A study on human DNA discovered that the modern human genome has very few traces of the Neanderthal DNA. Natural selection removed the Neanderthal DNA because of its deleterious variants. However, the same study implies that the Neanderthals might not have gone extinct, but were slowly assimilated into the modern human population.

Tens of thousands of years ago, modern humans who travelled from Africa met and interbred with the more archaic humans, the Neanderthals. The result is the modern man that we know today or the hybrid descendant of interbreeding among human species.

A study looked into modern human genomes with the main purpose of tracing the Neanderthal genes and where these genes are specifically located. The lead author of the study, Ivan Juric is an evolutionary biologist at the University of California in Davis.

The study was published last Tuesday, Nov. 8 at the journal PLOS Genetics. Juric and his team discovered that modern Europeans and Asians who have mated with Neanderthals may have inherited valuable Neanderthal mutant genes. These mutations bring health benefits like reducing inflammation.

However, another study discovered that the amount of Neanderthal DNA present in modern man outside of Africa is so minute, only 1.5 to 2.1 percent. A draft sequence was conducted on the Neanderthal genome and its results were published in 2001. This suggests that natural selection might be in play.

Juric said to LiveScience that modern humans and Neanderthal interbreeding produce descendants that carry DNA segments containing deleterious alleles, meaning potentially harmful mutations. Through the years, natural selection purged these deleterious genes thereby wiping out modern man's Neanderthal ancestry.

Scientists explain that this is how natural selection works. Weak genes are purged in favor of strong ones to ensure the propagation of the species according to Christian Science Monitor.

Do Neanderthals carry inferior genes? No, but their gene pool is much smaller causing mutations. Neanderthal's population size is far smaller than modern man. This results to inbreeding and consequently deleterious mutations.

Scientists suggest that if things were reversed and the modern humans have smaller populations, then modern man might bear a more angled face, brawnier bodies but still larger brains. Evidence suggests that they bury their dead and even offer flowers on the graves. Neanderthals may be archaic but unlike earlier human species, they are capable of having sentiments.