From John Hawks’s presentation that connected our species to that of Neandertal using genetic, fossil, and geographical evidence, I was able to draw connections to material we had covered in AP Biology. Like our gene sequencing worksheet that simulated the comparison of nucleotide base pairs among species, research of the same vein had been done with the chromosomes of Homo sapiens from different parts of the world and with the fully intact chromosomes found in Neanderthals. From this application of genetics, scientists were able to conclude that most humans have about 3% of Neanderthal in their genes, with the exception of Africans who had shared less commonality with Neanderthals.
This reminded me of allopatric speciation and Darwin’s theory of gradualism, which differs from Gould’s theory of punctuated equilibrium that suggests that species rapidly branch off from a common ancestor and remain evolutionarily stable for some time. Given that Homo sapiens were once able to breed and produce viable fertile offspring with the Neanderthals, as demonstrated by our crossing of genetic information, they were truly not separate species. When Hawks noted the comparable percentages of Neanderthal DNA in different ethnic groups, I thought about how the branching of the common ancestor between Neanderthals and Homo sapiens could have been caused by allopatric speciation. Because the early evolution of Homo sapiens took place in Africa and that evidence supports Europe as the hearth for Neanderthals, it made sense to me that their divergence from a common ancestor was the result of allopatric speciation. Perhaps groups of the humanoid ancestor moved away from each other and gradually acquired differences that led to the branching of Homo sapiens and Neanderthals. But this speciation was not complete, and when the African Homo sapiens encountered the European Neanderthals, they were still able to reproduce.
Another interesting component is how our common perception of Neanderthals is shattered by genetic research. Before, when scientists had only been able to analyze their bones, they made pejorative conjectures about their intelligence and behavior. These assumptions were largely incorrect as they interpreted their extinction as a result of unintelligence. Yes, they were less adapted to some environmental condition that caused their demise, however, they did show intelligence; Neanderthals communicated and crafted weapons and cooked grains. Additionally, Homo sapiens did breed with Neanderthals, suggesting that there was enough sustained similarity and bond for that relationship to occur and leave remnant in our genes.