Patterns in the Fossil Record

Science Daily has a post on research about patterns in the fossil record that comes out of the Santa Fe Institute.  They write:

Throughout life’s history on earth, biological diversity has gone through ebbs and flows — periods of rapid evolution and of dramatic extinctions. We know this, at least in part, through the fossil record of marine invertebrates left behind since the Cambrian period. Remarkably, extreme events of diversification and extinction happen more frequently than a typical, Gaussian, distribution would predict. Instead of the typical bell-shaped curve, the fossil record shows a fat-tailed distribution, with extreme, outlier, events occurring with higher-than-expected probability.

While scientists have long known about this unusual pattern in the fossil record, they have struggled to explain it. 

Now, at last, there is something of an answer.

“Within a lineage of closely related organisms, there should be a conserved evolutionary dynamic. Between different lineages, that dynamic can change,” says [Andy] Rominger. “That is, within clades, related organisms tend to find an effective adaptive strategy and never stray too far. But between these clade-specific fitness peaks are valleys of metaphorically uninhabited space. It turns out, just invoking that simple idea, with some very simple mathematics, described the patterns in the fossil record very well.”

Sometimes, it just pays to rethink something from a different angle. This may open up doors to understanding other patterns in the fossil record.