Convergence detected in the genetic structure of bats and dolphins

Apologetics and the progress of science
Apologetics and the progress of science

We have to start this post with the definition of convergence in biology.

In evolutionary biology, convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches.

It is the opposite of divergent evolution, where related species evolve different traits.

On a molecular level, this can happen due to random mutation unrelated to adaptive changes; see long branch attraction. In cultural evolution, convergent evolution is the development of similar cultural adaptations to similar environmental conditions by different peoples with different ancestral cultures. An example of convergent evolution is the similar nature of the flight/wings of insects, birds, pterosaurs, and bats.

All four serve the same function and are similar in structure, but each evolved independently.

Jonathan Wells explains the problem that convergence poses for naturalistic evolution:

Human designers reuse designs that work well. Life forms also reuse certain structures (the camera eye, for example, appears in humans and octopuses). How well does this evidence support Darwinian evolution? Does it support intelligent design more strongly?

Evolutionary biologists attribute similar biological structures to either common descent or convergence. Structures are said to result from convergence if they evolved independently from distinct lines of organisms. Darwinian explanations of convergence strain credulity because they must account for how trial-and-error tinkering (natural selection acting on random variations) could produce strikingly similar structures in widely different organisms and environments. It’s one thing for evolution to explain similarity by common descent—the same structure is then just carried along in different lineages. It’s another to explain it as the result of blind tinkering that happened to hit on the same structure multiple times. Design proponents attribute such similar structures to common design (just as an engineer may use the same parts in different machines). If human designers frequently reuse successful designs, the designer of nature can surely do the same.

I’m a software engineer, and we re-use components all the time for different programs that have no “common ancestor”. E.g. – I can develop my String function library and use it in my web application and my Eclipse IDE plug-in, and those two Java programs have nothing in common. So you find the same bits in two different programs because I am the developer of both programs. But the two programs don’t extend from a common program that was used for some other purpose – they have no “common ancestor” program.

Now with that in mind, take a look at this recent article from Science Daily, which Mysterious Micah sent me.


The evolution of similar traits in different species, a process known as convergent evolution, is widespread not only at the physical level, but also at the genetic level, according to new research led by scientists at Queen Mary University of London and published in Nature this week.

The scientists investigated the genomic basis for echolocation, one of the most well-known examples of convergent evolution to examine the frequency of the process at a genomic level.

Echolocation is a complex physical trait that involves the production, reception and auditory processing of ultrasonic pulses for detecting unseen obstacles or tracking down prey, and has evolved separately in different groups of bats and cetaceans (including dolphins).

The scientists carried out one of the largest genome-wide surveys of its type to discover the extent to which convergent evolution of a physical feature involves the same genes.

They compared genomic sequences of 22 mammals, including the genomes of bats and dolphins, which independently evolved echolocation, and found genetic signatures consistent with convergence in nearly 200 different genomic regions concentrated in several ‘hearing genes’.

[…]Consistent with an involvement in echolocation, signs of convergence among bats and the bottlenose dolphin were seen in many genes previously implicated in hearing or deafness.

“We had expected to find identical changes in maybe a dozen or so genes but to see nearly 200 is incredible,” explains Dr Joe Parker, from Queen Mary’s School of Biological and Chemical Sciences and first author on the paper.

“We know natural selection is a potent driver of gene sequence evolution, but identifying so many examples where it produces nearly identical results in the genetic sequences of totally unrelated animals is astonishing.”

Nature is the most prestigious peer-reviewed science journal. This is solid material.

There is an earlier article from 2010 in New Scientist that talked about one of the previous genes that matched for hearing capability.


Bats and dolphins trod an identical genetic path to evolve a vital component of the complex sonar systems they use to pursue and catch prey.

The finding is unusual, because although many creatures have independently evolved characteristics such as eyes, tusks or wings, they usually took diverse genetic routes to get there.

Analysis of a specific gene has now demonstrated that although bats live in air and dolphins in water, where sound travels five times faster, they independently evolved a near-identical gene that allows them to accept high-frequency sound in the ear – vital for sonar.

The gene makes prestin, a protein in hair cells of the cochlea, which is the organ in the inner ear where sonar signals are accepted and amplified. Prestin changes shape when exposed to high-frequency sound, and this in turn deforms the fine hair cells, setting off an electrical impulse to the brain. So the protein has the important jobs of detecting and selecting high-frequency sounds for amplification.

When researchers examined the molecular structure of the prestin gene from a range of animals, they found that the variants in echolocating bats and dolphins were virtually indistinguishable.

Indistinguishable genes in animals that don’t share a common ancestor? Maybe a better explanation for the evidence we have is – common designer.

6 thoughts on “Convergence detected in the genetic structure of bats and dolphins”

  1. The echolocation system could be considered “irreducibly complex” … There is no reason for those pieces to have evolved except to work together.
    So, those genes, which are identical, somehow managed to write themselves – twice. Right.
    (I mean, I’m skeptical, but if you don’t like my “I doubt it” then do the math. The probability of 200 genes being identical without being related is ridiculous. The time for that to occur is longer than the existence of the universe, I’m willing to bet.)

  2. A theory that can incorporate completely opposite sorts of evidence is a vague and useless theory, at best. If having similar traits can be explained by common ancestry when it’s convenient and explained by other factors when it’s convenient, it’s a plastic theory that can explain anything. And a theory that can explain anything explains nothing.

  3. Continuing to enjoy your posts, Winteryknight. The one today is especially interesting.
    I have often wondered about DNA. If the string of our DNA contains elements of all our ancestors; their habits, traits,and possibly knowledge accquired, then does that explain how some people can, without training, education, or exposure, speak a second language, write and perform music, etc. ?

    1. DNA does not include knowledge (such as ability to play music) acquired by our ancestors. DNA, or specifically, epigenetics, can convey information about environmental conditions for a few generations to allow children born to people in certain circumstances (such as very cold weather or very little to eat) to have their metabolisms already adjusted to survive better.

      Epigenetics has to do with markers placed on the DNA to adjust the way it folds and how much genes are expressed. And these markers can, in some cases, be passed down to children and persist through several generations. However, they are not permanent, and can be modified during a person’s lifetime in response to environmental conditions.

      But DNA cannot pass down specific learned skills like playing music or speaking a language. Some people may have a quicker ability to learn language or music than others, but they cannot be born with the ability to play/write music or speak a language they never heard. These are learned behaviors, not genetic traits.

  4. So how do you tell the difference between separate production of similar things from re-use of the same thing in similar situations?

    ” I can develop my String function library and use it in my web application and my Eclipse IDE plug-in, and those two Java programs have nothing in common.”

    Why would you re-write your String function library if the existing parts of it work fine? You wouldn’t, and don’t. If the situation is similar you use the same code.

    If two different people were developing a web application and an Eclipse IDE plug-in we might not be surprised to see similiar components. If we saw the same components we’d think that someone had been using someone else’s code (and if it’s without permission we might have a bit of a row).

    The identity of one component with another is strong evidence that one person designed it. (The chances of two coming up with identical code being too low). The non-identity of one compnent with another is strong evidence that we do not have just the one designer: a designer would re-use code rather then re-do coding.

    So is this the same gene in bats and whales?

    If these specific genes are identical then evolution has a problem.

    Conversely, if these specific genes are not identical then design has a problem.

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