Friday, January 22, 2010

Destroying "Intelligent Design" into single-cells :)

I wish I had more time to read up on science articles that are not too complicated for me.  I am glad with this recommendation that Ron Bailey had.  This article, in the Journal of Eukaryotic Microbiology that offers a lit-review of the evidence that punctures the argument of the Intelligent Design folks.  And the evidence is all from the single-celled world! 

While it is true that I will not be able to comprehend the finer details of the terms used, I was blown away by this paragraph in that article:
When one considers the tremendous diversity of protistan forms (see Adl et al. 2005), the array of body plans among the Cambrian metazoa pales in comparison. In terms of biological diversity it can be argued that no group approaches that of the protists, especially if one considers that all the plants, fungi, and animals, including the famously diverse Coleoptera, are merely sub-groups of the protistan clades Archaeplastida and Opisthokonta (Adl et al. 2005). Even with the exclusion of the multicellular ‘‘higher’’ eukaryotes, the morphological and physiological diversity among protists is staggering. The major clades of protists contain everything from photosynthetic autotrophs to amitochondriate flagellates and are found in virtually every habitat on Earth (Foissner 2008). The extant diversity of the protists should therefore be seen as the ‘‘background radiation’’ of the eukaryotic Big Bang, with the Cambrian radiation of the metazoa being a subsequent event within a specific group.
I had no idea that there was such a tremendous diversity of those tiny single-celled critters.  The metaphor of the "background radiation" before the biological big bang also really, really appeals to me
And when I read the following paragraph, I thought how cool it will be if the DNA had some kind of a time-stamp on it!!!  I mean, that time-stamp alone can come in handy in everything from crime-scene-investigations to solving the puzzle of when life originated.  Hey, maybe it is encoded somewhere and we are yet to figure it out :-)
As readers of this journal know, DNA sequences are not like birth certificates, stamping an organism with the time and place of its origin. Ancestries inferred from DNA-based methods are founded on comparison of sequence or genomic data, evidence-based modeling of how DNA changes over time, and calculations of the most credible relationship between genetic sequences or patterns. This is just as true for variable number of tandem repeats (VNTR, or so-called ‘‘DNA fingerprint’’) analysis, which is broadly accepted in courts of law, as it is for deep phylogenetic analyses encompassing hundreds of millions of years of evolutionary history. For that matter, acceptance of ‘‘written geneaological records’ requires confidence that the records are not false or misread. Therefore, all methods for determining the history of an organism (except for the direct observation described in the previous section) require theory and well-grounded inference, just as stratigraphic analysis does; they stand or fall together.

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