Genealogy Books - The Journey of Man: A Genetic Odyssey

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Spotlight customer reviews:
Customer Rating:

Summary: Absolutely great
Comment: The book presents the author's lifetime experience in using genetic indicators to develop the
journey of mankind from 60,000 years ago from our ancestral home in Africa, to populate all the
continents. He explains all the science and discusses contrary theories, to preserve a sound base
of credibility. Numerous interesting contributory themes are also discussed, like the linkage of
genetic migrations to the development of language. Overall, it is highly readible and very
informative. I would highly recommend it for all those who wish to understand and appreciate our
worldwide human family.

Customer Rating:

Summary: The Journey of Genetics
Comment: The Journey of Man, recently recommended by a friend in Dallas, is a story of state-of-the-art
genetic research to trace the geographic history of homo sapiens based on, as I understand it,
polymorphisms or mutations in human DNA. The idea is that by identifying these and analyzing their
frequency of occurance in various areas of the world, the sequence in which they occurred can be
deduced and, thus, the associated physical path by which we populated the world can be identified.
The conclusion is that homo sapiens began about 50,000 years ago in north-eastern Africa, then
spread to Australia, etc. The thought process nicely ties in related data from archaeology,
anthropology, and other sciences to support and/or refute the genetic results. A very good book,
aimed at laymen and easy to read, although not particularly well-edited and sometimes over-uses
analogies to the point that you wish he'd just go ahead and say it.

Customer Rating:

Summary: Very interesting thesis, very readable
Comment: The book presents, based on genetic, archeological, climatological evidence, a possible (or
probable?) route for the dispersion of men through our planet, from its birth in Africa. The
evidence is clearly presented, in an organized and very understandable way. It makes a very
interesting reading on a subject that is as appealing as it is controversial.

Customer Rating:

Summary: The Journey of Man: A Genetic Odyssey
Comment: If you have ever questioned where Adam and Eve started and how planet earth was populated this is a
must read. Doctor Wells located the oldest Africans he could find,took blood samples, then using his
DNA knowledge, produced DNA markers. He continued this process around the world and by examining
the DNA markers he could determine the path of primitive people and where they started. He produced
a readable technical book that leaves the lay person with a clear understanding of where we started
and where and when the first Adam and Eve left the trees and stood up on two feet.
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Customer Rating:

Summary: Clear explication of a still uncertain theory
Comment: Not much more than 50,000 years ago, something happened in East Africa that set humans on the move,
and by about 10,000 years ago they had occupied almost every place on Earth, though it took another
9,000 years or so to get to the really good spots like Maui.
At least, that is how geneticist
Spencer Wells interprets the evidence. The very short time span requires severe revision of the
archaeological evidence.
Fully modern human bones have been found in Israel that are dated to
about 100,000 years ago. Although equally modern fossils don't show up in Europe for another 60,000
years or so, the assumption has been that man's move out of Africa began at least 100,000 years
ago.
Using changes in the molecular structure of the Y-chromosome, Wells and other geneticists
believe that something -- he calls it the First Big Bang -- happened to a human, who lived somewhere
in or near Ethiopia, around 50,000-60,000 years ago. That something did not show up in our skeletons
but did mark the final evolutionary step to our current level of ability.
It could have been
behavioral, although Wells is inclined to think it was some form of structural change in the brain
that was closely tied to the beginning of language.
The new capabilities then made it possible
to survive in novel habitats, and worsening climatic conditions in East Africa made it desirable to
find some.
Genetics tells us we are all very closely related -- there is hardly any variation
in our genes as between "races," a doubtful concept in human taxonomy anyway.
Variation piles
up over time, particularly in long stretches of DNA that are, so far as anybody has been able to
determine, inactive.
When a small band of people move, they take with them only a tiny
fraction of the total variation of their larger group. Therefore, the more variation today within a
local group, the longer it has been intact.
There is more variation on the Y-chromosomes of
the men in an African village than among all the men in the rest of the world. Therefore, humans
originated in Africa.
Geneticists believe they can not only measure but time these changes,
although the timing is dependent on various assumptions that are uncertain to a degree. The goal of
researchers like Wells is to interpret the gene sequences to fit other, paleontological or
climatological, data without torturing the evidence too much.
The Y-chromosome determines male
sex and therefore passes down from father to son. There is a strictly female record of descent in
our cells, too, the mitochondrial DNA; but there is much less of it, so changes on the Y give much
more precision in measuring mutations.
In "The Journey of Man," geneticists deduce that around
50,000 years ago, Africans started migrating, sticking to the coastal areas they already knew how to
exploit. Within 10,000 years, they were in Australia.
We humans spread quickly but not equally
quickly in every direction. In some areas, humans had to wait tens of thousands of years for the
slow processes of climate to open up desert and mountain barriers that were too hard to cross. />Thus, Europe was settled very late, despite its closeness to Africa.
The same evidence says
modern humans replaced Neanderthal humans; we did not descend from them.
The Y evidence also
tends to shoot down evidence -- already equivocal -- that put humans in the New World more than
about 12,000 years ago.
And it demonstrates, Wells says, some unexpected relationships. For
example, northern Han Chinese are more closely related to their northern neighbors than they are to
southern Han Chinese, despite the closer connection of their language dialects.
These various
lines of evidence should allow us to retrace our ancestral steps, says Wells, but "many indigenous
peoples are now refusing to participate in scientific studies."
He regrets this, not only
professionally, but because the Third Big Bang -- the transportation revolution that is mixing up
populations more than ever before -- will within a couple of generations obliterate the kind of
genetic sleuthing that made "The Journey of Man" possible.
The Second Big Bang was
agriculture, and that, he says, led humans to Hawaii. Hunter-gatherers had to go where the food was;
Polynesian navigators could choose where to sail.
Wells' explication of what researchers like
Wells think they know is first rate. I remain somewhat skeptical about the accuracy of the so-called
molecular genetic clocks. Therefore, 3 stars. if the doubts about the 'clock' are resolved in the
favor of Wells et al., then the rating would bump up to 4.

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