The main idea of this book is that humans are not necessary that different from other apes and have a lot in common with everything living in their DNA. It also provides history of human expansion all over the world and elimination of all our close relatives like Neanderthals who left us a bit of DNA and a few bones to discover. Author contemplates on commonality of our DNA so we all have common ancestors from not that long a go, and meaningless of primitive division of humans into races and such. Finally the big point here is that evolution is continuing and future changes are not really predictable.
This book is about humans and their DNA. It discusses multiple humanoid species that existed in the past and then for one reason or another disappeared leaving ecological space for the one and only survivor specie – contemporary humans. It is also about our DNA history, its present and what future can bring to us via results of DNA research.
Part One: How We Came to Be
- Horny and mobile
This starts with evolution and continuously changing life forms, of which humans is just one example. Author then discusses rejection of usual tree like interpretation and proposes somewhat different graph:
Then he follows with discussion of DNA structure and how to read it into separate genes. After DNA author moves to human movement from their place of origin in Africa all over the world:
Author goes into a bit of details about archeological, paleontological, and DNA analysis methods for obtaining this information.
- The First European Union
Here author discusses European population and how it come to be from the time of Neanderthals, that where successfully disappeared by humans. There is interesting discussion of type of food our ancestor subsisted on based on our DNA’s enzymes production such as Amylase. Then author discusses impact of cooking that started some 300,000 years ago and invention of agriculture that practically led to wiping out hunter-gatherers. He provides supporting evidence including typical discussion of lactose tolerance and not so typical discussion of blond and red hair. Author looks in some details on DNA make up of British Islands’ population and impact of plague. He ends chapter with the note about slow tempo of human advancement out of Africa, which was slow enough to provide time for evolutionary development of DNA differences. The evidence discussed consists of DNA variances and different cultures, such as Clovis, identified by tools used. The inference is that all Native Americans Indians are genetically close enough to confirm the idea of movement via Bering when continents were connected.
3 These American Lands
This chapter starts with Viking and Columbus, and then quickly moves to American Indians and how they get here. For some reason author discusses contemporary method of joining Indian tribes in USA retelling Navasupai story. At the end of chapter author points out that Americans, as nation of immigrants, have all kind of DNA mixes and discusses a bit his own family DNA.
- When We Were Kings
This is about impossibility of pure DNA because of geometrical progression of ancestors: 2 parents, 4 grandparent and 2100 for 100 generation, which is something like 2500 years – clear impossibility. The inference is that we all relatives and math confirm that it is correct. Author then go into a bit of genealogical discussion and ends up with explanation of problems with inbreeding.
Part Two: Who We Are Now
- The End of Race
Author starts this chapter with his recollection of encountering some racist teasing as a child and then moves to DNA and the story of unsuccessful search for biological foundation for racism retelling story of Darwin’s cousin Francis Galton – founder of eugenics movement. Obviously there are lots of differences of characteristics between individuals of different races, but most important point is that they do not exceed differences between individuals of the same race, making the very notion of race meaningless. To illustrate this author discusses results of research of genetic grouping of people. This grouping starts with division of everybody into two groups and then expanding it to more and more groups. The result is unexpected when algorithm groups people by DNA in such ways that is completely different from their races. After that author discusses various genetic diseases and inclination such as alcoholism, concluding that genetic influence is greatly overstated.
6 The Most Wondrous Map Ever Produced by Humankind
This starts with discussion and betting by the group of scientists on DNA length in 2000 when it was in process of decoding. Everybody overestimated its length because the common notion was that genes have direct link to specific function of organism, when in reality it is much more complicated and it is rather: complex, environmentally dependent genes combination link to function. Now, decades after DNA decoding the huge progress was made, but we are still far away from complete understanding how this staff works. Author discusses “genome-wide association studies” (GWAS) that seek to establish understanding of diseases by analyzing genome association of multiple people with the disease. He also discusses twins’ studies that demonstrate that link of DNA and some disease is not really simple and direct.
This is about link between genome and crime and other behavioral problems. As example author uses MAOA – the chemical disproportionally found in individual with behavioral deviations. Nevertheless the link is complex and could hardly be defined as having causal character. The final part of the chapter discusses intergenerational transmission of environmental impact. It is done on very interesting case of consequences of mass starvation in Netherlands in 1944. The key here is that it is highly developed country with great levels of documentation of all events, including health histories over generations. The result is interesting because it does support suggestion that this artificial famine did have impact across generations. Finally author spends a bit of time discussing epigenetics that kind of brings back Lamarckian approach.
8 A Short Introduction to the Future of Humankind
The main point here is that future is already here including modifications to DNA. It happens via mutations all the time. Research demonstrated that the same gene checked in 6500 people has 1.5 million single letter mutations. Since there are billions of people in the world the much more complex mutations are bound to happen all the time. There is also phenomenon of the same functional changes due to mutations in different genes, which makes sense because few functions and features linked to one gene only. So we are good with variety, but the second part – selection is becoming mute because survival pressures are not what they used to be if one takes into account abundance of food, shelter and advanced medicine. Nevertheless author final conclusion is that humanity is still in process of evolution because evolution is change + time and neither of this could be eliminated.
Author completes it with brief discussion of uniqueness of both species and individuals, which is created by constant recombination of bits and pieces of DNA present in millions of lives in the past so genome could be considered a history book without end and it would be read, reread, and updated for future as long as humanity exists.
MY TAKE ON IT:
So I guess it is not a big news that we are all relatives and have 99% common DNA. It is interesting how exactly humans moved around the globe and how much it could be traced in our DNA. Similarly it is obvious that there is no real scientific foundation for the notion of race because DNA variety within any race is higher that between races. I guess the problem is that DNA has little to do with cultural differences and human propensity to divide everybody into US and Non-US is more related to culture than to DNA. It is also interesting how author narrates impact of DNA decoding with unexpected number of genes: too few to explain features of human organism that eventually led to creation of new, supplemental to genetics field – epigenetics. I think that eventually it would open the new area of conscientious efforts to use epigenetics to improve development of young humans by creating individually designed environment with ability to control real impact by analyzing epigenetic changes. It would probably take a lot of time to move there, but result could be much happier people that we are now.