Sunday, December 31, 2006
Walt Brown Weighs in on the Canyon
Wednesday, December 27, 2006
The Tsoan Monobaramin
Lightner's basic points:
- Ovis (sheep) interbreed readily with each other
- Capra (goats) interbreed readily with each other
- Capra and Ovis mate often when in the same location. While viable offspring is rare, there are confirmed cases.
From the chart, it seems that the main confirmed data linking Ovis to Capra was a viable hybrid of O. Canadensis with C. Hircus.
UPDATE -- apparently my eyes deceived me. I don't have it in front of me, but Jean let me know that I misread the chart and Capra and Ovis are linked by a hybrid of O. aries and C. hircus.
She also pointed out the significant homology between the sheep, goat, and cattle genomes. Goat and cattle are the most closely aligned, both having the same number of chromosomes (60) and similar layouts (both have 29 pairs of chromosomes with the centromere near one end). The sheep genome differs slightly, but can be easily explained by two robertsonian translocations, which Lightner points out seems to be nonrandom and has a driving mechanism.
I find the genetic data very interesting, but would caution the reader against assuming too much, considering that the genome may not even be the primary originator of form.
Lightner pointed to an interesting paper, Parental origin and the timing of de novo Robertsonian translocation formation.
Lightner, Jean. "Identification of Species within the Sheep-Goat kind (Tsoan monobaramin)," Journal of Creation 20(3):61-65.
Environmental regulation of gene expression
Gilbert argued that the environment regulates and instructs gene expression through:
- The neuroendocrine system (example: Butterflies are differently colored based on ecdysone, which is produced based on temperature and daylight signals)
- As an embryonic inducer (example: Bacteria help gut formation)
- As a transcriptional modulator (example: proper methylation is dependent on diet)
Gilbert's main thesis is that the environment provides information to the developing organism. I actually agree with his thesis, but I don't think that what he has presented is a forceful argument for the proposition.
If I give you a set of instructions, and the instructions have a requirements list, if the requirements were not available then the end result would be different, probably a little worse off. For example, if you were baking bread and lacked flour, that would lead to improper bread formation (though I know a few cooks who could probably pull it off). That doesn't mean that the flour is in any meaningful way instructing the bread-making. The instructions are still fully-contained within the recipe and/or the cook's mind. If the requirements are not present, the result is deficient, not different.
If, however, the recipe says "buy X from the store and follow the preparation instructions on the package (varies by brand)", then in fact the ingredients are instructing the development of the recipe. Having different brands gives you different results, but none of them are deficient. Gilbert's paper suffered greatly because he used deficiency as a substitute for difference.
If the environment is truly instructing the organism (and I think it is), here's some things we may expect to find:
- If an organism is transplanted from one environment to another, it will develop symbioses with different bacteria after a generation or two.
- Different (healthy) diets of mothers will cause different methylation patterns. These methylation patterns will activate/repress genes as appropriate for the type and quantity of food being consumed. The methylation patterns will prepare the new baby for the nutrition available.
- Different temperatures/conditions will cause a change in an organism that will benefit the organism in the environment they will face, for the season they will be born into..
Gilbert's previous paper actually made a much better case, and I'm surprised he mentioned it only briefly. It focused on predator/prey relationships that were managed by kairomones (where the prey would develop differently based on predators in the area!) among other things.
Anyway, I have great hope for this line of research, but this particular paper doesn't get us there.
Saturday, December 09, 2006
BSG 2007 and a Request for Help
Along those lines, I am requesting help for my own research project for the conference. I am looking for someone else in one of the following areas:
Those are pretty broad categories, I know, but there are several different directions I could take the research, and it largely depends on who I can find to help! Anyway, email me at firstname.lastname@example.org with the subject BSG 2007 if you are interested in possibly helping. You can be as involved or uninvolved as you want, but at minimum you have to be willing to co-present at the 2007 BSG conference.
Note that this project has nothing to do with the age of the earth, so OECs and ID evolutionists are welcome to help out as well.
Anyway, if you have the slightest inkling to want to help, let me know and I'll get you further details before you say yes or no.