Genetic Convergent Evolution Strains Credibility

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Posted on September 6, 2013 in Darwin and Evolution, Genetics, Mammals

Convergent evolution” is the term given to similar designs that shouldn’t be related.  Recent widespread examples threaten to make the term lose any coherence it might have had.

Bats and dolphins:  It’s been long known that bats and dolphins, thought to have diverged in the mammalian family tree xx million years ago, both use echolocation.  What was not known till now was that the similarities proceed all the way to the genetic level.  In Nature, Erika Check Hayden said, “A new analysis suggests that many genes evolved in parallel in bats and dolphins as each developed the remarkable ability to echolocate.”  By many, they’re talking three orders of magnitude. The title is “Convergent evolution seen in hundreds of genes.

Each of these genes, presumably, mutated independently in the two groups, since their presumed common ancestor would not have had the well-developed sensory apparatus for this “complex physical trait.”  Charles Q. Choi on Live Science tried to preserve the credibility of the “convergent evolution” explanation.  It’s not clear how helpful it is, though, to pile on examples:

Bats and dolphins may live in radically different worlds, but the fact they both evolved a type of sonar means they resemble each other genetically, researchers now find.

When different species live similar lives, they can evolve similar traits, a phenomenon known as convergent evolution. For instance, dolphins, sharks and the extinct marine giants known as ichthyosaurs all differ from each other greatly in origin — dolphins are mammals, sharks are fish and ichthyosaurs were reptiles. However, they evolved very similar body shapes that help them live fast lives in the water — streamlined forms, stabilizing dorsal fins and crescent-shaped tails for traveling great speeds over long distances.

Recently, scientists found hints that convergent evolution caused species to resemble each other not just at the physical level, but also the genetic one.

Expecting maybe 10–30 genetic similarities, researchers found 200, in genes related to hearing and sight.  “These similarities were not seen with non-echolocating animals,” Choi said.  Joe Parker (Queen Mary College, U of London) explained this “surprising result” by attributing greater power to blind, undirected processes: “Natural selection can be a very powerful force for shaping genetic sequences, and the outcomes of that process can be very similar, even in unrelated organisms.”  Hayden made evolution out to be some kind of detective:

Different organisms often independently evolve similar observable traits such as anatomical or functional features, but the genetic changes underpinning such ‘convergent evolution’ are usually different. The new study, published today in Nature, hints that evolution may be finding the same genetic solutions to a problem more often than previously thought.

Science Now expressed no doubt at all in the explanatory power of convergent evolution, even if it must rely on blind, aimless mutations.  The article “Bats and Dolphins Evolved Echolocation in the Same Way” says –

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 article continues, “Nature is full of examples of convergent evolution,” listing wings as an example that evolved 4 times in birds, bats, insects and flying reptiles.  “Biologists have assumed that these novelties were devised, on a genetic level, in fundamentally different ways” – an assumption that might have fit with the randomness of mutations.  The new study undermines that assumption.  One scientist not involved with the study remarked, “The biggest surprise is probably the extent to which convergent molecular evolution seems to be widespread in the genome.”

This finding could have devastating effects on the ability of evolutionists to separate homology and analogy.  It basically scrambles the signal of natural selection.  Science Now ends,

The discovery that molecular convergence can be widespread in a genome is “bittersweet,” [Todd] Castoe [U of Texas] 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.”

That’s on top of the difficulty of building Darwinian trees in the first place (see 6/05/13).

Birds, too:  A paper in Nature on “Evolutionary origins of the avian brain” claims that encephalization (brain enlargment) evolved independently multiple times in birds, mammals, and dinosaurs: “The hyperinflated forebrains of birds and mammals evolved independently, possibly in response to different sensory cues; derived olfactory capabilities versus enhanced visual acuity.”

This is not an article about convergent evolution.  It is an article about dogmatic faith.  Evolutionists cannot, and will not, face up to facts that contradict their theory.  They always manage to fold the unexpected into their tale.  God could not have made it clearer that animals have common design rather than common descent by exhibiting hundreds of cases that could not have diverged by an evolutionary process.

Attributing convergent evolution to the environment is a dodge that merely displaces the “creative power” of un-creation to another mindless entity subject to chance.  And calling natural selection “a very powerful force” is, once again, a fallacy.  Natural selection is not a force.  It is a mindless, careless bump in the road, like one of those hubs in a pinball machine.  It is not going to force the animal to score a point without an intelligent agent controlling the action.

To have flight evolve, or sonar, or legs, or eyes – by an undirected process – just a single time would defy credibility.  Yet evolutionists readily speak of multiple instances of independent evolution of these things without a hint of embarrassment.  “Convergent evolution” is not an explanation for what is observed.  It is silly dogma pretending to be scientific explanation.  Don’t fall for its jargon name “homoplasy” which means, etymologically, “same form,” or for the false dichotomy “homology” (i.e., via common ancestry) vs “analogy” (i.e., not via common ancestry) – a distinction that embeds Darwinian assumptions in the terms.

 

2 Comments

tjguy September 6, 2013

Convergent evolution is a “HEADS I WIN. TAILS YOU LOSE! argument that shows that evolution is not falsifiable — at least when it comes to evidence for or against common descent.

rockyway September 6, 2013

This finding could have devastating effects on the ability of evolutionists to separate homology and analogy.’

Didn’t Darwin claim that homology was the best evidence for “his” theory of evolution? (Hasn’t Dawkins said the same?) Didn’t he use morphological ‘similarities’ between apes and human beings to prove descent?

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