Scientists Reveal Evolution's 'Big Bang' Agrees with Darwin's Theory
Most modern groups of animals appeared between 540 and 520 million years ago. Now, scientists have learned a little bit more about what is called the "Cambrian explosion." They've pieced out the rates of evolution during that time and with the new findings have resolved "Darwin's dilemma."
When the evolutionary explosion occurred during this time, our planet was changed forever. The incident was arguably one of the most important evolutionary events after the origin of life. Yet these seemingly impossibly fast rates of evolution baffled researchers and have been exploited by opponents of evolution. Unfortunately, because the ancient fossil record is incomplete, there's been little in the way of hard evidence to show off how evolution's Big Bang took place.
In order to learn a bit more about the Cambrian explosion, the researchers quantified the anatomical and genetic differences between living animals. More specifically, they focused on arthropods, which include insects, crustaceans, arachnids and their relatives.
"It was during this Cambrian period that many of the most familiar traits associated with this group of animals evolved, like a hard exoskeleton, jointed legs and compound (multi-faceted) eyes that are shared by all arthropods," said Greg Edgecombe, co-author of the new study, a news release. "We even find the first appearance in the fossil record of the antenna that insects, millipedes and lobsters all have, and the earliest biting jaws."
The researchers established a timeframe over which these differences accumulated with the help of the fossil record they had in addition to mathematical models. These models seemed to reveal that moderately accelerated evolution was enough to explain the explosion of diversity.
"In this study we've estimated that rates of both morphological and genetic evolution during the Cambrian explosion were five times faster than today--quite rapid, but perfectly consistent with Darwin's theory of evolution," said Michael Lee, the lead author of the new study, in a news release.
The findings are important for understanding the theory of evolution. More specifically, they show that this particularly rapid rate of change is certainly within the realm of possibility.
The findings are published in the journal Currently Biology.