Where Do Genes Come From? Part 2: De novo Genes

Author: Bryan Moyers

Editors: Theresa Mau, Alex Taylor, and Kevin Boehnke

“The probability that a functional protein would appear de novo by random association of amino acids is practically zero.” ~ Francois Jacob, 1977

If you’ve ever gotten into arguments about evolution, you may have heard the argument that goes something like this: A new gene randomly forming is as improbable as a tornado blowing through a junkyard and assembling a working 747. The above quote by Francois Jacob shows that scientists have been pretty skeptical about this idea, too.

But something seeming unlikely doesn’t mean that it doesn’t happen. As we learned last time, most mutations are harmful, and most gene duplications are lost—but the rare times when they are beneficial, a new gene can have a huge effect on species survival.

So, is it possible that a protein-coding gene might form randomly? Continue reading “Where Do Genes Come From? Part 2: De novo Genes”

Of Sporks and Scorpions: Where Do Genes Come From? (Part 1)

Author: Bryan Moyers

Editors: Theresa Mau, Alex Taylor, and Kevin Boehnke

What exactly separates us from other animals?  For that matter, what makes any species or group of species special?  How is life so diverse?  How can cephalopods camouflage themselves so well, and how did platypuses become so bizarre?

Part of the answer is in genes.  Genes are sections of DNA that perform a specific function, usually after being translated into proteins by special cellular machinery.  Every species has genes that code for proteins, but different species have different numbers of genes. Humans have around 20,000, fruit flies have around 18,000, and the tiny water-flea has around 31,000 genes. Different sets of genes produce animals with different structures and functions.

Continue reading “Of Sporks and Scorpions: Where Do Genes Come From? (Part 1)”