Relics of Eden: The Powerful Evidence of Evolution in Human DNA [Paperback]

The focus of resistance to Charles Darwin's "dangerous idea" was, and remains, the place of the human species. Even in Darwin's time, most educated people could perceive how natural selection solved many of the issues of life Nature posed. Humans, however, were excluded from the process in the minds of some. The thought of humanity emerging from the African continent millions of years ago stuck in the craw of those who wanted our species to be something special. That reluctance to accept the human heritage is shown to be false by this fine volume. Daniel Fairbanks offers us an excellent overview of how humans came to be. In doing so, he utilises the firmest and most secure tool in science's kit. If similar physiology and the fossil record wasn't sufficient, genetic research has proven beyond doubt that our heritage rests on the primate lineages beginning in Africa thirty million years ago.

Early genetic studies demonstrated that the genome of chimpanzees and humans were strikingly similar. More recent work has examined those similarities in greater detail. The evidence shows how specific areas in the human and chimp genomes are often duplicated exactly. Fairbanks, after noting how DNA's structure has some deceptive tricks up its molecular sleeve, explains how these have been used to trace the links between apes and humans. There are "transposons", segments of DNA that "Cut and Paste" themselves to new locations. We have many of these, but they seem to have settled down to become analytical tools. There are pseudogenes, retroelements, introns and other characteristics which add to the researcher's analytical tool kit in making studies across species. Just one example, locating pseudogenes, has permitted mapping of the divergence of orang utans, gorillas, chimpanzees and humans. Many more such examples abound in this book.

He explains how our cells contain DNA segments "independent" from the main DNA molecule in the cell's nucleus. The little energy-providing mitochondria are the result of bacteria invading ancient cells and taking up residence. These supplied the larger cell with energy while the host provided shelter to these miniscule entities. Further, he shows how the Y chromosome, which determines if the human embryo will be male, has its own "markers" to trace changes. From this, he begins to match up the human and ape genomes in building his explanation of our roots. One of the more unexpected finds was the merging of two ancient ape chromosomes into one in humans. Apes have 24 chromosomes to humans 23. Fairbanks explains how we know the fusion took place by pinpointing the loci indicating it.

Perhaps the most gripping chapter of this book is "A Spectacular Confirmation". This segment resulted from the mapping of the full Chimpanzee Genome in a manner similar to the Human Genome Project. An excellent diagram portrays the two genomes together, with the similar and differing areas clearly mapped out. One of the first things the reader will note are the little arrows showing how some human and Chimp chromosomes are reversed relative to each other. He goes on to explain how natural selection can bring such inversions about and what, if any, impact they have.

Lest all this appear to be an overwhelming academic treatise, have no fear. Fairbanks' intention is to bring this information to the widest possible audience. He does so with an almost conversational style. That clarity is enhanced by the fine illustrations accompanying the text. Only rarely is he forced to recapitulate the eye-warping string of As, Ts, Cs and Gs making up your DNA. In so doing, however, he points to the significant segment and explains its importance. That wide audience, of course, includes the element of the population still resisting the idea of natural selection and how it works. In "When Faith and Reason Clash", Fairbanks demonstrates how the US "creationist" element is misguided in claiming that evolution by natural selection and their god cannot co-exist. He shows how misconception and sometimes outright chicanery have combined to mislead the US population into continuing to buy into the Biblical "creation" account at one level or another. It's interesting in this regard that while he addresses mitochondrial DNA and the Y chromosome, he fails to point out the "first couple" of the creationist Bible would have lived eighty thousand years apart according to that research. Given the title of this book and the audience he addresses, this might be considered a major oversight. In all, this is a highly informative book, free of polemical thrusts or deep philosophical concept. It's straight science, well presented and should end one part of the struggle over our roots. [stephen a. haines - Ottawa, Canada]

(from my amazon.com review)

Shubin's excellent work Your Inner Fish looks at human evolution from the perspective of paleontology and anatomy: how structures such as hearing and vision developed. Shubin shows how genetic material is such that implanting a mouse gene that triggers the growth of an eye into a fruitfly can trigger the growth of an eye--a fruitfly eye. So the basic building blocks help establish evolution. Fairbanks comes at human evolution from a different angle--genes and DNA. Where Shubin was out in the Canadian Arctic searching for fossil evidence, Fairbanks could work in a lab.

Fairbanks' interests lie in the DNA evidence: comparing human DNA with that of chimpanzees, orangutangs, and other animals. You'll gain a good understanding of transpons, retroelements, and pseudogenes, and how these can be used to analyze evolutionary processes: the evidence is as solid as fingerprints. The DNA makeup of the immediate common ancestor of both humans and chimpanzees, for example, can be deduced. Another interesting point that Fairbanks talks about is the using the diversity of current human DNA to determine human origins. The greatest diversity in the DNA of any species is at the point of origin. As people brought seeds, for example, to a new part of the world, they were bring mostly one strain--little diversity in the DNA. The greatest human diversity is in Africa: you can gather DNA and do not have to be in the field in Olduvai Gorge (the DNA work backs up Leakey's discoveries and work). Native American DNA matches most closely with Asians: this is further evidence for the land bridge and migration from Asia.

There are lots of diagrams of genes, DNA, and chromosomes to supplement a very well-written text. Fairbanks' work is a fine scientific complement to the field work of the Shubins, Leakeys, and others, and he makes a very compelling case.

One of the best things about this book is how concise it is. Fairbanks sticks to his aim and pulls it off spectacularly. The book is split into 3 main sections, so I will review them individually.

The first part of the book consists of genetic evidence for evolution and immediately proves the book to be worth buying. Each section is concise and easy to follow as he piles up the evidence, giving the feeling that he could have easily kept going on and on.

The next section should be unnecessary, but sadly, considering the overwhelming ignorance of creationists, is a necessity. It is here where Fairbanks addresses the issues of faith and science and again is adept at sticking to the point.

The book finishes with the appendices,of which there are 3. The first two are perfect for those who have gained an appetite for genetics from the first part of the book, or for those who considered the first section to be light reading. It is more technical than the earlier chapters and goes into more detail for some of the examples. The third and final appendix discusses the history of evolutionary theory and genetics and makes for interesting reading.

This book has already been suggested as an excellent companion to 'Your Inner Fish' though I would suggest anyone interested in evolution should buy this book.