Bio Anth 196

Independent Assortment

The distribution of one pair of alleles into gametes does not affect the distribution of another pair.

Bipedal Adaptation Femur

The femur is angled so that it positions the lower leg directly under the body. This angle on the femur is called the bicondylar angle or carrying angle. This allows for a more efficient weight transfer from femur, to lower leg, to feet, to ground. In addition, the femur gets longer (as does the entire leg). This increases stride length (distance covered per step). A longer leg takes fewer steps to cover the same distance as a shorter leg, which is more efficient (and explains why, in part, a tall person can outrun a baby)

early attempt to classify human diversity (4 parts)

phenotype; ethnocentric and teleological; biological determinism; taxonomically arbitrary

Unique things only evolved on human lineage

Less sexual dimorphismSmaller face (resulting from cooking our food) Reduced canines ("fang" teeth) Language and an even bigger brain More complex tool use

Relative Dating: Using Stratigraphy

Sedimentary rocks are formed layer by layer. Over time these layers--or strata--pile up on top of each other. This means that bottom layers are older than top layers. So fossils found in these different layers can be dated in a relative sense: this one is older than that one.

Directional selection

Selects one direction, tall or small and changes to the best fit.

Transmission Genetics

The study of how traits are passed on from parent to offspring.

Forensic Anthropology

The study of skeletal remains and other evidence in order to determine the causes and context of death with respect to legal and criminal matters •Contemporary sites •Attributes of individual •Legal/criminal matters

Bioarchaeology:

The study of skeletal remains from archaeological sites (10kya to historical) in order to determine the biological context of life and death from a cultural and archaeological perspective. •10kya to recent •Cultural attributes •Population attributes

Primate evolution: The Miocene

Three major groups of fossil hominoids (ape-like creatures) appear during the Miocene. African forms Fossils date from 23 to14 million years ago European formsFossils date from 16 to 11 million years ago Asian formsFossils date from 16 to 7 million years ago

Spurious correlation

a correlation based on an unmeasured third variable

Traits that distinguish living nonhuman primates from all other mammals include

a mostly tropical distribution

The extinction of predators or an "adaptive breakthrough" can trigger

adaptive radiation

Professor Lawler is a ________.

all of the above

Contest competition for food is

associated with strong, differentiated dominance relationships

Organization of the brain

brainstem, controls metabolic activities (digestion, heart beat, breathing) cerebellum, associated with balance, coordination, movement cerebrum "higher"brain functions, divided into lobes (thinking, judgment, language) Cerebrum is divided into frontal, parietal (2), temporal (2), and occipital lobes. The Primary cortex: This is the first area to receive sensory input (as when someone tickles your foot with a feather) and the area that sends out the signal for motor output, or movement (as when you move your foot away from the feather) Association cortices: other regions associated with hearing, vision, speech etc.

Malthus

competition between individuals may be intense

Science seeks a ______, _______, and ______ understanding of the material world

rigorous, systematic, empirical

biological profile

estimation of the deceased's sex, age, stature, and ancestry, along with diseases and injuries, as derived from analysis of skeletal remains With respect to skeletal remains, bioarchaeologists and forensic anthropologists begin to analyze the material to develop a biological profile of the remains. This includes determining:

Davidson Black, Franz Weidenreich and Pei Wenshong

excavated at Zhoukoudian (CHINA) uncovered over 100 fossi ls attribut ed to H. erectus

______ is a subfield of biological anthropology

forensic anthropology

Cladogram

shows the evolutionary relationships among groups of organisms

Heritability is defined as

the extent to which offspring resemble their parents

Deviation from the Hardy-Weinberg equilibrium at a genetic locus implies

the genetic focus is evolving

Lyell

uniformitarianism- past and current geological processes are the samegradualism, deep time

Antibiotic application

usually kills 100% of bacteria due to mutation, it is likely that one cell has evolved resistance to the antibiotic

All of the following are found in A. afarensis except

very little sexual dimorphism in body mass

It is likely that the common ancestor of chimps and humans possessed some sort of ______ and ______.

warfare....culture

Homo habilis: Some basic facts

•Dates from 2.4 to 1.5 mya•Found in East and South Africa•Modern bipedal gait (fully terrestrial)•Mixed diet: meat + vegetarian•Increased manipulative ability in the hands

Charles Lyell

-Challenged Catastrophism -many fossils showed gradual change over long period of time. -introduced "uniformitarianism"- past and current geological processes are one and the same.

Jean-Baptiste de Lamarck

-Theory of evolution by inheritance of acquired characteristics (first mechanistic theory of change) -Mechanism = How it works -drew attention to heritability

Contemporary Human genetic variation

A lot of human genetic variation can be explained by two patterns: •Local migration and gene flow (results in "clines") •Founder effects and colonization (results in sharp divisions in gene frequency) Repeated migration and back migration often creates genetic similarity between geographic regions because the entire migration route becomes populated with settlements. small amounts of mating between towns (small horizontal arrows), even with large amounts of mating within a town, will "smooth out" the gene frequencies across space (individuals from one town bring "their genes" over to another town). This creates a cline Cline: gradual change in frequency of gene over geographic space. Single migrations by small groups with little additional migrations into the area can result in founder effects, his creates sharp divisions in gene frequencies in geographically close areas

Taphonomy and tool use in South Africa

Another thing that caused bones/horns to be oddly shaped was due to the local geology in S. Africa back when A. africanus was around. The landscape had lots of underground caverns, because the water-table would rise and carve out an underground cave. Some of these caves had openings onto the surface. Upon dying millions of years ago, bones from A. africanus and other prey animals could fall into these caves from the surface. And over time, the caves filled up with brecia—a "cement-like mixture of rock". The breccia would put pressure on the fossil bones, causing them to fracture in weird shapes; thereby producing the "tool-like" and "weapon-like" appearance and leading Dart to conclude A. africanus made these tools and weapons. But it was all due to geology, not A. africanus!

Key features of Paleoanthropology

Evolutionary (uses evolutionary principles)• Multidisciplinary (many different fields contribute to paleoanthropology)Key features of paleoanthropology:• Disproportionately represented in popular media (Only dinosaur paleontology is as publicly popular)• Mercurial (fast-changing as new species are constantly being discovered)• Contentious (Can run into problems with religious origin-stories; Paleoanthropologists have big egos and don't often share fossils they recover; pseudo-scientists point to paleoanthropology research to support the existence of non-existent creatures such as Bigfoot and The Yeti)

Medical Anthropology

Explores relationship between culture and health.

Primate evolution: The Oligocene

First good evidence of fossil anthropoids (the group that contains monkeys, apes, humans). Early Oligocene, fossil anthropoid monkeys of Old World (found in Africa) Late Oligocene, fossil anthropoid monkeys of New World (found in South America Aegyptopithecus(larger, eats fruits/leaves) Apidium(smaller, eats fruits/seeds/insects) Fossil platyrrhines are anthropoids •South American fossil primates show up in late Oligocene •Their resemblance to African anthropoids suggests that they likely came from Africa rather than N. America (recall that there were Eocene primates in N. America and Europe)

Both Forensic anthropology and Bioarchaeology

Genetic information• Individual Identification• Ancestry• Sex Context of death •Injury •Trauma Skeletal information• Age• Sex• Ancestry• Injury, stress, disease

Genetic Diversity and Race

Genetic variation falls along a continuum across geographic space (meaning there is gradual change in gene frequency as one moves north to south, or east to west). There are no sharp genetic divisions that correspond to separate groups of people. add in sampling areas from India and South Asia (pink circles on previous slide) the seeming sharp genetic divisions becomes more of a continuum of gene frequency differences across geographic space. More simply the seeming "big differences" become obliterated.

Primate Evolution the Miocene

Genus: Proconsul This is an African Miocene ape that is a small bodied arboreal creature Genus: Dryopithecus This is a European Miocene ape is mostly a frugivore of medium size Sivapithecus This is an Asian Miocene this is likely ancestral to modern orangutans

Which species of hominid is characterized by shovel-shaped incisors

Homo Erectus

Homo Sapien Skin Variation

Homo sapiens, are characterized by intraspecific variation in many traits, such as height, weight, eye color, hair color, and skin color. Some of these traits are heritable and fixed among different populations. For example, individuals with African ancestry have darker skin than individuals with Northern European ancestry. This fixed difference in skin color evolved because African and European populations were living in different environmental conditions (different in the amount/intensity of sunlight) for hundreds of generations. The two groups "evolved" to deal with the different amounts of sunlight, which ultimately led to permanent differences in skin color.

Later Human evolution and migrations

Homo sapiens, once evolved, continued to migrate into new lands, eventually populating the entire world. Some major "recent" migrations were: •Australia (50kya) •The New World—North and South America (after 30kya) •Remote Oceania—Hawaii, and other far-away Pacific islands (4kya)

Cultural Attributes

Humans have complex cultures and there is evidence that chimps also possess cultural attributes So it is possible that some form of primitive culture characterized our common ancestor.

Bipedal Adaptations: The Skull Base

In humans, the head is centered on the spine. The spinal cord leaves through a downward facing foramen magnum (foramen means "hole") In quadrupeds, the foramen magnum is further back on the skull

Organization of the cerebrum

*Hemisphere*: one half of the cerebrum divided down the midline. *Sulci*: grooves on the brain, the "troughs" *Gyri*: ridges on the brain. The "rounded up" part. *Neurons*: basic cellular units of the brain and nervous system.

Laboratory processing and curation

- All artifacts, evidence, and/or skeletal material is brought back to the lab for analysis - These items are inventoried and analyzed - In forensic cases, the data constitute legal evidence and a *chain of custody* must be established a chain of custody is a formal and well-documented record of who gets to view/handle the evidence. This is a measure to prevent "evidence tampering" (for example, a prosecutor might tamper with the evidence so as to result in a guilty verdict of an innocent person). No chain of custody is needed in bioarchaeology

What Genetics Tells Us

- tells us why certain individuals are similar - tells us why certain individuals are different - can help us determine relationships among individuals, groups, species.

Erasmus Darwin

-First proposed idea of the origin of species through evolution in "Zoonomia" -common ancestry and life in the sea -however did not have a mechanism for evolution

Jon Ray

-First proposed that interbreeding organisms be called "species" -Similar groups of species be called "genera" (singular = genus) -fixity of species

George du Buffon

-First suggested that species were not completely fixed (they degrade) -a dynamic relationship between organisms and environment -believed world was old, not young

Carolus Linnaeus

-First systematic classification of organisms (genus species, e.g., Homo Sapiens) -added class and order-species were static and created by divine creator -implicitly challenged "great chain of being"

Identity and Identification: Time since death

-In order- Death Cooling/Rigidity Bloating Skin slippage Liquefaction Deflation Skeletonization In forensic anthropology, "time since death" is very important. If detectives find a dead body that is still warm, this means the individual was recently killed and the killer could still be in the vicinity. If detectives find a decomposed skeleton, this means the victim died a long time ago and the killer had plenty of time to escape far away. These stages of decomposition have time periods associated with them, meaning that a corpse in a given stage of decomposition can be studied to determine time since death. Along with decomposition, different species insects and bacteria invade a decaying body. So another way to determine time since death is to look at what species of insects and what bacteria are present in the body at a given stage of decomposition. SLOWER DECOMPOSITION •Buried body •Cold conditions •Wrapped/Contained bodies •Mass graves RAPID DECOMPOSITION •Surface deaths •Summer/drier conditions •Unwrapped bodies •Single burials

How allele frequencies change

-Natural drift -Genetic Drift (accidental deaths) -Mutation -Migration

Human biological variation: altitude

-Oxygen less concentrated at high altitudes. -Leads to hypoxia: lack of oxygen in body -Over short-term: body increases respiration and heart rate, and produces more red blood cells -Over the long-term: Populations living in high altitudes have larger lungs, larger heart mass and slower rates of maturation Over short-term: Any humans who visits an area high-above sea level will experience the following: the body increases respiration and heart rate, and produces more red blood cells—this is a way to "pull" as much oxygen from the environment as possible and get it to your tissues, since high altitude environments don't have much oxygen to begin with. Over the long-term: Populations that permanently live in high altitudes have evolved the following: larger lungs, larger heart mass and slower rates of maturation. This is a way to "slow down" growth so the body can "pull" what little oxygen little oxygen is available, using their bigger lungs and heart. These are heritable traits that characterize, for example, Sherpas Oxygen less concentrated at high altitudes. Leads to hypoxia: lack of oxygen in body. But some populations have evolved to live in high altitudes.

George Cuvier

-Recognized that fossils could be grouped with modern organisms -older fossils were less like modern organisms than younger fossils -rejected the concept of evolution and argued for the "fixity of species" Catastrophism

Mutation

-occurs when the sequence of bases in a gene is altered -interfere with an organisms ability to produce vital protein-may lead to a new variety within the species, hence, evolution -most deleterious(harmful) or neutral -somatic ones (cancer) are not inherited.

Historical Perspectives - Races

1). Phenotypic: Classifications were based on an arbitrary but visible aspects of the phenotype: skin color, hair type, nose shape (but little thought was given to why some traits were used and not others) 2). Ethnocentric: those doing the classifying placed themselves at top of the classification scheme (often European scientists would place their own race as most civilized whereas other races were viewed as less as civilized) 3. . Biological determinism: This was the mistaken idea that social and cultural characteristics are genetically determined and thus form part of the racial features that characterize a particular group. E.g., a scientist might notice a particular culture dances and sings a lot; hence "drumming/singing/dancing" would be used a (mistakenly) biologically—determined characteristic to racially classify this group. 4. Taxonomically arbitrary: The major problem here is that scientists were trying to subdivide the human species into smaller groups—believing such smaller groups corresponded to "real" biological divisions. But such subdivisions were quite arbitrary, even though the scientists didn't think they were. Racial Classification late 1800's -Notice that White people are at the top... no surprise that the fellow who came up with this classification was a white European. -the scientists lists high-level Primate taxonomic groups (such as families, e.g., Cebidae) along with human groups, such as "Negrito" and "Mongoloid". Hence there are taxonomic groups above and below the species level in this diagram (families, and within-species groups). This "classification" is far from objective and scientific.

Strategy of Paleoanthropology

1. Find suitable field sites where fossil humans may be found 2. Initial survey of site for fossils, some initial dating of rock strata 3. Full-scale excavation for fossils 4. Analysis and interpretation: Chronology, Paleoecology, Archaeology, Anatomy,

Cline and Founder Effects

ABO blood type system Three genes: A, B, O. Six genotypes: AB, AO, BO, OO, BB, AA Four phenotypes: type A, type B, type AB, type O A and B are dominant to O, and co-dominant with each other

The Biological Profile: Age

AGE: As individuals grow, their skeleton/teeth change as well Researchers can study these changes to determine age at death (i.e., when growth stops) -Lots of changes happen from 0-21 years, so identifying age at death is easier during this period -Fewer changes happen from 21 onward, so identifying age at death is more difficult during this period Teeth and mandibles are durable. It is possible to calculate age from the eruption pattern of teeth (both milk teeth and permanent teeth—remember diphyodonty, a mammalian trait—diphyodonty helps forensic anthropologists do their job) For example, if you find a jawbone with only the first molar erupted (present in the jaw) but no others, you would conclude that you found an individual who is 6-7 years old (see red circle) There are other skeletal indicators of "age at death" including the pubic symphysis, which is the "joint" that connects your two pubic bones (that are located behind your genital region). The diagrams below give rough ages at death as determined by the pubic symphysis—this measure is not very precise! Pubic symphysis When youre born, your long bones in arms/legs come in three pieces: the shaft and two "end caps" of the joints. As you grow, these endcaps fuse onto the shaft forming a single bone. This happens before the age of 12. One can use the fusion of the epiphyses ("bony ends") to the shaft of the bone as an indicator of age in children from before birth to age 10-12. Recall "Turkana Boy"

Adaptation vs Adaptive Pehnotypically Plastic

Adaptations different environmental circumstances—these are fixed, heritable traits. e.g., darker skin in tropical populations(here the adaptation is skin color) Dark skinned parents have dark skinned offspring; light skinned parents have light skinned offspring. Adaptive Phenotypically Plastic Responses to environmental circumstances e.g., the ability to tan when visiting tropical regions(here the adaptation is the capacity to respond) Parents and offspring—whatever their skin color—have the ability to tan when exposed to lots of sunlight

What is a half life?

Amount of time it takes for 50% of material to change (or decay) Assume (on right) in the past that a rock gets shot out of a volcano with 100% radioactive atoms. Volcanos often cause rocks to have 100% radioactive isotopes. And we know (from geochemistry) that these atoms have a half-life of 5 million years. If the half-life is 5 million years, we know that after 5 million years have elapsed, the ratio of radioactive to stable atoms in the rock will look like this (on right), because half of the radioactive atoms have "decayed" (changed) into stable form (red)

The Biological Profile: Sex

Another component of the biological profile is determining sex (male versus female) from skeletal material. Males and female skeletons differ slightly in different skeletal regions, including the pelvis and the skull. Many differences are evident in the skull of adult males and females.

Human biological variation: skin color

Another visible source of phenotypic variation among humans is skin color Over the short-term: human skin can change color based on exposure to sunlight (tanning) to protect it from UV radiation Over the long-term: a population's average skin color reflects adaptations to protect it from UV radiation Skin is the largest organ of the human body 2 square meters of skin on average adult, and 2mm thick Skin is the most visible aspect of our phenotype Skin conveys health status and personal identity/ethnicity Three substances which influence skin color: •Hemoglobin (gives skin a reddish color) •Carotene (gives skin an orange-ish color) •Melanin (gives skin a dark/light color) Melanin is the most important determinant of skin pigmentation: more melanin = darker skin Melanin is produced by melanocytes (= cells that produce melanin). Melanin is granular in form, like tiny tiny grains of sand All humans have same number of melanocytes Humans differ with respect to the amount and size of melanin produced. Darker skin = larger/more melanin produced. Melanin absorbs UV radiation from sunlight, thereby protecting skin UV radiation is most intense along equatorial regions There is evidence that skin color is adaptive UV radiation will damage folate acid (a B vitamin) Folate acid is necessary for DNA synthesis, red blood cell formation, and spermatogenesis (in males). Low folate acid can lead to birth defects (e.g., low fitness). So melanin protects skin from the destruction of this essential vitamin Small amounts of UV radiation is necessary for the body to manufacture vitamin D The body uses cholesterol in the skin + UV radiation to synthesize vitamin D. Vitamin D important for bone growth and important during pregnancy and lactation.

Infant Stage

As child grows, it can begin eat solid food provided by dad and mom: the benefit of mother's milk to the infant decreases with age. As infant grows larger, mom incurs a larger energetic cost for nursing her ever-growing baby Infant: continue to nurse me (it's a free meal after all).Mom: you are getting too big and I need to save my energy for future pregnancies. This conflict of interest explains the widely-known pattern of weaning-tantrums, since mom and offspring have different ideas of when to stop nursing

Homo erectus fossils found in africa

At Koobi Fora in 1975, an almost complete cranium of Homo erect us was recovered. It dated to 1.8mya Another cranium was also recovered dating to 1.6 mya These were found by Richard Leakey (son of Louis and Mary ) In 1984, a discovery was made by Alan Walker, Richard Leakey, and colleagues: known as "Turkana boy Dates to 1.6mya •Very complete skeleton and cranium •11-12 years of age •1.6m tall (5' 3") at age 12 so likely to have reached 1.85m (6' 1") as a full-grown adult •Body shape was long and linear Cranial capacity 880cc

Reorganization of the hominin brain

Brodmann area 10 (or the frontal pole of the prefrontal cortex). This area seems to be involved with "mental multi-tasking, such that we can continue to perform one brain function, while starting or finishing another brain function.

Which ONE of the following statements is TRUE

Buffon suggested there was a dynamic relationship between organism and environment

An evolutionary scenario for skin color- Chimps vs Hominins

CHIMPS: -Primitive skin color is light -Forest cover provides more protection from UV radiation -Smaller group size means less ectoparasite transmission, no selection for body hair reduction HOMININS -Larger groups means more ectoparasite transmission, so selection to eliminate fur -Savanna means more sunlight and new adaptations to deal with heat/UV radiation against light colored skin. Sweat glands and bipedalism contribute to lowering heat load. -And the loss of body hair necessitates protecting naked skin via melanin production

Juvenile Period (3-12)

Childhood (3-7yrs)• After weaning, but still dependent on parent for food/ protection. Children begin to play with objects/dolls...to pretend (this is a useful skill that leads to the adult capacity to empathize/sympathize with others). Pretend play is a precursor to empathy and understanding the thoughts of others •Brain growth continues into early childhood Juvenile (7-12yrs) •Socially dependent on parent •Major time of learning social skills to be used during adulthood. •Children of this age engage in a lot of peer-play with their age-mates. This allows them to learn social skills that will be valuable as adults.

Chronometric Dating: Absolute Dating

Chonometric dating is a way to get an absolute date on a fossil. Half-life is the time it takes to reduce the number of radioactive atoms in a rock by 50% Geologists measure the age of rocks using the ratio of radioactive to stable atoms in the rock based on the half-life of the radioactive atoms.

Language versus communication

Communication usually modifies behavior of recipient Examples: •scent-marking •facial expressions •postures •vocalizations •Communication is universal among animals Language: Language is a unique system of communication used only by humans. Some major and unique criteria that characterize language are as follows: Spoken: we use words and have anatomical specializations for producing speech. That is, language (excluding sign-language) is spoken using sounds made from our throat and mouth. Semantic: We use sounds that comprise words, and words are linked to real-world objects, events, actions...words have meaning that are understood by others who speak the same language. Phonemic: Our words assembled from small arbitrary sounds called phonemes; they are arbitrary because different languages have different arbitrary sounds for the same objects (tree, arbol, baum, in English, Spanish, German) Grammatical: Language has a complex system of word classes (e.g., verb tenses) in order to talk about past/present/future, and also a system of word order (called syntax), since word order matters: "dog bites man" versus "man bites dog" ...the former is par-for-the-course for postal workers, the latter is psychotic behavior.

Taphonomy and tool use in South Africa

Dart argues A. africanus had an osteodontokeratic tool culture. Osteodontokeratic means a "bone-tooth-horn tool-box" which was, according to Dart, a set of tools and weapons that A. africanus used to kill prey and even kill other A. africanus individuals. South African fossil sites are characterized by a lot of sharp-shaped bones and horns that, to Dart, were used as weapons/tools made by A. africanus.

Homo habilis

Discovered by Louis Leakey •Husband of Mary Leakey•Father of Richard Leakey•Father in law of Meave Leakey•Grandfather of Louise LeakeyThe Leakey family are all famous paleoanthropologists...3 generations of them! Louis Leakey found the first Homo habilis fossil at Olduvai Gorge in Tanzania (Africa) in the 1960'sThis is the same site where P. boisei is found •No sagittal crest•Small molar teeth•Found in close association with tools The fossil material was found in close association with many stone tools. So the implication was that this species was making stone tools.Leakey named this new fossil "Homo habilis" (roughly meaning "handyman"), referring to its presumed tool-making capabilities Brain sizeH. habilis had a larger brain than any australopithecine Tool useH. habilis made tools (at the time, no australopithecine was associated w/tools) The new fossil material was fragmentaryAnd other paleoanthropologists didn't like that he named a new species on the basis of its association with stone tools (the view back then was that you named new species based on the anatomy of the fossil, not the fossil's association with stone tools)So Leakey needed better fossil specimens to secure his fossils as a legitimate species. He enlisted the help of his son Richard Leakey Richard Leakey set up his own camp at Koobi Fora, Northern Kenya (Africa)It was a very productive fossil siteAnd he found Homo habilis!(and also found P. boisei—a robust australopithecine)

Hominid Evolution: Backgrounnd

During Miocene there is a trend toward cooler temperatures. That is, the earth's annual temperatures were, on average, cooler each year. So the early Miocene was warm and environments were mostly forests, but the later Miocene was cooler, and this caused forests to disappear to be replaced by Savana-type environments (grasslands plus trees) This change in environments imposed new selective pressures on the species in those habitats and at the end of the Miocene one of the ape-like creatures speciated (split into two) to become the first hominins.

Homo sapiens

Earliest Sites in Africa/Middle East (160-100 kya) Later Sites in Europe/Asia/Australia Earliest Skeleton Dated at 160 kya •Vertical forehead •Small browridges •Chin •Small incisors (relative to Neandertals and other hominins homo sapiens have longer limbs than Neandertals (and other hominins) Also, our skeletons are less robust (less stocky) than Neandertals •More robust facial features than later Homo sapiens •Cranial capacity 1450cc •Does not have Neandertal traits (e.g., no midface prognathism or wide nasal opening) There are three current viewpoints regarding the origin of modern humans: 1) Complete replacement model •H. sapiens first evolved in Africa from H. heidelbergensis• Some H. sapiens then moved into Europe and Asia •The ones that moved into Europe and Asia DID NOT interbreed with existing hominins in these areas 2) Partial replacement model •H. sapiens first evolved in Africa from H. heidelbergensis• Some H. sapiens then moved into Europe and Asia •The ones that moved into Europe and Asia DID interbreed (red lines) with existing hominins in these areas 3) Regional continuity model There was no single geographic location where H. sapiensevolved. Instead, due to lots of migration (and gene flow) among hominins across Africa, Asia, Europe, H. sapiens evolved simultaneously in these three regions. Their ancestors were the hominins who previously occupied these regions. Under this model, the species of Homo we see in the fossil record are not "true" species because they are assumed to interbreed and thus not reproductively isolated from each other Genetic data show that there was some interbreeding between early Homo sapiens and other coexisting hominins in the past. Particularly between Homo sapiens and Neandertals. Thus, of the three models, the fossil data and the genetic data best support the PARTIAL REPLACEMENT MODEL It is called this because as Homo sapiens first evolved in Africa and then some of them moved into Asia and Europe while the other hominins there mostly disappeared (hence they were "replaced" by incoming Homo sapiens) INTERBREEDING There is about 1-4% similarity between H. sapiens DNA of modern Europeans and Asians (but not Africans) and neandertal DNA Genetic evidence supports a partial replacement in Europe and Asia Anatomical evidence supports partial replacement in Middle East and in some Central European sites In Asia, more complex scenario as new discoveries have suggested partial replacement or even regional continuity. The received view today is that of partial replacement Humans reached the following regions at the following times:•Australia (50,000 years ago)•The New World (20000 and 12000 years ago)•Remote Oceania (Hawaii and other Pacific Islands) at 4000 years ago. It now appears that there was more than one migration into the New World: One at 20kya and one around 12kya

Racial Concepts in Physical Anthropology

Earnest Hooton and his student Carlton Coon (The Origin of Races) Races were biological entities Used morphological criteria such as skull morphology (dolicephalic vs brachicephalic) t races of humans existed and were thus waiting to be "discovered" by the scientist. They often used anatomical (arbitrary) criteria to delineate human races. They never once stopped to consider the idea that perhaps "races" don't exist as real biological categories (as opposed to arbitrary divisions based on social stereotypes)

How unique is human language?

FOXP2: a gene that is important in language and speech production. The gene was discovered because a family in Britain was characterized by a severe language impairment. Since this disorder ran in the family, it was suspected to be genetic. FOXP2----> Protein Gene expression related to language "circuits"during development FOXP2 Mutant-----> Nothing Severe problems with speech and language production OXP2: Once researchers had located the FOXP2 gene, they were able to look at the DNA sequence, and associated protein (amino acid) sequence in humans, as well as the similar DNA region in chimps and humans. In humans there are two key protein differences relative to chimps/gorillas. HUMANS: two key protein differences likely arose through mutation at some point in human lineage and helped contribute to language production (also note that Neandertals have these two key changes)

Inferred behaviors of Homo erectus

First widespread species, colonizing seasonal habitats. Chi na, Java, Turkey, Italy, and other Eurasian locales (as well as Africa) Large brain suggest s a more human like pattern of growth Used and possibly controlled fire?? More compl ex tool kit as Achulean have more craftsmanship/modification Tools used in butchering big game May have "embraced culture" as an adaptive strategy

Pre-Darwinian view

Fixity of species & the Great Chain of Being (traces back to Aristotle)

Forensic ondontologists

Forensic odontologists (forensic anthropologists who specialize in teeth) can compare dental x-rays taken from the individual while alive to those taken from the recovered (dead) individual. An individual may be identified by the pattern of tooth eruption, tooth position, and dental work so Dental x-rays are similar to a fingerprint—they are pretty unique to each individual

basicranial flexion

High basicranial flexion is associated with a longer vocal tract Some reconstruct Neandertals with little flexion New reconstructions reveal increased flexion Basicranial flexion is taking a set of measurements on the underside of a skull and then looking at the "side view" of these measurements (side view shown on right)

Bipedal Adaptation: The Vertebrae

Humans have two distinct spinal curves to keep weight centered above pelvis...again it's more efficient to keep weight inline with the pull of gravity- Cervical curve Lower (lumbar) vertebrae are very large in humans in order to support weight of trunk, arms, head. All else being equal, a large fat disc can support more weight than a small thin disc. And your vertebrae ("back bones") are basically discs of bone that run up your spine from your pelvis to your head. They are smaller at the neck area (since they only support the head) and larger lower down (since they support the torso, arms, neck, and head)

Adult period (18 onward)

Increased adult brain size linked to... Prolonged brain growth after birth and during childhood... increased importance of culturally transmitted information... Thus selection for an extended life cycle, with slower development and more time for learning -Fully sexually mature -Skeletal growth stops (by about 18, you're as tall as you'll ever be) -Major period of reproduction -Major period of parental investment

Taphonomy: the study of what happens to an individual after death

It is important to distinguish if this skeleton was deliberately buried—a cultural process...or whether an individual died, rolled down a hill and randomly ended up in a hole (that kinda looks like a shallow grave) in a "fetal position" and then decayed. Upon recovery, how would you determine if the individual was intentionally buried in a fetal position by their friends, or that the individual died and randomly ended up in a shallow hole curled up in a fetal position? This is what taphonomists study: what was human intention (e.g., a deliberate burial) versus random processes (a death that mimics a burial but was actually random). Bioarchaeologists are particularly interested in distinguishing if a given skeletal structure occurred antemortem (before death) or postmortem (after death). If you experience an injury during your lifetime, you heal and this will be registered on your bones. Wounds that occur at the time of death or soon-after do not healFor example, tooth loss during life leads to a different mandibular structure than tooth loss afterlife. If you lose a tooth while alive, the tooth socket "seals over" with bone. But on a dead individual that is buried, if a tooth falls out of the tooth socket, the tooth socket stays open. So on the skull on the left, the open tooth sockets are postmortem damage to the skull, but the sealed-over tooth sockets reflect tooth loss (and healing) while the individual was alive (antemortem injury)

Homo Habilis (ape Human thing) as a scavenger

It was originally thought that Homo habilis (and A. africanus) was a skilled hunter and was using the tools it made to butcher meat of the prey it killed.More recent views, however, suggest that H. habilis was likely a scavenger (similar to vultures and hyenas), as was A. africanus. Scavengers let other creatures (e.g., lions) do the killing; they then wait to scavenge what's left (after the lions are done eating). Tools were likely used to scavenge remaining meat from the carcass. Homo habilis made crude stone tools (Olduwan tools) but these were used for scavenging meat from bones, not used for hunting down animals. But scavenger animals must be smart (vultures are smart) The larger brain in H. habilis could be due to things like:Observation, learning, and memory in order to make crude stone tools. The need to learn large carnivore habits, that is to be a scavenger takes skill to anticipate when a predator is going to make a kill. H. habilis was a terrestrial biped and probably used its hands to :Carry tools Carry scavenged meat

Sickle Cell anemia and malaria

Malaria, an infectious disease, kills many, many children Malaria is caused by Plasmodium parasite and transferred to humans by a bite from a mosquito But the malaria-carrying mosquito is only found in some regions. As humans moved into areas where the malaria-carrying mosquito was present it brought humans into year-round contact with malaria This caused new selection pressures on humans, since malaria can kill you having sickle cell is advantageous in malaria-present environments The Plasmodium parasite cannot complete its life cycle in individuals with sickle cell (since the sickle-shape of the red blood cells prevent the parasite from reproducing) So sickle cell individuals are more resistant to malaria than non sickle-cell individuals The interplay between malaria and sickle-cell anemia results in a Balanced polymorphism: Heterozygotes have a fitness advantage over both homozygotes, so the S allele is maintained in these areas and explains its relatively high frequencies in these areas

Chronometric dating: Absolute dating

Many naturally occurring elements come in different varieties, called isotopes, and some isotopes are radioactive Over time, radioactive atoms in the isotope change into stable atoms in the isotope The Half life is the time it takes to reduce the number of radioactive atoms by 50%. Different radioactive isotopes have different half-lives. We can measure the ratio of radioactive to stable atoms to get a sense of how old the material is,

Prenatal Stage

Mom gave half her genome to her daughter via the process of reproduction, so mom is 0.5 (or 50%) related to her offspring (as is dad). Relatedness: the proportion (or percentage) of genes you share with your relatives (also called kin). You are entirely related to yourself, only 50% related to your mom or dad, only 50% related to your (full) siblings, and only 25% related to your grandparents, and 12.5% related to your cousins. Relatedness provides a simple reason why you are more likely to run into a burning building to save your little sister than some random homeless guy. You are related to sister (because you both received copies of the same genes from mom and dad). You aren't related to homeless guy (you don't share copies of genes in common that you got from a recent common ancestor) so why risk it? You are entirely related to yourself, only 50% related to your mom or dad, only 50% related to your (full) siblings, and only 25% related to your grandparents. Offspring viewpoint: I have a greater interest in my own survivorship than I do in the survival of any future siblings Mom's viewpoint: I have an equal interest in the survival of all my offspring. Maternal-offspring conflict Offspring will want more investment than parent is often willing to give •Offspring related to itself by 1.0 •Offspring is related to Mom by only 0.5 mother offspring conflict begins in utero Anywhere between 30-75% of all pregnancies are spontaneously aborted during first two weeks. This could reflect selective elimination of the embryo by the mother For pregnancy to be sustained, high levels of maternal progesterone (a hormone from mom) are required. These high levels of progesterone are in turn stimulated by the fetal hormone: chorionic gonadotrophin Embryos unable to produce this hormone are lost (spontaneously aborted) during menstruation The ability to produce high-levels of chorionic gonadotrophin may be an indication of embryonic quality (whether the embryo is healthy and will survive). What's going on here? Gestating then nursing an offspring is a huge investment of time and energy. If mom invested in a poor-quality embryo that died at age 3, this would be huge loss of time/energy, so evolutionarily, mom's reproductive system has figured out a way early-on to determine if it is "worth it" to invest in a given embryo or not.

Reorganization of the Hominin Brain

Olfactory bulbs (part of brain that detects/interprets smells/scent) became smaller during primate and human evolution Primates, and particularly humans, are not good "smellers." In contrast, there are trained dogs that can "sniff" early-stage lung cancer from the exhaled breath of humans. Yes, dogs can actually smell early-stage cancer in humans—please let that thought detonate in your head! In humans, the size of the olfactory bulbs is ~ 0.1cc volume. In wolves/dogs, ~6cc in volume Reflects our decreased reliance on smell as a sensory mechanism, and our concomitant increase in our reliance on vision. In humans there was an increase in the frontal lobe. This area is particularly large in humans Frontal lobe is associated with analytical reasoning, cognition, memory, and judgment. It's basically the brain region that allows us to understand very nuanced social interactions and signals. For example, humans are very good at "stepping into someone else's shoes"—we can step into the mind of others, so to speak, to understand what someone else might be thinking. We can also understand irony and sarcasm—things our frontal lobe helps us with. Our Primary visual regi on (or visual cortex) shifts to interior and back part of the brain. As our brain got bigger overall, our parietal lobes (on the side-part of the brain) got bigger, and this pushed our visual processing region to a more interior position

Primate and Human Brains

Primate brains, and especially human brains, are large when compared to other mammals Encephalization: the degree to which brain size exceeds body size. It is a statistical measure that occurs when you plot brain size against body size for a bunch of different species. Species that fall above the line of expectation are encephalized. So why did our brain get so big? The social brain hypothesis suggests that it was the amount of social interactions that selected for a larger brain. Primates in a social group must be able to know: •Who to avoid •Who to help •Who is their kin •Who is their friend •When to compete •When to yield •Deception •Alliance formation

Primate Evolution

Primate evolution is largely confined to the Cenozoic Era (from 65 million years go to the present) There are many many more extinct species of primates than living ones. We can only look at a few basic highlights of primate evolution epoch by epoch

Were early hominins hunters and violent creatures?

Raymond Dart, a noted paleoanthropologist, promoted the view (in 1920) that A. africanus was a skilled hunter, and even a predator of other australopithecines. He argued that A. africanus used sharp bone tools and sharp animal horn weapons (such as bull horns) to slay prey, and even to kill other hominins (He adopted this latter view because some hominin skulls had puncture marks on them that seemed indicative of being clubbed on the head with sharp horn). Basically, A. africanus would kill a prey animal and then fashion its bones and horns into tools and weapons to do more killing!

infectious disease

Refers to diseases that are caused by •bacteria •viruses •fungi •parasites Does not refer to degenerative or genetic diseases or abnormalities

How do we know how old a particular fossil is?

Relative dating: this fossil is older than that fossil In relative dating all you can say is "this fossil is older than that one" or "this fossil is younger than that one" Chronometric dating: this fossil is 3.6 ± 0.2 million years old. In chronometric dating, you are assigning a numerical date to the fossil's antiquity using special geochemical techniques.

Pre-Australopithecine hominins

Sahelanthropus (probably not a hominin) COUNTRY: Chad SITE: Toros-Menalla Orrorin (most likely a hominin) COUNTRY: Kenya SITE: Tugen Hills Ardipithecus definitely a hominin COUNTRY: Ethiopia SITE: Aramis Ardipithecusramidus COUNTRY:Ethiopia SITE:Middle Awash

Post Reproductive Period

Senescence: the technical word for "aging" or the deterioration of body function as we grow older. As we age through adulthood, our fertility declines and physiological functions slow/deteriorate -Menopause is the gradual cessation of the menstrual cycle subsequent to the loss of ovarian function in women -Women rarely give birth after the age of 45 and reproduction becomes more difficult and more costly with age Female post-reproductive period -Menopause and continued life without the possibility of reproduction is unique to humans when compared to other primates... -It is thought that menopause evolved to switch ("force") women to stop reproducing themselves and to start taking care of their daughter's offspring. This is known as the "grandmother hypothesis" The rationale is that an older woman can enhance her fitness by taking care of her daughter's offspring (so that daughter can do other things, including have more offspring).

Human Biological Variation: Temperature

Short-term response to heat: Vasodilation—expansion of blood vessels and increased blood flow to the skin (let's blood flow to skin surface so that it can release heat "trapped in the blood" to the environment, thereby cooling you off) Short-term response to cold: Vasoconstriction—narrowing of blood vessels and reduced blood flow to the skin. Blood holds "trapped heat" and vasoconstriction keeps this warm blood away from the skin so it doesn't release heat, thereby keeping you warm. LONG TERM ADAPTATIONS In cold climates:Populations inhabiting these areas for thousands of years have evolved larger body size, shorter limbs. This results in a "rounder shape." A rounder body shape means there is more internal mass, relative to skin surface, which is good for retaining heat in cold areas In hotter climates:Populations inhabiting these areas for thousands of years have evolved smaller body size, longer limbs. This results in a tall, "lanky" shape. A lanky body shape means there is more skin surface area (relative to internal mass) which is good for releasing heat in hot areas We lose heat through our skin, so having more skin surface area, or less of it, (due to a particular body shape) is an adaptation contributing to thermoregulation

Human genetic variation and infectious disease

Sickle cell anemia and malaria In sickle cell anemia, a mutation results in an abnormal red blood cell. In a population where sickle cell is found, there can be three genotypes: AA, AS, SS (the two alleles are A = normal, S = sickle) Most people are healthy if they have the AS genotype Most people die or cannot reproduce if they are SS (and AA is also healthy)Therefore two phenotypes: Healthy, sickle-celled

Bipedal Pelvis Adaptation

Since bipedalism deals with legs, one place where changes occurred was the pelvis (since this structure connects the legs to the torso). In bipedal humans our pelvis becomes shorter (top to bottom), and the ilium portion becomes more "bowl shaped Shortening the pelvis top to bottom makes for a much more efficient transfer of weight from the torso, across the pelvis, and down to the legs. Muscles always shorten (contract) across a joint to produce movement. The gluteal muscles (our butt muscles) stabilize our torso front-to-back when moving. With each step, your torso has a tendency to pitch forward (as your leading foot touches down). The gluteals keep your torso upright so you don't fall on your face. Main point: gluteus maximus stabilizes the torso front-to-back (so you don't fall on your face) and gluteus medius/minimus stabilize it side-to-side (so you don't fall on your elbows) during walking.

Brain size and intelligence

Some scientists use cranial capacity but this doesn't work within a species, that is the intraspecific range of human brain sizes is from about 1350cc to 1500cc across all humans, but there is no strong correspondence between size and intelligence. However, cranial capacity does generally predict intelligence across lots of species, as when one compares mice, raccoons, cats, dogs, monkeys, humans. Most estimates of the genetic basis of intelligence (as measured by IQ tests) suggest that 50% of variation in intelligence is due to genetic variation. This means there is about a 50% contribution from the environment (early nutrition, schooling, etc.) there are equal contributions from genes and environment to the differences in intelligence we see across humans One thing we use our intelligence for is to produce language

areas in which australopithecines are found:

South Africa and East Africa australopithecines were first discovered in South Africa, hence the name: "southern ape"(Austral = south) (Pithecus = ape)

Things to know!!

The correct sequence of the appearance of certain hominins (oldest to youngest top to bottom) Australopithecus afarensis Australopithecus africanus Homo habilis Homo ergaster Homo erectus Homo heidelbergensis Homo neandertalensis Homo sapiens Australopithecines 450-500cc; H. habilis 600-800cc; H. erectus 900cc; H. heidelbergensis 1100-1200cc; Neandertals 1520cc; Homo sapiens 1300cc Raymond Dart, CK Brain, and Eugene DuBois Zhoukodian robust/gracile australopithecines are found in East and South Africa; Homo habilis is found in East and South Africa; Homo ergaster is found in East and South Africa; Homo erectus is found in Europe and Asia; Homo heidelbergensis is found in Africa, Europe, and Asia; Neandertals are found in Europe and the Middle East; and Homo sapiens first evolve in Africa and spread into Europe and Asia. 1) Omomyids are Tarsier-like; Adapids are Lemur-like 2) Anthropoids first arise in the Oligocene 3) Sivapithecus is ancestral to modern Orangutans.

Bioarchaelogical sites and crime scenes

The field site/crime scene is the primary data source for bioarchaeologists and forensic anthropologists Sites can be found by accident, by surveys, or by systematic searching Archaeological techniques are used to preserve the location and context of sites All possible contextual data is gathered and cataloged All relevant data (e.g., artifacts, bones, criminal evidence ...everything!) are sought after, collected, mapped, and recorded Data are collected so that the entire site/crime scene can be reconstructed in a different location (like a crime lab, or other area)

identity and identification

The frontal sinus has a unique shape in humans. Sinuses are "air-spaces" inside your cranial bones lined with epithelial tissue (this is the tissue that gets inflamed during allergy season leading to sinus discomfort). There are several sinuses as shown in diagram on left. Provided that there are x-rays of the frontal sinus taken from an individual while alive, forensic anthropologists can compare antemortem (while alive) and postmortem (after death) x-rays to identify individuals from the frontal sinus, which has a unique configuration across all humans. Genetic analyses can be used to identify recovered bodies in forensic cases. It is possible to compare the genetic profile of a dead person to 1) their same genetic profile taken while the individual was alive to see if a match exists; or 2) the genetic profile of the individual's relatives to see if a match exists. Genetic data are better than bony data for identifying individuals, as it is possible to get DNA from almost any human remains, and DNA is also useful because family members share DNA, making identification of unknown victims easier.

Bipedal Adaptation: The Foot

The human foot has a longitudinal arch that helps to absorb shock and add spring to each step. Chimps are more flat-footed with no arch Heel strike(deeper impression at heel-strike) Toe-off (deeper impression at toe-off) As is evident, our big toe is "inline" with our other toes, rather than splayed out to forming a grasping toe, as in apes. Our big toe and other toes are shortened (so we don't trip over them...since really long toes would get in the way of each step).

Industrial epidemiological transition

The industrial epidemiological transition refers to our society transitioning out of being mostly farmers to more reliance in technology/industry/mechanization •Beginning around 1750 or so, things began to change as technology and mechanization started to appear (steam engines, factories). •There was better awareness about germs. And beginning in the 1900s, increased use of technology to fight diseases: antibiotics, public-awareness, mass-immunizations •This led to a new way that humans died: as infectious diseases were being treated/controlled less folks started dying from infections and started dying from "old age" diseases. •It was even thought that society could eventually "conquer" infectious diseases A switch—an epidemiological transition—from diseases caused by infectious agents to ailments mostly associated with old age Optimism and arrogance:Staphylococcus went from "extremely dangerous" to "easily managed minor infection". 1948: U.S. Secretary of State George C. Marshall indicated that the conquest of all infectious disease was imminent. But bacteria can evolve resistance to antibiotics very quickly!! The analogy to bacteria resistance is straightforward... The trait is "resistance" (not milk-yield) and humans are unknowingly selecting for increased resistance every time they use antibiotics or especially every time they put antibiotics in the food supply, such as putting antibiotics in chicken feed, or pig food (so the chickens/pigs—which we eat—don't get sick while in the coop/pig pen). These antibiotics then get into the food we eat and the ground-water. These antibiotics act as selection pressures on bacterial strains. What does selection do...? Over application of antibiotics imposes strong selection on bacterial populations, by killing off non-resistant variants more quickly—rapid evolution of resistance occurs (more rapid than w/out selection) The period of roughly 1750 to 1970 was characterized by: •increased reliance on technology •lots of population growth •use of antibiotics •better transportation •more urbanization and pollution •expansion of land-use

Non-human primate communication

The presence and/or location of individuals The "state" of sender: •Sexual receptivity •Emotional excitement •Confidence (lost calls)The state of the environment •Predator location •Food location Modes of communication: Tactile (grooming, hugging, touching) Visual (facial expressions, body positions) Olfactory (smelling) Vocal (speech, bird songs)

Paleoanthropology

The study of human evolution as a biological and cultural process

Pre-australopithecines:

There are three important genera of early pre-Australopithecine hominin. These creatures all date from about 5-8 million years, right around (or just after) our own lineage split from the lineage leading to modern chimps. •Sahelanthropus •Orrorin •Ardipithecus If any of the above three genera show evidence of bipedalism, then by definition they are a hominin; if they don't then they are an ancestral chimpanzee

Present Day Fossils

They represent a small fraction of past life--not all individuals of a species will become fossils•They are rare and occur only under specific geological conditions (drier conditions are better/more conducive for become a fossil; wet humid conditions are less conducive) •They can be sample-biased. Teeth/jaws of extinct creatures more likely to be recovered because these are the hardest, most durable body parts—delicate bones, such as an ethmoid or hyoid (bones in your nose and throat respectively) or very small bones, such as ear ossicles, are rarely recovered.

Homo heidelbergensis

This human species is thought to be ancestral to both Neanderthals and modern humans This species inhabited Africa, Asia, and Europe also called: "archaic Homo sapiens" Thinner cranial bones than H. erect us (but thicker than modern humans here is a prominent browridge (like H. erect us) but the browridges are rounded Lots of variability in fossils so some researchers break up H. heidelbergensis into many different species From AFRICA(Broken Hill 1) : the heavy and rounded browridges and large brain case FROM EUROPE (steinheim): Heavy and rounded browridges and large brain case FROM ASIA (Dali): Heavy and Rounded Browridges and Large Brain Case TECHNOLOGY •Very likely cont rolled and used fire •Built shelters and structures •Ate many different types of food •Possibly hunt ed large game •Levallois tools—tool-making technique . This is an even more advanced way of making a stone tool. It produces an "arrow-head" type tool that has a very sharp surface. The design element is the final blow, which removes a flake that is chipped on one side and flat on the other: this produces very sharp edges on the flake that can be used for cutting

Hypothoses on Bipedalism

To carry objects: walking on two legs frees up the hands to carry tools, infants, or food. To better hunt: walking on two legs allows you to carry a spear, or bow and arrow, and also chase prey with these weapons To better find/gather food: Standing on two legs allowed our ancestors to reach food in tall shrubs, and to carry this food back home. To see over tall grass: Perhaps standing on two legs allowed our ancestors to better spot predators such as lions and cheetahs on the savanna.

3 categories of Races

U.S. Immigration policies built categories based on these three main regions: Northeast Asia (Mongoloid) Western Africa (Negroid) Northern Europe (Caucasoid) And these categories were then "reified" (meaning to be made real), since one could walk down city streets in the USA in, say, 1950 and mostly see three types of people represented: African-Americans, European-Americans, and Asian-Americans. Hence, three races came to be taken as a biological fact, rather than simply "who arrived from where."These terms are no longer used

The Human Condition

We can apply evolutionary concepts to modern human problems •Issues of "race" •Bacterial resistance •Aging •Population growth This requires that we strive to •Understand our evolutionary legacy •Respect our place in the environment

Geology, Paleoecology, Chemistry, Evolutionary theory, primatology, anatomy, archaeology, cultural anthropolgy, psychology

What are major fields and sources it draws from?

fossil-bearing sites, fossils, artifacts

What are the major types of Paleoanthro data?

6-8 million years ago

When did ape species undergo a speciation event to split into two linages?

Many early human ancestors are found in East Africa. This is because there is a rift-ridge zone, where two continental plates are being pulled apart. 4 million years ago, they were closer together. A hominin walking around back then could die and become a fossil. It would have gotten buried in lots of sediments over time. But because the plates are today being pulled apart, it is exposing the long-buried fossil hominin.

Where are many early hominin sites found?

What questions does paleoanthropology answer

Why did we become bipedal?• Who is our closest living relative?• When did language evolve?• How many extinct species of hominins are there? • What makes humans unique?

Zhoukoudian

Zhoukoudian is an important site that was occupied intermittently for over 250,000 years (460-230kya) The site shows archaeological evidence of evidence of fire-control, cooking, and hunting. ancient "fire pit" (circular set of ashes) and lots of stone tools and animal bones, suggesting H. erectus was butchering and cooking animals.

Human Biological Variation

concerns morphological, physiological, and genetic variation among human groups as humans settled in different areas, they had to deal with different ecological challenges...since living in Alaska or Siberia is different than living in the Amazon jungle....they had to adapt to different environments The environment can influence the expression of a trait -Interactions between environment and genes which result in our ability to make short-term changes to our traits, such as getting a suntan Environment(sunlight) Genes(Determining Skin Color) Phenotype(skin color) Over many generations selection has acted on different populations to create genetic differences in skin color SKIN COLOR/TANNING However, any individual regardless of their skin color, also has the ability to get a suntan. This is a physiological ability to change a trait (e.g., skin color) over the short-term (since suntans are not permanent, and not inherited) Such changes are brought about by regulatory genes. Regulatory genes are genes that "communicate" with skin color genes, and regulatory genes are also genes that receive "signals" (or stimuli) from the environment (such as intense sunlight) Adaptive phenotypic plasticity: selection creates the ability for traits to temporarily change due to the environment and the action of regulatory genes The ability to make beneficial physiological adjustments in phenotype in response to the environment. Such changes are not inherited, but the capacity to make such changes is inherited and adaptive. Adaptive = beneficial to fitness Phenotypic = some trait Plastic = a fancy word for "changeable" "adjustable"

Were early hominins hunters or scavengers?

early hominins such as Homo habilis and even australopithecines were clever, bipedal hunters. More recent evidence they are scavengers (they wait for lions to kill prey and eat their fill, then they scavenge what is left of the killed prey); they were not hunting themselves.

Expensive Tissue Hypothesis

for the brain to increase, metabolic energy must be taken from another part of the body.. in humans the gut got smaller because the diet became less demanding because of COOKING. Broke down tissues so that less energy was needed for metabolic processes. It is thought that in our evolutionary past (about 1mya) hominins started to incorporate much more meat into their diet due to hunting and scavenging. So over time, we evolved smaller guts, freeing up energy to be used elsewhere. Humans switched to include more meat in their diet. Meat is a high quality resource that is "brain food" Further, when humans hunt, it is a complex, cooperative endeavor, which can also reinforce the need for increased brain size. It is important to note that the expensive tissue hypothesis can operate at the same time as the social brain hypothesis. And more realistically, it was likely a lot of different factors (increased hunt ing, larger social groups, and other stuff) that selected for a larger, more complex brain in humans

Strepsirrhines

have a tooth comb

In a malaria-present environment, a heterozygote individual (genotype = AS) who carries one normal and one sickle cell allele is more likely to

have better survival relative to the AA and SS genotypes

Robust australopithicenes

have molar teeth with thick enamel

Acheulian Tools

he tools associated with H. erectus (in Asia) and H. ergaster (in Africa) are called Acheulian tools. They are larger and more symmetrical than Oldowan tools; they are found in Africa, Asia, Western Europe. To make them, a core is modified on both sides to produce a "tear-drop"shaped tool, that is symmetrical on each side, hence it is sometimes called a "biface" reflecting that each side looks the same. The tools were used to cut up animal carcasses, but researchers debate if meat was scavenged or hunted

What is a hominin?

hominin: a bipedal member of the evolutionary lineage leading to modern humans (used to be called a called "hominid") •Phylogenetically—evolutionary-tree-based• Diagnostically—"key-trait-based"

biological determinsim

idea that social and cultural characteristics are genetically determined and correspond to "racial" phenotypes

One condition for the evolution of reciprocal altruism is

individuals interact on more than one occasion

Vitamin D

manufactured in body using UV radiation and cholesterol in the skin; important for bone growth and important during pregnancy and lactation; lack of it can lead to bone deformities

The biological profile: Injury, stress, disease

marks/scars on our hard tissue like bones and teeth can help determine patterns of injury and disease Forensic anthropologists and bioarchaeologists can study these scars in order to determine patterns of injury and disease. Broken bones, even when "set back in place" will leave a scar on the on the bone surface (as in the diagram on the right). In some cases, broken bones, when set improperly (or not set at all) can heal in very abnormal ways Adult teeth provide indicators of nutritional stress and malnutrition that occurred during childhood. When the enamel on teeth only partially develops, it forms an enamel hypoplasia (usually lines or pits in the tooth enamel) Bioarchaeologists would be interested in this type of information. For example, if bioarchaeologists recovered an entire population of adult individuals from an archaeological site, all of whom had enamel hypoplasias, it would suggest that these individuals, when young, experienced some sort of famine or malnutrition. This would be valuable information to have when reconstructing the past lifeways of this population. Repetitive and/or asymmetrical activities and stress can re-shape skeletal elements. Bioarchaeologists and forensic anthropologists can study these patterns to infer activities. For example, men from a particular culture might always use their right arm to hunt fish with a spear from a canoe. This repetitive right-arm only activity will lead to their right arm being larger and more robust than their left arm. If the culture dies off and is later recovered as skeletons by bioarchaeologists, then the researchers can study the asymmetrical arm bones, noting the larger size of the right arm bones, and from there go on to reconstruct the activity (i.e., hunting w/spear) that produced this skeletal pattern

Lamarck

mechanistic theory of change acquired characteristics

Eukaryotic cells

more complex/multicellular contain a nucleus

identity and identification

more of concern to forensic anthropologists; rely on having some record or tissue samples of the individual while alive; can be determined through teeth; frontal sinus; genetic analyses In fact it is so important in forensic cases to identify (provide a name to) an individual, that unknown individuals are often given "stand-in" names: John Doe/Jane Doe Bioarchaeologists are less concerned with assigning names to the skeletons they study. The are much more concerned with reconstructing past behaviors, cultures, lifeways, than knowing individual names. However, most rely on having some record and/or tissue samples of the individual while alive

Is language an adaptation?

most likely that the capacity for language was the direct target of natural selection The argument, made by some influential scientists (e.g., Noam Chomsky), was that language arose more as an accident, in the sense that natural selection was "targeting" other things and not directly targeting language ability, as below: Large-brain + consciousness + learning + culture = language as a by-product This by-product view is no longer supported. Others (e.g., Steven Pinker) argued persuasively that the capacity for language was the direct target of natural selection. Language is an adaptation!

Lithic (stone) tool technology

most tool modifications of either the flake or core; used for cutting, hammering, chopping, etc. A flake is the small piece of rock that is "chipped off" a bigger piece of rock (a core is the larger rock, with a flake chipped off).

Post Industrial Epidemiological Transition

new viral and bacterial agents; old diseases in new locations; new diseases from new environments; pop growth, deforestation and consumerism, globalization and urbanization What we are finding now is all sorts of new infectious diseases: New viral agents•1983 - HIV-1- Acquired Immunodeficiency Syndrome •1989 - Hepatitis C Transfusion related •1991 - Guanarito Virus Venezuelan Hemorrhagic fever •2020 - COVID-19 Coronavirus disease CAUSES Population growth: more use of natural resources and more by-products such as pollution, this can lead to global warming. As the human population size increases, there is a larger need for goods and services (e.g., transportation, food, fuel), and all of these can lead to an increase in CO2 levels (as a by-product). Release of CO2 into atmosphere causes earth's annual temperatures to rise by trapping heat This small change (about 2-10 degrees over next 100 years) can have major impacts: Deforestation and consumerism: moving into new habitats increases risk of zoonoses and can lead to new diseases -Coltan: a mineral used in liquid crystal displays such as cell phones, computers etc -Increased global demand leads to Coltan mining in Central Africa -Political instability. Miners subject to bad conditions and hunger. Increased hunting of bushmeat, eating exotic animals such as gorillas. This can lead to a higher risk of zoonotic events Zoonotic: a disease that is transmitted to humans through contact with a nonhuman animal Globalization and Urbanization: more densely packed people, easier to move around globe, making it easy to spread a disease High population densities and many people living in cities rather than in the countryside Increased rates of transmission due to rapid movement of people using air travel, so infectious diseases can spread rapidly New diseases that can thrive in cities such as Legionnaires Disease (which exploits air conditioning systems) Overuse of antibiotics in agriculture (as additives to diet of dairy and beef cattle) Over-prescription of antibiotics for non-bacterial ailments, such as flu viruses All of this has resulted in "very fit" bacteria. That is, some bacteria strains are able to resist all the antibiotics we currently possess

Both ____ and ____ proposed natural (not supernatural) mechanisms for evolution

none of the above

Fitness is defined as

none of the above(an organism's ability to survive and reproduce)

To find Expected frequencies

p^2 + 2pq + q^2- plug in calculated frequencies

Lithic (stone) tool technology -Ways of making tools

pressure flaking : You press two rocks together to make a flake or core (you don't bang them together) Direct Percussion: The fancy name for banging one rock into another to produce a flake or core

The hypothesis suggesting that the fossil record shows long periods of no change and new adaptive characters form "quickly" at speciation events is called

punctuated equilibrium

homo

received wisdom in paleoanthropology for a long time. That one species of early Homo (H. habilis) gave rise to H. erectus, which gave rise to archaic H. sapiens, which eventually evolved into us But this view has changed a bit because of :•New fossils discovered •Issues of chronology (new dates for fossils) and a re-examination of specimens •Genetic information

Epidemiological Transitions

relationship between human mortality and infectious disease among populations. Researchers talk about "transitions" with respect to how we died from infectious disease over our evolutionary history. There are three epidemiological transitions corresponding to changes in our civilization: •Agricultural •Industrial •Post-industrial (present) Epidemiological transitions happened over our time from our hunter-gather past, to our transition to agriculture, to our transition to industrial/mechanized society, to our transition to post-industrial/super-technological society. Hunter Gathering -2mya Agriculture/Sedentism-10kya Industrial- 1750 Post Industrial-1970 mortality is certain, so essentially these transitions refer to different ways humans died with respect to infectious diseases (the flu) versus other sources of mortality (car crashes).

Why did language evolve?

social gossip, The social gossip hypothesis suggests that language functions to exchange social information about group members when group sizes are large. Basically, language is grooming at a distance. Social contract, The social contract hypothesizes that language functioned to establish trust and prevent infidelity among male-female monogamous units. social flare Basically, this is the "marriage vows" hypothesis, where monogamous males and females publicly proclaim their fidelity to each other in front of other group mates. This public proclamation is then intended to prevent infidelity when males and females are apart. Hence, language evolved as a means to vocally signal fidelity and could be a form of "mate-guarding" as in "I'm taken, sorry!" BASED ON Ancestral mating system was monogamous, and marital units live in close association with larger groups, thus increasing chances for infidelity and The division of labor kept male and female mates apart for days on end (e.g., male hunting trips) Social Flare The social flare hypothesis suggests that language evolved and functioned as a means for males to attract females. The social flare hypothesis suggests that language is a sexually-selected trait, in that females choose males on the basis of their ability to verbally communicate. Hence, female choice drove the evolution of language. Males use "verbal flare," humor, and artistic expressions to impress females. Language is a sexually selected trait

Taphonomy

study of what happens to something after it dies. Taphonomists are like "forensic scientists" for paleoanthropology—they dig into the details of a given fossil site and also scrutinize previous paleoanthropolgical explanations.

Population Genetics

the study of how genes are distributed within an interbreeding group.

Race is biologically difficult to define

there is no valid evolutionary basis for dividing up human diversity into only three categories Some, but not all, human variation is continuous and graded across geographical space (meaning there aren't "clear" divisions between different groups) We tend to psychologically recognize differences among groups, particularly when comparing extremes

Sahelanthropus tchadensis

• 6-7mya (million years ago) •Cranial capacity about 320-380cc (chimp = 370-410cc) CC means "cubic centimeters" (1 cc = roughly a sugar cube) •Large browridges (a bone above the eye orbits—in some creatures it is very pronounced, in others it is smaller) •Foramen magnum is somewhat anterior suggesting (to some researchers) that this creature is a biped; other researchers say it is posterior indicating quadrupedalism Sagittal crest

Orrorin tugenensis

• ~ 6mya• Researchers note the femur (thigh bone) is indicative of a bipedal creature Teeth show chimp-like features--honing complex. A Honing complex is when upper canine rubs against lower first premolar. The lower premolar acts as a "sharpening stone" to sharpen the upper canine every time the creature opens/closes its mouth

Ardipithecus ramidus

•4.4 mya• -Found by Tim White and colleagues •Foramen magnum is anterior/centered (indicating a bipedal creature) •Pelvis and toe bones suggest bipedalism (bowl-shaped pelvis, short toes)•However, the foot also has a widely divergent big toe (meaning the big toe is opposable with the other toes—like our thumb is—indicative of a grasping foot. •This creature was a biped that also was capable of climbing trees (using its opposable big toe to wrap its foot around branches)

Were early hominins hunters and violent creatures?

•Bones and horns of prey animals were not prey animals killed by A. africanus•Bones and horns of prey animals are not used as tools or weapons•In fact, A. africanus are the hunted rather than the hunters In the 1980s, an archaeologist (and taphonomist) named CK Brain came to a different conclusion from Dart (he reinterpreted Dart's original interpretation of A. africanus fossils and the supposed "tools/weapons" made by A. africanus): in studying the fossil bones/horns and A. africanus fossils, CK Brain was able to show that the bones/horns (that Dart thought were tools made by A. africanus) were in fact due to hyenas, who scavenged/ate deer and other prey animal's bones and chewed them into odd shapes A. africanus were the prey, not the predators!

Agricultural epidemiological transition

•Hunting and gathering ancestral mode of life •Small groups of individuals •Loosely connected, low population density •A bacterial or viral infection could wipe out the group but it wouldn't affect other groups •Groups can move out of "infectious areas" Across various continents, humans began to adopt agriculture/domestication (around 10kya) •This means they started to grow their food around them (plant crops) and keep livestock for food/milk •But agriculture/domestication requires clearing of forests leading to increased contact with new diseases •Further domestic animals were vectors(agents that carry a disease) for infectious disease, (e.g., cows could harbor fleas, which could jump from cow to rat to human)•Having a steadier food supply led to settlements/towns with higher population density, and infections could spread more easily through these sedentary settlements

Homo Erectus

•It is both bigger in size, and bigger brained•It is found in sites outside of Africa (for the first time)•It has more advanced tool Homo erect us differs from H. habi lis in terms of: •Brai n size•Body size•Cranial shape•Dentition Brain size• Range: 750-1250cc• Average of 900cc •Larger brain than H. habilis, smaller brain than Homo sapiens (modern humans) Body size•As tall as modern humans•Sexually dimorphic (more than modern humans)•Thicker long bones Homo erect us anatomy Cranium •Large browridges (technically this is known as a supraorbital torus—no one really knows the function of these large browridges) •Thick cranial bones •Low forehead •Skull is widest from ear to ear (H. sapiens skull is widest at temple areas) •Nuchal (or Occipital) Torus(a "bar" of bone at the back of the head near the neck—no one really knows its function) Teeth Shovel -shaped incisors(No one knows what the function is, but they are little ridges of enamel on each side of the inside of the upper front teeth) Molar teeth are larger than H. sapiens, probably because H. sapi enscooked their food, which means softer food and select ion for smaller teeth

Hooton's Racial Classification 1926

•White -Mediterranean -Ainu -Keltic -Nordic -Alpine -East Baltic •Negroid -African Negro -Nilotic Negro -Negrito •Mongoloid -Classic Mongoloid -Arctic Mongoloid -Malay Mongoloid -Indonesian .providing evidence that such divisions are arbitrary and based on the scientists' own biases rather than "true" and "real" biological divisions within Homo sapiens.

Why anthropologists avoid the term "race"

•local adaptation •genetic drift •migration and mating among populations •cultural practices regarding marriage To common folks, "race" tends to imply the above—vast biological differences among groups. And the term is loaded with "cultural baggage" stemming from racism. Genetically, we are similar to the above (full single overlapping circle)—genetic variation is mostly shared across all humans (in fact only about 8% of genetic variation is unique to each region). Small genetic differences DO exist among individuals and populations and continental regions BUT...Broad geographic regions (Africa, Europe, Asia, North/South America) are NOT vastly genetically distinct from other region.

Historical Perspectives 2

Anders Retzius, a Dutch scientist in the 1800s, developed a measure of cranial shape that could classify people as follows: dolichocephalic: long, narrow head (northern Europe, some African population brachycephalic: wide head (Southern Europe)

Steps in Bioarchaeology/Forensic investigation

1. Data from field site or crime scene 2. Laboratory processing and curation 3. Biological profile 4. Taphonomy 5. Identity and identification

Homo habilis from Koobi Fora

1470

Antibiotic revolution

1928 - Alexander Fleming discovers penicillin 1952 - Joshua & Esther Lederberg discover that some bacteria are genetically resistant to penicillin 1965 - Over 25,000 antibiotics developed If an infection can't be cured with one antibiotic, there were others available.

Pleiotropy

A single gene having multiple effects on an individuals phenotype When a single locus controls more than one trait.

Homo habilis anatomy

A. africanus - skull more rounded; larger brain (630-775 cc); less prognathic; smaller molars Homo habilis- Skull more rounded(<530cc) Larger brain (630-775cc) Less prognathic Smaller molars Postcranial anatomy•Longer Legs•Long, strong thumb•Short, straight fingers•Broader fingertips with better blood/nerve supplyBasically hands are better adapted for fine manipulation, such as making tools.

The first australopithecine to be found in association with tools is

A. ghari

Homo erectus is most associated with the following tool industry:

Achulean

Why do we age and then die?

Antagonistic Pleiotropy, which is the concept that genes that are beneficial early in life can have a negative affect later in life. In young males: high testosterone increases sex-drive and ability to compete for mates, which is good for that individual's fitness. In old males: high testosterone can cause prostate cancer, which is lethal and bad for fitness. So essentially, there are genes that help us when young (increase our fitness) and hurt us when older, but the fitness increase they gave us when young is more than enough to offset the fitness cost when old, so these genes cannot be selected out of the population, instead they remain in it causing us to get old and die.

Body Adaptations

Bicondylar angle carrying angle of the femur to position leg directly underneath the body Humans have two distinct Spinal Curves to keep weight centered above the pelvis Gluteus maximus helps stabilize trunk since it has a tendency to pitch forward The human foot has a longitudinal arch that helps absorb shock and add spring to each step The spinal cord leaves through a downward facing foramen magnum

The Human Life Cycle

Biological anthropologists are interested in the evolution of the human life cycle. By life cycle, we mean biologically relevant stages of development Most stages in the life cycle are marked by some physiological transition (e.g., end of nursing) Prenatal (Birth) Infant (End of weaning) Juvenile (Onset of puberty) Subadult (End of skeletal growth, fully fertile) Adult (Low or no fertility) Post-Reprod.

Bipedal Adaptation

Bipedalism is a major anatomical innovation. It involves the reorganization of several anatomical regions •Pelvis•Femur•Vertebrae•Foot•Skull base

Applications of Archaeology and Forensic Anthropology

Both fields utilize rigorous methods to produce biological (and behavioral/cultural) information about individuals during their lifetime and especially after their death Bioarchaeology •Mortuary/cemetery archaeology •Health and disease studies •Subsistence change Forensic anthropology •Mass fatalities •Individual criminal cases •War crimes/war dead

genetic analysis

COMPARE Genetic profile of unknown victim vs DNA from individual who is known to be missing Genetic profile of unknown victim vs DNA from family members who have a missing relative

An evolutionary scenario for skin color

CAUSES TO LOSE HAIR FROM PRIMATE TO HOMININ -Mating -less parasites -Bipedal stance/sunlight changes the primitive skin color in our early hominin ancestors is likely light skin that does not contain much melanin. chimps have lighter skin under their hair, and darker skin in hairless regions (e.g., face). And thick body hair/fur protects the skin from UV radiation. So early hominins likely had thick body hair to protect their skin (similar to chimps) and lighter skin underneath their fur/hair But somewhere along our evolutionary path, early hominins lost their body hair (yes, we have small amounts of body hair, but nowhere near as much as furry chimps...we have essentially naked skin relative to apes). It is hypothesized that our early hominin ancestors (such as Australopithecines and early species in the genus Homo) started forming large social groups. All else being equal, a larger social group means each person has a greater chance of catching a disease or parasite from another group member. So there is a larger probability of transmitting ectoparasites (lice, fleas) in larger groups. This would result in selection to reduce body hair/fur, since this is where ectoparasites live. More simply... A "naked-skinned hominin" would have fewer parasites Once early hominins lost their body hair, this might have become a mate-attraction strategy. Individuals may have picked mates on the basis of how little body hair/fur they had. And being hairless is a good way to signal your parasite-free bodies to potential mates. So there was initial selection to reduce body hair due to parasite-load and further selection due to mate-attraction. Sweating is a good way to cool off the body. When a bead of sweat forms on your forehead and it evaporates—this process of evaporation literally is pulling heat away from your body. It is called evaporative cooling. (Dogs cool off by panting, which evaporates moisture on their tongue, cooling them off). Naked skin is more efficient at producing evaporative cooling because it is all about getting the sweat to evaporate and thus "pull" heat from the body. If one has really furry skin, fur holds wetness/moisture longer, so this would slow down the process of evaporative cooling. So loosing our body hair/fur resulted in selection for more sweat glands, especially since hominins were inhabiting the sunny savannah environment and not in forests with tree cover. The lines show the heat-load during the time of day. You can see that adopting a bipedal stance lowers the heat load of an individual because there is less body surface area exposed to the sun, especially at noon when the sun is at its hottest. So standing up and walking allows the wind to cool off the body better (since winds are stronger as you move from the ground up) than being closer to the ground in a quadrupedal position.

Behavioral Features likely to be found in our common ansestors

Culture Tool Use A lot of evidence for tool use (i.e., manipulating a natural object to achieve a desired goal) in chimpanzees. And of course humans also use/make tools Warfare Warfare, once thought to be uniquely human, has been well documented in several chimpanzee communities Hunting Chimpanzees regularly hunt animals to eat.Humans also hunt and eat meat

Catastrophism is associated with which early scientific thinker

Cuvier

Urban Anthropology

Deals with issues of inner cities.

Paleoanthropology

Does not necessarily rely on direct observations (certainly not of the past)However, paleoanthropology can generate testable hypotheses:•If humans evolved, then fossil humans can be found. This is a testable hypothesis that can be confirmed by discovering fossil human ancestors. •Our LCA (last common ancestor of humans and apes) lived in Africa. Ever since Darwin, researchers noticed similarities between human anatomy and that of the great apes. Darwin (rightly) suggested chimps had the most similar anatomy, so thought our last common ancestor of chimps and humans would be found in Africa. Paleoanthropologists reconstruct our evolution using "bits and pieces" (of fossils and other data)

Recombination

During meiosis genetic material can be exchanged between homologous chromosomes.

The ocean floor and continents are positioned on major plates called

Lithospheric plates

The Olduwan Tool Industry

Louis Leakey named the tools found in association with H. habilis "Olduwan tools". Named after Olduvai Gorge They are very simple tools: hammers, choppers, mostly core type tools At the time, no Australopithecines were found with tools, so tool-use was thought to be a trait associated with the evolution of the genus Homo his is because a typical fossil assemblage for H. habilis contained the following: •H. habilis bones (fossilized)•Bones of prey animals (fossilized)•Stone tools The implication being that H. habilismade tools and then used them to hunt, kill, and butcher prey animals

Were early hominins hunters?

More recent evidence they are scavengers, not hunters. How do we know this? Hominins likely ate things like deer (African deer). But so did lions. Some deer bones fossilize, and those fossilized deer bones show evidence of two things: scratches from lion's teeth, and scratches from stone tools. However, the order of how those scratches got there shows that lions did the killing of the deer and ate the deer (leaving the first set of scratches on the deer bones), and when the lions left the carcass, along came Homo habilis with their stone tools to scavenge the remaining meat off the deer bones (thereby leaving a second set of scratches on top of the lion teeth scratches on the deer bones)

Neandertals

Neandertals are found between mostly between 130kya and 30kya (the earliest fossils show up around 250kya Some consider them a subspecies of Homo sapiens :Homo sapiens neanderthalensis Others consider them a separate species:Homo neanderthalensis The Original Cavemen The Neandertals are distributed across the western part of Eurasia NOT FOUND in far east (like china) Neandertals have:• Rounded, thin-walled cranium• Low foreheads •Large brain size 1245-1740cc. Average is 1520cc (as large or larger than modern humans) Large rounded brow ridges (pneumatized, which means the largeness comes from the fact that they have large air-filled spaces in them, called sinuses) Mid-face prognathism (unique to Neandertals: their nose area is a bit "puffed out" likely due to lots of air-filled sinuses in this area Large nasal opening (unique to Neandertals: the nasal opening is large allowing more volume of air per inhalation/exhalation ANATOMY Occipital bun—this is a globular (rounded and "sticking out") area on the back of the skull. It is unique to Neandertals. No chin. Only humans have a small bump of bone that juts outward on the front midline of their jawbone (mandible). In neandertals, the mandible at front-midline slopes backward Very worn anterior teeth; this is to say, the front teeth are chipped and worn down; likely they were using their front teeth as a gripping device Taurodont tooth-roots in molar teeth. Your teeth, from outside to inside, consists of enamel (hard white stuff that makes contact with food), dentine (layer beneath enamel), and the pulp cavity, which contains the blood vessels and tooth nerve. Taurodont just means that the pulp cavity is enlarged. (see diagram upper right). No one knows the function of this, but it does mean that if you find an isolated molar tooth, you can determine if it is Neandertal or not. Neandertals were relatively short in height (compared to modern humans), and robust and heavily muscled (we know they had large muscles because the muscle attachment sites on their bones are larger than human muscle attachment sites) They had thick long bones (bones in the arms/legs) and large joints at elbows, knees, hip, ankles, wrist. Neandertals where strong, stocky individuals, likely engaging in risky types of behaviors such as big-game hunting in cold climates Their nasal area is large and they were "barrel-chested"...all this points to an anatomy that was capable of living in cold climates. The large nasal opening that is filled with sinuses allows air to be warmed up as it enters the nose and moves into the lungs, and the "barrel-shaped" torso is good for conserving heat BEHAVIOR Neandertal lifespans were not long; they tended to die around age 40+. The fact there was a male of about 30+ yrs old, who had several debilitations suggested that Neandertals looked after him—they were compassionate to those less able. and the fact that they buried their dead (along with flowers and decorations) suggests some sort of symbolic-type behavior, akin to religion TOOLS Mousterian tools are even more refined, thinner, more complex tools with even more cutting edge than the Levallois tools of H. heidelbergensis. There is also evidence of spear-heads being attached to spear shafts using glue Neandertals also used non-stone materials such as bone, wood, ivory for tools and for "jewelry" BEHAVIOR •Neandertals incorporated large quantities of meat into their diet •Neandertals hunted big game •Evidence of cannibalism (yes, there is some evidence that Neandertals ate other Neandertals, this is evident from stone tool cut-marks found on Neandertal bones, which suggests that Neandertals were cutting into Neandertal bones. It is unknown if they were just eating people who already died, or actively killing people to eat) "teeth as a tool"Anterior teeth are often chipped Made shelters •Made hearths and fires •Cooked their food •Made clothes out of animal LANGUAGE? To produce language in the form of spoken words (speech) requires bot h specialized anatomy of the throat /mouth; as well as specialized brain regions- No evidence The thoracic vertebrae of the Homo erect us in Africa suggest s they are not capable of regulated breathing The fact that Neadertals buried their dead and had large brains, suggests that they could think symbolically (think in abstract ways), which is what language consists of: different sounds being "symbols" for different words. EVIDENCE OF LANGUAGE he Hypoglossal canal is a hole where cranial nerve passes through from brain to innervate the tongue. •The tongue plays major role in speech production in terms of modifying air in the throat •Size of hypoglossal canal (the size of the hole) might reflect size of nerve fiber, the implication being that a larger nerve would mean more control over the movement of the tongue. •It was noticed that Neandertals and modern humans have large hypoglossal canal, other hominins do not.•This was a good idea but likely wrong but it turns out the size of the canal (the hole) isn't a good predictor of the size of the nerve.

Subadult period (12-18 years)

Onset of sexual maturity (secondary sexual characteristics and sexual interest) Lower rates of skeletal growth up to sexual maturity followed by a growth spurt after puberty. No other primate has an adolescent (i.e., subadult) growth spurt in height, though some show a gain in weight

Primate evolution: The Paleocene

Pleasiadapiforms are a diverse and successful group of early primates that inhabited what is now present-day North America and Europe. There were many species that belong to the larger group Pleasiadapiforms. Very small body size• Some primate features (but some also had some more primitive non-primate features, such as claws) •Mostly insectivores

Thomas Malthus

Populations have the potential to increase at a faster rate than resources -as a result there is intense competition among individuals -Eugenicist- don't let certain people reproduce

Cultural Anthropology

Studies how human societies adapt to local conditions using learned, socially transmitted behaviors.- study of human cultures and society

Examples of adaptive phenotypic plasticity:

Temperature adjustment Altitude adjustment UV Radiation Adjustment In all cases, there is an evolved ability for any individual to physiologically adjust to the external environment over the short-term. But populations that have evolved over the long-term in these regions have evolved fixed traits that allow them to adapt to local conditions

Primate evolution: The Eocene

The Adapoids. Found in N. America/Europe •Likely diurnal •Quadrupedalism/ leaping •Lemur-like The Omomyids. Found in N. America/Europe •Likely nocturnal •Vertical leaping •Tarsier-like Both of these groups have traits that are diagnostic of primates (e.g., nails, post-orbital bar). They are fully primate and do not have any primitive mammalian traits.

Hardy-Weinberg equilibrium (H-W)

The H-W equilibrium tells us how alleles will be distributed into genotypes in the offspring in a very, very large population under the assumptions of.. -No mutation -No migration -No natural selection -No accidental deaths -No random mating

Primate Social Behavior and Intelligence

The Social Brain Individuals in a social group need to keep track of their social interactions and those of others. In large primate groups there are more interactions to keep track of. And it has been shown that primates that live in larger social groups have larger brains (see graph on previous slide). It is also thought that the ancestral size of human groups was even larger than most primate groups, on the order of 150+ individuals. Hence, during human evolution there was selection for a larger brain so that individuals can keep track of complex social interactions. •A. afarensi s400-500cc •Homohabi lis600-775cc• H. ergaster/erectus 800-1250cc •H. heidelbergensis average ~1200cc •H. neanderthalensis 1245-1740cc •H.sapiens1100-1550cc In humans the neocortex (or cerebrum) is the part that gets even bigger during human evolution Brains can be reorganized three ways •A region can become larger or smaller •A functional region can change position •A new region can emerge

Disruptive selection

The average individuals are less fit.

Stabilizing selection

The average individuals are most fit.

The Biological Profile: Ancestry

Traits of particularly high frequency among populations (shovel shaped incisors among some Asian populations), or culturally specific traits pertaining to particular groups In forensic anthropology it is possible to use a suite of skeletal traits to statistically assign an individual to an ancestral geographic area It is also possible to assign an individual to an ancestral geographic area using genetic data. Both genetic and skeletal assessments of ancestry are estimates! "With 82% certainty, we feel this individual is of Asian decent." With about 85% accuracy, a USA-based forensic anthropologist can distinguish ancestry from a skull when a combination of features is used. By "ancestry" we mean where the individual's ancestors came from in a broad geographic sense: Europe, Africa, Asia. This is to say that one could determine from a skull that an individual is Asian-American but not where in Asia that individual's ancestors came from (China or Japan or Korea or Thailand, etc.) However, each individual feature (e.g., orbit shape) will show lots of variation

Continental Drift

What indirectly helps paleoanthropologists do their job?

Traits that distinguish living nonhuman primates from other mammals include

dermatoglyphs or "finger prints"

Eugene Dubios

found the first fossils attributed to Homo erectus in 1891 in Java (Indonesia). Two key specimens were recovered: a skull cap and a femur. The femur shows evidence of arthritis or some sort of inflammation (red circle); this resulted in abnormal bone growth on the femur, so this individual walked with a limp.

John Ray

genus and species fixity of species