1. Transition animal / human
The human is a communicating animal, but it is an animal.
The transition from animals to humans should be simple, yet it is almost impossible to achieve it peacefully. So we need a bit of insolence.
Subsequently, we use the term “human” to speak of the homo genus, and not to speak of homo sapiens for example.
The homo genus is part of the tribe homini which also includes the pan genus (chimpanzees), this tribe is included in the subfamily Homininae, of the family Hominidae of the superfamily Hominidea of the order Primate of Mammals…
This image comes from Wikipedia.
Recent studies have yielded troubling results, where the exact sources are never quoted accurately. However, these results are almost the same everywhere, from a very mysterious study.
They are as follows: 98.7% of the human (no details about origin) genome is identical to that of the chimpanzee, which means about 40 million nucleotides of about 3 billion are different. Another study, still mysterious and a little more recent (2006) cites 96%, indicating that the new percentage would reflect the missing details in the first, while another (2007) also cited 93.5% with the macaque.
Note that the Y chromosomes of chimpanzee and human (unspecified) are particularly different (30%) compared to the rest of the genome.
That is all for the chimpanzee who, is our closest “family”, even though some would say it’s the Bonobo…
As for what we consider to have been species of the genus homo through the ages, you will find a list here: http://fr.wikipedia.org/wiki/Homo.
I will speak only about those that concern us.
That is to say, for now, homo sapiens and homo neanderthalensis. We will review the studies about them, and try to solve the problems we will meet in light of the conclusions previously established.
Former analysis (started in 1997) on mtDNA comparison of homo sapiens, homo neanderthalensis and the chimpanzee, show little difference in mtDNA in modern humans (all origins), which suggests that the mtDNA of modern human comes from a small group of original individuals, it is there the famous “Out of Africa” theory comes from.
It is the same among Neanderthal, who also shows little differences in the mtDNA of different individuals, that also suggests that the mtDNA of Neanderthals comes from a small group of some individuals, distinct from homo sapiens because both mtDNA – at least on the test cases – do not overlap.
In chimpanzees, the differences in the mtDNA of different individuals are more pronounced. It was concluded – rather quickly – to this that Neanderthal and sapiens were not mixed, and that modern human, from all origins came from this small group of humans from Africa. That, since mtDNA of Homo sapiens and Homo neanderthalensis is too different.
Recent studies affect the genome, ie, nuclear DNA, of whom we call “modern human”, and Neanderthal.
These studies give completely different results. In short, modern human shows that, relative to its origins, 0-4% of its genome comes exclusively from Neanderthal. This is where « the numbers war » begins. We will base our study on this analysis, and that is why it is not very important to speak about details now, but if you read the press on the results, you can see titles like “Neanderthals and Sapiens were mixed but the neanderthal genes is a small part of human genome since it is only 1 to 4%.”. Well no, 1-4% of the genome derived exclusively of the Neanderthal human is a huge percentage, and even disturbing, because it represents about … all the margin of the homo genus. This means in other words that people with 4% of genes that are exclusively Neanderthal are more Neanderthal than Homo sapiens. But no one will tell that, because the 4% are European, and the 0% are African, and then the whole theory is to review and in addition the results are terribly embarrassing.
Thus, some other articles, perhaps more honest, will tell you that our (whose?) Genome is 99.7% identical to that of Neanderthals. Indeed, it takes a different way, but these articles will avoid to talk about the 0-4% at the same time, or, with different and very imprecise words, and more and more articles shows the study as a bad news: “This sequencing has to duplicate the genome and comparing it to ours (whose?), they found that 99.7% of the Neanderthal genome was identical and that 1-4% of our DNA would come from Neanderthal. “
Let us finish this introduction with a video. (11.01.2011):