Wednesday, February 18, 2015

A Darwin Day Exchange

Darwin Day was last week, or as religious apologists call it "question evolution day." In that spirit, I posed a question to those not sold on the theory.

What aspect(s) of evolution do you have a problem with?
  • Is it that you don't believe in heritability?
  • Is it that you don't believe natural selection is a sufficient mechanism to propagate beneficial genes and weed out harmful or useless genes?
  • Is it that you don't believe in genetic mutation?
There was one apologist who answered saying that they didn't believe in heritability--he actually didn't believe that traits were based down from parent to child. I asked if he noticed that black parents typically have black kids and that tall parents usually have tall kids, but to that he said anecdotal evidence can't be used to show anything. Luckily, only one respondent went to this extreme a denial.

There was another apologist who didn't believe natural selection is a sufficient mechanism for the theory. I asked him to hear out this simplification of the process:
You have a random selection of rabbits in a room with the only food source on the ceiling. They all need to get up on their hind legs and stretch to try and get the food, but only about half can actually reach. Very quickly the ones who can't reach starve, most before mating. The remaining rabbits go about their lives, stretching for their food every day. Eventually they have kids. Given that the mating pool is taller rabbits, the next generation of bunnies inherit traits from taller rabbits--making the new generation taller, on average, than the group we started off with.
Say we very slowly raise the ceiling, weeding out rabbits that don't meet the new minimum height to eat. Each generation would be taller and taller as the shorter die off. Given that mutations occur, (which this apologist admitted do occur) some rabbits might even be taller or shorter or more or less stretchable or better or worse jumpers than the heritable gene pool suggests. Those with an advantage, the better jumpers, the more stretchable, the taller, whatever then mate and pass on their new mutation while useless mutations die off.
The apologist actually agreed that this would happen. So...does he believe in evolution now? Of course not. Once he couldn't deny evolution on a scale of a lot of generations he opted to deny evolution on a scale of a whole lot of generations. The vague micro- versus macro-evolution divide.

Yet another apologist argued that mutations and heredity happen, but only as changes or improvements on preexisting traits. In his words "this can give you blue eyes instead of brown but it cannot create eyes." He then went on to list the various cells that are absolutely required for a working photoreceptor in an effort to show that multiple mutations with no benefit would need to exist for generations before anything light sensitive could kick off the evolution of an eye...then I pointed out single-celled organisms that exists today, euglena, that demonstrates phototaxis (movement according to a light source) via a photoreceptor literally called an eyespot. At this point his brain seemed to get caught in a feed back loop.

There are many ways to deny evolution, just none that I've found are internally consistent or based on reality. For a reading of the exchange that prompted this post click here.

1 comment:

  1. Their sacred conclusion isn't based on evidence and has to be protected at all costs, even at the expense of personal integrity.