Science News
by MikeGeneLet's do a brief tour of some of the interesting science that has been done recently. We'll start with a demonstration that the eukaryotic nucleus can have direct access to the environment. While this was demonstrated in the single-celled Tetrahymena, I would not be surprised to see this pathway discovered in multicellular organisms. Direct communication with the nuclear contents is already made possible by lipid hormones and thus there may be other contexts where direct access is useful.
Recently, the regulatory sequences immediately adjacent to 6,280 genes on the DNA of chimps, humans and the rhesus macaque were compared and helped to confirm that much of the significant evolution involves changes in such regulatory regions (similar findings were also recently seen in comparative analyses of yeast). Not only do these data help to strengthen the perspective of evo-devo, but also my own perspective of Evolution Genes.
I've previously suggested the perspective of evolution as a form of learning. On a somewhat related note, along comes Jim Stone, who "discovered that learning in previous generations indirectly induces the formation of a latent memory in the current generation and therefore decreases the amount of learning required." In other words, "learning within each generation could guide evolution of innate behaviour over future generations." Juicy.
Chandra Wickramasinghe is back with further evidence to support his hypothesis of panspermia: "The researchers calculate the odds of life starting on Earth rather than inside a comet at one trillion trillion (10 to the power of 24) to one against." If the panspermia hypothesis was ever validated, I would feel quasi-validated. 
Finally, the potential of the RNA world is being more fully extracted with its crucial role in the evolution of the nervous system. The research focuses on alternative splicing and helps us appreciate introns from a possible teleological angle. Keep in mind the biotic RNA world is not the same thing as the geological RNA world (something I should post about).
August 16th, 2007 at 9:10 am
Since the late 1960's my perspective has been that biological evolution is essentially a form of "machine learning."
I was originally inspired by Fogel, Lawrence J., Alvin J. Owens, & Michael Walsh. 1966. Artificial Intelligence Through Simulated evolution. Wiley. NY. The idea that evolution is a form of learning recurs throughout the history of evolutionary thought. However, in the late 19th century the Neo-Darwinists definitively separated the two subjects.
"Construction of the phenotype from the information coded in the genome is often called the gene expression process in biology. Transformation of the DNA to the protein structure plays an important role in this process. Since the structure of the protein determines the efficacy of the DNA, gene expression can be viewed as the process of computing the mapping of the genotype to the phenotype. For some reason, it does not directly compute this function using the DNA itself. It first transforms the DNA representation to mRNA and subsequently to protein before evaluating its phenotype. Representation transformations play an important role in efficient problem solving in many fields such as physics, mathematics, engineering, machine learning, and optimization. Therefore representation transformations in gene expression allude intriguing possibilities. However, very little is understood about the role of gene expression in evolutionary search."
http://www.cs.umbc.edu/~hillol/Kargupta/ga.html
Marc Toussaint. 2004. The Evolution of Genetic Representations and Modular Neural Adaptation. Logos Verlag Berlin.
http://www.marc-toussaint.net/publications/toussaint-03-thesis.pdf
In nature we find beautifully complex organisms. The only way a stochastic search scheme like evolution can find such systems is by adapting the genetic representation. This work develops a theory on the implicit adaptation of genetic representations during evolution. Non-trivial genotype-phenotype mappings, neutrality, and the adaptation of phenotypic variability form the core of this theory. Complex, highly structured phenotypic adaptability, and rich innovatability triggered by neutral reorganizations of the genetic code can be explained in these terms. Some ideas are also transferred to neural adaptation.
http://homepages.inf.ed.ac.uk/mtoussai/
http://www.iscid.org/boards/ubb-get_topic-f-18-t-000027.html
Comment by Rock — August 16, 2007 @ 9:10 am
August 16th, 2007 at 9:12 am
From the link:
Rather than supporting panspermia this information indicates how shoddy are theories for the origin of life. This is more of the same asssociation of organic chemicals with cell generation. It lacks causal specificity. It also ignores some unpleasant realities namely, the destructive effects that a space environment would have on nucleic acids over extended periods of time. If nucleic acids are absent from the mix then so is much needed evidence for life arising through a chemical process.
Comment by Bradford — August 16, 2007 @ 9:12 am
August 16th, 2007 at 1:04 pm
I'd be very interested in seeing this calculation.
Comment by chunkdz — August 16, 2007 @ 1:04 pm
August 16th, 2007 at 2:24 pm
chunkdz,
I'll venture a guess it will fall under the rubric:
There are lies, damn lies, and statistics, and for those who need to prove absolutely anything, there is Bayes' Theorem with sufficiently vague assumptions, impenetrable symbology, and irreproducible algebraic manipulations.
Comment by David Heddle — August 16, 2007 @ 2:24 pm
August 16th, 2007 at 10:14 pm
Here's some more science news:
Volume 1, Issue 1 of AntiMatters, a scientific journal dedicated to publishing articles from a non-materialistic scientific perspective. AntiMatters is published by quantum physicist Ulrich Mohrhoff whom some of you are familiar with.
Take a look, I think you will find it most interesting. . .
Comment by mcromer — August 16, 2007 @ 10:14 pm