Genome complexity: de novo or orphan genes (Introduction)

by David Turell @, Wednesday, February 17, 2016, 15:49 (2983 days ago) @ dhw

No one knows how they arise or how they work as part of the evolutionary process. this is because they are 'new', not related to any in he past:-http://www.evolutionnews.org/2016/02/reader_asks_are102596.html-"Despite these disagreements, de novo genes do exist. But when their origin -- where they came from -- is discussed, it reveals yet another assumption of evolutionary biologists. Evolutionists say, "Look, these orphan genes arose de novo. We can see how they might have been spliced together from similar DNA present elsewhere in the genome, or they might have come from non-coding DNA that has acquired a promoter or transcription factor binding site, and so is now expressed, and makes a functional protein, in the right place and at the right time." -"These sentences reveal the second assumption -- that the existence of these new genes indicates there are natural processes to make them. After all, it must be possible to splice or activate new sequences to make TRGs, because there are TRGs (taxonomically restricted genes) . -"That's an assumption of naturalism. The problem is there is no evidence to show that those proposed mechanisms actually work. There are no experiments that I know of to demonstrate that splicing yields functional products. Attempts in the lab show that splicing together even related protein domains yields non-functional products. Also, no one has shown that it is easy to acquire a promoter or transcription factor binding site so as to turn inactive, non-coding DNA into expressed, functional DNA. Getting a functional protein from random non-coding sequence is impossibly hard and would have to be demonstrated. If the function is regulating other genes via RNA, that would have to be proven to be feasible, too.-***-"Bear in mind that TRGs can be up to 10-20 percent of a taxonomic group's genome, and may encode many of the special proteins unique to that taxonomic group. That's a huge chunk of DNA to arise by natural processes alone, and a big challenge for common descent. I am thinking of the phylum Cnidaria here. All Cnidaria (sea anemones, jelly fish, and Hydra for example) have tentacles with specialized cells called cnidocytes or nematocysts, which eject a little barbed tubule with a toxin into whatever touches them. They use these cells to capture and immobilize their prey. Many of the specialized proteins needed to make the nematocysts are TRGs specific to the phylum Cnidaria. Cnidaria are among the oldest of all extant phyla. Was their origin unique?"-Comment: Origin still unknown. Lots to explain. Could they be designed as drivers of complexity?


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