Posted by: Mr. C | May 9, 2008

Biology Textbook Mentions Evolution Controversies

This is an interesting post from Evolution News about the controversy stirring around a soon to be published biology textbook and the potential questions it raises about evolution.

Here is an excerpt:

——————————————————————-

No, I don’t much like the paranoid or ominous-sounding phrase “science establishment,” but for the moment, it will have to do. (I have in mind organizations such as the National Academy of Sciences, the major professional scientific societies that regularly issue anti-ID edicts [you know who you are], and lobbying groups such as the National Center for Science Education.) There is a growing disconnect between statements issued for public consumption by “the establishment,” about the certainties of evolution, and the actual state of evolutionary theory, as one finds it in the primary research literature, at meetings (such as the one Timmer attended, and where I often find myself), and in personal conversations and communications with evolutionary biologists (I speak from long experience). As that distance — that disconnect — increases, an inevitable crisis looms.

Here’s an example. Natural selection, as Darwin discovered, explains the origin of biological complexity, novelty, and innovation. There’s a stock phrase that populates any number of official statements about evolution. One could utter that statement in any biology classroom around the USA, and no one would blink. You know: Darwin found the process by which new structures evolved, where they did not exist before.

Now here’s the opening argument from a research paper I happen to be reading this week, from the evolutionary theoretician Armin Moczek (2008):

Given its importance and pervasiveness, the processes underlying evolutionary innovation are, however, remarkably poorly understood, which leaves us at a surprising conundrum: while biologists have made great progress over the past century and a half in understanding how existing traits diversify, we have made relatively little progress in understanding how novel traits come into being in the first place.

Advertisements

Responses

  1. Natural selection technically is not the source of novelty; it merely selects favourable traits so that they become more prevalent in the population.
    Basically, variation + selection –> evolution (i.e. allelic frequency within a population)
    That’s the mechanism of natural selection, and it’s been demonstrated in the laboratory (e.g. with bacterial cultures, Drosophila, etc), in silico, and in the wild (Darwin’s finches, marine snails, etc). but selection does not explain how the variation occurs. However, we know that variation does arise through spontaneous mutations (indels, duplications, inversions, frame shifts, polyploidy, etc), recombination, etc. The main issue is as to how these mechanisms can act to create the evolutionary novelties observed in the natural world. This is where the relatively new field of evolutionary developmental biology, or evo-devo comes in. Evo-devo scientists are discovering that mutations in regulatory genes can produce variation. For instance, mutations in the Bmp4 gene have been shown to affect beak morphology in Darwin’s finches, which can be selected for or against.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Categories

%d bloggers like this: