Evidence for evolution, Installment 1: Endogenous retroviral sequences

by seattleniceguy 38 Replies latest jw friends

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  AlanF

  AlmostAtheist said:

  : The retroviral infection would have occurred in only one member of the species, true? Then it would have spread through the population via reproduction. Today, do all members of the species carry it? If so, why? Wouldn't there be lineages that carried it and others that don't?

  I don't know the answer for sure, but based on my knowledge of how genetic characteristics spread through a population as explained by my readings on the so-called "mitochondrial Eve" theory, it may work like this:

  When a new characteristic that is neutral in terms of natural selection is introduced into an individual, random genetic drift occurs. This means that, purely by chance, the characteristic may or may not spread into the rest of the population over many generations. It's about as likely to die out as it is to spread. However, if it spreads sufficiently, the chances are virtually certain that it will end up in all individuals, as individuals that don't have it die out. Again, all of this is purely statistical in nature. It has to do with the fact that, in a large sample subject to "random walk" statistics, the extent of variation (or the length of the "random walk") is unlimited.

  This means that, depending on how far back in the lineage the new characteristic appeared, any number of individuals in a population may or may not have it.

  AlanF
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  seattleniceguy

  AlanF,

  When a new characteristic that is neutral in terms of natural selection is introduced into an individual, random genetic drift occurs. This means that, purely by chance, the characteristic may or may not spread into the rest of the population over many generations.

  I believe that endogenous retroviral sequences are different from what you described for two reasons:

  • Retroviral sequences can never be erased from the DNA, unlike genetic traits in general, which may disappear through breeding with individuals that do not have them.
  • All offspring of an individual with the retroviral sequence are guaranteed to receive it.

  The more I think about this, the more I see how it is inevitable that it will quickly move through into the entire population.

  SNG
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  hooberus

  Large scale function for ‘endogenous retroviruses’

  http://creationontheweb.com/content/view/6146/
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  BurnTheShips

  Scientific myths continue to fall. These retroviral sequences serve a purpose.

  http://www.physorg.com/news145038245.html

  More than 50 percent of human DNA has been referred to as "junk" because it consists of copies of nearly identical sequences. A major source of these repeats is internal viruses that have inserted themselves throughout the genome at various times during mammalian evolution.

  Using the latest sequencing technologies, GIS researchers showed that many transcription factors, the master proteins that control the expression of other genes, bind specific repeat elements. The researchers showed that from 18 to 33% of the binding sites of five key transcription factors with important roles in cancer and stem cell biology are embedded in distinctive repeat families.

  Over evolutionary time, these repeats were dispersed within different species, creating new regulatory sites throughout these genomes. Thus, the set of genes controlled by these transcription factors is likely to significantly differ from species to species and may be a major driver for evolution.

  There is a reason for everything.

  BTS
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  Deputy Dog

  sng

  The phenomenon described above is not that of finding DNA that codes for the same protein in multiple different species. It is the phenomenon of finding the DNA for an entire retrovirus at the exact same spot in two different species.

  Why wouldn't this have as much to do with the retrovirus as it does with the host?
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  cameo-d

  Very intriguing post.

  I wonder what a creationist could say to pooh-pooh it.

  I would think one could be able to see where creation and evolution merge.

  The human form and spirit was "created" and then eventually there was on-going genetic manipulation which has caused "evolution".
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  stillajwexelder

  this was a great series and I agree with AlanF- Climbing Mount Improbable was a great read
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  Midget-Sasquatch

  Hooberus,

  Since viruses actually replicate themselves by taking over the transcription machinery of their host, I'm not at all surprised by the findings (its interactions with transcription factors). So lets assume that they've found some functions for even up to 50% of "Junk" DNA.

  How does that invalidate the basic premise of this entire thread? That one can look at the insertion points of ERVs in different genomes and can draw out lines of descent matching what one would expect with evolutionary models?
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  Tuesday

  Wow, cool subject. For me, this and the merged chromosome 2 is the death knell for people who say evolution didn't happen.

  Someone here asked if there was a beginners version of Evolution they could read about, I think I can do one better in that if you go to youtube search for the username DonExodus2. He has a whole series that is very much in layman's terms. It is a fantastic series that I enjoyed alot.

  The final point I'll make is regarding this comment:

  Personally, I don't know if evolution is true or not, no one can really "prove it" beyond a reasonable doubt, yet.

  Whenever someone says this it usually is a confusion between First Cause and Evolution. Evolution is the transitioning of simple species into larger complex ones. If you want evolution to solve the first cause argument, it won't. However Abiogenesis does answer how life could come from non-life. Then Evolution proves how these simple organisms that were formed can then evolve into larger organisms. For the proof of evolution, there is so much it's crazy. Usually the biggest thing that opponents of evolution say is "We haven't seen anything evolve yet". However, we have. Just type in "Observed Evidence of Speciation" in google and you'll get hundreds of references. If I could suggest just two, the first is based on that old addage that "Hybrids don't reproduce" I introduce the red wolf which is a hybrid of a fox and a wolf. They indeed did not reproduce until recently, there are now enough of them that they do reproduce. Of course science being science since it now does reproduce it is considered a species. So technically still hybrids don't reproduce (mainly because when they do they are reclassified). The second example you should read is about the Italian Wall Lizard who when introduced Croatia developed a cecal valve. This is essentially a second stomach so that it could digest plant materials. This is pretty hard to miss as proof of evolution, the original Italian Wall Lizard is still available for documentation, the Croatian version developed this change in 30 years time.

  Hopefully that helps with yet more proof of evolution.