Nemesis writes:
Aside from this, the GLO gene apparently can make jumps in between the evolutionary tree.
No claims of genes "jumping" were made by the Answers in Genesis article, let alone the original paper.
Nosy writes:
I have been reading over the article. It claims to show that reseach casts doubt on the idea of pseudogenese being support for common ancestry.
Unfortunately, I haven't been able to get a copy of the original paper (which the AIG article chooses to cite with three different footnote numbers rather than one), which would be extremely helpful in analyzing AIG's analysis.
The original paper (
PMID: 14703305) is from a Japanese journal I have never heard of before: The Journal of Nutrional Science and Vitaminology. While I'm not saying this discounts the research in any way, it is important to note that it is not in a genetics journal.
Working a bit from the somewhat confusing abstract - the functional rat gene has twelve exons, and the non-functional human pseudogene retains five of these exons. They compared differences in guinea pig and human sequence for these five exons using rat as the baseline sequence.
From the AIG article recounting the paper, it seems that about one-sixth of the nucleotides differed from rat; of these, about half differed at the same position in the same way. They then quote the original article:
This extremely small probability indicates the presence of many mutational hot spots in the sequences.
For some reason AIG "jumps" to the conclusion that this destroys pseudogene-based comparisons as a means of examining common ancestry. There are some issues:
- No one in the scientific community is attempting to build tree-of-life level phylogenies with a single portion of a single gene.
- Mutational hot-spots are an area of active investigation by evolutionary biologists, who exclude some types of hot-spots from phylogenetic analysis.
- They selectively examined exonic sequence that may be under some level of selection even in psuedogene form (which is perhaps why both guinea pig and human genes mutated to having four stop codons - to prevent unnecessary or aberrant transcripts).
- Examination of the entire remnant of the gene in question may have revealed an entirely different pattern of inferred relationships than that using the exonic sequence alone.
- They only used three species. It would be interesting to repeat the research including more than one functional gene, as well other pseudogenes (fruit bat and chimp).
- AIG is assuming that rats and guinea pigs are more genetically similar to each other than humans, simply because they are both in the order rodentia. Without data this is just a layman's assumption.
- The research hasn't been replicated. Maybe some of the "guinea pig" sequencing reactions were contaminated with human DNA.
These are just some potential problems off the top of my head. The primary reference cited by AIG, if reproducible and expanded upon, might serve as an interesting foundation to study how mutations accumulate in a non-random manner as genes "degrade".
However, such a simple analysis of one specific portion of one pseudogene in only three species in no way falsifies the method of using genetic sequence to establish common ancestry.
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