A reminder from SARS-CoV-2

Provoking nature beyond a point can lead to unimagined and irreversible consequences for human beings

Viruses are one of the most persistent and potent forces of evolution, writes Pranay Lal in his new book, Invisible Empire: The Natural History of Viruses. As SARS-CoV-2 has shown, a virus is a force to be feared. “Everything about viruses is extreme, including perhaps, the reactions they evoke,” says Lal as he profiles this abundant life form with the help of photographs, illustrations, anecdotes and paintings. An excerpt from the book:

Much as we baulk at the idea, we are not unique. The human species, like all other living things, is an amalgam of creatures pieced together, gene by gene, and passed down by different life forms over deep time. Our genes were handed down to us from our ancestral ape, monkey, pig, shrew, gecko, fish, worm, grass, moss and bacterium, with several other creatures in between. Without genetic mutations, there would be no humans or, for that matter, any other life form that we see around us. These mutations — tiny errors in replicating the genetic code — occur randomly each time a cell (or virus) makes copies of itself, thereby becoming the starting point for an unexpected evolutionary journey. A very tiny number of mutations successfully create variation in a population. Natural selection then amplifies traits and creates variants which eventually can evolve into distinct species. These changes could be anything that confers an ability to thrive better in an evolving environment — blending a chameleon more effectively into a forest that is drying up; extending the necks of okapis and gerenuks so they can more easily nibble on the overhanging foliage of tall trees; or simply helping microbes evade a strong immune response and allowing them to attach themselves to a cell.