Human Evolution From Ape-like Ancestors Flashcards
What can we learn from Fossil evidence?
Learn about physical appearance , how they changed over time.
Bone size, shape, markings show now hominins moved around
What are the most common fossils?
Teeth, lower jaws, facial and upper cranial bones of skull
Skulls found in fragments
Femurs
Very rare are : feet, hands, pelvis, spine
What features give us an idea of evolutionary history?
- Bipedalism (spine and pelvic girdle)
- Brain size
- Teeth (dentition)
- Prognathism ( jaw sticks out markedly)
- Palate shape ( roof of mouth)
- Cranial ( sagitial) and brow ridges
How does bipedalism show evolutionary changes?
Early hominins pre-adapted to bipedalism, had freed arms,for climbing.
Climate changed, habitat changed from forest to Savannah
Ancestors adapt to environment, find new sources
How did bipedalism advantage early hominins?
- live in greater variety of areas
- see danger from predators
- gather food and make tools
How do we know if a fossil was bipedal?
A Foramen magnum that is positioned further forward
A shorter, broader pelvis - weight in upright position
An s-shaped spine - enable posture
What can we tell by brain size?
Drastic climate changes in enviro, allowed ancestors to survive, A a larger more complex brain, capable of processing new information.
What were average brain capacities of ape and hominins?
Ape - 395 cc
Early hominins- 435 cc
Homo sapiens - 135o cc
What evidence can we gather to see how humans evolved from ape like structure?
A) Fossil evidence
B) genetic evidence(mitochindrIal DNA)
C) cultural evidence