In bats and whales, convergence in echolocation ability runs deep

In bats and whales, convergence in echolocation ability runs deep

"The natural world is full of examples of species that have evolved similar characteristics independently, such as the tusks of elephants and walruses," said Stephen Rossiter of the University of London, an author on one of the studies. "However, it is generally assumed that most of these so-called convergent traits have arisen by different genes or different mutations. Our study shows that a complex trait -- echolocation -- has in fact evolved by identical genetic changes in bats and dolphins."

Another example of what I like to call the "singularity of life." Amazingly, the incredible diversity of life on this planet is all based upon the same genetic underpinnings. Every single organism that we know of, from bacteria to bonobos, uses DNA as the blueprint for function and development. The DNA of every organism is composed of two sugar-phosphate "backbones" joined by four chemical bases (adenine, thymine, cytosine and guanine) to form a double helix. It's as if the music of life were composed using jjust four notes. The same four notes yield algae, alligators, and arthropods. Amazing.

Nature is conservative. Energy is precious and not wasted. Adaptations that work are not lightly discarded. So strategies that work pop up again and again, in organisms that are related really only in the respect that they both have DNA. Cephalopods and vertebrates evolved spectacular optical organs (there is still much debate as to whether the eye evolved just once or on many different occasions - my bet is on multiple occasions). Bats and birds both fly. Bats and dolphins both echolocate. It remains to be seen whether all instances of convergence share specific groups of genes in similar fashion to the echolocation described in this article, but we can be assured we haven't heard the last of this subject.