Context:
Studies show that we, Human Beings (Homo Sapiens) have inherited regions of host genomes from Neanderthals, which are an extinct species of hominids that were the closest relatives to modern human beings, that increase the risk of getting severely ill and protect against the SARS-CoV-2 virus.
Relevance:
GS-III: Science and Technology (Genetics and Biotechnology), Anthropology
Dimensions of the Article:
- Modern humans
- Did Neanderthals compete with us Homo sapiens, or was there cooperation?
- What are Neanderthals? More about Human Evolution
- Findings of recent studies regarding Covid-19
Modern humans
- ‘Modern’ humans have populated the earth from long before the Iron Age, for some 300,000 years, cohabiting Mother Earth along with other pre-human hominins.
- Because bones of one of these ‘others’ were first discovered in the Neander valley, just east of Dusseldorf in Germany, they were called ‘Neanderthals’.
- This hominin arose about 430,000 years ago and did not evolve in Africa, as Homo sapiens did. Early humans first encountered them when they migrated out of Africa.
Did Neanderthals compete with us Homo sapiens, or was there cooperation?
- Answers to such questions have come, one fragment at a time, from studies on the genetics of populations from Asia and Europe in places where migration brought the two species face to face.
- ‘Modern’ humans interbred with the locals in these regions. Recently a thigh bone of such a cross-bred individual became available.
Example of Interaction:
- A more recent genetic analysis of one set of samples from the region showed that Neanderthals came to the Bacho Kiro cave in Bulgaria first, more than 50,000 years ago and left their stone tools.
- Next came modern humans in two or more waves, and littered the cave with beads and stones about 45,000, and then 36,000 years ago.
- Genome-wide data of three human males who lived in this cave 45,000 years ago show that all three had Neanderthals in their family lineage, from just a few generations ago.
- This clearly showed that the modern human population in that region had interbred with the ‘locals’ and produced a cross-bred group of people – modern with Neanderthals.
- This cross-bred group had 3.4%–3.8% Neanderthal ancestry (in modern non-Africans it is about 2%).
Genetic connections
- Tracing the genetic lineages of the findings in the Bacho Kiro cave in Bulgaria, it is somewhat surprising that no traces are to be found among today’s Europeans.
- However, the three human males who lived in the Bacho Kiro cave 45,000 years ago are connected to present-day East Asians and Native Americans.
- The descendants of these Eurasian cave dwellers appear to have packed up and moved eastward, finally enduring the hardship of crossing an ice-age Bering Strait into the Americas.
What are Neanderthals? More about Human Evolution and Findings of recent studies regarding Covid-19
Click Here to read more about Neanderthals, Human Evolution and connection with Covid-19
Conferring immunity
- Further studies on the genomes of the Neanderthals themselves allow a comparison with those of modern humans and give us a glimpse of the genetic changes in the DNA sequences of the two.
- The chunks of genomes inherited from Neanderthals were whittled down to 2%.
- Having adapted to colder regions for 400,000 years, the Neanderthals gave us out-of-Africa humans variations in skin and hair colour better suited to the cold, as well as adaptive variants for metabolism and immunity – to help better adjust to strange new food sources and to unfamiliar disease-causing viruses in the new environment.
-Source: The Hindu
