Denisova hominins
Denisova hominins or the Denisovans are archaic human subspecies, presently extinct, that thrived across the lower and middle Paleolithic, presently in the Asian region. On the other hand, the Neanderthals, or the Homo neanderthalensis are an archaic human subspecies that thrived around 40,000 years ago in the Eurasian region (Rogers, Bohlender & Huff, 2017). They were subjected to extinction as a result of competing with or by being exterminated by modern human beings, diseases, or changes in climate. It is still not clear when these groups of living things made their split from the present-day humans, but they were being depicted as being brutish, stupid and primitive o the early 20th Century (Sankararaman et al., 2016).
With a view of understanding the success of the evolution of modern humans, it is vital to make an in-depth comparison of their genetic composition with related organisms and not just through understanding the fossil records. Due to the long distance between the chimps and human beings, the closest organisms to modern-day humans are the Neanderthals. It was suggested that about 20% of the DNA belonging to Neanderthals were survived in modern humans, usually being expressed in the diseases, hair and the skin of the modern-day people. The other closely related Denisovans came to be known due to their DNA. Therefore, the study of the mitochondrial genomes has proven to provide us with a catalogue of derived amino acids that is preliminary to all the species, giving us clear evidence of these three lineages. The genomes further give us additional gene flow evidence between the three lineages after modern humans changed human evolution since the time they left Africa.
According to the ancient DNA sequence, the Neanderthals came to be known as being from a clade that was different from the modern humans, as well as being different from humans in about four times as much as the humans were different from each other. The mitochondrial DNA is very ideal in the sequencing from the fossil materials as it is abundant as compared to the DNA in the nucleus. On the other hand, the Denisovans are Neanderthal sister group that is closely related, as the data from mtDNA shows. The Denisovans were living in the Siberian Denisovan Cave and were generally observed as having haplotypes that were not related to the modern humans and the Neanderthals. They, therefore, diverged from the Neanderthals and modern humans around 1 million years ago.
Ancient DNA has largely helped in the clearer understanding of the Denisovan and the Neanderthal demographics, as well as making out their history and their size. The Neanderthal genomic data indicated that their numbers were very small as they were nearing their extinction. These two groups had also a small group due to their deleterious genomic variants that they were carrying. These demonic variants were mainly deleterious as they were located in the regions of protein-coding in the genomes, therefore causing a change in the sequence of the amino acid in the proteins when the change in the sequence of genomic sequence changed. Any change in the amino acids ultimately affects the change in the protein sequence by the amino acids. The other reason for their low population was the low levels of heterozygosity, the number of genes in a genome consisting of more than one variant.
The sequencing of archaic genomes has enabled us to learn about our evolution, and not just about Neanderthals and the Denisovans. The human genome was only compared to the ape family, for identifying derived genomic changes between the chimps and humans. The genomes from Denisovans and Neanderthals were important in providing new and crucial samples for comparison to note the deviations unique to modern humans after the separation from these common ancestors. By so doing, genetic variants that were as a reason for our success have been identified. The genomes from Neanderthals and Denisovans have further given proof of interbreeding and interactions with humans. The data derived showed the process of gene flow from these two groups into the human populations, between the Denisovans and Neanderthals as well as from humans into the