Primates

Question 1

What animals come under Prosimians?

Answer 1

Lemurs and tarsiers

Question 2

What animals come under Anthropoids?

Answer 2

Monkeys, apes and hominids

Question 3

What are the differences between old and new world monkeys?

Answer 3

New world:

Widespread nostrils and a flat nose

Prehensile tail common and all are arboreal

Thumb not opposable

Old world:

Narrower nose, downward pointing nostrils, reduced importance of smell

Never a prehensile tail and are quadrupedal

Thumb is opposable

Question 4

What differs humans from others?

Answer 4

Erect posture

Elaboration of Brian, behaviour and speech

Increased cranial capacity (1.4L compared to 0.4 of a chimp and 0.5 of a gorilla)

Enlargement of frontal lobe - gives high forehead

Reduction in jaw musculature and ridges of skull for muscle attachment

Prolonged post-natal development

Question 5

What features were found on Lucy? (Australopithecus)

Answer 5

Brain was 1/3 of a Homo

Bipedal

Heavy jaw and a crested skull

Question 6

What are the two models for the origin of modern day H. sapiens?

Answer 6

Multiregion model:

Geographically variable forms of H. sapiens evolved in parallel in different parts of the world

Gene flow accounts for similarity

Neanderthals evolved into European H. sapiens

Out of Africa model:

modern H. sapiens evolved from H. Erectus ancestor in Africa then spread out

Outcompeted Neanderthals and other hominids

Question 7

What is the evidence for the two models of H. sapiens origins?

Answer 7

Multiregional:

distribution of H. Erectus and neanderthal fossils

Out of Africa:

long coexistence of H. Erectus and sapiens in some places

Only African fossils show full transition of types

mtDNA suggest African ancestor 200kya

Greater genetic diversity in African humans

DNA for neanderthal remains in Europe genetically very different from modern day Sapiens