I don’t usually front-page my mailbag entries, but I thought I would start doing it with a few: partly to remind myself to post them more often, and partly because some questions I really do get from a lot of readers, and I’d like to draw more attention to answers. Here’s a recent e-mail:
Hi Professor Hawks, I wondered if you could recommend any materials for people like myself who have a very limited knowledge of biological 'things'? I'm trying to 'prove' evolution as I must admit I 'see' design when I look at things like dna and how the cell works. I read a book by Ken Miller recently that presented a good case for evolution. He cited the example of the elephant and how the earliest 'kinds' of elephant were quite different physically to our modern elephant (smaller trunks and ears). I thought at the time, that this might only prove variation but not that the elephant was a different kind of animal. Dogs can vary wildly but are still dogs?? I wondered what main 'proofs' you would cite for evolution? One last question: is it possible to tinker with dna in say a chimp embryo and cause it to be more human? Sorry if that question is silly. This shows my ignorance. I'm supposing that now we have mapped our dna, we can reverse engineer back to say an ape? Couldn't a computer programme simulate this? If you programme in the chimp genome and the human genome and tell the computer to reverse engineer or forward engineer to meet each other? Is that a possibility? If yes, this would surely prove evolution. Many thanks in advance if you get the chance to reply. I'll understand if you don't.
Have you looked at the book, Why Evolution Is True, by Jerry Coyne? It provides a very good account of some clear examples of evolution. Also, you may be interested in some of Carl Zimmer’s work. His book, Evolution: The Triumph of an Idea is now a few years old but still a very good read. For a more rigorous treatment, he has a very readable textbook: The Tangled Bank: An Introduction to Evolution. I wouldn’t usually recommend that my blog readers turn first to the level of an academic textbook, but this one is well-written for the general reader. His recent book on viruses is also very good.
There’s a book I often recommend to people without a lot of biology background because it shows the interdependence of organisms in nature; The Ghosts of Evolution: Nonsensical Fruit, Missing Partners, and Other Ecological Anachronisms by Connie Barlow, covers plants surviving today that depended upon now-extinct animals like mammoths and dodos. This one also makes an interesting gift for parents who are interested in biology and evolution, but not looking for an academic course on it.
On your other question: In reality scientists can already “tinker” with the DNA of model organisms like mice in order to examine the function of particular genes. Already, there are many strains of mice who have been genetically engineered to express the human version of certain genes. However, doing this procedure on a very large scale, with many genes at a time, is presently not possible.
Understanding the effects of one genetic change, or a handful of genetic changes, is very complicated. At the moment, science is not capable of simulating the effects of many genetic changes across a genome. This is the direction we are going, as we try to uncover biological networks and their workings.
Good luck in your quest!