Fortunate Flaws in Evolution
Once upon a time, 500 million years ago, the amphioxus, a jellyfish-like spineless creature (see photo) who lived at the bottom of the ocean, experienced two successive DNA doublings, instead of just one doubling. This “flaw” in the usual way in which DNA is replicated and transmitted is what eventually led to the evolution of humans and other vertebrate animals. This latest scientific tale trumps the common place, and misled, notion of “evolution” as something teleological, and replaces it with an understanding of evolution as a process of mutations and creative adaptations—even, accidents—whether fortunate or fatal.
Organisms that reproduce sexually typically inherit two copies of their genome, one from each parent, but what happened at this ancient breaking point is that somehow, the invertebrate animal inherited twice the usual number of genes. Moreover, in the next generation, the error repeated itself resulting in another doubling of the number of copies of each gene.
Many of these duplications were very unstable and therefore, they were lost quickly, long before humans evolved. However, some of these genome duplications survived and thrived—and thus we are currently carrying around Cambrian Age genomic patterns.
It is these same ancient DNA doublings which are the cause for the excellent intra and intercellular communication systems in the human body. However, it is when these advanced communication systems break down that diseases like diabetes, cancer and neurological disorders occur—and these breakdowns can be traced back to these genome duplications from the Cambrian Period.
The exciting news is that looking at these early genetic events could shed light on the nature of human and animal evolution (on a meta level) while also practically helping us to understand the true roots of these prominent diseases.