1. Human Evolution

2. Topics covered in slide show
Two theories on how evolution occurs
Phylogeny and Cladograms
Fossil Record and its gaps
Human Evolution as determined from fossil record
Are we still evolving?

3. Types of Evolution Gradualism Punctuated Equilibrium
Both play a role in evolution

4. Gradualism
Most evolutionary changes occur over long periods of time (when enviro. Is changing slowly)

5. Punctuated Equilibrium
Major evolutionary changes happen relatively rapidly and then are followed by a long period of very little change (occurs when species are exposed to new or rapidly changing enviro.)

6. Phylogeny and Cladograms
Phylogeny -Evolutionary relationship between organisms
Cladograms -Diagram showing the evolutionary relationship of different groups of species

7. Cladogram

8. Evolution of Hominid Species

9. Fossil Record and its Gaps
In evolution, one of the key sources of evidence in fossils
There are gaps in fossil record
Gaps don’t undermine all the other evidence of evolution
Scientific investigations are continually filling these gaps

10. Human Evolution as determined from fossil record
There is a rich fossil record of human ancestors
Homo sapiens first evolved in Africa and began spreading our from Africa years ago
Key evolutionary characteristics of humans:
Bipedalism
Large brain
Fine manipulation with hands

11. Migration of Early Hominids

12. Continued…
Humans closest related living species is the chimpanzee (closest relative)

13. Are we still evolving?
Rate of human evolution has been greater over the past several thousand years than during the past few million years
Eg. Evolution of lactose tolerance
Evolution of infectious diseases (HIV) and human’s evolutionary responses are being studied
Artificial selection of plants and animals has caused human population to explode

14. Continued Understanding our evolutionary past has many benefits
In the past, taste for sweets and fats were beneficial
Darwinian medicine (use of evolutionary theory to understand medicine) is insightful into cause and spread of disease

15. Continued
We have evolved a brain capable of knowing how to obtain a sustainable future
We have the tools and freedom to direct our unknown evolutionary future

16. Reference
Biology 11 Nelson 2011

17. Questions Did we evolve from the chimpanzee? Justify your answer
Trace the migration of homo sapiens.
Does Cultural evolution affect biological evolution? Justify your answer.