1. Evolution
A “Human” Perspective

2. Human Evolution
Human evolution began about 60 million years ago with the earliest primates: mammals with long snouts, sharp teeth and large eyes who lived in trees and fed on insects.
Three distinguishable traits evolved:
Flattened molars to eat plants
Grasping hands with opposable thumbs
Forward directed eyes

3. Primate Phylogeny
About 30 to 40 million years ago humans evolved into prosimian and anthropoid organisms
Prosimian  large eyes, nocturnal, long tail (lemur)
Anthropoid  diurnal, feed on fruits and leaves, enlarged brain, social groups and care for young (monkeys, apes and humans)

4. About 25 to 30 million years ago the anthropoid lineage split into
Old World monkeys  arboreal and ground dwelling, close together nostrils and tails are not prehensile (macaque, baboon)
New World monkeys  migrated to South America and evolved in isolation, exclusively arboreal, widely separated flared nostrils and prehensile tails (tamarin, spider monkey, howler monkey)
hominids  most are ground dwelling, longer front limbs than hind limbs and larger brain size relative to body size, no tails (orangutans, gorillas, chimpanzees and humans)
Humans (genus Homo) share a lot of traits with homininia
Bipedal motion (wide pelvis & curved vertebral column), enlarged brain, complex language, construction and use of complex tools.
Primate Phylogeny
Olive baboon
Southern Muriqui or wooly spider monkey

6. Emergence of Humans
Without fossil records Darwin linked apes to humans and that fossil records to prove it would be in Africa.
Hominina clade has many branching lineages and related species
Hominina  humans and other extinct members of their lineage arising from the most recent common ancestor that humans share with apes.
Australopithecines  6 different species between 4.2 and 1.0 million years ago. Generally a group of extinct hominids closely related to humans.

7. Emergence of Humans
As more fossils are found paleontologists attempt to put together phylogenetic tree for humans.
Homo genus  Africa, mya
H. habilis – mya, used tools, possibly speech
H. erectus about 1.9 million years ago and used stone tools and fire. Rounded head and smaller teeth…more like current human features. Definite speech. H. erectus moved out of Africa into Asia and Europe.
H. erectus  H. neanderthalensis and H. sapiens about years ago.
H. sapiens first appeared in Africa years ago and H. neanderthalensis was already living in Europe and Asia

8. Emergence of Humans

10. Competing Theories
Multiregional Hypothesis  anatomically modern humans evolved in parallel in a number of places (Africa, Europe, Asia). Gene flow accounts for them not becoming distinct species.
Regional genetic diversity arose due to regional selective pressures over about 1 million years.
Monogenesis Hypothesis  H. sapiens evolved only in Africa and then migrated displacing Neanderthal and other H. erectus populations.
Regional genetic diversity arose in humans with the past to years, that is, since H. sapiens left Africa.
Homo sapiens vs. Neanderthals

11. Competing Theories

12. Did we come from Africa?
If this is true then there should be the greatest amount of genetic diversity there within our genes. The research backs this up. On a highly variable region on chromosome 12 there were 24 different versions discovered: 21 from African populations, 3 in European populations and 2 in Asian and Australian populations.
Similar idea with Y chromosome variability  there is more variability in Y chromosomes from Africa.

13. Did we come from Africa?
It has been found that there is greater genetic diversity among Africans than among Eurasians, and that genetic diversity among Eurasians is largely a subset of that among Africans, supporting the 'out of Africa' mode
African populations have been located in Africa longer with more people so there is more genetic diversity as a result.
Populations that migrated did not have as many people therefore there is less genetic variability in other areas of the world.