ANT 3514C – Introduction to Biological Anthropology
Lab 8: Primate Evolution
Summer A 2018
Examine the fossil evidence uniting and separating stem primates from crown primates
Identify traits that support the inclusion of fossil primates within major clades
Assess the functional implications of the mosaic of traits found in early fossil apes
Produce a brief behavioral summary of an extant primate from observation
To gain an overview of the primate fossil record from the Paleocene – Miocene.
Understanding the origins of any group of animals is difficult. While evolutionary theory offers a
strong foundation for
this process occurs, our visible evidence is limited to the fossil record,
which is only a small representation of past life. Though trillions of individual animals have
lived during Earth’s history, much less than 1% ever become fossils, less than 1% of those fossils
survive tectonics, volcanism, and erosion, and less than 1% of those will be found and studied by
people. Our full understanding of evolution is limited by this incompleteness of the record.
Most theories about how animals originate are
explanations. For instance, primates
have grasping hands and feet, a high reliance on vision compared to many other mammals, and
nails instead of claws. But which of these traits appear in the last common ancestor (LCA) of all
living primates? Knowing this
information would allow us to test
our hypotheses about which
adaptations allowed early primates
to flourish. Anthropologists
interested in the question of primate
origins often study “stem” primates.
Stem taxa are extinct groups not
directly ancestral to a living clade
(also known as the “crown”), but
that share a close common ancestor
with the ancestor of the crown.
Investigating the traits of stem
primates can help us determine the
traits of the LCA of living primates, even without recovering its fossilized remains.
Hominoidea includes modern humans, chimpanzees, bonobos, gorillas, orangutans, gibbons, and
all of their extinct relatives since their divergence with old world monkeys. Modern apes are
much less diverse and have a smaller geographic distribution (other than humans) compared to
old world monkeys. However, the fossil record of the Miocene epoch reveals that apes were once
extremely diverse and distributed throughout much of Africa, Europe, and Asia. All modern apes
use below-branch suspensory locomotion in the trees, and the human shoulder girdle shares
many features with other apes indicating a suspensory past.
suggests that the last