Revisiting convergence: making teeth, shells, claws, nails (Introduction)

by David Turell , Tuesday, August 20, 2019, 23:09 (1711 days ago) @ David Turell

Appears to have developed many times in different lines of organisms:

https://phys.org/news/2019-08-biominerals-nature-recipe-evolved.html

"The materials that animals make from scratch to build protective shells, razor sharp teeth, load-bearing bones and needlelike spines are some of the hardest and most durable substances known. The recipe for making those materials was one of nature's closely held secrets, but powerful new analytical tools and microscopes have peeled back much of the mystery, showing, at the nanoscale, exactly how a wide array of animals use precisely the same mechanisms and starter chemicals to make the biomineral structures they depend on.

"Now, in a report published today (Aug. 19, 2019) in the Proceedings of the National Academy of Sciences (PNAS), a team led by Pupa Gilbert, a University of Wisconsin–Madison professor of physics, shows that the recipe for making shells, spines, and coral skeletons is not only the same across many modern animal lineages, but is ancient—dating back 550 million years—and evolved independently more than once.

"The findings are important because they help stitch together an evolutionary narrative of biomineralization. The fuller picture of a process ubiquitous to animal life on our planet not only tells us something important about our world, but the details may one day be harnessed by humans to produce harder, lighter, more durable materials; tools that never need sharpening; more faithful biomedical implants; and the possibility of human intervention in things like rebuilding the world's coral reefs.

"'The finding that biomineralization evolved independently multiple times, using the same mechanism, tells us that there is a strong physical or chemical reason for doing so," says Gilbert, a world expert on the process of biomineralization. "If one organism starts making its biomineral that way, it outcompetes all others that either don't make biomineral or make them differently, it doesn't get eaten, and gets to transmit that good idea down the lineage.'"

"The new PNAS report builds on a series of seminal discoveries by Gilbert and her colleagues. In past studies, the Wisconsin physicist has shown that the process of biomineralizations works the same in vastly different classes of animals, ranging from mollusks like abalone, to echinoderms such as sea urchins, and to cnidaria, a large group of animals that includes corals, jellyfish, and sea anemones. These phyla, or broad groups of animals, have no common ancestor that was already biomineralizing, thus they must have evolved biomineralization mechanisms independently. Therefore, Gilbert says, "it is extremely surprising that when they started biomineralizing in the Cambrian (more than 500 million years ago) these three phyla started doing it in precisely the same way: using attachment of amorphous nanoparticles.'"

Comment: Another example of God using patterns of development in managing evolution