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Evolutionary Relationships In Echolocation — An Obsession that Smothers Wonder


Sarah Chaffee commented here the other day, “Some materialists criticize the feeling of ‘awe’ itself as a problem for people, especially the young, in getting with the program and embracing evolution. You can see why.” Yes, you can. As Evolution News observed yesterday, the obsession with evolutionary relationships in echolocation smothers what should be a response of profound wonder. Another paper will illustrate further. It is also found in Science Advances. 

Converging LCA, LCAW, and LCATW

Liu et al. announce, “Genomic and functional evidence reveals molecular insights into the origin of echolocation in whales.” Some relevant acronyms: LCA = Last Common Ancestor; LCAW = Last Common Ancestor of all Whales; LCATW = Last Common Ancestor of Toothed Whales. You can see where they are headed. Like the German team referenced here yesterday, these five scientists in China strain at a bat and swallow a whale of a mammal. Glossing over the amazing engineering required for echolocation, they dive right into the nitty gritty of molecular phylogeny.

Echolocation allows toothed whales to adapt to underwater habitats where vision is ineffective. Because echolocation requires the ability to detect exceptional high-frequency sounds, fossils related to the auditory system can help to pinpoint the origin of echolocation in whales. However, because of conflicting interpretations of archaeocete fossils, when and how whales evolved the high-frequency hearing correlated with echolocation remain unclear. We address these questions at the molecular level by systematically investigating the convergent evolution of 7206 orthologs across 16 mammals…. 

Rescuing common ancestry requires lots of “convergent evolution” again. Similarities appear where they should not, and don’t appear where they should. Watch the word convergent appear six times in the Abstract:

We address these questions at the molecular level by systematically investigating the convergent evolution of 7206 orthologs across 16 mammals and find that convergent genes between the last common ancestor of all whales (LCAW) and echolocating bats are not significantly enriched in functional categories related to hearing, and that convergence in hearing-related proteins between them is not stronger than that between nonecholocating mammalian lineages and echolocating bats. However, these results contrast with those of parallel analyses between the LCA of toothed whales (LCATW) and echolocating bats. Furthermore, we reconstruct the ancestral genes for the hearing protein prestin for the LCAW and LCATW; we show that the LCAW prestin exhibits the same function as that of nonecholocating mammals, but the LCATW prestin shows functional convergence with that of extant echolocating mammals. Mutagenesis shows that functional convergence of prestin is driven by convergent changes in the prestins S392A and L497M in the LCATW and echolocating bats. Our results provide genomic and functional evidence supporting the origin of high-frequency hearing in the LCAW, not the LCATW, and reveal molecular insights into the origin and evolutionary trajectories of echolocation in whales.

An Awesome Protein

How strong are these insights? Actually, they dive into very fine details about one protein, prestin, and the number of “convergent amino acid substitutions” that might have something to do with evolutionary relationships. Remember, however, that “convergent evolution” is a scenario to get around the absence of homology. It gives evolutionists a way to have their cake and eat it, too. If proteins are homologous, evolution is confirmed. If proteins are not homologous but convergent, evolution is confirmed. 

When all is said and done, though, they’re not even sure the functional convergence they found in prestin has anything to do with the main thing: echolocation. They speculate that tiny changes in this protein might affect the transfer of charge across the membrane of hair cells in the air. So? “However, little is known about the biological and physiological implications of this difference for mammalian high-frequency or ultrasonic hearing.” All that work for nothing! “Nevertheless, more experimental research on prestin or other echolocation-related genes is necessary to reveal the molecular mechanisms underlying mammalian high-frequency or ultrasonic hearing and echolocation.” The end.

Too bad they stop there. Prestin is actually an awesome protein. A finely-tuned molecular motor, it regulates the response of hair cells in the cochlea. Wouldn’t you like them to describe how it works so well?

Missing the Main Thing 

Do you get the idea in these papers that the authors have missed the main thing? The research claims to be about echolocation, but gets bogged down in seemingly irrelevant details in attempts to promote common ancestry. Even then, the details they strain at so carefully leave a fuzzy picture. It’s like working a jigsaw puzzle and forcing pieces together that don’t fit well. Is this the kind of science that the public deserves? Wouldn’t it be much more useful to learn how echolocation actually works?

Near the end of the Illustra documentary Living Waters, Discovery Institute’s Paul Nelson stands in awe of a breaching humpback whale. After biologist Richard Sternberg presents a severe genetic challenge to Darwinian mechanisms in the whale’s reproductive system, Nelson returns to what should be “the main thing” for any scientist. He mentions how he and his daughter were awestruck by the beauty and variety of tropical fish they saw snorkeling on vacation. An appreciation of beauty and wonder would be good for science, he says:

The data from genetics, and molecular biology and a host of other fields have proven impossible to reconcile with undirected material causes.

And, if science is an open-ended search for the truth, regardless of where the evidence leads, then what difference should it make if it leads to an intelligent cause?

I want to understand the world. I want knowledge. I want to know what’s true about the world, and the assumption that living things are not random assemblages, but that there’s a rational logic underlying them. That assumption is enormously fruitful for yielding knowledge. And if it’s knowledge that you want that’s the direction you should go.

All you need is an open heart, open eyes, and open mind, and that signal of design that’s there in nature will be clear to you. Unmistakably. It’s everywhere.

Agreed. Perhaps it is awe-inspiring to evolutionary biologists to try to work a puzzle, trying to find how everything is connected by common ancestry. It sure keeps many of them employed.

Photo: Humpback whale, via Wikimedia Commons.