The always engaging science writer, Carl Zimmer, has an excellent piece at his Discovery Blog, The Loom, about the role viruses have played in the development of, and continuation of, the human species. From the piece:
We all started out as a fertilized egg: a solitary cell about as wide as a shaft of hair. That primordial sphere produced the ten trillion cells that make up each of our bodies. We are not merely sacs of identical cells, of course. A couple hundred types of cells arise as we develop. We’re encased in skin, inside of which bone cells form a skeleton; inside the skull are neurons woven into a brain.
What made this alchemy possible? The answer, in part, is viruses.
...Evolution is an endlessly creative process, and it can turn what seems utterly useless into something valuable. All the viral debris scattered in our genomes turns out to be just so much raw material for new adaptations. From time to time, our ancestors harnessed virus DNA and used it for our own purposes. In a new paper in the journal Nature, a scientist named Samuel Pfaff and a group of fellow scientists report that one of those purposes to help transform eggs into adults.
Read the entire fascinating piece at The Loom.
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