4.2 Primate Evolution: The Big Picture

Question 1

What is adaptive radiation

Answer 1

rapid speciation within a lineage to fill different ecological niches -usually follows major change in environmental circumstances

Question 2

when did mammals appear

Answer 2

200 mya

Question 3

When did dinosaurs disappear

Answer 3

65 mya

Question 4

homologous traits

Answer 4

traits shared by different species due to a common ancestry

Question 5

parallel evolution

Answer 5

independent evolution of a similar trait in different species

Question 6

convergent evolution

Answer 6

different species with very different evolutionary lineages evolve similar traits

Question 7

Analogous traits

Answer 7

traits shared by different species resulted by convergent or parallel evolution

Question 8

5 major stages in primate evolution

Answer 8

1. first radiation in late cretaceous - appearance of first primates from common ancestor
   - slight divergence from insectivore ancestor
   - tooth indicates broadening of diet
2. second radiation in paleocene
   - grasping hands
   - nails
   - vision
   - 2 major lines - lemur and tarsier
3. early or mid Eocene
   - primitive monkeys, arboreal quadrupedallism
   - larger brain, vision
4. late olivine/early miocene
   - monkeys and primitive apes
   - diet
   - arboreal
5. late miocene
   - appearance of first true apes
   - large barrel like torso
   - limbs for climbing
   - terrestrial adaptation

Question 9

after second radiation primates dominated by 2 major prosimian families

Answer 9

Adapidae - lemur like
Omomyidae - tarsier like

Question 10

Oligocene fossils from Fayum common characteristics

Answer 10

• quite small
• frugivores - fruit
• arboreal quadrupeds
• diurnal

Question 11

When did primitive apes first appear in fossil record of East Africa

Answer 11

start of miocene

Question 12

Miocene climate

Answer 12

cooler, drier conditions