midterm 2
Super Class Tetrapoda
*Colonization of land by animals
Class mammalia modifications
- Homeothermic - • Change in sensory focus - • Modified feeding apparatus - others
Unlikely hypothesis for bipedalism
- threat display - swimming -better vision -carrying food - hunting
interesting
-Birds are reptiles -Birds are dinosaurs -We are not reptiles
Paleocene Primates
-Plesiadapiforms- "primate-like mammals" -Not considered true primates -Lack essential primate traits multituberculate (rodent like... huge tail) plesiadapiform rodent
Morphology of paranthropus
-huge molars -big, molariform premolars -tiny incisors and canines -thick enamel -fortified mandible Very wide and dish shaped face Orthognathic Very pushed up face Strong sagittal crest Postorbital constriction Huge molars big , molariform premolars Tiny incisors and canines Thick enamel Fortified mandible (heavily built with lots of bone)
what are the cenozoic epoch? from youngest to oldest
1. Holocene (1.0 - today) 2. Pleistocene (2.6 - 1.0) 3. Pliocene (5.3 - 2.6) 4. Miocene (23.0 - 5.3) 5. Oligocene (33.9 - 23.0) 6. Eocene (55.8- 33.9) 7. Paleocene (65 M.a - 55.8 M.a)
theories of why bipedalism evolved
1.Bipedalism first evolved among arboreal miocene apes as a feeding mechanism and was retained in hominins 2. Bipedal posture allows for efficient harvesting of fruit from small trees 3. Erect posture allowed hominids to keep cool 4. Bipedal locomotion leaves the hands open to carry things
Paranthropus Aethiopicus
2.5 mya hominin with teeth and skull structures specialized for heavy chewing
Australopithecus gahri
2.5 mya Bouri, ethiopia 2.5 Ma Morphology Small canines and premolars Huge molars Sagittal crest
Australopithecus Africanus
3 Ma to 2.2 Ma Taung Child Bipedal bc foramen magnum Found in south africa
Australopithecus deyiremeda
3.5 m.a Robust jaw and thick enameled teeth Smaller teeth that differ from Au. afarensis
Kenyanthropus
3.5 mya K. platyops Means kenyan man Has a flattened face and small teeth Lived in east africa 3.5 ma to 3.2 ma Very small molars Lived in woodland and savanna environments
A. ramidus
4.4 mya Cranial capacity 300-350 cc Midfacial projection but reduced subnasal prognathism Foramen magnum placed beneath the cranium No canine honing facet Reduced canine Reduced sexual dimorphism
When did hominids first appear?
6 ma but there was a wider range of hominids during 2 and 4 ma
Australopiths
A colloquial name referring to a diverse group of Plio-Pleistocene African hominins. Australopiths are the most abundant and widely distributed of all early hominins and are also the most completely studied.
illium
A flaring blade of bone on the upper end of the pelvis
Angiosperms
A flowering plant which forms seeds inside a protective chamber called an ovary. ---> After the breakup of pangea --- flowering plants called angiosperms appeared and spread Angiosperms depend on animals to pollinate them They produce fruit Primates filled these niches!
Proconsul
A genus of early Miocene proconsulids from Africa, ancestral to catarrhines. 10 genera and 15 species The smallest proconsulids were about the size of a capuchin monkey The largest proconsulids were about the size of a female gorilla Earliest was found in kenya around 27 MA Most recent founf in africa dated 17 ma Proconsul share several derived features with living apes and humans that we dont see in haplorhinne primates No fleshy pad or tail Big brains Substantial sexual dimorphism Frugivorous thin tooth enamel walked quadrepedally
argon-argon dating
A high-precision method for estimating the relative quantities of argon-39 and argon-40 gas; used to date volcanic ashes that are between 500,000 and several million years old.... more accurate than potassium argon dating like a sophisticated version
fungi
A kingdom made up of nongreen, eukaryotic organisms that have no means of movement, reproduce by using spores, and get food by breaking down substances in their surroundings and absorbing the nutrients Fungi Like animals, storage of glycogen, same mitochondrial codon for tryptophan, hydrolytic enzymes, similar mitochondria Clade diverges 1.5 ba with physical evidence appearing ca. 600 Ma and land fungi at 400 Ma.
uranium-lead dating
A method of dating zirconium crystals in igneous rocks that is based on the ratio of uranium to lead........ USED IN CAVES IN SOUTH AFRICA WITH FLOWSTONE PRECIPITATION ..... used a lot with south african hominoid fossil remains
faunal dating
A method of relative dating based on observing the evolutionary changes in particular species of mammals, so as to form a rough chronological sequence
Gymnosperms
A plant that reproduces without flowering----> During the first 2/3rds of the mesozoic, the forests were dominated by gymosperms (trees like contemporary redwood, pine, and fir)
Orrorin tugenensis
A pre-australopithecine species found in East Africa that displayed some of the earliest evidence of bipedalism. 5.8 -- 6.1 MA Tugen hills, kenya Bipedal More similar to modern humans than lucy Was more similar to australopithecus Evidence of bipedality: shape of femur neck and cross section of bone
kenyanthropus platyops
A proposed genus and species of biped contemporary with early australopithecines; may not be a separate genus. West turkana, kenya 3.5- 3.2 MA LIKE LUCY Morphology Flat face Small molars Small brain Probs just a very damaged skull of A. afarensis
thermoluminescence dating
A relative dating method in which the energy trapped in a material is measured when the object is heated. ---> heated tools
thermoluminescence dating
A relative dating method in which the energy trapped in a material is measured when the object is heated. ---> heated tools.... measuring the density of trapped electrons in the crystal lattice ..... HEATED TOOLS THAT CAN BE DATED FROM 100 YEARS AGO TO 1,000,000
Pangea
A supercontinent containing all of Earth's land that existed about 225 million years ago.
Torque
A twisting force on the pelvis when walking
abductors
Abductors Muscles that cause your torso to not tip while walking... they are muscles that run from the outer side of the pelvis to the femur
diff between adapids and omomyids
Adapids were larger than omomyids, and they had longer snouts and smaller orbits than the omomyids had. The shape of their teeth suggests that they fed on fruit or leaves. Adapids likely looked similar to lemurs of today. Omomyids were small primates that fed mainly on insects, fruit, or gum. They likely looked similar to modern galagos or tarsiers.
Class Amphibia
Amphibians Amphibians are ectothermic, tetrapod vertebrates of the class Amphibia. Modern amphibians are all Lissamphibia. - Scientific name: Amphibia - Phylum: Chordata - Higher classification: Batrachomorpha - Rank: Class Class Amphibia • Spend at least part of their lives in the water • *Can also live on land • Most skin, no claws • Frogs, toads, salamanders, newts, etc.
electron spin resonance dating
An absolute dating method that uses microwave spectroscopy to measure electrons' spins in various materials. TEETH
australopithecus deyiremeda
An australopithecine, overlapping in time with Au. afarensis in East Africa Woranso- mille, ethiopia 3.5 Ma Morphology Similar to A. Afarensis Smaller teeth and distinct facial anatomy
what was the ancestral mammal like?
Ancestral mammal Small Active- high metabolism Well insulated Nocturnal Poor vision Good olfaction Insectivorous
paranthropus engaged in heavy grinding and chewing not ripping and tearing
Anteriorly placed sagittal crest Orthognathic Wide face Really moving its mouth side to side in a GRINDING FASHION
Canines in early primates
Anthropoid monkeys have canines (men larger than female) Mainly used for fighting NOT meat eating Some primates also use canines for feeding (opening fruits, killing prey) Controlling for body size, some primates have canines that are longer and stronger than those of any living carnivore, exceeded only by sabertooth
Propliopithecids
Ape-like anthropoids dating from the early Oligocene, found in the Fayum area of Egypt ---> 2.1.2.3 Arboreal quadrapeds Zeuxis Prob not pair bonded
When did apes first appear?
Apes first appeared during the miocene epoch--- 23 ma to 5 ma
Ar. ramidus
Ar. Ramidus Appears a million years after Ar. Kadabba Dated 4.4 M.a There was a huge amount found Has a distinctive suite of dental traits Thicker molar enamel Reduced sexual dimorphism in the canines And no honing on pre-molars The smaller canines suggest that Ar. Ramidus was less frugivorous than modern primates Was a generalized omnivore and frugivore Characteristics of the feet and pelvis indicate that Ar. Ramidus walked upright Retained the opposable toe but the other 4 toes were evolved for bipedal locomotion Has a shorter and broader ilium (pelvis bone) Hands and forearms suggest they didn't knucklewalk Palms and fingers are more short
Bipedalism removed selection against brain size increase
Arboreal life (need to hang on immediately after birth) requires babies to be precocial Increased encephalization produces altricial babies Arboreality constraints brain size by selecting against altricial babies Could it be a consequence and not a cause
Isotope
Atoms of the same element that have different numbers of neutrons.... used in radiometric dating
Australopithecus
Au. Amenensis, Au. Aferensis, Au, deyiremeda, Au. Africanus, Au. gahri, Au. sediba Found in south africa Had a small skull and teeth Reached sexual maturity early
Australopithecus Gahri
Australopithecus Gahri lived about 2.5 Ma in east Africa Gahri means suprise Large molars
development of australopithecines to paranthropus
Australopithecus afarensis → p. Boisei Australopithecus africanus → p. Robustus '
Australopithecus aferensis
Australopithecus aferensis Found in east Africa from 3.6 - 3.0 M.a LUCYYYY Many people believe Au. aferensis evolved from Au. anemensis
Taung Child
Australopithecus africanus First specimen of australopithecus Raymond dart: Taung Child Australopithecus africanus Southern ape of africa Then comes australopithecus Africanus and Paranthropus Robustus Gracile: africanus Built finer Robust: robustus Built bigger
The oldest Australopithecus
Australopithecus anamensis comes from sites in kenya and ethiopia Dated between 4.2 M.a and 3.9 M.a
ecological preferences
Australopithecus likely inhabited a variety of woodland and grassland habitats ---- never too far from trees They also exploited lots of dietary niches Adaptations suggest strong chewing apparatus Nuts tubers seeds Large anterior teeth Ripping tearing puncture (fruits Evidence from dental isotopes show a shift to more grassland foods around 3.6 MA
What species did they diversify into during 4 and 2 Ma
Australopithecus, Paranthropus, Kenyanthropus, Homo
australopithecus bahreghazali
Bahrelghazali Bahr el Ghazal, Chad 3.4-3 Ma Morphology Similar to A. Afarensis Biggest diff but thin enamel
benefits and costs of high rank
Benefits of high rank -Access to resources -Less harassment/stress Costs of seeking high rank -Time lost -Wounds
biology of human pair mating
Biology of the human mating pair-bond Extreme need for parental investment Babies can't do anything (altricial) We have very little sexual dimorphism (15%) relative to apes (50%) Testis size and sperm count suggests moderate sperm comp Penis size and shape unique among the apes, possible for sperm competition An argument used to justify philandery (cheating) No baculum (penis bone) Ovulation hidden (we have no estrous swellings Females have permanent breasts, likely because of their fat storage for mobile hunter- gatherers Exaptation = current function is not evolutionary or developmental functions As with bonobos, sex has a broader function in humans than in chimps... it binds partners together chemically, psychologically, keeping them together in order to invest in the bable Evidence that female orgasm <1 min or before or <45 min after male ejaculation increases the chances of sperm reaching the uterus .... Increases the emotional/behavioral connection While the pair bond is ubiquitous in humans, the variation in the strength of the pair bond and the existence of intra= species mating systems diversity are the products of FICTIVE KINSHIP-- such alliance formation requires symbolic cognition
Australopithecus cranial volume
Brain cavity capacity 466 cc 30% bigger than apes but much smaller than modern humans
Class Reptilia
Class Reptilia *Lay eggs on land • Dry skin with scales and claws • Homodonty (all have the same teeth) • One group led to birds (theropods)
How did climate change effect hominoid diversity?
Climate changes in the late middle miocene reduced hominoid diversity in asia and europe As it became cooler, many ape fauna became extinct During the early and middle miocene, ape species were plentiful and monkey species were not, in the late miocene and early pliocene, many ape species became extinct and were replaced by monkeys
what is the best prediction of mate preferences?
Culture predicts people mate preferences better than their sex does Knowing where a person lives tells you more about what they value in a person than what their sex is Cultural explanations and evolutionary psychology are not mutually exclusive
difference in mating tactics cause misunderstandings
Differences in mating tactics may contribute to misunderstanding between men and women Women do more false negatives as they underestimate men's commitment They also overanalyze men's intentions Men do more false positives and over estimate women's sexual interest womens fear of getting pregnant and mens fear of missing out on a reproductive experience
Louis and Mary Leakey
Discovered a 1.8 million year old hominid in Africa Mary took a drive and discovered in Laetoli Tanzania (lots of footprints)
Imperfect correspondence between primate and human social systems
Dissociation of proximate and ultimate behavioral mechanisms Fictive kinship (non-biological) expands human social flexibility cultural things hoarding foods Articulation and reification of abstract ideas Integrity, freedom We put energy around these things WE ARE CULTURAL ANIMALS
When did the first haplorhhines come about?
During the oligocene epoch many parts of the world became colder and drier The continents looked like they look today 43 ma to 23 ma Tropical evergreen forests became tropical deciduous
Sahelanthropus Tchadensis
Earliest known primate Has a mix of derived and shared characteristics Found in Chad Foramen magnum found under the skull Flat face Massive brow ridge small brain
weather in the Paleocene
Early Eocene Temperature spike 5-8 degrees carbon due to massive injections of carbon into the atmosphere Warmest period in cenozoic Causes unknown
problems with the savannah hypothesis
Early hominins often associated with forest dwelling animals Significant grasslands began well before hominin lineage Severe aridity and associated grassland expansion began AFTER earliest bipeds
earth history
Earth history -4 ½ billion years ago -Earliest evidence for life on earth is 3-4 billion years ago - 3.5 billion years ago signs of photosynthesis
Where did the Australopithecus live and what did they eat?
East Africa Australopiths lived in a wide variety of woodland and grassland habitats Australopithecus ate a wide variety of foods Adapted to the cooler environment by eating tough foods like nuts, seeds, roots, and tubers (potatoes) We can figure out what they ate by looking at the carbon isotope of their teeth enamel
P. Boisei
East turkana, olduvai, tanzania, Konso, Ethiopia 2.2 - 1.0 MA Habitat Riverine system and gallery forest 500-550 c.c.
third party opinion towards incest
Edward Westenmark speculated that childhood propinquity stiffles desire Tawainese minor marriage In minor marriages - the bride is adopted into the family of her future husband during infancy The kids who grew up together had absolutely no interest in consummating the marriage so their husband's fathers would beat the newlyweds Kibbutz age mates Jews organized into utopian groups of children that were raised in communal nurseries There was no sexual experimentation or marriage between kids In a study of kibbutznik only 14 married from their same group Third party attitudes towards incest Our aversions to inbreeding extend beyond our attitudes towards our own mating behavior We are disgusted at thought of having sex with our children and other people having sex with their children Women are more averse to a situation than men People who had opposite sex brothers and sisters were disgusted more
EEA
Environment of Evolutionary Adaptedness\ Environment of evolutionary adaptedness- the social, technological, and ecological conditions under which human mental abilities have evolved Have discovered how adapt humans are at detecting imbalances in social exchange and violations of social contracts.... In regards to reciprocal altruism
who is more powerful? metharia or eutheria?
Eutheria
why is the nature/nurture debate is a false dichotomy
Even highly canalized traits can be effected by the environment
Features of A. sediba
Features of australopith Long upper limbs Primitive ankle bones 420 cc (juvenile) Molar cusps positioned like australopithecus Modern features Geometry of humerus and femur suggest habitual bipedality Pelvis Small premolars and molars Gracile facial features Modern precision grip
female counter strategies to infanticide/ aggression
Female counter-strategies: sexual swellings Large brightly colored swellings advertise fertility Swellings usually last longer than the window of highest fertility, so this is not an honest review Swellings attract many males who attempt to mate with females By mating with many males, females spread paternity uncertainty
female friends as a strategy
Female friends Females most often prefer kin but can form friendships among unrelated females Strong alliances among females can protect females from male aggression Bonobos vs chimps
Distribution of females
Females mainly compete over access to food Defend solitary range Perhaps sharing range with 1-2 males Group living Larger groups win gegen small groups Females often live in groups with female kin Dominance hierarchies Higher ranking females get more food More food → more babies
use of male friends as a reproductive strategy
Females may affiliate and mate mainly with preferred males 1-2 male friends in savanna Leader male in baboons Dominant silverback in gorillas Females may concentrate paternity rather than diluting Male who is confident of paternity protects infants Risky if takeover
Ar. kadabba
From 5.8 to 5.2 M.a Like Sahelanthropus.. Contains a mix of new and old dental traits Thick enamel but canine sharpens itself on the first premolar Toe bone indicates bipedal locomotion
Orrorin tugenensis
Genus name means original man 6 ma A bunch of bones Thick teeth enamel Found in kenya They assessed the femur and saw it was more human like than apelike
Paranthropus
Genus of vegetarian hominins includes P. aethiopicus, robustus and boisei.
Paranthropus
Genus of vegetarian hominins includes P. aethiopicus, robustus and boisei. P. aethiopicus, P. Robustus, and P. boisei Means parallel to man Similar to Australopithecus from the head down but had a huge skull and teeth modified for chewing power
which other apes showed canine reduction?
Gigantopithecus Ouranopithecus Ramapithecus Smaller just female apes of some species not diff species
reasons for dominance hierarchies
Group selectionist view -Good for species Gene-selectionist view -Individuals should assess likelihood of winning or -losing -Selfish strategy to avoid costly fights -Dominance hierarchies emerge as individuals learn about competitive ability of other group members -Higher ranking females produce more babies than lower ranking females -Higher ranked mothers produce daughters who mature faster -Survivorship of daughters is higher if mothers rank is high
Class agnatha (jaw-less fish)
Hagfish living today No true paired fins Filter feeders Armored covered with enamel like substance
homo
Homo H. Habilis, H. rudolfensis, H. erectus Had larger brains and smaller teeth..... They developed more slowly than contemporary hominin species
inbreeding avoidance
Inbreeding avoidance: the offspring of genetically related parents have lower fitness than do the offspring of related parents Inbred matings (relative matings) and outbred matings Inbred matings are more likely to be homozygous for deleterious recessive traits Inbred offspring are less robust and have higher mortality geneticists believe that each person carries the equivalent of 2-5 recessive alleles that are lethal
Eutheria: true placental mammals LIKE MOST MAMMALS
Includes most of common mammals Longer gestation so young are more developed when born Chorioallantoic placenta functions much longer, facilitating fetal maternal exchange and blocking mother's immune response Eutherians are more powerful than Metatheria
Why is it difficult to distinguish relationships between pilo-pleistocene hominins?
Inferring the phylogenetic relationships among the pilo-pleistocene hominins is difficult As the fossil record becomes richer, it is harder to figure out Hard to know what is homologous or convergent BUT the absence of a secure phylogeny does not not allow us to understand human evolution
states of theory of mind
Intentional States or Advanced Theory of Mind Level 1- "I believe this" the max for monkeys Level 2 - " I believe that you suppose that something is the case." Identifies two distinct belief or intentional states Chimps by 4 and 5 Level 3- "I believe that you think that I think this" HUMANS CAN DO 4 AND 5
effects of climate change in 10 Miocene, Pliocene
Isolates warmer pacific ocean from colder atlantic ocean Influx of cold water from the arctic ocean into the atlantic ocean Isolates most of africa from warmer and humid indian ocean air More dramatic temperatures clines lead to more polar ice and lower ocean levels → earth becomes cooler and drier
australopithecus anemensis
Kanapoi and Allia Bay, Kenya, Asa Issie, Ethiopia 4.2- 3.9 MA Habitat: woodland biome Morphology Reduced, pointed canines Thick enamel Strongly built tibia Human like humerus Long, curved fingers Phyletic evolution
ARA-VP-6/500
Known as Ardi Represents most of the skeleton of an individual Weighed 112 lbs Stood 3 ft 9 in tall Lived in a woodland habitat dotted with patches of dense forests Had a brain the size of a chimp Had a flat face but the middle protruded... much like a chimp Had the foramen magnum on the bottom of the skull = bipedal locomotion
Insectivore teeth
Long crests on molars, good for shearing chitin huge canines and incisors ... smallest
Mating between close relatives is very rare among nonhuman primates
Lots of mechanisms that help the chance of parental mating not happen Like fathers leave when the daughter hits puberty And daughters dont mate until the fathers leave
Australopithecus aferensis
Lucy Hadar, Ethiopia.... Laetoli, Tanzania
australopithecus sediba
Malapa S. Africa 1.95-1.78 Ma Tentative evidence that this species may have inhabited or accessed a forested environment Thought it was closely related to the genus homo THIS SPECIES MIGHT BE THE TRANSITION FROM AUSTRALOPITHECUS TO HOMO
male aggression while mating
Male aggression -keep other males away -And to induce females to mate more exclusively with them -Gombe chimpanzees: sexually coercive males sire more offspring --- Infanticide- Males sometimes kill infants they are unlikely to have fathered
Types of male competition in different breeding systems
Males overlap several solitary females or single male groups -Males invest heavily in fighting ability -Strive to keep other males out, fighting, calling, etc Pair living -Males invest in mate guarding rather than fighting -No sexual dimorphism Multimale groups -Within group comp for access to females -Males invest in both fighting ability and fertilization ability (larger testes) Male male comp in one male groups -Male takeovers -Prize is great -Vicious fights
Males vs Females reproduction
Males vs Females Distribution of females limit male reproductive opportunities Males attempt to manipulate female behavior to their advantages
Metatherian: marsupials POUCHES KANGAROOS
Marsupials used to be all over the world Young are birthed early because of mother's immune system: primitive choriovitelline placenta breaks down and endangers fetus No placenta Mixing of blood from mother and offspring At birth infant isn't more than two forelimbs and a sucking mechanism Infants crawl up to the marsupium (pouch) and attaches to nipple Continues the development in marsupium Internal gestation
timeline of primate evolution
Massive climate disruption; extinction of dinosaurs; primitive primate radiation Placental mammals become common after dinosaur extinction PETM; origin of crown primates Circumpolar currents established; origin of crown anthropoids Africa docks with Eurasia; climate and biogeographic effects; crown hominoid origin E. African uplift; Messinian Salinity crisis; hominin origins Onset of modern glaciation: origin of genus Homo
Australopithecus sediba
Means well-spring Dated to 1.98
how men and women differ on preferred spouse age
Men and women differ about the preferred ages of their partners Women want older and men want younger this is not always based on fertility for men Sometimes they just want a girl with good music taste
how does evolutionary theory explains marriage patterns among the kipsigis? a group of East African pastoralists
Men usually have many wives and the women are in their late teens and the man is in his early 20's The dad pays a dowry (bride-wealth) and it is a very high sum The couple has very little say The groom's father prefers a woman who will be very fertile and lives far far away from her family so she is not called to help The bride's father must weigh the pros and cons and may not always accept the highest dowry
traits of ape evolution?
Mobile joints Long life history Intelligent Suspensory locomotion Generalized diet
How do contemporary apes differ from monkeys?
Monkeys feed and live on the tops of trees Apes live and feed on the bottom They have no fleshy pads on their bottoms They use their long arms to bridge gaps in the trees instead of leaping like monkeys Do not need a tail for balance
Early primate fossils found?
Morotopithecus (21 MA) Early miocene ape First evidence of climbing adaptations Seemed to live in dry semi-open to open environment E Kembo (20-17 MA) Early miocene ape The textbook will refer to these apes as pre-consul Not as ape like in locomotion Many other features are more ape-like Encephalized Slow life history Increased forearm motion and strength Lack of tail Dryopithecines (12-9.5 MA) Best known of the eurasian miocene hominoids Suspensory adaptations similar to modern apes Probably ancestral to living great apes Ouranopithecus 9.6- 8.7 MA Potential ancestral african ape Known from greece Similar cranium to african apes No known fossil gorillas and only a few chimpanzee teeth
What is our evidence that australopithecus was bipedal?
Morphology:arboreal Cranially-oriented scapular glenoid Curved phalanges Long toes High intermembral index Morphology:terrestrial Anteriorly placed, downward directed foramen magnum Distinct foot arch Distinct valgus knee Short, broad pelvis A. africanus 3.5-2 MA Little foot discovered Demonstrated that the toes are in line with the rest of the foot.... Only a little abducted = bipedal hominin Discovered then the rest of the hominin
what are the effects of rifting?
Much of africa gets cooler and drier Widespread tropical forest and rainforest begins to give way to more open deciduous forest, gallery forest (next to a lake or river), and savanna Some Fauna retreat to refugia
stem cattahrines
NW monkeys
crown cattarhines
OW monkeys and apes
What are the two types of eocone primates?
Omomyidae (like tarsiers and galagos) and adapidae (like lemurs)
dominance hierarchies
One primate beats out the other primate Very obvious in some species Less obvious or undetectable in others
What other animals showed bipedalism?
Oreopithecus Ape Non-primates Adapted by chimps
P. boisei and P. robustus
P. Boisei and P. Robustus had diff diets Teeth are similar but carbon dating suggests differences
WHAT IS THE ONLY SHARED, DERIVED CHARACTER IN THE SKELETON OF ALL LIVING AND FOSSIL PRIMATES?
PETROSAL AUDITORY BULLA
Plesiadapiforms
Paleocene organisms that may have been the first primates, originating from an adaptive radiation of mammals. More than 135 species in 11 families First evidence from 65 MA and persisting well into the Eocene until 37 MA Long grasping fingers and other primates like arboreal traits (Carpolestes divergent big toe with nail) Dentition is primate like
Plesiadapiforms
Paleocene organisms that may have been the first primates, originating from an adaptive radiation of mammals. ----> Plesiadapiforms - a group of fossil animals found in what is now montana, colorado, new mexico, montana Show us what old primates were like From 65 ma to 55 ma A time very wet and hot
Plesiadapiforms
Paleocene organisms that may have been the first primates, originating from an adaptive radiation of mammals. ----> Plesiadapiforms - a group of fossil animals found in what is now montana, colorado, new mexico, montana Show us what old primates were like From 65 ma to 55 ma A time very wet and hot lived during the Paleocene
Paranthropus boisei
Paranthropus boisei was a robust P. robustus Tanzania Larger bodies and molars Skull specialized for heavy chewing Thick molar enamel 2.2 ma to 1.3 ma
Paranthropus robustus
Paranthropus robustus is a more recent species found in southern africa Massive skulls and teeth Came about 1.8 ma and disappeared around 1 Bigger brains Bipedal Sexual dimorphism 4.5 and 80 lbs Males grew longer
plants
Photosynthetic, non-mobile, lacking obvious nervous or sensory organs, cellulose cell walls First photosynthesis
prothera --- egg lasying mammals PLATYPYUS
Platypus and echidna are living today Young born from a tough leathery eggs Mammalian characteristics but also "reptilian" in some aspects Have mammary glands but lack nipples
climate change effects in 30 Ma Oligocene
Polar water no longer mixes with equatorial water Build up of ice caps at the poles Water levels go down; more land is exposed Temperatures drop throughout much of the world
when did primates appear in south america?
Primates appear in south america for the first time during the oligocene but we aint sure how they got there and when
When did primates with modern features first appear?
Primates w/ modern features appeared in the eocene epoch 54-34 ma America and europe still connected Was even wetter and warmer than the paleocene In the eocene primates we see the beginnings of modern primates Grasping hands and feet w/ nails no claws Hind limb - dominated posture Large brains Full orbital convergence
Australopiths in the trees
Probably didn't sleep in trees during the night Were better adapted to climbing than humans but worse than chimpanzees
terminal adaption and feedback loops
Probs not one cause it' s hard to go back to quadrupedalism after becoming bipedal
Carbon-14 dating
Process of estimating age of once living material by measuring the amount of radioactive isotope of carbon present in material...... used for measuring dead organisms (like animals) must be younger than 40,000 years. after an organism dies it goes from carbon 14 to nitrogen 14. You measure carbon 14 to carbon 12.
Trail of fossil footprints
Proves that they had a striding gate The tallest was 4'8'' Could be Au. afarensis, Au. deyiremeda, Kenyanthropus platyops
Dissociation of proximate and ultimate behavioral mechanisms
Proximate (hunger for eatings) → ultimate (nutrition leads to reproductive success) .. chips Pleasure sought in sex → reproductive sucess .. condoms
effects of climate change in 22 ma Miocene
Reduced and then eliminated contribution of warmer indian ocean water to N. Atlantic Dramatic climate shifts in circum- mediterranean regions Faunal interchange between africa and Eurasia
Fayum, Egypt
Richest Oligocene fossil beds in the world. Lots of early Anthropoids Rich fossil locality spanning 3 million years on the Eocene/Oligocene boundary First undisputed ancestors to platyrrhines / catarrhines More than 20 primate genera preserved here
australopithicus origin and development (ontogeny)
Section through teeth and you can see little tree ring-like enamels that help you assess the age of death All taxonomy of hominids is based on the Taung Child M1 eruption show that dental development is close to a chimp
south african cave deposits
Sediment dissolves as ground water goes up → dolomite Was a death trap for hominins falling in Really hard to figure out geologically
When did the hominin community diversify?
Several hominin species lived in africa between 4 Ma and 2 Ma
A. ramidus postcraniel capacity
Short broad pelvis Abductable big toe that was used to stabilize in bipedal locomotion Primitive foot with some bipedal features Length of arm to leg (intermembral index) close to 1 ............ No suspensory or knuckle walking adaptations Wrist suggests arboreal palmigrady Walking not on knuckles but palms
The australopithecus skull is apelike bc
Skull is apelike Flared out at the bottom Has Subnasal Prognathism The nose is pushed out Jaw joint is shallow Dentition is apelike Large and procumbent molars There is a space between the upper canine and incisor This is referred to as Diasteme
Parapithecids
Small monkey-like Oligocene primates found in the Fayum area of Egypt ---> a very diverse group that is now divided into 4 genera and 8 species 2.1.3.3 formula
Australopithecus is human in these ways
Smaller front teeth Large premolars and molars that are heavily enameled Has an intermediate jaw not quite parabolic (humans) and not quite u- shaped (apes)
hypotheses of the increase of primate intelligence
Social intelligence hypothesis: predicts species living in larger groups are more intelligent Have higher neocortex based on how big the group is This is not the same for solitary apes Behavioral flexibility hypothesis: predicts that frugivores are more intelligent than folivores and that extractive foragers are more intelligent than others (great apes more intelligent than monkeys) May be multiple and complementary explanations for increased intelligence Evolution is historically contingent (subject to change)
sperm competition theory
Sperm competition More common in multimale communities
Laurasia and Gondwana
Split again (180 million years ago) laurasia north and gondwana south
P. Robustus
Swartkrans, kromdraii, s. Africa 2.0 -1.5 Ma Habitat Dry grasslands riverine system 530 cc
the ratchet effect
The concept that humans continually improve on improvements, that they do not go backward or revert to a previous state. Progress occurs because improvements move themselves upward, much like a ratchet. Emulation learning produces a slow ratchet effect Imitation learning produces a fast ratchet effect, due to greater fidelity of transmission between generations. No Need to reinvent the wheel of each generation em·u·la·tion effort to match or surpass a person or achievement, typically by imitation. im·i·ta·tion the action of using someone or something as a model.
parentel investment theory predicts mate preferences
The differences in mate preferences are also predicted by parental investment theory Women value good finances more than men Men value good looks more than women Men value chastity more than women No society in which women value chastity more than men do
Sahelanthropus tchadensis
The earliest pre-australopithecine species found in central Africa with possible evidence of bipedalism. Oldest hominin 6-7 MA, Chad Dating? Hard to tell Cause of dunes Discovered in 2001 by Ahounta Dkimdoumalbaye Habitat: lake, forest, riverine, wooded savanna
Weather in the miocene?
The early miocene was warm and moist, but by the end of the epoch, the world had become much cooler and arid
continental drift
The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations
When did hominoids expand?
The middle miocene epoch saw a new radiation of hominoids and the expansion of hominoids throughout much of eurasia They had harder teeth and skulls than preconsulids
Taphonomy
The study of how bones and other materials come to be buried in the earth and preserved as fossils.
Paleomagnetism
The study of the alignment of magnetic minerals in rock,specifically as it relates to the reversal of Earth's magnetic poles; also the magnetic properties that rock requires during formation
evolution of mammals
The transition from therapsids to crown mammals is one of the best documented cases transitions in the fossil record • Occurred gradually • Many transition fossils
oligopithecids
These primates share many primitive features with the Eocene strepsirrhines. However, they also share some derived features with contemporary haplorrhines. Only some members of this group have a 2.1.2.3/2.1.2.3 dental formula. Members of this group may have ranged beyond the Fayum into North Africa and the Arabian Peninsula.
parapithecids
This is a relatively diverse group of fossil primates, the largest of which were the size of a guenon, the smallest were the size of a marmoset. They had a 2.1.3.3/2.1.3.3 dental formula and unspecialized, primitive teeth.
Propliopithecids
This is a somewhat diverse group of fossil primates. Although they were larger in body size, they still showed signs of arboreal quadrupedalism. They had a 2.1.2.3/2.1.2.3 dental formula and ate mainly fruit.
unlikely hypothesis on the origin of bipedalism
Threat display Wading and swimming in water Better vision Stood up to carry Hunting We were deff more prey than hunters
what are the three domains of life?
Three domains of life -Bacteria Has no nucleus Single cells -Archaea Split from nucleus 3.8 billion years ago single cell without nucleus loves extreme temperatures -Eukaryotes Has a cell 2.7 billion
Why do primates have large brains?
Tool use Language Cooperative hunting Social behavior Primates have complex stratified social relationships Vervet screams by Seyfarth and Cheney Infant scream All females look at mother Chacma baboons Food source that juveniles couldn't acess Juvenile saw unrelated female with food and screamed as if threatened Mother came and chased female Juvenile then got food Primate societies Individuals know how to whom they are related and can use info for concealment deception
the principle of superposition
When artifacts are found in rock or earth that is layered, the deeper layers hold the older artifacts old layers are covered by newer layers
The climate has changed substantially during the last 65 million years, first becoming warmer and less variable, then cooling, and finally fluctuating widely in temp
When continents restrict circulation of water from the tropics to the poles, world climates seem to become cooler Larger bodies of land are colder During the period of peak warmth known as Miocene, there were palm trees as far north as oslo and alaska
M1 eruption
When the first molar (M1) emerges is usually a good predictor of when species will reach sexual maturity ranged from the ages of 2.9-3.9 in australopiths
why do we not group bacteria and archaea together?
Why not group bacteria and archaea? -Archaea are more closely related to eukaryotes and prokaryotes -We don't form groups with primitive characteristics like a lack of nucleus
diffs in dental morphology?
Wide parabolic dental arcade Thick molar enamel Reduced canine teeth Large molars
the principle of faunal succession
Within any layer of rock (stratum), different types of fossils succeed one another in the same relative order
apatite crystals
a crystalline material found in tooth enamel
Omomyidae
a family of early primates that radiated during the Eocene epoch between about 55 to 34 million years ago - Must be nocturnal bc they have HUGGEE orbits -Varying teeth so they could all eat what they wanted fruit, insects, gum They may have been able to leap from branch to branch - like tarsiers and galagos
Adapidae
a family of extinct primates that primarily radiated during the Eocene epoch between about 55 and 34 million years ago. Smaller eye orbits... probs diurnal Look like living lemurs Do not have a tooth comb Were bigger than the omomyids Their postcranial bones indicate they were quadruped aboreals Ida found in frankfurt
what did the discovery of carpolestes Simpsoni tell us?
a fossil that displayed grasping evolved before leaping and orbital convergence
deep time
a framework for considering the span of human history within the much larger age of the universe and planet earth we cannot comprehend
australopithecus tool use
a good indicator of australopithecus behavior Tool use is not well documented but able to be assumed Stone tools!!!!! Lomekwi 3.3 Ma tools Dikika 3.4 Ma Cut marks Kantis 3.4- 3.5 MA NONE IS REALLY COMPELLING
what belongs to euarchonta?
a grand order of primates Primates Tree shrews Flying lemurs THEY ARE ALL FAIRLY CLOSELY RELATED
stratum
a level or layer of the earth
potassium-argon dating
a method of dating rocks from the relative proportions of radioactive potassium-40 and its decay product, argon-40. ----> volcanos we measure the potassium 40 that transfers to argon 40. Volcanic rock that must be 500,000 years old.
Glaciation
a process by which glaciers form and spread Modern systems of glacials and interglacials begins roughly 2.4 Ma Many species go extinct (maybe significant in human evolution) Temperate organisms invade Africa Adaptations towards abrasive, drier climate diets: elephants, antelope, pigs, human
rain shadow
a region with dry conditions found on the leeward side of a mountain range as a result of humid winds from the ocean causing precipitation on the windward side
What is the petrosal bulla?
a small bony covering that protects the middle ear in the base of the skull. Other mammals have an auditory bulla, but only primates have one that is fused to the petrosa (a bony plate) before birth.
It is argued that a. Ramidus used bipedal locomotion terestrially as needed and clambered arboreally
a unique combo similar to features of the earliest apes E. Kembo
what are the trait explanations for crown primates? are they false?
a. visual predation----- traits evolved for better insect predation b. grasp leaping hypothesis--- traits evolved for the purpose of grasp leapin both a and b are false
lordosis
abnormal anterior curvature of the lumbar spine (sway-back condition) - proved australopiths were fully bipedal on the ground - but they probs walked slower than us
Therapsids
an extinct group of reptiles from which mammals evolved.... warm blooded and covered in hair
developmental timing
australopithecus probably developed at a similar rate to humans than chimps
Thomas H. Huxley
believed we must combat and not mimic or run away from ancestors (chimps) Think of primates explanatory power
differences between modern humans and other living hominoids
biped, large brain, slow development, teeth arcade, cultural adaptation
what does it take to be a biped
bipedal locomotion distinquishes hominids from hominoids In humans..... They have the thickest cortical bone along the lower edge of the femoral neck Knees that lay close to the midline of the body The human femur slants down and inward to meet with the knee
Class Aves
birds Class Aves • Feathers derived from scales • Homeothermic • Wings • Beak with no teeth in living birds
zygomatic arches
bones that form the structure of the cheeks
hominin evolution?
canine reduction bipedalism
What are Milankovitch cycles?
changes in Earth's orbit and orientation to the Sun Eccentricity in the earth's orbit varies - 100,000 year cycle Axial tilt varies from 22.1 - 24.5 C ---- 41,000 year cycle Precession (wobble) of the axis varies -- 26,000 year cycle
lacustrine sediments
deposited in lakes
mosaic evolution
diff traits evolve at diff rates
Ardipithecus
earliest recognized hominin genus (5.8-4.4 m.y.a), Ethiopia A. KADABBA 5.2 --- 5.8 A. RAMIDUS 3.9 - 4.4 Habitat reconstructed as mostly wooded with a higher water budget than today supporting a rich flora and fauna
Oligopithecids
early catarrhines not specially related to either hominoids or cercopithecoids; very primitive (epitomized by Catopithecus).
Folivore
eats leaves --> not intense canines but large premolars ... bugger than frugivore
the origin of crown primates?
first appeared in the eocene epoch... they displayed Grasping hands and feet Nails Hind limbs dominate locomotion Shorter snouts Eyes frontated and enclosed in bony ring Large brains
australopith sites
follow the rifts (cradle of mankind)
Sivapethicus ?????
fossil looks like an orangutang.......
Morotopithecus bishopi
found in Uganda appears to look like an ape and not a monkey Other early miocene apes were similar to morotopithecus in their dentition but more like monkeys in their postcranial anatomy more derived than preconsulidae
Frugivore
fruit eater Frugivore - large incisors to peel the fruit... very small molars ... in between
What came first... orbital convergence, nails, or grasping hands and feet?
grasping hands and feet
what is the defining trait of hominins?
habitual bipedalism
the black skull
he black skull: P. Aethiopicus Lake turkana, kenya; Laetoli, tanzania 2.6- 2.3 Ma 410 cc Marked prognathism Pneumatized mastoid--- lots of bubbles in the brain Compound temporal nuchal crest Sagittal crest anterior and posterior Large anterior and posterior dentition Molariform premolars Wide, dish shaped faced
changes in the miocene period
it rained less and species left the trees and became terrestrial
fallback foods
items consumed when preferred foods are not available - all primates have these
Parts of the brain that have evolved in primates
larger brain structure - Cerebellum - Brains stem
the principle of original horizontality
layers of sediment are generally deposited in a horizontal position
The australopiths matured rapidly
like chimps not humans
inbreeding avoidance hypothesis
natal dispersal behavior minimizes the likelihood of mating with relatives
likely hypothesis for for bipedalism
orthograde posture for arboreal feeding is a pre-adaptation for bipedalism - good example is an orangutan in trees mcgrew: carrying hypothesis - to carry weapons or tools (knuckle walking constrains chimp tool use) erect posture keeps you cool - quadrapeds take up more social radiation
alluvial
pertaining to soil deposits left by running water--- a river
what does the menarche say about the brides?
plump women whose menarche (first menstruation) occurred at an early age fetched the highest bride wealth payments Among the Kipsigis the age of the menarche is a good indicator of female reproductive success Although already having a baby would show good reproductive success, they don't like that and view success as a weight The wealth of grooms father has nothing to do with how big the bride wealth will be.... Because wealth is very unstable among the kipsigis
Sahelanthropus morphology
primitive ---- large thick brow ridge, tiny chimp cranial capacity (320--- 380 cc) derived--- reduced prognathism, smaller canines, foramen magnum is pushed under the skull
traits of bipedalism above the hind limb?
pronograde (4 legged) to orthograde (biped) locomotion with orthograde locomotion.... the verterbreae is shortened and broad, they also increase in size from the neck to the pelvis, there is a lumbar curvature, and the foramen magnum rotates under the head
how did anthropoid primates get to the new world?
rafting potentially Rafting hypothesis Primates rated primates to south america from africa Has happened before: hurricane transferred from Quadalupe to Anguilla (200 miles) and created a new thriving population Weather patterns demonstrate any primates floating off from Africa have the potential to land in South America Land masses can float across water surfaces
magnetic reversals
reversals in magnetic field of earth--> We can date sites by magnetic reversals as they are constant
colluvial sediments
sediments deposited primarily through the action of gravity on geological material lying on hillsides or mountains
Traits of bipedalism below hind limb?
short pedal phelanges long metatarsals hallux (big toe) double arched foot ankle restricted to flexion-extension broad femoro-tibia (the joint knee) valgus knee (knees that cave in)
what relates all of the features of paranthropus?
strong chewing (mastication) -massester muscle (cheek) -temporalis muscle
Endosymbiosis
symbiosis in which one of the symbiotic organisms lives inside the other.
Paranthropus (beside humans)
the clade does not tell us much about our own taxon
why was sahelanthopus a hominin?
the foramen magnum position, the reduced canine implies it is either a hominin or female ape all in all really no good evidence
Rifting
the process by which Earth's crust breaks apart; can occur within continental crust or oceanic crust Mantle plume causes doming of the crust Subsequent erosion reduces weight of the crust above the plume Heat and magma make the crust brittle and volcanism occurs Down faulting of the crust forms rift
endosymbiotic theory
theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms Endosymbionts are smaller symbiotic partners living inside a host organism, establishing endosymbiosis. The symbionts may live within the host's cells (intracellular) or outside cells (extracellular) in multicellular hosts.
Origins at evolution of hominoidea
there was a split in the oligocene epoch.......... a single jaw (rukwapitheus fossil) and single tooth (nsungaethpithecus fossil) was discover
sexual dimorphism in australopithecus
there was definite male-male competition
Crowns and stems
they are crown catarhines and stem cattarhines
how were early hominids diff from apes
they walked upright the hominin chewing apparatus changed (bc diff food types)
the australopiths were sexually dimorphic
this suggests intersexual dimorphism -They had body size sexual dimorphism -but no canine size sexual dimorphism
The savanna hypothesis
tried to explain why hominids became bipedal The savanna hypothesis Opening of the forest terrain into grasslands offered apes a new niche, which then produced selection for more bipedalism
Ardipethecus
two types: Ar. Kadabba and Ar. Ramidus
the principle of cross cutting relationships
younger features cut across older features
Class Chondrichthyes (cartilage fish)
• Chondrichthyes. Chondrichthyes (/kɒnˈdrɪkθiiːz/; from Greek χονδρ- chondr- 'cartilage', ἰχθύς ichthys 'fish') is a class that contains the cartilaginous fishes: they are jawed vertebrates with paired fins, paired nares, scales, a heart with its chambers in series, and skeletons made of cartilage rather than bone. Sharks, rays, etc. • Cartilage doesn't ossify • * three semi-circular canals for balance/motion sensing • * two pairs of fins
superdivision amniote
• *Eggs of amniotes have an amnion: a water-tight membrane near the outer surface Amniotes (from Greek ἀμνίον amnion, "membrane surrounding the fetus", are a clade of tetrapod vertebrates comprising the reptiles, birds, and mammals. Amniotes lay their eggs on land or retain the fertilized egg within the mother, and are distinguished from the anamniotes (fishes and amphibians), which typically lay their eggs in water.
rates of evolution
• 4.55 Ba — 570 Ma • First appearance of life ca. 4.0 Ba • Eukaryotes appear ca. 2.7 Ba • Multicellular animals evolve ca. 600 Ma • 1.3 By: evolution from non-nucleated to nucleated cells • 2.1 By: evolution from primitive eukaryote to multicellular animals • 600 My: evolution of diversity of animals on the planet
gracile australopith species
• A. afarensis • A. "deyiremeda" • A. africanus • A. "bahrelghazali" • A. garhi • A. sediba
Class Placodermi (jawed)
• Archaic *jawed fish • Extinct • Also armored • Predatory fish up to 30ft in length • *first teeth are modified scales
• Change in sensory focus
• Forebrain enlarged for olfaction and tactile senses • Presence of whiskers for tactile sense
Homeothermic
• Hair for insulation • 4 chambered heart (separate oxygenated blood from de-oxygenated blood) • Muscular diaphragm • Secondary palate separates breathing from chewing • Sweat glands
Taxonomy and the major adaptations in human evolutionary history
• Kingdom Animalia: locomote and ingest food • Subkingdom Metazoa: multicellular animals • Phylum Chordata: have (at some point in development) a primitive notochord (flexible, supportive rod), dorsal nerve cord, pharyngeal slits, and a tail; bilaterally symmetric, metameric segmentation, and a circulatory system
others
• Mammary glands/nurse young • More vertical limbs for efficient locomotion • Non-continuous growth • Three middle-ear bones • NOT give live birth
• Modified feeding apparatus
• Only one bone on each side of the jaw • Heterodonty (why is this useful?) • Teeth only replaced once • Increased range of motion in chewing
robust paranthropus species
• P. boisei • P. aethiopicus
Class Osteichthyes (boney fish)
• Salmon, trout, goldfish, etc., etc. • Inherit paired fins and semi-circular canals • * Bony skeleton • Sarcopterygii: lobe-finned fish • *Lungs; large, fleshy fin bases • Pulled itself from pond to pond in swamps
Subphylum Vertebrata: the vertebrates
• Vertebrates posses a vertebral column • May be bony or cartilaginous • 8 classes of vertebrates ???