COVID-19 connection with Neanderthal Genomes

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 (Biotechnology)

Dimensions of the Article:

1. What are Neanderthals?
2. Human Evolution
3. Findings of recent studies regarding Covid-19

What are Neanderthals?

• Neanderthal, (Homo neanderthalensis, Homo sapiens neanderthalensis) are a member of a group of archaic humans who emerged at least 200,000 years ago during the Pleistocene Epoch (about 2.6 million to 11,700 years ago).
• Neanderthals were replaced or assimilated by early modern human populations (Homo sapiens) between 35,000 and perhaps 24,000 years ago.
• Neanderthals inhabited Eurasia from the Atlantic regions of Europe eastward to Central Asia, from as far north as present-day Belgium and as far south as the Mediterranean and southwest Asia. Similar archaic human populations lived at the same time in eastern Asia and in Africa.
• Because Neanderthals lived in a land of abundant limestone caves, which preserved bones well, and where there has been a long history of prehistoric research, they are better known than any other archaic human group.
• Consequently, they have become the archetypal “cavemen.”

Developments regarding our understanding of Neanderthals

• Until the late 20th century, Neanderthals were regarded as genetically, morphologically, and behaviorally distinct from living humans.
• However, more recent discoveries about this well-preserved fossil Eurasian population have revealed an overlap between living and archaic humans.
• Neanderthals lived before and during the last ice age of the Pleistocene in some of the most unforgiving environments ever inhabited by humans.
• They developed a successful culture, with a complex stone tool technology, that was based on hunting, with some scavenging and local plant collection.

Human Evolution

Human evolution is the evolutionary process that led to the emergence of anatomically modern humans, beginning with the evolutionary history of primates—in particular genus Homo—and leading to the emergence of Homo sapiens as a distinct species of the hominid family, the great apes.

Stages of Evolution of Human:

• Dryopithecus
• Ramapithecus
• Australopithecus
• Homo
  • Homo habilis
  • Homo erectus
  • Homo sapiens
  • Homo sapiens neanderthalensis
  • Homo sapiens sapiens

Findings of recent studies regarding Covid-19

• A region on host chromosome 3 acts as a significant genetic risk factor towards getting seriously ill and, at the same time, a group of genes on chromosomes 6,12,19, and 21 protect us against the virus.
• About 50% of South Asians carry the region in chromosome 3 from Neanderthal genomes, the same region that makes us more prone to getting severely sick with the virus.
• A part of host chromosome 12, previously shown to protect against the virus, also was inherited from Neanderthal genomes. Nearly 30% of South Asians bear the chromosome 12 region.
• While specific genes from Neanderthals are working against the virus and protecting us from getting a severe disease, others are associated with an increased risk of getting critically ill. This push and pull effect may be one of the intriguing facts about how the selection of genes happens during evolution.

-Source: The Hindu