A hypothesis suggests that the most ancient ancestors of humankind were fish. It was precisely these prehistoric fish that paved the way for the ongoing process of evolution.
Around 360 million years ago, a mass extinction event drastically disrupted life on Earth, wiping out most of the fish species that existed at that time. The species that were fortunate enough to survive opened a new era for the diversity of modern vertebrates.
Dr. Lauren Sallan, the head of the research team from the University of Chicago, described: “Everything was shattered; it was a global extinction event. It reorganized the biodiversity of vertebrates in both freshwater and marine environments, creating an entirely different world.”
Is this the ancestor of humankind?
The extinction occurred almost at the end of the Age of Fish (the Devonian period, from 416 million to 359 million years ago), making way for species present in Earth’s aquatic environments.
The armored fish (placoderms) and lobe-finned fish (similar to modern lungfish) dominated the aquatic world, while ray-finned fish, sharks, and four-legged animals (tetrapods) were in the minority.
However, between the Devonian and the subsequent Carboniferous period, placoderms disappeared, and ray-finned fish quickly replaced lobe-finned fish as the majority group, a “population shift” that continues to this day.
Dr. Michael Coates, another lead researcher from the University of Chicago, stated: “There was a significant, unclear event at the end of the Devonian. This event reset everything back to square one, and some ‘underdeveloped’ species managed to spectacularly evade disaster to survive.”
Before going extinct, lobe-finned fish and four-legged animals had made their initial movements to live on land.
The surviving species appear to be the most ancient ancestors of the majority of terrestrial vertebrates today, including humans.
This research was published at the end of May in the journal: Proceedings of the National Academy of Sciences.
Source: MSNBC.com
