1. Human Evolution pp
As a species, humans, Homo sapiens, are thought to have evolved around 100,000 years ago
Is this very long ago in evolutionary time?

2. Hominids = humans and their recent ancestors Does not include apes
Human Evolution pp
Hominids = humans and their recent ancestors
Does not include apes
Key features:
Opposable thumbs, thumbs can close against other fingers
Teeth arrangement
What natural selection is selecting for opposable thumbs?

3. Primates = order (group) that includes humans, apes, monkeys…
Human Evolution pp
Primates = order (group) that includes humans, apes, monkeys…
Similarities
Movable fingers and toes
Forward facing eyes
DNA
Old world monkeys don’t have a prehensile tail New World monkeys do (tail that grabs)
Why the difference in monkey tails?

4. Evolution of bipedalism = walking upright on 2 feet.
Human Evolution pp
Evolution of bipedalism = walking upright on 2 feet.
Cup-shaped pelvis: supports organs in chest and stomach
S-shaped spine: supports body upright
What are the natural selection pressures for bipedalism?

5. Other important changes in Human evolution: Tool-making
Human Evolution pp
Other important changes in Human evolution:
Tool-making
Complex Language
Large brain-to-body ratio
Is it only about how big the brain is?
Species
E/S ratio
small birds
1/12
lion
1/550
human
1/40
elephant
1/560
mouse
horse
1/600
cat
1/100
shark
1/2496
dog
1/125
hippopotamus
1/2789
frog
1/172
(Kuhlenbeck, 735)