Reconstruction of The First Mammal's Genome Suggests It Had 38 Chromosomes

Scientists don't know a lot about what the first mammal looked like, but they do know that every mammal on Earth is descended from it.

Thanks to new research, we now know how it looked.

An international team of scientists has pieced together a likely genome for the common ancestor of mammals.

A wide range of species from all three types of mammals were included in the analysis.

Chickens and Chinese alligators were compared to other animals.

The complete set of chromosomes was reconstructed at 16 points. The point where the tree splits into multiple branches is called a nodes.

The species at the beginning of the mammal tree probably had 38 chromosomes, according to researchers.

Nine of the smallest chromosomes were shared with the ancestors of mammals, birds, and reptiles.

The evolutionary stability of the order and orientation of genes on chromosomes has been shown by this remarkable finding.

The genes involved in developmental functions are found in many of these areas.

The researchers looked at how chromosomes were broken apart.

A rich source of genetic variations that play a role in separation through evolution can be found in the section of the chromosomes heavily affected by rearrangements.

When therians split from the monotremes, the highest rate was observed.

The results have implications for understanding the evolution of mammals.

It is believed that the earliest mammal was the tiny, rat-like mammal called Morganucodon, which lived around 200 million years ago. The fossil was found in Wales in 1949.

It's a sister group to the mammal line, but it isn't considered a common Ancestor.

The Tritylodont genera is a clade of mammals. The first mammal species would have lived around the same time as the first fossils of Africa and North America.

The paper was published in the national academy of sciences