From Biol301

Contents 1 Primate Evolution 1.1 Four (4) Adaptations for life in the trees 1.2 Classification of Primates 1.2.1 Prosimions 1.2.2 Anthropoids 1.2.2.1 New World Monkeys 1.2.2.2 Old World Monkeys 1.2.2.3 Apes 1.2.2.3.1 Five (5) Extant Ape Genera 1.2.2.3.2 Evidence of Homos being from Africa 1.2.2.3.3 Ape Phylogenetic Tree 1.2.2.3.4 Figure 34.38 Notations

Primate Evolution

• Did we evolve from monkeys? Yes
  • Did we evolve from extant monkeys? No
• Did we evolve from apes? Yes
  • Did we evolve from extant apes? No

Four (4) Adaptations for life in the trees

1. Binocular vision: forward facing eyes with lots of overlap.
2. Opposable thumbs: for grabbing branches and such.
3. Rotating shoulder joint: good for swinging.
4. Extended parental care: compared to other mammals; no way a baby primate could keep up.

Classification of Primates

• Order Primata (with 2 suborders)

Prosimions

• Lemurs: 14 species; from Madagascar
• Lorises and Tarsiers: nocturnal; Africa

Anthropoids

• New and Old World Monkeys form a paraphyletic group (figure 34.35)
• Old World Monkeys are more closely related to humans than they are to New World Monkeys.

New World Monkeys

• Golden Lion Tamerins
• Long, prehensile (can grasp) tail, all arboreal

Old World Monkeys

• Africa: Colobus monkeys, baboons (mandrils)
• Asia: Macaques (includes Rhesus), Langurs (temple dwellers)
• Tail is just for balance
• Many are terrestrial; baboons are on the ground 90% of the time, sleep in the trees.

Apes

• Tail has been evolutionarily lost (but they show vestigial traits)
• Long front arms for swinging (especially the gibbons)
• see figure 34.45

Five (5) Extant Ape Genera

1. Gibbons

• 16 species
• SE Asia

2. Orangutans

• orang = man; utans = forest;
• 2 species
  • one from Borneo, one from Sumatra
  • able to interbreed
• SE Asia

3. Gorillas (Gorilla gorilla)

• 1 or 2 species
  • one from the mountains, one from the lowlands
  • able to interbreed
  • morphologically different
• Africa

4. Chimpanzees

• 2 or more species
  • Common chimp and pigmy (Bonobo) chimp
• Africa

5. Humans (Homo)

• 1 extant species
• Africa

Evidence of Homos being from Africa

• 90% of human ancestral fossils are from East Africa (Kenya, Tanzania)
• Closest relatives are from Africa
• Genetic diversity in DNA is highest in Africa (suggesting our ancestors have been there longer such that there was more time for the DNA to mutate)

Ape Phylogenetic Tree

• We drew this tree in class.

Figure 34.38 Notations

• Australopithecus afarensis: 4 million years ago (MYA); Lucy
• Homo habilus: 2 MYA
• Homo erectus: 1.5 MYA
• Homo sapien (cro magnum): 100K YA (0.1 MYA)