Monday, November 2, 2009

Response to Robert Carter

By Kristopher Hite

This rant was composed after reading about a "geneticist" named Robert Carter who recently gave a three part lecture series in Fort Collins, Colorado on how Darwin was wrong and "modern science" disproves evolution.

Intelligent design proponents sure know how to put on a show. Sad to see that they really never talk about actual science. I'd like to know how our collective modern understanding of genetics, species, biochemical processes, proteins, plate tectonics, and sedimentation disprove evolution. To me the scientific method has uncovered an enormous amount of data to back up some of Darwin's fundamental postulations.

Evolution by means of natural selection through descent with modification. That was Darwin's novel concept and that has indeed withstood the test of time. Emerging information is constantly incorporated into the overarching theories that make up the cornerstones of modern science. And evolution is one of these cornerstones.

Since I opened by complaining that Robert Carter did not anywhere in this article talk about any actual science let me follow my own advice. While studying biochemistry it is impossible to avoid making some observations that can be very well explained by evolution. This happened for me recently while contemplating the molecules known as the porphyrins. These are the conjugated macro-cyclic rings that hold iron in its place in hemoglobin (the proteins in blood that shuttle oxygen around the body). These SAME molecules - the porphyrins - are also used by plants to hold magnesium atoms in place to do some of the key enzymatic reactions converting light energy to chemical energy in the chlorophyll. In both humans and plants the same set of enzymes build the porphyrin molecules though in the end the molecules have different functions. However, when the genetic disease porphyria arises in an animal a strange thing happens. The mal-formed porphyrins revert to their plant function as light harvesters. Indeed these molecules exist as non-functioning metabolites in any animal with a gall bladder. Called bilins these molecules serve no function other than to make the bile the green color. But in plants the "phycobilins" actually decorate the thylakoid membrane within the chloroplast and help harvest and subsequently direct light energy into the photo-centers (where the reactions that turn light energy into chemical bonds happen). In a human patient with porphyria these bilins build up to high concentrations in the skin, blood, urine and tooth enamel.

The tooth enamel is where an observer can see these molecules revert to their evolutionary heritage. When UV light is shone on the teeth of a patient of porphyria, the teeth glow! The mal-formed porphyrin molecules are reverting to their plant function - harvesting light energy! In this one instance we see that the biochemistry of humans and plants are one and the same.


We do have a common ancestor with all life in fact, and the keys to understand this fact lie in the base paired code of our genome. We can see what we call homologs. Basically these are genes that are the same in more than one species. But not only that, we can trace back, through molecular phylogeny, certain genes that have duplicated and then diverged in their ultimate function. The porphyrin-containing family of proteins is one example but there are thousands of others. This simple observation blows the "irreducible complexity argument" favored by so many intelligent design proponents, out of the water because it explains how the seemingly infinite complexity of the cell can actually be explained by the emergence of new genetic "concepts" by the process of gene duplication and divergence.

Until a vast majority of the global population can move past this silly debate of whether all living things on earth were created "as is" by an invisible sky-father 6,000 years ago, or the product of millions and millions of years of evolution by natural selection driven by descent with modification, we really can not move forward toward any kind of sustainable future. In fact, if we keep bickering about this nonsensical non-science we will most likely have a real-world rapture of our own making in the form of global resource wars caused by climate refugees, resource depletion, and overpopulation. Only by understanding why the dodo and the dinosaur went extinct can we hope to postpone our own extinction.
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