KnightWhoSaysNi

One of the most powerful and persuasive pieces of evidence for evolution and common ancestry are vestigial molecular characters. These are genetic fingerprints of genes that have been rendered non-functional. They create an embarrassing problem for creationists who reject that humans had common ancestry with other animals.

My most favourite example is the gene that synthesizes vitamin C for most animals, except for primates and a few others. Humans and primates have the gene but a mutation rendered it non-functional, turning it into a pseudogene (it should be noted that all primates share the same the same type of mutation for it).

We also once had the capability to smell a lot better. 70% are our odorant receptor genes are now pseodogenes, while those of other mammals are fully functional. There are some other examples mentioned <a href="http://www.talkorigins.org/faqs/comdesc/section2.html#molecular_vestiges" target="_blank">here.</a>

At some time in the past, we had ancestors who can synthesize their own vitamin C and can smell better, but mutations made these genes non-functional. Despite the loss of function of these genes, they did not affect survivability and they continued to pass on their genes to the next generations.

I suppose a creationist could argue that the loss of function of these genes all occured within the human time frame after the Fall. But in the case for the vitamin C pseudogene, how would they explain the amazing coincidence of the other primates developing the exact same mutation!

Does anyone know any other recent cool findings showing vestigial molecular characters in the human genome? I'm predicting that biologists will find more of these types of pseodogenes eventually, if they haven't already been found. For example, I wouldn't be surprised if they find a pseudogene that codes for making gills that allows us to breathe underwater, or a pseudogene that gives us a lot more body hair, or a long tail, or claw-like fingernails, etc...

Something else just occured to me that would be an interesting test for macro-evolution.

From looking at the G-banding, telomeres, and centromeres of human chromosome 2 and chimp chromosomes 2p and 2q, we obviously have strong evidence of a chromosome fusion event (see <a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=001509" target="_blank">this post</a>). Now if we take our ancestry even further back into the past, there must have been other fusion events that occured.

Do we in fact find evidence of pseudogenes in our DNA that represent ancient, but long non-functional, centromeres and telomeres? Has any interesting research been done on this? Do we have some interesting 'jigsaw puzzle' similarities with fish, amphibians, and other animals based on vestigial telomeres and centromeres and the G-banding?

[ October 11, 2002: Message edited by: Nightshade ]</p>

scigirl

Nice post, nightshade.

In answer to your question - yes there are lots and lots of examples of pseudogenes, and also duplicated genes, in many different species. Just do a search on <a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi" target="_blank">pubmed</a> sometime!

scigirl