A study published Friday in the journal "Nature", reports on the genome sequencing of the sea sponge Amphimedon queenslandica
, from the Great Barrier Reef, off the coast of Queensland in north-east Australia. The research shows that the genome of this sponge is “remarkably similar to other animal genomes in content, structure and organization”.
, the result of more than five years of research
by an international team of scientists led by Dr. Bernard Degnan of the University of Queensland, required the extraction and sequencing of DNA from sponge embryos and illustrates how all contemporary animals, from sea sponges and corals, to fish, butterflies and humans, evolved from ancient and long-extinct ancestors, the very first multi-cellular animals.
" This incredibly old ancestor possessed the same core building blocks for multi-cellular form and function that still sits at the heart of all living animals, including humans,"
Professor Degnan said.
"We have found that sponges and humans, and their common ancient ancestor, share an amazing number of genes. Given how simple sea sponges are, this was completely unexpected.”
According to Degnan and his collaborators, the evolution of these genes not only allowed the first animals to develop in the oceans but allowed the evolution of the full biodiversity of animals living today.
The results of this study support and confirm earlier findings regarding the occurrence in sponges of the genetic sequences that control the existence of neurons and synapses of the nervous system in animals.
The evolution of sponges, however, did not conduct to the development of this complex system. It is believed that the genes responsible for nervous cells and their connections may have first been expressed
in primitive sea creatures that lived about 600 millions years ago, currently represented in the oceans by anemone and jellyfish.