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,