In chapter one of the Ancestor's Tale, Dawkins warns us to avoid two misconceptions which are
1. The historian is tempted to scour the past for patterns that repeat themselves.
2. Temptation is the vanity of the present: conceit of hindsight
Dawkins tells us to stay away from these misconceptions because to study evolution we must be convinced that there is no premeditation that has laid the path of evolution one way or the other in hindsight of the future. It's better to think that everything happens for a reason and doesn't happen to creat a future event.
In chapter two of the Ancestor's Tale, Dawkins explains human origin with concepts such as Y-chromosome Adam and mtDNA Eve. Y-chromosome Adam is known as the all-male line on common and mtDNA Eve is known as the all-female line ancestory. These two concepts are more traceable than genes in general. Scientists have determined the timing and history of human migration by using these two concepts. Evolutionary biologist Alan Templeton came up with a theory about our migration out of Africa called "Out of Africa Again and Again". He used a coalescence theory for lots of seperate genes instead of just one. Using this theory he concluded, by using 13 haplotypes, that there were not two major migrations out of Africa but three.
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Also remember The Ancestor's tale mentioned that they had multiple partners.
ReplyDeleteFor the resons you outline then, we agree that there are more challenges in knowing how many times we migrated out of africa.
ReplyDeleteKelly,
ReplyDeleteI politely disagree with you on the one point that you stated "It's better to think everything happens for a reason and doesn't happen to create a future". I believe that everything that has happened in the course in our universe, and planet Earth have existed for spontaneous reasons that as humans' we are just beginning to comprehend scientifically. I believe that our planet and solar system is like one huge chemistry experiment; and that whatever mixes (DNA or molecules) is spontaneous creation of evolution. I do agree with your one point in your quote that people shouldn't look to the past to believe that the earth and its inhabitants future are only going to be determined by past evolutionary changes in natural selection, etc... because as I believe everything is both shaped by the environment and its conditions, and on population dynamics.