Thursday, June 23, 2011

Counters to Conservapedia (Part 10): Observing Speciation

Now for our next installment of correcting Conservapedia's misconceptions of Evolution.  Here is an interesting one:
There are no historical records of anyone directly observing one species evolving into another, which would certainly be something worth writing about. Surely of the millions of species we have, someone would have witnessed one come into existence had it evolved.
This misunderstanding shows up quite often and is, as you can guess, wrong.  It presents a fundamental error in how science works.  The writers of Conservapedia seem to suggest that we can only truly know that some has happened if it is directly observed.  While science does use observation as an important tool, much of science is determined through another powerful tool, inference.  By looking at empirical evidence obtained in the field or the laboratory, scientists can make inferences about what happened.  Without inference, no criminals could be convicted without an eyewitness.  Yet, most Creationists willingly accept the results of forensic science to convict a murder on nothing more than a DNA sample.

DNA provides strong evidence because of our unique patterns of nucleotides.  Well, each species also has a unique pattern which provides ample evidence for the inference of common descent.  The use of DNA in evolutionary biology has revolutionized our understanding of the science.  DNA studies confirm evolutionary predictions and produces new species histories.  As most people know, humans and chimpanzees share roughly 98% the same DNA, gorillas share slightly less, orangutans less and so on.  This DNA evidence allows us to infer our species place within the animal kingdom among the Great Apes.

Like DNA, we have numerous lines of fossils showing the evolution of whales, horses, camels, reptiles, birds, primates and, even, humans.  But also like DNA, these fossils help us to infer what happened in the distant past.  These do not represent direct observation, which Creationists seem to require.  Species are changing from generation to generation all around us.  We can see quickly changing in the fur color of the desert pocket mouse or the peppered moth.  Scientists went to the Galapagos Islands every year to measure the beak sizes of the population.  When a drought hit the island, they measured changes in the average beak size as the available food changed.  An important principle of evolution describes the big changes that occur to species through incremental changes from generation to generation.

But my favorite examples of evolution in action are ring species.  In Northern California, you can find a population of very diverse salamanders.  The species has spread out down both sides of the Central Valley.  While separated by a large valley and unable to reproduce with each other, the species develops two different adaptations to survive.  On one side, the population acquired camouflage to blend into the environment, on the other the population became bright colored to mimic a poisonous newt.  When the two different populations meet at the southern end of the valley, they do not recognize each other as viable mates.  As David Wake says in the following video, these populations are well on their way to become two species right before our eyes.  Please, watch the clip for a better understanding of how these cute little salamanders destroy the Conservapedia argument.

3 comments:

  1. Don't suppose you'd like to tag all your "Counters to Conservapedia" with (say) Conservapedia? I'd like to link to them as a set on RationalWiki.

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