Primate and Human evolution

Chapter 16

I. Primate OriginsA. Primate –a group of mammals that includes

lemurs, monkeys, apes and humans.

B. Primates all have the following characteristics:

1. Opposable Thumbs

a) for holding and grasping

2. Binocular Vision (2 eyes in front of head)

a) Allows for depth perception

3. Large brain volume

4. Flexible arm joints (shoulders and elbows)

5. Feet that can grasp things

Various Primates

Lemur

Chimpanzee

I. Primate EvolutionC. Similarities among the groups of primates

suggest that they share an evolutionary history1. Similarities include

a) Fossil evidenceb) Anatomical c) Geneticd) Biochemical (DNA)

D. Humans did not evolve from monkeys, but they do share ancestors.

I. Primate EvolutionE. Classes of Primates

1. Strepsirrhines-small, large eyed, nocturnal primates

a) non-human likeb) date back to 50 myac) includes lemurs, lorises, pottos, galagos

2. Haplorhines-primates with larger brains and more upright posture than strepsirrhines

a) Consists of tarsiers and anthropoids

II. Anthropoid EvolutionA. Anthropoids – Human like primates

1. Includes old world monkeys, new world monkeys, and homonoids

a) New world monkeys 1) Prehensile (grasping) tail – acts as a

5th limb for gripping and climbing2) Spider monkeys and marmosets

b) Old world monkeys 1) No prehensile tail2) Colobus

monkeys and baboons

worldwide distribution of the monkeys

II. Anthropoid Evolutionc) Hominoids

1) Even more human-like, walked upright on two legs

2) Evolved 5-8 mya3) Includes apes and humans

a) Apes include chimps, gorillas, orangutans, gibbons and

bonobos

PRIMATES

A. Anthropologists suggest that the evolution of ancestral hominids occurred in response to environmental changes that forced some ancestral apes to leave their treetop environments and move to the ground in search of food.

III. Hominid Evolution

III. Hominid Evolution

B. Other human traits that separate them from the apes and monkeys:

1. Larger brain

2. Bipedal

3. Bowl shaped pelvis for birthing young with larger brains

4. Curved spine (able to be more upright)

III. Hominid EvolutionC. Incomplete fossil finds of early human

skulls, in Africa, shows that early humans evolved only 1 - 2.5 million years ago.

1. Australopithecines – Early hominid (“southern apes from africa”)

a) Possessed both apelike and human like characteristics

b) Named her “Lucy”

III. Homonid Evolution

D. Then came Homo habilis (“handy man”)1. Large brains and the ability to use tools2. Evolved around 1.5 and 2 mya

E.Then came Homo erectus (“upright man”)1. larger brain and more human like brain

a) Fossils evidence indicates this group used fire, tools and lived in caves

b) Spread through Africa, Asia and into Europe before going extinct 300 000 – 500 000 years ago

F. Then cam Homo sapiens 1. Evolved about 100 000 – 400 000 years ago in Africa, the Middle East and Asia

2. Resemble homo erectus but have a much larger brain case (skull)

G. Neanderthals lived in Europe, Asia and the Middle East from 35 000 – 100 000 years ago

1. Skilled hunters, spoke a language and had religious views

2. Thick, heavy bones

III. Homonid EvolutionH. Cro-Magnons - A more modern type of

homo sapiens spread through Europe between 35 000 and 40 000 years ago

1. Identical to modern humans in many aspects

2. Did not evolve from neanderthals

3. Neanderthals were a side branch of homo sapiens

III. Homonid Evolution4. Fossil evidence suggests that

Humans have not changed anatomicaly for the last 200 000 years

The

End

possible evolutionary pathway for the evolution of homo sapiens