final monday Flashcards
paleoanthropology
the study of humans and primates in the broadest possible sense.
relative dating
determines the sequence in time by showing which specimen is older, does not give the exact date.
Chronometric dating
determines an exact date, but is subject to statistical fluctuation.
stratigraphy
makes use of the geologic process known as super position, which refers to the cumulative and constant build up of earth surface or mantle.
fluorine dating
a process that uses the collection of fluorine that flows through with the bone with water, but collection depends on the site and water available. so doesn’t really date unless same found at same site.
biostratigraphy
using the comparison of animal remains to determine the time of a site. pigs are found are usually 1.5 to 2 mya so the site you usually find them at is that old.
chronometric dating cont.
the constant rate of radioactive decay for a radioactive atom
carbon 14 decay
takes 5,730 for one half of 14C to decay, the rate is constant. all organisms take in carbon-12 and carbon-14.
- carbon eventually changes during fossilization.
- any circumstances must be payed attention to, even though charcoal is the best option to use for carbon dating. collection of c14. though you can use charcoal.
Argon Dating
2 types:
-potassium argon dating;has a half life of 1,25 billion years, good for 100,00 years or older. really best represented in volcanic rock, and applied only to fossils found in cites wit volcanic ash. east Africa with hominin evolution lies between two beds
aergon–argon dating
irridating the potasium isatope to create the argon iastop AR-39 better becuase the measure can be extracted from one single argon gas.
dendrochronology
tree ring counting, there is a maser chart that shows wider rings depending on the available moisture. in dry areas and periods usually accumulate a ring per year.
fission-track dating
relies on tracks that uranium leaves on obsideon and other igneous rocks. leaves constant tracks and can help measure from several hundred thousand
mosaic evolution
evolutionary changes that occur over stages in time. we see a lot of intermediate forms but lack modern characteristics.
Hominoid
all apes and humans, both
present and past
hominin
humans and their ancestors following their split with their chimpanzee.
hominid
humans and the great apes, not including gibbons.
Cenozoic
. epochs
paleocene
1st primate like mammals
ii) Eocene
first true primates, later becam eht first anthropoids
iii) Oligocene
adaptive radiation of anthropoids
iv) Pliocene
: radiation of hominin, later fisrt members of genus Homo.
v) Pleistocene
evolution of dispersal of genus homo including anatomically modern humans
vi) Holocene
beginning of agriculture through present.
h) Primate precursers in the Paleocene epoch
i) Before the anthropodic radiation the animals that werw trying to make it could after the extinction of the competitive animals, they would be able to survive.
ii) Plesiadipaforms:
not primates, primitive traits, far apart incisors from rest of teeth.
eyes on the inside of the head.
lacks the postorbital bar.
no grasping ability. has clas.
why move to the trees?
socioecological constructs.
tree resources
food
requirmens for life in trees
all primates have these traits
- 3d spacial orientation, depth perception for leaping from branch to branch. overlapping fields of vision, stereoscopic vision to gauge distances.
- agile body: be able to turn their bodies in mid-air, retention of primitive features with 5 digit.
the eocene
50-55 mya, plesiadipaforms are found mostly in north america and europe during the paleocene, but extinct in eocene. true primates appear because of subtropical climate.
omomyids-
similar to tarsians nocturnal fruit and insect eaters,
adapids
diurnal fruit and leaf eaters, similar to lemurs and lorises.
Oligocene
newly evolved anthropoids became established and spread during the Oligocene. 55-50 mya
anthropoids
the relationship between fossils primates and anthropoids isnt clear, do appear closely related to tarsiers that to lumrs. anthropoids evolved fairly early but may have evolved from a different group other than omomyids or adapids. first appear in the oligocene era, 43 to 23 mya, the transition is associated with cooler temperatures starting in middle eocene. expansion of grasslands and reduction of forest, southward movement of primates.
OWM
most fossil evidence of anthopoids come from climates like africa south america and eastern asia
- reduction fo snout and nasal areas.
- fully elcosed eye socket,
- small arboreal
- generalized quadripeds.
- aegyptopithecus is an example of first OWM.
NWM
most dental remains. narrow jaw with protruding incisors, no living counter parts to these species. common origin in early oligecene. no reasonable ancestor in NWM
early NW and OW were similar.
the spread might have been by rafting, like giant clumps of vegetation getting blown across sea by storms. .
OWM vs Apes
the split occured 25 to 30 MYA. Rukwapithecus first early ape fossil, partial jaw containing one premolar and 3 molars.
miocene apes
23 MYA the Miocene, cooler drier conditions. open grasslands
-apes begin a specialized branch of anthropoids. followed by adaptive radiation.
-in the miocene apes greatly outnumber the monkey,
-dental and cranial features
-postcranial structure more generalized than modern apes, knuckle walking might have been a more recent adaption
Genus Proconsul- (23-17 MYA) unspecialized quadrioed that lived in trees. gaps nect ot he canine teeth. variability in size over all.. sexually dimorphic so polygynous, has both derived traits and primitive traits.
derived: no tail, shoulder and elbows are apelike.
monkey limb proportions same length, arms and hands are monkey like.
proconsul
quadriped, gap next to canine teeth (diastema) variability in sexual dimorphism, no tail, shoulders and elbows are apelike but hands and arms are monkey.
-skull is more ape like, y-5 molars.thin molar enamel.
sivapithacus
miocene era late miocene 14-7 mya, large low cusped molars, postcranial bones very few, not bipedal, thick molar enamel shorter larger jaws for seeds and harder foods, reduced canins allowed rotary eating. shped like orangotang(skull), comes from proconsul.
ardipithicus
after proconsul,
orrorion
..
autrioprlithocene
was in the east africa, etheopia. large faces, cheeks flare, no saggital crest, large incisors.
Lucy austrioporlithicus afarensis and leatolli
south africa,
robust forms
peranthripus:
-aetheopithicus and boisie ate hardier grittier foods.
gracile autrioperithicine
…
paranthripus
highly specialized chewing molars, bigger cheek bones,
sagital crest
…..
bipedal models
tool use model: started walking before tool use, developed bipedal before tool use so it does not show brain development of toolu se to be bipedal.
preadtor avoidance model
in the savanah to see over the grass lands, but apes could be temp bipedal, and also could reveal you.
reproduction model
more efficient for carrying babies. but no real evidence to show sexual behavior.
temperature regulation model
to keep warm by less sun hittting oyu and higher wind speed, other animals arent bipedal.
food acquisition model
energy efficiency to carry food, but primates eat where the source is at
bipedal feeding model
primates tend to eat, food in trees so a lot of time in trees.
genus homo
tools, teeth begin to shrink. flatter face,
homo habilis
east africa, first specimens found in direct connection to tool use. handy man translate. smaller teeth than gracile, more modern molars,frontal lobe smaller than modern humans so migth be some speech.
oldawan
simple chopping, probably used by ustrioprolithecene and habilis use. associated with prisecced bones. scavenged for food and brought back to base.
homo rudolfensis
slightly larger brains and size but still more primitive, either or neither led to ergaster.
pleistocene
ice age, 12 mya glaciers started disappearing.
homo erectus
found in africa, asia and europe, femur is modern brain is smaller, biped came first, 1.8 to 200,00, brain capacity was pretty high. strong crania, strong neck muscle and bone attatchments, face pertrudes more, large ridge above eye orbits. bigger chewing jaws.
dminsi
morpholigicaly similar to ergaster, oldawan tools, relatively small brain and body size.
nariokotome
strapping youth, 12 years old but big for a child, as tall as an adult.
post natal growth
H. erectus could not give borth to big headed babies,
ergaster vs habilis
ergaster is more complicated, use cave for shelters and a cooperative hunter, used fire but not know that they cn make fire. fisrt fire was 1.4-1.5 mya
stone tool tech
evolved oldawan tools were used by habilis, 1.4 MYA new tool tech appeared in africa known as acheulaen tradition.
acheulean tradition
boface tools, worked on both sides, flatter and straighter sides, soft hammer percussion: using a softer material wood or bone to absorbs more of the shock or blow.
hunting
ergaster and erectus hunted, bones were fragmented because better use of the carcase. developed smaller guts and efficient use of energy for hunting, torso and legs developed for longer walking and running.
homo erectus(asia)
still used oldawan tools but also might use bamboo, not much change in brain size or cranial morphology. in java 1.6 mya, spreads to china by 800,000 kya
Homo ergaster (africa)
1.8 MYA and 1 MYA spreads to africa, disapears by 600 Kya, PERHAPS ADOPTED TO dryer condotions than erectus in asia.
middle pleistocene
archaic homosapiens, between 800kya and 500 kya we see transoformation of ergater in hominin with larger brain, lots of variation but not H. sapiens yet.
homo heidelbergenisis
400 KYA large brained modern homo pop. substantially larger than ergaster, more vertical and higher heads, more rounded back of skull, had acheulean tool use, so hand axes and core tools. wooden javelins, large game hunters.
levallots technique
some points are halved allowing them to be tied to some sticks,
heidelbergenisis in asia
200 KYA, Eurasia/africa or shows evolution of erectus in asia. coexisted with erectus.
denisova cave
represent early migration out of africa erectus,
Homo floresiensis
3 feet tall, very small brain, primitive features long arms and non arched feet. dwarfism that happens on islands, they derived from erectus and hunted dwarfed animals.
