Saturday, April 21, 2018

Relentless Evolution

We modern humans are the products of 3.6 billion years of evolution, governed by genetic mutations, genetic recombination (through sexual reproduction) and the overriding process of natural selection.  Even among the global human population, differences have developed as tribes have adapted to their environment (e.g. darker skin in those native to the Tropics and more adipose tissue in those native to the Arctic region).

Today I came across an article in the New York Times which reports on a study from the journal Cell.  It describes an anatomic alteration present in the Balau people of Southeast Asia, a coastal culture that has long sustained itself by deep diving to spear fish and to collect mollusks from the sea bed.  Known for their ability to remain underwater for prolonged periods of time, members of this tribe were found to have enlarged spleens (an organ that is also enlarged in other diving mammals such as seals and which plays an important role in the diving reflex observed in all mammals).  Of particular interest is the fact that all Balauns have enlarged spleens, even those who do not engage in diving; this suggests that it is an inherited trait, emplaced by natural selection.  Researchers suspect that this diving culture developed as sea levels rose at the end of the Pleistocene, forcing islanders to rely on marine creatures for their sustenance.

Many humans, especially those inclined toward mysticism, believe that we humans are the pinnacle of creation, the Chosen Species.  In fact, we have evolved from other primates and continue to evolve.  Hundreds of thousands of years from now, if we have not destroyed our planet, we may well have evolved into a new species.