Reviewed by Maurice A. Williams
In Search of Lost Genomes
by Svante Pääbo
Basic Books (Perseus Books Group)
2014, ISBN: 978-0-465-02083-6, 275 pages, $27.99
I have always been interested in animals and anthropology. I was amazed when the double helix structure of DNA was discovered in 1953 and astounded when the human genome was mapped in 2003. Other than curiosity, I never followed these two discoveries until 2014, when I read Neanderthal Man: In Search of Lost Genomes announcing the discovery of the Neanderthal genome in 2010. This intrigued me. DNA is composed of microscopic minute chemical molecules embedded in soft, high-moisture tissue. I am amazed that anybody can detect its presence in living tissue, but if scientists say so, I’m sure they can. But detecting these molecules in fossilized bones really piqued my interest, so I read the book. I’m not versed in microbiology or in anthropology, so I wondered if I would get anything out of reading this book. Actually, I did.
Svante Pääbo does a good job explaining difficult concepts to the average reader. I could not grasp in detail how he did his work, but he explained it well enough that I understood it and felt comfortable with it. His book is not only a scientific treatise on his work in developing the genome of Neanderthal Man, it is also an interesting autobiographical account of his experiences in his career in anthropology and with the many scientists he worked with. He also includes some purely autobiographical detains about his life. His book is a very interesting read about a truly gifted man.
When the author was thirteen, his mother took him to Egypt where he picked up a life-long interest in Egyptian mummies. In 1981 the twenty-six year old Pääbo, while a medical student at the University of Uppsala in Sweden, became intrigued in the possibility of obtaining DNA from Egyptian mummies. He expected that would shed light on who the ancient Egyptians were and how they are related to present-day humans. He had the opportunity to test if he might be able to do this by experimenting on a piece of beef liver obtained from a local meat market. His procedure was to take a minute sample of the material he wanted to test and join it to a plasmid (a carrier molecule prepared from a bacterial virus) and introduce the plasmid carrying the foreign DNA into live bacteria where it would be replicated along with the bacteria’s DNA into hundreds or even thousands of copies of the foreign DNA. Success with calves’ liver launched him into his quest for the DNA of mummies.
After many failures, Pääbo realized that the Egyptian mummification procedures destroyed the DNA. So Pääbo shifted his interest to finding DNA in Neanderthal fossils. By that time, laboratory procedures and laboratory equipment had improved substantially, making a task that would have been extremely difficult with the primitive procedures he used on the calves’ liver much easier when he started on Neanderthal DNA. His quest for Neanderthal DNA began in earnest one night in 1996 when a graduate student working for him phoned him to say he succeeded in getting a sample of DNA from a Neanderthal arm bone, and it was not identical to human DNA. Encouraged, Pääbo decided to put maximum effort into investigating the DNA of this ancient prehistoric man.
In 1997, Pääbo received a golden opportunity when he was offered a directorship in the Max Plank Institute for genetics in Leipzig, Germany. He accepted and did his major work on Neanderthal genome there. Pääbo wanted one of the objectives of the center to answer the question “What makes humans unique?” This should be an interdisciplinary institute where paleontologists, linguists, primatologists, psychologists, and geneticists would work together on this question. Author opines It should be an institute in evolutionary anthropology.
Pääbo had begun his search for Neanderthal DNA with mitochondrial DNA, which is transmitted from the eggs cells of all mothers to their offspring. But there are in addition two much longer strands of DNA in the nucleus of each cell, one coming from the mother and a matching strand coming from the father. Pääbo knows that if he wants to get the complete genome, he must obtain DNA from the nuclei, so his quest now shifts to nuclear DNA, and he uses newer and vastly improved lab procedures and testing equipment like the rapid pyrosequencing machine (which is well described on The Internet) to rapidly sequence DNA. Pääbo finally publishes his paper on the Neanderthal genome at Vanderbilt University in Nashville in 2010, bringing the applause of whole scientific community to the fifty-five year old scientist for this extraordinary achievement.
There are two theories of the origin of humans. “Out of Africa” holds that all modern humans (Homo sapiens) migrated out of Africa. The other theory, “Multiregional”, holds that Neanderthals and other hominoids coexisted in Europe and other areas and modern humans evolved where they were, outside of Africa, rather than evolving only in Africa. Author and anthropologists right now (2014) understand only 10% of the human nuclear genome. Pääbo continues with a discussion of what is currently known about the human genome, the position of modern man in the ancestry of apes and humans, and some detail of the experimentation that investigates these positions.
Paleontologists can not agree on how to define the ancient groups they study. Some see many different species among human fossils, others see few. Most fossils we see in museums look like humans because thy shared ancestors with us sometime in the distant past, but they often have no direct descendants today and represent ‘dead-end’ branches of our family tree. Author states: In my enthusiastic moments, I imagined that the sequencing of DNA extracted from fossils would eventually do away with all this uncertainty.
Pääbo and his team have been administering intelligence tests to baby apes and baby humans. Until 10 months of age, there is hardly any difference in the apes and humans. But at around 12 months, humans do something apes do not do: they start to draw the attention of others by pointing. Soon they point at everything just to draw attention. This is the first cognitive trait to appear in children but not in apes. Also humans early on tend to imitate what their elders do, like expressions and mannerisms. Also human parents and other adult humans try to modify and teach correct behavior in the children to a much greater degree than apes do. In contrast, there has been almost no teaching observed in apes. Whereas apes must learn almost every skill through trial and error, without parental activity teaching them, humans can much more effectively build on the accumulated knowledge of previous generations.
The author thinks there is a biological substrate necessary for acquiring human culture, but he is also convinced that social input is necessary for the development of human cognition. Neanderthals appeared between 300,000 to 400,000 years ago and existed until around 30,000 years ago. Throughout the tens of thousands of years of their entire existence, their technology did not change much. Only at the very end of their history, when they may have had contact with true humans, does their technology change in some regions. And they did not migrate over open water to reach other shores.
I picked up on Neanderthal technology not changing for the 270,000 to 370,000 year duration of their existence on earth, whereas human technology has changed drastically in the past 100 years. I see that human technology and culture has changed at an unbelievably exponential rate ever since the beginning of recorded history some 6000 years ago. Even in my lifetime I see a phenomenal increase in human technology. Plus humans are the only physical life forms that cook their food and fashion clothes for themselves. I think something is missing when anthropologists compare humans to other life forms. I think there is a spiritual dimension to being human, something above the sum total of the molecules and genes that are built into the human body, something not composed of matter and not occupying space.
I observe humans being involved in things no animal has ever been involved in, like interest in the purpose of life and appreciation in art, music, exploring the universe. No animal does any of those things. Humans are also very heavily involved in considerations about what is right and what is wrong in human conduct and in discovering the ultimate truth about the world we live in. As far as I know, no animal has ever done any of those things and yet look at how much time and energy humans devote to them.
I’m very interested in learning the science of the world we live in, and I enjoy reading books like this one. I’m sure scientists will eventually arrive at the core of correct science about the world, but today, I think scientists are missing something. I think there is a spiritual dimension to being human; something that should be addressed if we are ever to understand what makes a human different from an animal.
About the reviewer: Maurice A. Williams is an author of inspirational articles and poems and has published a book: Revelation, Fall of Judea, Rise of the Church. Prior to his retirement, he was Director of Research and Development for a firm that did business all over the world. He has traveled to many countries himself. He is also author of technical articles in scientific journals and chapters in technical books. He has four children and six grandchildren, and lives at home with his wife. You can visit his Web Site http://www.mauriceawilliams.com