Commentaries on Our World

Evidence For Evolution

Molecular Sleuths Track Evolution Through The Ribosome

A new study of the ribosome, the cell's protein-building machinery, sheds light on the oldest branches of the evolutionary tree of life and suggests that differences in ribosomal structure between the three main branches of that tree are "molecular fossils" of the early evolution of protein synthesis.

The new analysis, from researchers at the University of Illinois, reveals that key regions of the ribosome differ between bacteria and archaea, microbes that the researchers say are genetically closer to eukarya, the domain of life that includes humans. The study appears this week in the Proceedings of the National Academy of Sciences.

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Animal Evolution - The Development Of Nerves
University of Queensland researchers have traced the origins of one of the most important steps in animal evolution - the development of nerves.

Professor Bernie Degnan, from UQ's School of Integrative Biology, together with PhD student Gemma Richards and colleagues from France, have traced the evolution of the nerve cell by looking for pre-cursors in, of all places, the marine sponge.

"Sponges have one of the most ancient lineages and don't have nerve cells," Professor Degnan said.

"So we are pretty confident it was after the sponges split from trunk of the tree of life and sponges went one way and animals developed from the other, that nerves started to form.

"What we found in sponges though were the building blocks for nerves, something we never expected to find."

Professor Degnan said the science involved came from the relatively new area of paleogenomics, which is the study of ancestral genomes to paint a more accurate picture of animal evolution.

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