Expert: John Shea - 6/6/2011

Question
Dear Sir,

I’m a medical student at Alfaisal University and currently researching the field of human evolution and adaptation as a part of my course at the university. During my research I came along some questions that I still can’t find reasonable answers for it. I would be so glad if you could please help me answer the following questions:

1-   Science have showed that the human being have evolved from an ape-like creature that adapted to the external environments.  If this is true, who is Adam then? the Christians, Jewish  and Muslims belief in Adam as the first ancestor of man and that was clearly mentioned in the Christian bible, Hebrew Bible and the Quran by God, the creator. Who are these creatures that science believe they are the ancestors of man? Does that mean that Adam was an ape-like man?  Why are they considered ancestors of man and not other creatures, monkeys for example or just different types of apes that are extinct now?

2-   What explanation can you give for the 2-3 species of human ancestor that existed at the same time period and in the same geographical area along with the Homo sapiens that is believed to be the evolved version of its ancestors? (Doesn’t evolution occurs only when the parents pass adaptive genes to their offspring and over generations these genes become dominant throughout the whole population?) Doesn’t this prove the religious belief that these creatures do not belong to the human being and they are just different types of apes or they have adapted to the external conditions, but within their own species as an ape? (Exactly as the adaptation of the human beings now).

3-   Most of the fossils (of what’s considered to be the ancestor of man) shows that they are genetically very close to each other, except when  we compare them to the early Homo sapiens’ genome; there is almost a 2 % difference which is a very large amount of genes. This huge difference doesn’t exist between the other species within the genus Homo. What explanation can you give for this gap between them and the Homo sapiens?

4-    How can evolutionist sketch a model for the human ancestor from very few bundles of bones and skulls (sometimes partial skulls) and include the whole body? Can that be known from its genetic materials or are these models nothing more than predictions for the physical appearance?

5-   Who is the future man in another 6 million years time?  What’s the possibility that he can evolve in the future or is this the final version of man? What are the most changes predicted to occur in the human being? And why?  

6-   The pace of environmental changes (including the global warming) is increasing very rapidly compared to the pace of adaptation of the human beings, How will the human be able to overcome these challenging changes and survive in the upcoming years?

I hope answering these questions will not take a lot from your own time. I really appreciate your help and I would be so grateful if you could please provide me with the information as soon as possible. Thank you very much.

Best Regards,
Mohammad El Chami,

Answer
Dear Mr. El Chami
1. Adam is a mythological character from the origins stories of the ancient Hebrews,probably a metaphor for something that made sense 5000 years ago, but whose meaning has changed over the years.  He is a common feature or Hebrew, Christian and Islamic religious beliefs because the latter two religions incorporate the origins myths of the Pentateuch into their sacred books.

2. Those surviving contemporaries of Homo sapiens are not ancestral to Homo sapiens.  They are descendants of mutual common ancestors who lived much earlier in time.  Nothing in science can prove religious arguments.  The latter are, by their nature, claims about supernatural agency that cannot be falsified by scientific means.

3. The 2% estimate of genetic distance between ourselves and chimpanzees is based on different standards of comparison than the ones between living humans and DNA from recent hominin fossils.  We have DNA from only a small number of recent Homo sapiens and a few Neandertals.  Neandertals are considerably more different from us than any living human is from any other living human.  The are also deeply divided among themselves (phylogeograpy).

4. Reconstructions are based on principles from comparative morphology. This is a very complex subject and beyond my expertise.  However, we are beginning to get a better idea about how some particular skeletal morphologies are influenced by genetic variation.  This research is called "evolutionary development" in English.  A good example of this work in anthropology is Daniel Lieberman's (2010) Evolution of the Human Head.

5. This is impossible to answer scientifically -nobody knows and nobody alive will ever know.

6. Humans are pretty good at modifying their behavior in response to climate change.  The only problem with recent change is that there are a lot more people around.  A human population of 1 million would have no problem coping with modest global warming.  They could just abandon the equatorial regions and cluster around arctic and antarctic until the next Ice Age got going.  But, when you have 7 billion people, many of which are irrevocably tethered to urban centers, you don't have that kind of flexibility.  Short answer: We'll handle it. There will be fewer people around, but  in the near future, there will still be people.

If you are new to studying human evolution, two good books to get you started are Clive Finlayson's The Humans who went Extinct and Peter Andrews' and Christopher Stringer's The Complete World of Human Evolution.
My best wishes for success in your studies.  
Sincerely,
John Shea