Shocked by a series of modern creatures with body parts 600 million years ago

On the outside, they are ordinary modern sea creatures, but inside are chromosomes with an ancient structure preserved from 600 million years ago.

Research led by Dr Daniel Rokhaer from the Department of Molecular and Cellular Biology at the University of California at Berkeley says these are the invertebrates that still swim in many oceans today, including several species of sponges. and jellyfish.

Fire jellyfish Rhopilema esculentum, one of the creatures included in this study - (Image: Bill Abbott, Creative Commons License)

New analysis shows that Earth's first multicellular animals carry their genes on 29 chromosome pairs. When the first marine animals emerged and evolved into invertebrates ranging from sponges to worms, many of these chromosomes remained the same for more than half a billion years.

Species included in this study include Branchiostoma floridae, a pretty flower-like species; a brush-like sea creature called amphioxus; freshwater sponge Ephydatia muelleri; fire jellyfish Rhopilema esculentum.

Sometimes we ourselves carry some of these primitive pairs of chromosomes, which have been "reconstituted" through many duplications, fusions, and rearrangements.

The findings, published in Science Advances, say the findings show that evolution is a conservative process, and that despite billions of years, countless generations, and patterns of change, many ancient things will forever be linked. Linking a planet's life on a complex family tree. They also found similar conservation of DNA on chromosomes in several species.

While invertebrates preserve their primitive pairs of chromosomes fairly completely, vertebrates like us choose to "mix" them up as we evolve, Dr. Rokhaer and colleagues say. Learn more in the announcement.