The NOVA series “Becoming Human” describes the discoveries of several different
ID: 50506 • Letter: T
Question
The NOVA series “Becoming Human” describes the discoveries of several different fossilized remains found in Africa of human ancestors. These discoveries are changing the way scientists think about the evolution of our species from ape like ancestors. It is becoming clear that the earth and specifically the African rift valley, a few million years ago, was going through severe climate changes. In part II there is new evidence about when humans became essentially hairless and the selective advantage for this change.
For your post, choose one of the discoveries above, (bipedalism, or brain size, or hairlessness, or relationships with neanderthals) and describe the selective pressures found in the environment that might have contributed to its development. Do some additional research on the web to determine if the views presented in this NOVA series regarding the trait of your choice are supported by other scientists or do other scientists disagree. Moreover, can you see any parallels or lessons that relate to the climate changes we see right now and the future of human evolution? Finally, comment on whether the research presented in this NOVA series changed your view of the theory of evolution. Does it provide further support for the theory or does it call into question the validity of the theory as a whole?
Can you please help me? Thank you so much!
Explanation / Answer
One of the discoveries and selective pressures associated with it are:
Bipedalism-
1. One of the oldest theory for bipedalism includes the advantage of being capable of carrying food or other portable items over long diistances
2. When forests receded due to environmental changes, humans started to move to savannas which had tall grasses and humans needed to stand up to see over these grasses which helped in survival.
3. Forelimbs were freed for foraging
4. Bipedalism allowed humans to realize the use of hands. They started using hands for tool usage or protecting themselves.
5. Bipedalism allowed for long distance running and walking in an energy efficient manner.
6. It is also considered an adaptation to cool body in hot temperatures in savannas. Sanding up helped expose less surface area of body to sun and heat and also allows for more heat to escape from body sides.
The view of the scientists varied with the trait or discovery proposed. Some were positive about it while others simply rejected it.