Revisiting convergence: bats and dolphins (Introduction)

by David Turell , Sunday, February 03, 2019, 02:13 (1910 days ago) @ David Turell

Used the same genes to develop echo-location:

https://www.sciencemag.org/news/2013/09/bats-and-dolphins-evolved-echolocation-same-way

"Dolphins and bats don't have much in common, but they share a superpower: Both hunt their prey by emitting high-pitched sounds and listening for the echoes. Now, a study shows that this ability arose independently in each group of mammals from the same genetic mutations. The work suggests that evolution sometimes arrives at new traits through the same sequence of steps, even in very different animals. The research also implies that this convergent evolution is common—and hidden—within genomes, potentially complicating the task of deciphering some evolutionary relationships between organisms.

***

" in 2010, Stephen Rossiter, an evolutionary biologist at Queen Mary, University of London, and his colleagues determined that both types of echolocating bats, as well as dolphins, had the same mutations in a particular protein called prestin, which affects the sensitivity of hearing. Looking at other genes known to be involved in hearing, they and other researchers found several others whose proteins were similarly changed in these mammals.

***

"The analysis revealed that 200 genes had independently changed in the same ways, Parker, Rossiter and their colleagues report today in Nature. Several of the genes are involved in hearing, but the others have no clear link to echolocation so far; some genes with shared changes are important for vision, but most have functions that are unknown.
“The biggest surprise,” says Frédéric Delsuc, a molecular phylogeneticist at Montpellier University in France, “is probably the extent to which convergent molecular evolution seems to be widespread in the genome."

"Genomicist Todd Castoe from the University of Texas, Arlington, is also impressed: “I’m pretty convinced they are finding something real, and it’s really exciting [and] pretty important.” However, he is critical about the way the analysis was done, suggesting that the approach found only indirect evidence of molecular convergence.

"The discovery that molecular convergence can be widespread in a genome is "bittersweet,” Castoe adds. Biologists building family trees are likely being misled into suggesting that some organisms are closely related because genes and proteins are similar due to convergence, and not because the organisms had a recent common ancestor. No family trees are entirely safe from these misleading effects, Castoe says. “And we currently have no way to deal with this.'”

Comment: So convergence is a problem for research. Not if God designed and dabbled with pre-planning or control of mutations.