Lecture 2: The evolution of man
The lecture will be a brief recounting of the story of the evolution of man, based on fossil evidence and DNA studies.
The evolutionary sequence of the ancestors of man can be traced in a relatively small number of fossil remains. The fossil record of the evolution of man is incomplete and future retellings of this story will be somewhat different as more fossil evidence is discovered and as the insights from DNA studies expand. The bare outlines are however available and tell the story of a species separated from other primates in times that are geologically recent.
Our species, with increased brain capacity, separated itself from all other species in terms of capabilities and accomplishments, leading to dominance over other animal species and over the immediate environment. This trend has continued and has accelerated in most recent times.
As our knowledge of man’s ancestry and past history has increased we have become more aware that early man co-existed with other similar species, none of which was to survive much beyond the last Ice Age and into the post-ice Age times when man expanded outwards to populate much of the land surface of the globe.
Lecture Outline
1. The Fossil Record
2. The Fossil record of man
3, The Tree of life
4. DNA and Early Man
5. Primates
6. A timeline for man
7. Orrorin
8. Ardipithecus
9. Australopithecus
10. Homo habilis
11. Homo erectus
12. Homo heidelbergensis
13. Homo neanderthalis
14. Homo sapiens
15. Contemporaries of Homo sapiens
Denisovans
Homo floresiensis
Homo naledi
16. Out of Africa
17. Migrations from Africa
18. We come from mixtures
19. Summary
Concepts introduced in the second lecture:
- Earliest mammals go back to around 210 million years but only attained a more dominant role following the extinction of the dinosaurs 65 million years ago
- Man’s evolutionary history is dependent on rather few fossil finds and is subject to future revisions in light of new fossil finds and increasing insights from DNA studies
- Primates evolved from about 55 million years ago; man and chimpanzees shared a common ancestor some 6-7 million years ago
- A sparse but well studied series of fossil remains allows us to trace the evolutionary sequence of Homo sapiens and the migration of our species to populate the far corners of the globe
- A major factor in the evolution of man was a profound increase in brain size and complexity
- Our species has been around for 300,000 years, a tiny fraction of the history of life on Earth
- Man’s true dominance over all other animal species began late in the last Ice Age
- For the last 10-12,00 years man has truly become the master of the planet, and that mastery has increased with time as man’s capabilities have increased exponentially
We’ll explore the latter of these topics in the next lecture entitled The Cognitive Revolution.