Even though the Neanderthals became extinct approximately 40,000 years ago, some bits of their Dna still can be found in modern human genome. It´s believed that those little traces of DNA are disappearing from the human genome by natural selection and this is due to a larger mixing population (Humans) against a smaller population (Neanderthals). Although, Neanderthals interbred with people in the past, today their genes are more prevalent in the genomes of some world´s cultures than on others.
Neanderthals
This was a species in the genus homo that became extinct some 40,000 years ago.
They were stronger than modern humans and their average height was 160-168 cm (5.5 ft.) for males and 150-156 cm (5 ft.) for females. Fossil evidence suggests that the Neanderthals lived in Europe separately from humans in Africa. It was around some 45,000 years ago that modern humans and Neanderthals could have coexisted in Europe. This event could have introduced a disease that contributed to the extinction of the Neanderthals.
Natural selection
This refers to the capacity to survive and reproduce due to differences in phenotype. Scientists discovered that Neanderthal DNA sequences are being removed from the human genome at a slow pace. This is believed to have happened because the extinct species mixed with a larger population and created genetic variants that were wiped out.
Natural selection works in pro of those that are best fitted and numerous; that was the case in the humans that interbred with Neanderthals. Natural selection takes action against the genetic variants.
Extinction
It is thought that this species became extinct due to climatologic processes on earth, such as climate change. It´s also believed that they could have had violent conflicts with the largest human population then.
Another theory for their disappearance is that they were wiped out from the face of the earth due to absorption from interbreeding. Being classified as separate species from humans, they could probably have succumbed because of geological changes on earth and through the interaction they had with modern humans.
