Reconstructed the appearance of animals from 700 million years ago

Tiny and transparent, iridescent and sometimes phosphorescent: these were the animals that populated the Earth about 700 million years ago, in the so-called ‘explosion of the Cambiano’, during which the first complex species appeared. After more than a century of hypotheses and research, the identikit of the first animals is finally ready thanks to a new technique of chromosome analysis. The finding, published in the journal Nature, is the fruit of research conducted by Darrin Schultz, formerly at the University of California at Santa Cruz and the Monterey Bay Aquarium Research Institute, now at the University of Vienna. The study was conducted with Daniel Rokhsar of the University of California at Berkeley and Oleg Simakov of the University of Vienna.

Contrary to what has been believed so far, these first animals that moved in the water in search of food appeared before the sponges, which were instead sedentary.

The starting point of the researchers was the analysis of the genetic material of current animals that have preserved the most primitive forms, such as ctenophores and sponges and the tool that allowed us to go back in time was the analysis of the structure of chromosomes. “We’ve come up with a new way for us to get an in-depth look at the origin of animal life,” observes Schultz. “The common ancestors of all animals probably lived between 600 and 700 years ago, but it’s very difficult to pinpoint them because their soft tissues left no fossil traces,” Rokhsar notes. “By comparing genomes we are looking into the past and – he adds – we are learning a lot about our early ancestors”.

Researchers have studied in particular the way in which genes are organized within chromosomes and for the first time they have succeeded in reconstructing the genetic structure of ctenophores, starting from Hormiphora californiensis. They have thus identified some sequences that have been preserved over time and different from those observed so far in animal evolution. Going backwards, the researchers hypothesized that from a common ancestor that lived millions of years ago, the path of the ctenophores separated from that of the sponges

Source: Ansa

Share this article:

Leave a Reply

most popular