Counters to Conservapedia (Part 2): Genetic Diversity

If you remember, Conservapedia has a list of Counterexamples to evolution.  Sadly each of them represent a falsehood, misrepresentation, or error in what evolution actually is.  So I figured would help by countering their list and explaining where they are wrong.  


Here is part 2: 

Lack of genetic diversity among the Homo sapiens species. Were evolution and the old earth true, the human population would show a much larger genetic variance.[2]

 Compared to most species, we show very little genetic diversity.  No matter the ethnicity, you share 99.9% of your DNA with the person sitting next to you on the bus.  We are very similar.  The longer a species has been around, the more genetic diversity can be found in the species.  Because of our small genetic difference, we know that humans are a young species.  


According to genetic studies, the number of differences between humans and chimpanzees suggest they diverged from a common ancestor about 6 million years ago.  To date, fossil evidence continues to support this hypothesis.  


Because humans originated in Africa and have been on that continent much longer, native African populations show more diversity than any population on any other continent.  This supports the Out-of-Africa Theory.  Africa itself holds almost all of the variation found within the human species.


We also know that about 190,000 years ago our species experienced a bottleneck.  as Earth entered a new glacial phase, life for modern humans became very difficult and most died out.  According to genetic studies, our population became as small as 600 reproducing individuals.  Archaeology shows that the small population survived on the southern coast of Africa.  (More information can be found in a recent SciAm article from the August 2010 issue and here is the podcast link as well.)

Human Genetic Diversity: This map shows the greatest genetic diversity exists in Africa.  Because differences in DNA develop over time, the areas with the greatest diversity have held people for much longer.  As humanity began in Africa, we see that continent features the greatest differences in their DNA.

Ideology and Evolution

On the Huffington Post, John Farrell takes on John West's assertion that Darwin's views on race discredit evolution.  Because the anti-evolution crowd has failed to discover any credible scientific evidence to disprove evolution, they resort to name-calling one particular naturalist and blaming his discovery for every atrocity in the world since.  Let's look at this a little further.


Let's be clear: evolution is true.  Since 1859, no scientific idea have received more scrutiny and more examination.  Every experiment has confirmed the original hypothesis or has helped to shape our understanding of evolution.  Creationists have tried and failed many times to disprove evolution.  Because their "science" doesn't hold up, they resort to attacking the man who recognized what was going on.


Sometimes some people seem to think that Charles Darwin invented evolution.  He didn't.  He recognized the importance of selection in nature and provided a name for it.  Many people came before him and saw the power of selection (think farming and domestication), but no one had really applied that idea to all of the plants and animals- including humans.  He wasn't the only scientist at the time to understand natural selection (Alfred Wallace had the same idea at the same time) and virtually every biologist since has recognized the importance of natural selection and common descent.  Yet, with all the scientific evidence and consensus, Creationists have decided that they can disprove evolution by discrediting Darwin.


Americans hate racism or appearing racist.  We hate Nazis and the Holocaust.  With this in mind, Creationists love to label Darwin a racist, or at least more racist that his Victorian peers.  They blame him for the actions of Hitler (similar to blaming Jesus for the atrocities of the Crusades).  Sure, by today's standards, Darwin would be considered racist.  Victorians viewed their society as superior to all other peoples in the world.  Non-whites were presumed inherently inferior.  This anglocentric view affected most levels of the white world.  Similarly, Abraham Lincoln and Thomas Jefferson would seem racist while advocating against slavery.  Actually, Darwin voiced much displeasure with slavery and the way native peoples were treated as he saw them in his travels.  Too often, Creationists lie by misquoting Darwin to create a misrepresentation of the person who discovered the importance of evolution.


But for a moment, let us accept the notion that Darwin was racist.  In fact let's label all those who accept evolution as racist.  How would that affect the science?  How does that discredit the mountains of evidence from fossils, dissections and genes?  A personal ideology does not affect the truth of the matter.  Evolution is true.  All organisms share a common ancestor and change over time through the nonrandom selection of random mutations.  How a particular person feels about different races makes no difference on the veracity of evolution.  For that matter, a person's religious affiliation, political identity, or position on the the BCS farce has no affect on the the evidence of evolution.  


For the record: Darwin would be considered much less racist that his peers and I have no particular evidence to claim that any certain evolutionists are racist.  I merely proposed the idea to prove the point that it doesn't matter.  I tend to believe that an understanding of evolution should help us to be less racist as a society- we are all pretty much the same.

Counters to Conservapedia (Part 1): Extictions

Conservapedia describes itself as the Conservative answer to the liberal bias of Wikipedia.  They have an in-depth article on The Theory of Evolution.  If you haven't already guessed, the article features a long list of misunderstandings and misconceptions.  Every so often, I would like to counter their Counterexamples to Evolution on this site.  So I guess this is the first in a 60 part series.


From Conservapedia:
The annual rate of extinction of species far exceeds any plausible rate of generation of species. Expanding the amount of time for evolution to occur makes evolution even more unlikely.

The history of life is marked by five periods of accelerated extinction events.  Most notably, the 65 million years ago, all non-avian dinosaurs became extinct more or less at the same time.  In other periods, the trilobites went extinct as have roughly 99% of all species that have ever lived.  

On the other hands, background extinctions occur at a slower, steadier rate.  As we currently live during a the sixth mass extinction, current extinction rates are not similar to all of history.  The point being: extinction rates are not static.  Species go extinct at different rates depending on the environment and conditions.  To assume a constant rate of extinction shows a lack of understanding of natural history.

In evolution, speciation and extinction go together.  As species go extinct, their niches open up to new species to take their place.  When the dinosaurs went extinct, the mammals exploded onto the scene taking over the niches held by those big lizards (note: not lizards at all).  When new areas open up, existing species divide into various subspecies very quickly and eventually become different species with different adaptations and different behaviors.  The point being: speciation rates are not static.  Species develop at different rates depending on the environment and conditions.  To assume a constant rate of speciation shows a lack of understanding of natural history.