speciation

"These repeated incursions into freshwater at the early divergence stage likely accelerated speciation, and are key factors in explaining the extraordinary hyper-diversity of otophysans in modern freshwater faunas."

"The Cambrian period also had a massive speciation event, but the new models allow us to rule out oxygen and focus on other things that may have driven evolution during that time."

With speciation, an astonishing divergence of pollination mechanisms evolved, that exploit hawkmoths, bats and lemurs for a simple nectar reward.

The authors say the shift in migratory behavior is what drove speciation, though there's no way to tell whether migratory behavior was gained by one species or lost by the other.

"Consequently, the mutations already existed in a common ancestor and are therefore older than the speciation," says Wolf.