A Random Influx of DNA from a Virus Helped Vertebrates Become So Stunningly Successful | Scientific American

This article on the sudden evolutionary appearance of myelin quotes Robert Gould, an MBL Society Member and former Whitman scientist.

Charles Darwin proposed that evolution is driven by gradual variations in organisms that have a survival advantage in a changing environment. But University of Maryland evolutionary biologist Karen Carleton says that scientists have long grappled with the quandary that “evolution can happen abruptly, as described by Steven Jay Gould in [the theory of] punctuated equilibrium.” The question has always been: How does this happen?

A case in point is the sudden appearance of myelin, the multilayered sheath on nerve fibers that transformed the way neural impulses are conducted and turbocharged the transmission speed of these impulses. Myelin appears suddenly in vertebrates, animals with backbones that arose 500 million years ago. Not a trace of it is found in the ancestral line that preceded the arrival of vertebrates. A new study in the journal Cell provides an answer to this long-standing puzzle: the genetic instructions to make myelin were slipped into our vertebrate ancestor’s DNA by infection with a virus. Read more here.

Source: A Random Influx of DNA from a Virus Helped Vertebrates Become So Stunningly Successful | Scientific American