3. Canine size/dimorphism present and big (but still transitional/intermediate between apes and humans); reduced canines and anterior teeth Two from postcranial skeleton: 1. Brain a bit larger than an ape 2. Pronounced sexual dimorphism 3. Small bodies that are still adept in trees 4. Bipedalism Two "other" things: 1. Foot of Dikika child shows that grasping was easier when an infant than an adult (so when younger it could move toe more like other primates) 2. Footprints that are different but together show group behavior 3. Death assemblages ("First Family" from Hadar) since as many as 17 individuals were killed close to the same time, hinting that they might've lived together in groups 4. Possible sexual dimorphism that you can tell from the fossil size between men and females --> multiple males died together, probably lived in groups, with significant male competition
What are the key characteristics shared by all australopiths? Know two from the teeth, two from the postcranial skeleton, and two "other things" (e.g. life history, locomotion, behavior).
P. boisei - East and Central Africa P. robustus - South Africa
What are the paranthropus we have to memorize? Where did they come from?
-Brow ridges -Skull narrows behind the orbits -Receding forehead -Flattened skull -Broad, flat face -No chin
What are the primitive skull features of Homo erectus that they shared with homo habilis?
1. Genetic (living people and ancient DNA) 2. Archaeology (material culture) 3. Fossil record/Skeletal evidence (human fossils)
What are the three main kinds of evidence for the emergence of modern humans (one has two sub-types)?
Two main branches of australopith were: -Australopithecus -Paranthropus
What are the two main branches of australopith?
1) Morphology (main focus since we get it from fossils) 2) Genetics 3) Behavioral Ecology
What are three main ways to find out about extinct organisms and ecosystems?
inner ear modern morphology (doesn't appear until about 2 Ma) increased manual dexterity (especially in later hominins) increased brain size and complexity (later hominins)
What are three traits of bipedalism that modern humans have but the earliest bipedal hominins did not?
Warm and stable This made it perfect for investing in crops
What are two main things about cilmate the changed during the Holocene
1. Love! Happiness! 2. War! We killed them!
What are two possible ways in which humans may have contributed to their extinction?
C4 - grasses C3 - trees Teeth has C3; can tell you're eating trees C4; can tell you're a grass feeder Can be mixed!
What can stable carbon isotopes in teeth tell you about past vegetation and diet?
-If teeth water differs from isotope in nearby environment, you can tell there was migration -And animals living in cold, dry places tend to consume a higher abundance of the heavy oxygen-18 isotope in what they eat and drink because the heavy isotope doesn't evaporate from that environment as easily as it does in warm, wet conditions.
What can stable oxygen isotopes tell you about past water and diet?
-Homo diversifies again, changing in Africa but persisting in Asia -Homo erectus disappears -A new stone tool-making method appears (Mode 3) -Earliest modern humans turn up -Lots of climate change in a short period of time, coincides with a lot of variability -Eurasian hominins diversify, but the main events relevant to our story is in Africa --Biologically modern (first modern face, body and brain) --Behaviorally modern (first art, first clear symbolic behavior)
What happened after 700 ka (700,000 years ago)/The Middle Pleistocene
Ice age! in Pleistocene epoch
What happened around 2.6 million years ago?
Start of Cenozoic - warmer temperatures than before -Began to decrease after Eocene -Cooled off considerably in Pliocene -Pleistocene: extremely cold, with fluctuations. Ice Age -Rise in temperature during Holocene and has been increasing since
What has been the global trend in temperature (eg cooler or warmer) since the start of the Cenozoic? What does this likely mean for past environments
-With widespread landscape burning, the environments changed and became more open - more standing water --Malaria was always around, but not in such quantities close to dense human settlements -Infectious disease rise (zoonosis!) -Increase in malnutrition and disease -Anemia -Growth disruption and stunting -Cavities -Osteoporosis and osteopenia -Workload stress increase osteoarthritis All of these could be due to a lack of a well-rounded diet
What have been some of the health consequences of increased reliance on food production and what evidence do we use to make these inferences?
Homo erectus had super large brains compared to early Homo and australopiths Long period of development to grow the brain is only incipient in Homo erectus Long learning period of childhood to learn complex skills is perhaps in Homo erectus
What in only incipient/just beginning to occur in Homo erectus and perhaps just beginning in them?
Propose that the regular exploitation of large-animal resources—the "human predatory pattern"—began with an emphasis on percussion- based scavenging of inside-bone nutrients, independent of the emergence of flaked stone tool use. Evidence of percussion marks are shown on long bones. It's a smaller intellectual leap compared to sophisticated tool-making and is more plausible So hominids were after fat, not meat, which is more calorically dense and would give that energy surplus needed for larger brain development
What is "percussion scavenging" and what is one reason it may be a better explanation for early tool use than "meat-eating"?
a hominin includes humans and our upright-walking ancestors A hominin does not include chimpanzee or our common ancestor, as Hominins are a branch/lineage that lead to homo sapiens. Also chimps and last common ancestor wasn't bipedal
What is a hominin? Does it include chimpanzees? Does it include our last common ancestor with chimps? Why or why not?
One branch of Homo went extinct; if there's both habilis and rudolfensis at the same time, one of them went extinct and only ONE of them was ancestral to later species of Homo The one that became extinct likely had an unsuccessful adaptation, but what?
What is another thought about H. habilis and H. rudolfensis and branching
-Not enough data -Could also be climate change that drove them off -By the time megafaunal were in extinction window humans arrived --> humans are "the final blow"
What is controversial about the idea that humans killed off most of the megafauna at the end of the Ice Ages
1) Tool-making 2) Meat-eating 3) Homo Connection to intro: -There are more environments drying out and woodland habitats are in decline along with rise of threatening predators. Some groups strike two stones together and creates a sharp edge, using this tool to kill meat and eat it, leading to larger brain What makes it less certain: -in 2010, earliest tools and cut marks were found around the same time as earliest homo -But now, tools and cut mark evidence has been found way before the earliest homo, suggesting that tool-making didn't lead to the emergence of homo --Instead, it places origins of stone tool use and large animal consumption squarely within the time of Australopithecus -"Percussion scavenging" has been found and it might be linked to crushing bones and eating bone-marrow (which contains fat and is more calorically dense than meat)
What is the "First Triumvirate" of Paleoanthropology (according to me)? How are these three "evolutionary milestones" linked through the story as told in the intro of the lecture? Know one piece of evidence that has been discovered in the last ten years that makes these links less certain.
Skeletal remains Soft tissue remains Chemical analyses Other biological remains (parasites [mostly get from excavating ancient latrines], coprolites/fossilized turds, residues, macrofossils, microfossils) Burial taphonomy (basically study remains after they decompose)
What is the bioarchaeology toolkit?
When hominins became bipedal, the pelvis became narrower, especially in males (which is good for bipedalism, as it requires less energy) However, with a narrower pelvis, it's bad for giving birth to a big-brained infant --Humans are the only primates that have to rotate at birth, so you need a lot of assistance from others to help during birth
What is the biological tradeoff to the obstretical dilemma
-More complex technology (bone tools, mode 4 and 5 rice in tech, finely flaked points) -Symbolism: intentional piercing and carving and engravings on shell beads and ochre -Elaborate burials and houses -Carve paintings -Rock art
What is the evidence for early social and symbolic complexity in modern humans? Know at least three examples.
At least 400000 years old (H. heidelbergensis) -Nuclear DNA like Neanderthal (suggesting that Neanderthal descended from Heidelbergensis) -But mitochondrial DNA is like Densisovan --The results suggest they are more closely related to ancestors of Neanderthals than those of Denisovans - meaning the two groups must have diverged by 430,000 years ago. This is much earlier than the geneticists had expected. It also alters our own timeline. We know that Denisovans and Neanderthals shared a common ancestor that had split from our modern human lineage Oldest H. sapiens DNA is only 45,000 years old Oldest Neanderthal DNA is about 150,000 years old
What is the world's oldest hominin DNA
Most examples date between ~1.9-1.4 mya 1. Rounded cranium and bigger brain 2. Smaller molars and premolars, but large incisors and front teeth 3. Gracile mandible 4. Rounded upper jaw/maxilla - parabolic 5. Face doesn't stick out as much; less prognathism/more upright/vertical face 6. Cranial capacity slightly larger/face and brain case 7. Brow ridges 8. Smaller face than Australopithecus 9. No sagittal crest (heavy chewing muscle absent)
What makes homo different from the rest? (Cranial Characteristics) And what can you date theses characteristics from?
-End of the paleolithic: diversification in the diets of European hunter-gatherers - more small game, shellfish, and diverse, difficult-to-process plant foods -Collecting plant and animals Consequences: -Shift to more sedentary lifestyles -Larger populations -Larger human settlements -Agriculture! Plus dogs, sheep, and goats -Domesticated cattle and pigs came later
What other strategies might humans use to get more out of their same environments? What was the major consequence of each new strategy?
Because you can't go back to the start or else you'd have to cut off population (because hunter and gathering won't support a huge population)
What prevented large human populations from "returning" to hunting and gathering after starting food production?
"Turkana Boy" from Homo erectus
What skeleton is a representative fossil of human evolution?
1) Falsifiable 2) Worded in a way that they can be shown to be incorrect
What two things must a hypothesis be?
-First handaxes in Africa around 1.8 mya -Bifacial tool traditions went global -These acheuelan handaxes (made by taking core and chipping away and making a shape you imagined beforehand) required complicated intuition but also required practice, which is what you get from teaching and learning
What was different about homo erectus tools?
34-23 mya Cooler global temperatures and significant reconfiguration of tree habitats
What was the climate like when monkeys evolved and diversified? (e.g. very warm, cooling off, etc.)
Primates missing some features: Around 56 mya, after dinosaurs went extinct It was very warm and had extensive forests North America and Eurasia still connected FIRST TRUE primates: Around Eocene period (54-34 mya) - more primates in America but after a decline in cooling they go practically extinct there's more in Europe It started out very warm The steady decline of cooling = fewer trees
What was the climate like when primates first evolved? (e.g. very warm, cooling off, etc.)
1) Darwin drew upon the long-noted anatomical similarities between apes and humans and predicted that early human ancestors should be found in Africa, but there was the prevailing view that Africa had nothing to contribute. most workers expected to find earliest human ancestors in Eurasia 2) The ancestor was assumed to have walked with an ape-like posture and diet but to have had a LARGE HUMAN-LIKE BRAIN (because pinnacle of human success, should've been the first thing that evolved) So the piltdown man was perfect: large brain, primitive jaw, ape-like posture and from England *fit prevailing expectations and nationalist agendas* Because of piltdown man, no one believed in the Taung Child, which had a small brain, walked upright, and came from South Africa
What were at least two reasons some scientists were willing to accept that Piltdown Man was a genuine human ancestor? How did this influence their thinking about the Taung Child?
1) Piltdown man was revealed to be a forgery (it was an ape mandible and human cranium combined) 2) Enormous numbers of human fossils and artifacts have been discovered that fit Taung's similarities
What were two of the main things that had changed by 1950 that made the Taung Child come into greater acceptance?
-Australopithecus species had larger cheek teeth, thicker enamel and more moassive jaws than miocene hominoids -Paranthropus continued this trend with even larger cheek teeth and extremely massive jaws -Homo reverses this trend with smaller cheek teeth and gracile mandibles...WHY
What's a notable change in trends between Australopithecus, paranthropus, and then homo
First appears 1.8 mya - 150000 years ago Earliest occurrences in both Kenya and Ethiopia Overtime these handaxes become more and more refined and symmetrical (meaning more and more hours spent on it, so it must serve a large purpose, like maybe attracting females)
When and where does acheulean technology appear?
Can be applied to the "deep past" or very recent past
When can you apply the bioarchaeology toolkit
Oldwan starts at 2.6 Mya
When does oldowan start?
-Went largely unknown for 40 years, and was revived in the early 1900s
When was Mendel's work acknowledged?
730 - 127 kya
When was the Middle Pleistocene?
The earliest known homo was dated to be at 2.8 mya BUT only one partial mandible was found at 2.8 mya, and then a partial maxilla at 2.4 mya. In Ethiopia So we don't actually know anything else about the first members of our genus
When was the earliest known homo and what do we know about it?
First finding made in 1960-1961 Species were much less robust than P. boisei Stone tools had already been found; the new hominins were thought to be responsible One of the first homo habilis found was named Twiggy (after popular model), or OH24
When were Homo habilis fossils first found?
Gracile: -A. anamensis - East Africa *earliest one* -A. afarensis - East Africa *best fossil record* -A. africanus - South Africa Robust: -P. boisei - East and Central Africa *earlier* -P. robustus - South Africa *latest one*
Where did the following species live and were they gracile or robust? Au. anamensis, Au. afarensis, Au. africanus, P. robustus, P. boisei . Which was the earliest one? Which was the latest one? Which has the best fossil record?
Majority of Neanderthals have been in Europe, many Denisovans in Asia
Where did the hominins roam in the late pleistocene?
Africa, too
Where do Chimps live?
Africa
Where do Gorillas live?
Southeast Asia
Where do gibbons live
They live in southeast Asia too
Where do organgutans live?
All diversity comes from within Africa
Where does all diversity come from?
Either to maintenance, growth or reproduction
Where does food/energy go?
Selection works on variation that's available...crossing over recombines only existing traits Mutations gives new variation
Where does the initial variation come from?
Genetic drift is most common in small populations
Where is genetic drift most common in?
LARGEST GENE POOL WAS ALWAYS IN AFRICA
Where is the largest gene pool
Wallace! Darwin presented his ideas along with Wallace's, although Darwin rushed to publish his book On the Origin of Species
Who reached the same conclusion as Darwin?
Homo erectus - have known to have left beyond Africa and into Asia, and even possibly made sea crossings as bones were found in Indonesia
Who was the first hominin to leave Africa?
-Learning -Problem solving -Managing complex sociality -Extractive foraging (trying to get most calorie-dense food) and high sociality Cons: -Requires low extrinsic mortality and high energy input
Why are costly brains worthwhile?
The fossil record for homo are one of the poorest probably due to changes in the environment (rivers dry up and there's gaps in sedimentary layers, which contain the best spots for fossil preservation)
Why are one of the poorest parts of the African fossil record between 3-2 mya
-To put evolution into context -So we can understand how climate has changed in the past to learn how it may change or is changing -To learn about past diversity -See how environments impacts adaptations, changes in organism, etc
Why do we reconstruct paleoenvironments?
-Accumulation of wealth -Social stratification -Ownership of property and people -Women's roles as property -Have more time on your hands when you don't have to always go searching for food!
Why does emergence of cultural change such as social stratification appear most strongly in agricultural societies?
Context! -Gives us information on the past environment, climate, association and dating
Why is an understanding of geology important when studying fossils and past environments?
Bipedalism is a focus of early hominin evolution research because we wonder if our ancestor is knuckle-walking or suspensory (climbing) or bipdeal Bipedalism might have arisen from open lands (which might've lead to the ability to make new tools and carry things)
Why is bipedalism such a focus of early hominin evolution research? What was the environment like at the time it likely emerged?
Redundancy decreases chance that a random change will alter the primary sequence of protein produced A fail safe --> if error in sequence you still have back-up
Why is redundancy important with genetic code?
-Has fossils of strepsirrhines, haplorrhines (old and new world primates) -Primates started here before they spread; convinces that there is already a split in the lineages to both platyrrhines and catarrhines before New World monkeys came to the New World, but platyrrhines were the only group to move across -Now it's a desert but paleoecology: --Sub-tropical to tropical lowland coastal plain --Riverine forests and possibly swampy conditions --Brackish streams flowing to the Tethys Sea --Monsoonal conditions
Why is the Fayum an important fossil locality?
Tool-making is significant because it might have arisen: -division of subsistence labor (men and women do different tasks but then pool them together and share) -Food sharing -Central-place (home base) foraging -Regular large ungulate exploitation -Cooperative hunting --We eat things bigger than us
Why is the origin of tool use important?
-Many organisms share characteristics because they inherited those characteristics from a common ancestor - homologous features -Our closest living relatives are other primates - we share many shared, derived characteristics with them -Diversity in living primates can provide info about --How primates have adapted to different environments --How adaptations have been constrained and/or facilitated --What range of adaptations we might reasonable expect in an unknown (extinct) primate under a give set of circumstances --Identify patterns (like behavior)
Why study living primates?
Paranthropus were mainly called robust due to features of their face being less slender-like. Really big jaws and teeth (as well as large big jaw muscle, which causes an enlarged face). 1) large molars 2) sagittal crest enlarged attachment surface for temporalis 3) cheekbone flared out for enlarged temporalis Australopithecus most likely to our genus Homo (which have more slender-like features, so known as gracile) Two pieces of logic that would help make this conclusion: -Australopithecus came earlier, more likely to be ancestral to Homo -Large molars and temporalis muscle causes enlargement of face
Why was Paranthropus mainly called robust (know three "robust" features of its face)? Which branch was most likely ancestral to our genus Homo? Know two pieces of logic that would help you to make this conclusion.
Smaller animals have more net energy, higher basal metabolic rate, and more energy expenditure per unit body weight
Why would diets change due to body size?
Absolute/Chronometric Dating
You get an actual age in numbers with an estimate of statistical error
paleosol
a buried soil that formed at some time during the geologic past; gives info about precipitation, temperature and microfossils (if lucky)
microevolution
any evolutionary changes below the level of species (happens every generation); within species changes in the frequency WITHIN a population or a species and the effects of these alleles on the form, or phenotype, of organisms that make up that population or species. Changes which would not result in the newer organisms being considered as different species. Ex: Pesticide resistance, herbicide resistance, and antibiotic resistance by natural selection)
Differential reproduction
because of limiting resources, some individuals will survive and reproduce more than others
Agro-pastoralism
blend of agriculture and pastoralism
phylogeny
branching pattern of evolution based on shared, derived characteristics
genetic change
change in allele frequencies in the population through time
reproductive isolation
condition in which a reproductive barrier keeps two species from interbreeding; Separation of species or populations so that they cannot interbreed and produce fertile offspring
Flaked stone tools cut meat --> meat offers a higher-quality diet (energy surplus) --> Homo emerges from Australopithecus with larger brains and smaller teeth
connection of tool-making, meat-eating and origin of homo?
ethical concerns: colonialism -must negotiate an intricate balance between the interests of the clients who commission the work, and those of the community being studied
connections with applied anthropology and ethics?
-Males must compete for mating -Group itself is more vulnerable/easily seen from predators -Larger groups cause hierarchical access to food within the species
cons of living in groups
frugivore
eats mostly fruit. Slightly larger brains than folivores, probably because high in sugar (although seasonality might affect eating patterns)
insectivore
eats mostly insects
folivore
eats mostly leaves. Soft leaves - more protein
gummivore
eats mostly tree sap (high in sugar)
Peer-review
evaluation of scientific, academic, or professional work by others working in the same field; a review by people with similar professional qualification
Disruptive selection
favors extremes of a phenotype
Trace fossils
footprints, burrows, body impressions, etc that are not the hard parts of animals or plants. Can preserve behavior
Allochthonous assemblage
fossils were transported from different habitats and accumulated together
regulatory genes
genes that regulate expression and timing
African Multiregionalism
homo sapiens didn't arise from a single point in space. The entire continent was our cradle and humans originated from several diverse populations that lived across Africa. But early humans were repeatedly drawn together and pulled apart, and whenever they mated and mingled, exchanging genes and ideas in a continent-wide melting pot that eventually coalesced into homo sapiens
Life History: -Long longevity and long post-reproductive period -Long period of offspring dependency (very slow growth) -A period of adolescence (long transition period) -Relatively high fertility and multiple dependency Behavioral: -Three-generational system of wealth (resources/calories) flows; parents contribute to offspring and so on -Contribution of men to offspring care/provisioning -High levels of altruism and cooperation between kin and non-kin
how are humans as outliers among primates?
1) bad 2) good 3) neutral
how are mutations categorized?
3 yrs
human natural fertility population weaning average
locus
identifiable place on a strand of DNA; where a gene might reside (where it is on map)
niche separation
if species using the same habitat are too similar, there will not be enough resources and some species will do better than others For many primate species to co-exist in one habitat and to co-exist with other animals as well there is this. This may include separation in: -Body size -Activity pattern -Diet -Locomotion
speciation
in animals, always involves a splitting off of one species from another and their historical fates become independent from the ancestor
Law of Superposition
in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer younger than the one beneath it and older than the one above it
Expensive Tissue Hypothesis
in human evolution, there has been a trade-off between brain size (increase) and size of gut (decrease). Both are energetically expensive tissues. This started ~2 million years ago, with increased extra-oral processing of food, increasing digestibility. Also diet shifts to higher quality foods (eat less and get the same nutrition as lower quality foods). This allows gut size to decrease, which then frees up the brain to expand in size.
intensification
increase in resources and processes that increase agricultural yields
stablizing selection
individuals with the average form of a trait have the highest fitness; maintains the frequency of "middle ground"
vertical clinging and leaping
jumps from trunk to trunk or branch to trunk
haplorhine
larger body size post-orbital enclosure (eye sockets can fully close) no tapteum lucidem typically single births
-Grew up quickly compared to humans (which is still debatable) -Possible early weaning -Grew up slowly compared to apes --We know this from teeth and looking at nutritional disturbances in the way that your teeth grow, clearly show they grew up slower than apes
life history traits of neanderthals?
Proteins
made up of amino acids that have different function in the body
Omomyidae
major group of extinct primate that dominated during the Eocene Insectivorous; nocturnal; leapers Most likely we descended from them; as it's skeleton is highly similar to the Tarsius. Led to Haplorrhines.
life history theory
makes predictions for how organisms should allocate their energy throughout their lifespans (evolved biology) the action of selection on the timing and rate of events across the lifetime
multimale/multifemale with cohesion
many adult breeding males and females dominance hierarchies (matrilineal) high competition over food and mates all have a territory and move together Ex: baboons
neutral mutations
many mutations are this (or 1) silent if they occur in a non-coding or non-regulatory part of the DNA or 2) if they do not change the amino acid sequence, or 3) if they change a non-essential trait)
derived
new in comparison to what came before
Apes
no tail Larger brains than other primates greater reliance on visual sense bit more upright posture 2:1:2:3 Lesser apes and greater apes
Autochthonous assemblage
no transport of fossils; in their original spot
flake
sharp piece that is broken off
polyandrous
one adult female with many males that offer parental support assistance for twin infants (twins might have been evolutionary thing because there's constant support) highly unusual Ex: tamarins
one-male or harem groups
one breeding male with many females sexual dimorphism present (men are huge; females tend to stay small) resources generally more dispersed
chromosome
one pair of very long DNA molecules
MUTATIONS are the ONLY source of new genetic variation in populations of organisms
only source of new genetic variation in populations of organisms?
primitive
opposite of deritative
adaptive radiations
organisms diversify rapidly into many new forms, particularly when a change in the environment makes new resources available, creates new challenges and opens environmental niches
Primate body size is instrumental in determining when a primate focuses on for nutrition Ex: Gorillas nibble on a ton of leave and microbiome ferments the leaves Smaller primates have faster metabolism and are constantly eating (small and sugary food) Bigger mass --> rougher the diet can be Largest animals --> most likely to be folivores Small animals --> most likely to be frugivore, insectivore, gummivore
relationship between diet and body size?
Phylogeny
relationships that link relationships due to their evolutionary history of shared features and are often presented in "trees"
gene
section of DNA with identifiable structure or function
lake cores
sediments at the bottom of glacial lake provide a record of climate change extending back as far as 50,000 years. Also may provide microfossils or fossils. Preserves rainfall, vegetation and other weather variables and each layer was formed as microscopic organisms (diatoms/algae with a hard cell) alternated with clay and ash and give high precision record of climate change; dark soil indicates shift in climate and rise in lake level
Selection is always relative to the environment (natural selection) or mate choice (sexual selection)
selection is always relative to the ______ or _______
mutation
source of new variation in population
Aka Ardipithecus kadabba An early species in the hominin lineage. Lived approx. 4.5 mya Pretty complete skeleton....suggests bipedalism (still a small brain and divergent toe) Human-like teeth Woodland habitat (surprising, as we expected more savanna for first bipedal organism)
significance of Ardi skeleton?
analogy
similarity between organisms based on common functions or "analogous structures" with no assumed common evolutionary descent
homology
similarity between two or more organisms based on descent from a common ancestor, that is they have "homologous structures"
Strepsirrhine
small body size post-orbital bar many have a tooth comb some retain a grooming claw retain a tapetum lucidem (eyeshine), but the only problem is that you can only tell with living organism more emphasis on smell than other primates multiple births Ex: lorises, lemur and (galagos, part of lorises)
vervet monkey has alarm calls depending on the predator chimpanzee termite fishing --females do most termite fishing, males do most hunting -offspring learn mainly from mothers (observation) -food sharing is usually between mothers and offspring, or in cases of "begging" or "tolerated theft"
social learning examples
-Local behavior - artifacts came from local sources -Care for some older and infirm individuals -Small groups of related individuals (DNA evidence) -Overall population sizes likely low: didn't have same extensive social networks like us, and they didn't make many artifacts/don't move away from their base (which is similar to us, actually)
social life of Neanderthals
good mutations
some of these mutations are beneficial, by creating a new phenotype that is beneficial in the organism's environment
sexual selection
source of change in allele frequencies in a population based on non-random mating some individuals, with features that make them more attractive mating partners, preferentially reproduce (Bowerbird; peacock; mandrill)
anagenesis
species formation without branching off the evolutionary line of descent. does not always lead to the formation of a new species from an ancestral species. Is the transformation of a particular lineage of organisms to a different state, which can be justified as a new species from its ancestral species. involves evolution within a single lineage; Collective changes that transform once species into a different species with different characteristics Transformation of an ancestral species into a descendant through gradual stages (Requires common ancestor to be dead) Branching doesn't occur; one taxon replaces another without branching; does not promote biological diversity Evolution occurs within the branch
bioarcheology
study of human remains from archaeological sites
Ate a lot of meat (higher latitude more meat while lower latitude ate more plants) -Overall they adjusted their diet according to environment, which is a human-like tendency or feature -Accomplished hunters of large game - narrow diet with high meat content -Date palms, legumes, seeds (many cooked) -Regular throwing behavior -Active hunters and many injuries (women and children most likely had a more active role) -Bodies required high caloric maintenance
subsistence of Neanderthals
brachiation
swings bimanually through trees
Engravings on cave walls (Gibraltar) Eagle claws Fossil gastropod with ochre Black pigments predominate Same FOXP2 (language) gene
symbolic behavior of neanderthals?
cladistic taxonomy
taxonomic names are based on relationships, NOT relationships and overall similarity
-Mousterian (Mode 3): flake technology -Twister fibers -Adhesives - natural bitumen and birch sap mixture (which is a pretty complicated process) -Hide working (with lissoir, which is used to break and shape leather) -Right-handed -They mostly put stones on stick and used them hunt; didn't make tools from bones
technology of neanderthals
horizontal gene transfer
the acquisition of genetic material by one life form from another, unrelated life form, during the life course, and the passing of that novelty to the offspring ex: the first eukaryotic cells likely formed by one cell absorbing the other ex: in humans, many metabolic functions were likely acquired from bacteria through this process
nice space
the area that each species occupies within its ecosystem
theory
the branch of a science or art consisting or its explanatory statements, accepted principles and methods of analysis
Uniformity in space and time
the laws of nature are the same no matter where you are in space in time. The same processes in the past should be happening now. One of the assumptions of science
increase in population --> increase in diet breadth --> increase in carrying capacity --> increase in population --> increase in intensification --> increase in carrying capacity --> increase in population --> increase in food management --> increase in carrying capacity --> increase in population --> narrowing of diet breadth with domestication --> increase in population --> increase in food production
the path to food production
phenotype
the physical expression of the genes, or what we see
variation
there must be existing ______ within a population
shared
they all have it
microfossils
tiny animals and plants - usually microscopic
Mendel
tried testing the Blending inheritance Monk that conducted experiments on garden peas
heterozygous
two different alleles present at a locus (Tt)
homozygous
two of the same alleles present at a locus (TT)
Homo floresiensis Denosivans
two other species that lived at the same time as Neanderthals
solitary foragers monogamous or pair-bonded polyandrous one-male or harem groups multi-male multi-female cohesion multi-male multi-female fission-fusion
types of bonds
1) silent: occur in a non-coding or non-regulatory part of the DNA 2) do not change the amino acid sequence 3) change a non-essential trait
types of neutral mutations?
quadrupedal
uses 4 limbs like feet
quadrumanous
uses 4 limbs like hands
bipedal
uses hind limbs only
5 years
weaning average for chimps?
historical: -war -economics -social inequality
what are historical determinants of health?
-Monogenic traits
what is considered as mendelian inheritance?
genetic variation
what is essential if species are to adapt to changing selective pressures
-polygenic inheritance -pleiotropy (one gene influences more than one trait) -Genotype ≠ phenotype (environment plays a role)
what is non-mendelian inheritance?
mutation
what is the only source of brand new variation
macroevolution
what most people think of when they hear "evolution" Changes in organisms which are significant enough that, over time, the newer organisms would be considered an entirely new species. Evolution of major phenotypic changes. Evolution on a grand scale What happens "between-species" - evolution of genes, the accumulation of microevolutionary processes and "detectable in the fossil record" Ex: Evolution of the horse
crossing over random assortment of gametes
what provides something for natural selection to act on
NO Acclimatization: -phenotype determined by environmental conditions -can be short or long-term Adaptation -phenotype selected through natural selection -there can be selection FOR plasticity
Are acclimatization and adaptation the same thing?
-Shows misuse of population differences -Johann Friedrich Blumenbach tried to classify "races" based on skulls, as "races" thought to have deep evolutionary roots; derogatory social names used to classify biological roots
Describe early "physical" anthropology
Franz Boas measured immigrants and their children and showed that environment played a major role in phenotype He couldn't necessarily explain why environment played a major role in phenotype, just knew it was environmental role Try to understand all the factors that influence human biology
Describe later "biological" anthropology
Humans are omnivores, evolved to be excellent generalists Meat became relevant at some point between 3 - 2 mya, and this changed multiple aspects about or biology and behavior, such as: -Big brain -Altricial offspring -Tool-making and tool-using -Fire use -Social cohesion and predator avoidance -Social status ("showing off") -Resource control and distribution ("meat for sex")
Describe the evolution of human nutrition
-We don't know what they ate, because nothing of what it ate had existed before or exists today -Most likely they ate fat, not meat; living hunter-gatherers place great value on FAT, like on the eland - a fatty antelope --And it's been shown eating too many rabbits is bad = "rabbit starvation" = starving to death of eating too much lean meat (because too much lean meat can lead to protein poisoning) --What's interesting is that paleo diet lacks fat -Where they probably lived: grasslands were expanding; flexible diet, spent time between trees and open areas and ate resources from both --Carbon isotopes more spread out ---> eating from both open and closed habitat --So maybe eating berries out in grassland or in forest
What did our ancestors eat? And where did they live?
Study skeletal remains for medico-legal purposes and especially for the identification of unknown individuals
What do biological anthropologists do within forensic science
Methods now extend beyond human skeletal remains into soft tissues, chemical analyses, parasites, associated grave goods, other microfossils found in burials, taphonomy of burials
What do you mean by human remains when talking about bioarchaeology
Applies science to those criminal and civil laws that are enforced by police agencies in a criminal justice system
What does forensic science do?
A lot of people conflate biology, culture and environment Carolus Linnaeus did it on race Eugenics: improvement of humanity -Genetic purity of "fittest" individuals -Removal of "degenerate" traits -Society becomes healthier, more intelligent Modes of intervention -Restricted marriage -Controlled immigration -Segregation -Forced sterilization (over 60000 in the USA) -Extermination --Incorporated into Nazi rhetoric --Plenty of echos today
What is a problem most humans do with biology, culture and environment? How has it impacted our society
Study of human remains from archaeological sites But methods now extend beyond human skeletal remains into soft tissues, chemical analyses, parasites, associated grave goods, other microfossils found in burials, taphonomy of burials
What is bioarcheology
1. Human eat farm more meat than other primates (and just animal products in general, like cow's milk and eggs) 2. Humans have a much more varied diet (exception: maybe chimps and baboons, but still not as varied in other primates) 3. Humans rely more on extractive foraging (foraging that requires extra skills/technology, such as cooking that transformed microbiome gut biology)
What is different about human diet?
Idea that if we want to maximize our health, we must eat what our ancestors did
What is the idea behind the Paleo diet?
-With the paleo diet you can't eat dairy...but we've evolved to tolerate dairy and starch (through lactase persistence and amylase)...so do we go against our evolution
What's interesting about Paleo diet and human evolution
-Many ingredients in meals deemed Paleo would never be found together -Many ingredients are domesticated and not naturally found in the wild -Human diet is a culmination of evolved diets...so how far back do we go to define the paleo diet...especially huge transition to meat eating around 2-3 mya (so do we go even farther back or after that?) -Not only at what point in "Paleo" history do we pick a diet but at what place in "Paleo" history do we pick a diet?
What's the problem with discovering the "real" Paleo diet?
Meat became very important to human diet between 3 - 2 mya
When did meat become relevant to human diet?
Most human traits are continuous Suites of traits may tend to group together, but with many exceptions Cultural and environmental influences on phenotype Drift, gene flow, mutation, selection
Why can't we reliably tell groups from different places apart?
We know that all modern humans today share 99.9% of their genomes with one another Almost all coding DNA is shared - they are just different alleles of the same genes Culture and environment may affect which genes, all in a triangle
Why does there appear to be so much human variation
archaeothanatology
high resolution taphonomic approach which combines detailed observations in the field with the knowledge about how the human body decomposes after death (Step by step by step) Aim is to isolate the effects of natural processes (putrefaction and decomposition, erosion, bioturbation) in order to reconstruct the funerary treatment of the dead body Basically lots of physics and chemistry
Modern Evolutionary Synthesis
the modern theory of evolution that takes into account all branches of biology suggests that genetic mutations create heritable variation and that this variation is the raw material upon which natural selection acts
intersection between medical anthropology and biological anthropology integration of biological and cultural factors into the study of health (debate within the field that one part is not doing enough/doing enough research) one common theme: uneven distribution of health within and between cultures -social and historical determinants of health
what are biocultural approaches?
Social: -food -education -healthcare -neighborhood and environment -social and community context
what are social determinants of health?
the application of the methods and theory of anthropology to the analysis and solution of practical problems
what is applied anthropology
a physiological alteration that impairs health in some way -largely influenced by Western biomedicine -Examples: injury, infectious disease, nutritional disease and chronic disease
what is disease and what are examples
using the principles of evolutionary biology to better understand, prevent and treat disease...also uses studies of disease to advance basic knowledge in evolutionary biology -Why has evolution shaped physiological and molecular processes in ways that leave us suspectible to disease?
what is evolutionary medicine
the subjective experience of symptoms and suffering. It motivates changes in behavior to alleviate discomfort. Disease is the root of the illness, and experience of it may exacerbate disease It's informed by cultural contexts surrounding how to think and feel. Psychological, social and physical aspects. Example: stress and H. Pylori -H. Pylori causes ulcers (not stress), but once you get it, it's painful and stressful, which produces more stomach acid and in turn increases H. Pylori Example 2: Treat a patient with beta blockers, but doesn't treat economic costs, which can further stress and can make original body injury worse or hurt another body part
what is illness and what is an example
the study of social patterns of ill-health and disease transmission, and experiences of and knowledge about health, illness and well-being Subfield of sociocultural anthropology Cross-disciplinary Often ethnographic Study of health and health-related issues in social context
what is medical anthropology
social and cultural conceptions of a disease -cultural beliefs and reactions such as fear or rejection -what illnesses are "suitable" for medical treatment -the social role of those defined as sick or ill -what we expect a sick person to look and feel like based on cultural and societal values they grew up in
what is sickness and what is an example
sociocultural anthropology
what subfield does medical anthropology fall under?
shows how race is a social grouping shows that race: -shapes physician's diagnoses and treatments -can even change the definition of the disease -focusing on race and biological differences between race (when there isn't one) causes one to further divert access to proper health care due to social determinants -causes marginalization of groups
what's the importance of the biocultural approach to studying social determinants of health?
Environment comes in at two points: 1. It turns genotype into phenotypes 2. It selected among phenotypes
Environment and human phenotypic plasticity?
1. Nutrition -Twins: one male, one female -Mother was (incorrectly) told she could only breastfeed one child -Cultural preference for sons --Expense of formula can lead to parents over-diluting it or using milk powders or animal milks (so not proper nutrition) --Formula does not provide immunity against infections --Quality of water supply (which prepares formula) 2. Stress and Cardiovascular Disease -Chronic stress linked to CVD risk, heart disease, high blood pressure, diabetes, depression, anxiety disorder 3. Stress and cortisol: teachers -Burnout among teachers -Cortisol is high when we wake up (because it stimulates us) --Teachers that have high burnout had blunted cortisol awakening response...longer to wake up 4. Stress and cortisol: study of childhood adversity in the US -Low-moderate adversity had lower cortisol awakening response -Low-moderate adversity had less of a decline during the day -Flatter profile associated with: chronic fatigue syndrome, fibromyalgia, chronic headaches, cancer 5. Neighborhood and environment: Mohawk nation -3 industrial aluminum factories -Fish consumption near these factories associated with: infertility, decreased thyroid function, delayed or accelerated menarche, depending on chemical exposure
Social determinants examples?
Dental eruption is quite accurate until teeth are fully erupted In infancy can constrain age to within 4 months for some teeth After that tooth wears - but that isn't great at measuring because it depends on people's diet
How accurate is dental eruption
Ossification / epiphyseal fusion begins earlier in females Known age range for post cranial fusion - variation by individual, sex, population Aging - Pubic Symphysis -Furrows (billowing) on face fill in --> smoothed --> pitted in old age -Rigid at first and then fuses later on
How accurate is epiphyseal fusion?
Total energy expenditure is similar as we are all within an optimal zone Humans burn "hotter" than other primates but still "colder" than many other mammals
How are the metabolic constraints in humans against farmers, hunter-gatherers, and westernized humans?
-Mortuary treatment (was there trauma in burying remains? Were they just tossed in a ditch?) -Skeletal trauma: combat? or was trauma accidental? Was trauma/injury during (peri), before (ante), or after (post) death?
How can skeletal remains asks "big" questions about the past about violence?
-Basic approach: measurement of individual bones of people of known stature --> regression formula -Stature correlates with limb bone length across all ages
How can you determine stature
-Ancient noodles from a pot -Macro and micro-fossils residues from a pot can show if residues from a plant -Can find tools used to break plants and collect food -Signs of nutrient deficiency --Osteoporosis --Rickets -Coprolites (can also tell you about sanitation) and stomach contents, and the macro-fossils and micro-fossils within them -Isotopes to determine what was commonly eaten (nitrogen isotopes is indicative or more protein in the diet, while C isotopes can tell if the diet is based on more closed or open vegetation) --Can even look at isotopes over a lifetime if you collect multiple dental remains --> can examine differences in diet by age, sex and social status
How can you use bioarchaeological evidence to ask questions about/reconstruct diet?
See how humans are buried -Different grave goods -Different modes of interment -Different post-mortem treatments -Aspects of these can be used to reconstruct their life USE BOTH THE BODY ITSELF AND ITS CONTEXT
How do you use bioarchaeology to reconstruct human ritual and beliefs
Many different types Best preservation for soft tissue is extremely wet (Waterlogged), extremely dry, or frozen Conditions should be CONSTANT Trade-off in preservation: acidic bogs can preserve skin but not always skeletons or DNA Prevention of bacteria, chemical weathering, and mechanical weathering
How do you use soft tissue/mummies as part of the bioarchaeology toolkit?
-We are even more similar than our phenotypes would suggest (average genetic different is ~0.1%)
How does human genetic variation map out?
Darkest skin with most amount of solar radiation (near equator)
How does skin pigmentation distribution coincide with solar radiation distribution
-Geographic distribution of genotypes or phenotypes represented in clines -Many examples of recent microevolution: lactase persistence, amylase, sickle cell disease, Y-chromosome bottleneck -Polymorphic traits can differ in allele frequencies --Shaped by natural selection, gene flow, genetic drift
How is human population genetics microevolution? Recent examples
Biologically meaningful as: -an adaptation -Not necessarily reflective of descent -Many Eurasian skin and hair traits probably introgressed from Neanderthals anyway
How is skin color biologically meaningful
Only between 5 - 15% of total genetic diversity in modern humans is accounted for by the differences between continents, most non-coding BUT it depends on which genes you use and which individuals you sample
How much of total genetic diversity in modern humans is accounted for by the differences between continents, most non-coding
1. Start with the minimum number of elements (MNE) 2. Identify, side and age every bone element 3. Count the number of left and right elements 4. Whichever has more is the MNI
How to calculate the minimum number of individuals
Although a readily apparent trait and biologically meaningful as an adaptation, it's not a racial characteristic or reflective of descent. Plus many Eurasian skin and hair traits probably were introgressed from Neanderthals anyway
Is skin color a "racial" characteristic?
1. does not take into account time (Devo-evo and evo-devo), because gene activation may vary based on time of development. Evolution can even occur more quickly than we anticipated originally! 2. ignores interaction with environment over time -- too genetic based (especially when life forms alter their environments) 3. genes aren't the only determinant of phenotype
Know two reasons why the sequence of gene -> protein -> trait might be an oversimplification of reality?
Sexual dimorphism -In general, males are taller and stronger, bones are longer and rough muscle attachment areas -However, can tell sex if child hasn't gone through puberty Best to look at several features -Pelvis only - most accurate 90% to 100% accuracy (narrower = male) -Skull only - next most accurate 80 - 90% (look behind ears. Mastroid proveses bigger for male; More robusticity of the mandible = male; more protruding brows = male) -Long bones only - 80% accuracy (less accurate. Males tend to be on taller side but not always the case) -Morphological and metric assessment --Sex can be determined from several long bone measurements - measurements can be compared with known ancestral groups to determine sex
Methods for determining sex?
1. Behavioral 2. Short-term Acclimatization 3. Developmental Acclimatization 4. Habituation
Modes of Human Plasticity
-Restricted marriage -Controlled immigration -Segregation -Forced sterilization (over 60000 in the USA) -Extermination --Incorporated into Nazi rhetoric --Plenty of echos today
Modes of intervention to aid eugenics movement?
1. Protein - available mainly from animal resources 2. Fat - most wild game is lean 3. Salt - not evenly distributed 4. Calories - difficult to obtain 5. Micronutrients - iron, DHA, vitamins
What are the limited resources in the hunter-gatherer diet
combines Darwin's and Wallace's Theory of Evolutionary by Natural Selection and Mendel's Theory of Discrete Genetic Inheritance
What are the two components of the Modern Evolutionary Synthesis
1. Skeletal/dental development (until 18-25 years) 2. Deterioration *Cranial changes with age --> sutures begin to fuse overtime/with age; underdeveloped mandible as a newborn and then heads gets big and then it deteriorates
What are the two phases of skull growth
Example 1: Fever -Doctors often recommend medication to reduce fever -However, fever is an adaptive response to infection: --Faster neutrophil migration --Activation and proliferation of lymphocytes --Production of cytokines including interferon --Increased movement of lymphocytes --Inhibits the growth of bacteria and replication of viruses by reducing plasma iron --Unless it rises to dangerous levels, fever is actually helpful Example 2: Breast cancer and birth control -More lifetime cycles + progesterone --> cell proliferation every cycle = greater risk of mutation and greater risk of developing breast cancer -So birth control better mimics our evolutionary history than cycling every month Example 3: Co-sleeping, breastfeeding, SIDS -Many wealthy Western settings normalize solitary infant sleep (to foster sense of independence) --But is that what we would have evolved to do? --Out of 186 hunter-gatherers groups surveyed, 100% co-sleep ---But isn't that dangerous? A: the western bed was not designed with babies in mind, it's actually very safe for the baby -Breastfeeding: greater risk of SIDS when not breastfed --Breastfeeding keeps babies and mothers in a lighter stage of sleep, which promotes a greater awareness of what the other is doing --co-sleeping associated with more infant arousal --> less SIDS risk -Breastsleeping: breastfeeding + shared sleep is an adaptive behavior -US still says this is bad, other cultures (Japan, Guatemala) support it, so anthropologists are trying to advocate it more (application)
Examples of applied anthropology in evolutionary medicine?
-Responding to new or changing environments through learning and cultural innovation -Builds sophisticated system of acquired and transmitted knowledge
Explain behavioral plasticity
-Hunter-gatherer men will hunt more than needed to supply their nuclear family -Hunts fail more often than collecting -Hunts supply more people at a time than collecting -Hunts are visual displays that often involve much risk -Hunted foods are usually shared within the larger group -Showing off - males enhance their reproductive success by "showing off" to other group members through risky activities with a high return -Human foragers are typified by their sexual division of labor -Women's work may be lower status than men's work, even if it provides more calories
Explain connection between hunter-gathering and status?
-Flexible during early life -Becomes imprinted and permanent by maturity -Is not heritable: offspring will share characteristics only if they grow up in similar environment/stressors -Mold organism as they're growing, but don't pass it on to offspring -Ex: foot binding, corset shaping
Explain developmental acclimatization
Trauma is useful for assisting with identifying cause and manner of death Potentially useful for victim identification Can identify the type of fracture and its location can help you to: -Determine what instrument was used -Determine if accidental or intentional -Determine direction of force -Determine sequence of blows or shots -Establish history of trauma
Explain how trauma is helpful
Ancestors craved sugar and fat (we do too) The mismatch: Now we have too much fat in the environment, and we still crave the nutrients in all of these domesticates. The domesticates are now all bigger, stronger and more calorie-dense than their precursors - we have increased the bottom line too much
Explain mismatching of paleo diet today
-Temporary alteration of circulatory, respiratory, or other system to adapt to a novel or heightened environmental stressor -Once stressor is removed or reduced, system returns to its former state -Ex: climbing mountain slowly because high altitude...climb slowly so blood produces more RBCs for more O2
Explain short-term acclimatization
1. Horizontal gene transfer: the acquisition of genetic material by one life form from another, unrelated life form, during the life course, and the passing of that novelty to the offspring -ex: the first eukaryotic cells likely formed by one cell absorbing the other -ex: in humans, many metabolic functions were likely acquired from bacteria through this process 2. epigenetics: environmentally induced, heritable variations in gene function -ex: imprint gene and male infertility -ex: immunocomplex genes activated by levels of different hormones in the bloodstream 3. mutagenesis: the failure of DNA repair mechanisms (rather than mutation because of random, rare events such as cosmic ray bombardment) -ex: simply copy errors can lead to point mutations...if the gametes, they're passed on 4. Developmental Evolutionary Biology: the timing of gene activation in the life-course is crucial to the development of the phenotype. Thus the simplistic mapping of gene --> protein --> phenotypic trait is a gross oversimplification because it doesn't include the dimension of time -ex: testosterone not produced at right time, apparent sex goes from male to female 5. co-evolution: most if not all species have significant evolutionary relationships with other species -ex: human parasites 6. phenotypic plasticity and phenotypic integration: traits interact with the environment -ex: getting a tan 7. niche construction: life forms, consciously or not, alter their selective environments and are not always simply passive precipitates of a given selective regime -ex: early atmosphere was not full of oxygen until enough respiration from early organisms had built up -ex: humans have altered their selection environments through food production 8. hybridization
Three aspects of Extended Evolutionary Synthesis Why are they argued to not be adequately covered by MES
False: genetic differences do not map cleanly onto phenotypic differences --> so much phenotypic variation but genetic differences between humans is so little
True or false: genetic differences map cleanly onto phenotypic differences
-Health: factors that lead to disease and nutrition -Demography: age and sex profiles of a population -Migration: how people moved around (and we've improved in this thanks to ancient DNA) -Lifestyle: workload, habitual activities -Ritual: how people treated the dead, stratification, beliefs -Violence: scale and context of interpersonal violence
Ways to reconstruction past lifeways?
Melanin -Amount produced, size of melanin particles, the rate melanin is produced, and the location of the melanin in the skin
What affects skin color?
-Hormones, disease, copper/zinc deficiencies -UV radiation --Lightly pigmented = 50% UV block --Heavily pigmented = 95% UV block -Sex --Males produce more melanin than females -Age --Newborns of darker-skinned parents get darker with age
What alters melanin production
1. Develop a biological profile of the deceased -Age, sex, ancestry, stature, pathologies, trauma, other unique identifiers 2. Is it human? (many people often mistake non-human bones as humans) 3. Is it an ancient bone? Modern? (archaeological bones can be confused with modern forensic cases) 4. How many individuals are there? Calculate minimum number of individuals
What are the first things a forensic scientist tries to establish
