study guide!! Flashcards
uestions to think about:
1. What are the main methodologies used in the field of biological anthropology
scientific method
ethics
dna analysis
paleoanthropology
- What geological epochs correspond with human evolution?
Hominins first appear by around 6 million years ago, in the Miocene epoch, which ended about 5.3 million years ago. Our evolutionary path takes us through the Pliocene, the Pleistocene, and finally into the Holocene, starting about 12,000 years ago
first true primates?
eocene
what period and era associated w humans
Period: quaternary
Era: cenozoic
What was seen in the fossil record to suggest the appearance of primates in the early Cenozoic
Era?
• Plesiadapiforms
Cranium in wyoming Primate like - proprimates, not primates Early cenzoic (approx 60 mya) Western north america, europe Primate like - proprimates, not primates No postoribtal bar or convergent eyes; lacked opposability, claws, small brain, small rodent like teeth Primate like grasping ability
What adaptations are common to primates that separate them from other mammals?
forward-facing eyes,
a postorbital bar or fully enclosed eye orbit,
a large cranial vault, a reduced snout,
and a versatile dentition.
usually have divergent big toes and thumbs, grasping hands and feet, and nails instead of claws on their fingers and their toes.
three primate tenancies?
generalized skeletal structure, enhanced touch + vision, reduced smell, dietary versatility
Primates eat a wide variety of foods—they express dietary plasticity.
Primates invest a lot of time and care in few offspring—they express parental investment.
main primate characteristics
versitile skeletal structure emphasizing mobility + flex
enhanced sense of touch
enhanced sense of vision
mammal dietary fflexibility why?
multiple tooth types (incisors canines premolars molars)
reduced number of teeth (except for canines)
why are we interested in the placement and features of the orbit in primate crania?
Primates’ forward-facing eyes enable depth perception, a vital adaptation to life in the trees that has a selective advantage beyond arboreal life.
What is the connection between the environment and primate evolution? - 3 hypotheses
3 hypotheses: arboreal, visual, angiosperm
describe hypotheses for connection to enivronment w primate evolution
arboreal hypothesis
The proposition that primates’ unique suite of traits is an adaptation to living in trees.
visual predation hypothesis
The proposition that unique primate traits arose as adaptations to preying on insects and on small animals.
angiosperm radiation hypothesis
The proposition that certain primate traits, such as visual acuity, occurred in response to the availability of fruit and flowers after the spread of angiosperm
How are the non-human primates in South and Central America related to the non-human
primates in Africa and Asia?
Four alternative hypotheses have emerged to explain primates’ presence in South America
in short: migrated across atlantic and crossed from africa to antarctic to patagonia/SA
most accurate:
platyrrhines evolved from an African anthropoid and migrated across the Atlantic to South America. Evidence supports the second hypothesis. There were early anthropoids in Africa (Fayum) beginning in the Late Eocene, and they predated platyrrhines but looked remarkably similar to the earliest platyrrhines in South America (for example, they had three premolars). This resemblance indicates that platyrrhines originated in Africa before their appearance in South America. In addition, fossils indicate other similarities between animals in Africa and in South America.
Third, platyrrhines evolved from an anthropoid in Africa that migrated south (mainly) on land to Antarctica and then to Patagonia, at the southern tip of South America. The strong similarities between Old World and New World higher primates also support the third hypothesis. Migration across Antarctica would be impossible today, of course. However, migration over this major landmass would have been possible through much of the Eocene, when the climate there was much warmer and drier than it is today.
What can we learn from studying extinct primates that are ancestors to non-human primates?
Which (now fossilized) species gave rise to primates? To the first apes? To the first hominins? To the first modern humans? Which conditions drove natural selection and other processes that account for the appearance, evolution, radiation, and extinction of past primates and humans? This question pertains especially to the ecology of the setting the primates lived in—their habitat. Using models derived from the study of living animals, paleontologists can look at the bones of extinct animals and determine how they functioned during life and in what kinds of habitats they functioned.
Why is the hominin Ardipithecus ramidus intriguing to paleoanthropologists?
4.4 mya
Miocene and Early Pliocene at Aramis would reveal hominin ancestors having a mosaic of apelike and humanlike characteristics. These ancestors would have set the stage for all of later human evolution- proof first hominin was not chimp like
ossils show that hominins’ canines wore from the tips (not the sides) but had some honing or polishing on the sides of the third lower premolar
- . The oldest fossil hominin skeleton yet found, it predates Lucy’s skeleton by more than a million years
btwn pre aus and aus
