Life diversified when Earth was a snowball
Prehistoric animals may have started their drive towards explosive diversity when the Earth was a giant snowball about 540 million years ago, according to a new study.
WASHINGTON: Prehistoric animals may have started their drive towards explosive diversity when the Earth was a giant snowball about 540 million years ago, according to a new study.
Scientists, who analysed the fossil records and genomes of existing organisms related to species that belonged to the Cambrian period (the zoological era that spanned from 540 to 480 million years ago), found that a startling expansion in the diversity of life forms began early in that period.
During this apparently sudden outburst, known as the Cambrian explosion, all the major groups of animals seemed to materialize rapidly. The aim of the research was to figure out when different lineages of animals diverged from each other.
The results, published in the journal Science, suggested that many of Earth's early organisms developed the genetic programmes for their body plans during the Cryogenian period, which lasted from 850 to 635 million years ago, with the last common ancestor of all living animals originating nearly 800 million years ago.
These early creatures may then have flourished later in more favourable environments leaving behind enough fossils to survive up to now. PTI