LucidDreamer

I wouldn't say that it would be impossible, but I believe that it might be improbable. I admittedly don't know a great deal about 4 stranded DNA, but from what I know about double stranded DNA I don't think that a 4 stranded DNA molecule would be very stable. Since we assume that chemistry on other planets will work similar to our own I think a 4 stranded molecule would not be useful and therefore it would be not selected during evolution.

No way to tell. My guess is that it would be quite different because of the whole "butterfly effect."

Well, its saying that machinery involved in transcription (the process where DNA is copied to RNA) is prevented from working correctly when you use a triple helix instead of a double helix. So, that means that the current system of storing and translating our genetic code cannot operate with a triple helix. That could be just because life evolved around a double helix and doesn’t mean that a triple helix system isn't possible. Also, these studies were done on Eukaryotes, so you can't tell what effects a triple helix might have on a prokaryote from this article.

"Triple helix DNA alters nucleosomal histone-DNA interactions and acts as a nucleosome barrier. Oligonucleotides which form triple helical complexes on double-stranded DNA have been previously reported to selectively inhibit transcription both in vitro and in vivo by physically blocking RNA polymerase or transcription factor access to the DNA template. Here we show that a 16mer oligonucleotide, which forms triple helix DNA by binding to a 16 bp homopurine segment, alters the formation of histone-DNA contacts during in vitro nucleosome reconstitution. This effect was DNA sequence-specific and required the oligonucleotide to be present during in vitro nucleosome reconstitution. Binding of the triple helix oligonucleotide on a 199 bp mouse mammary tumour virus promoter DNA fragment with a centrally located triplex DNA resulted in interruption of histone-DNA contacts flanking the triplex DNA segment. When nucleosome reconstitution is carried out on a longer, 279 bp DNA fragment with an asymmetrically located triplex site, nucleosome formation occurred at the border of the triple helical DNA. In this case the triplex DNA functioned as a nucleosome barrier. We conclude that triplex DNA cannot be accommodated within a nucleosome context and thus may be used to site-specifically manipulate nucleosome organization." Nucleic Acids Res. 1995 June 25; 23(12): 2184–2191 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=307006

But going to the trouble to really understand a current scientific theory isn't as much fun as learning just a tiny bit and then coming up with my own crazy theory that appears to be better than the original because of my lack of understanding.

Chromosomes are not like boxes that store goods. The chromosomes are not a separate component from the DNA. The chromosomes are the DNA that is wraped around proteins called histones. The chromosomes just refer to a state that the DNA exists in when it is tightly condensed, in distinct units, and associated with certain proteins. Each species has a unique karotype that can be used to identify it. The amount of chromosomes and the banding pattern of each chromosome are specific for each species. Comparing chromosomes is a valid tool for identification of a species and determining the relationship between two organisms. Chromosomal comparison is just one of many independent forms conformation that establishes the common descent of life. It may not be broken, but why create a common flaw? Endogenous Retroviral Sequences are errors where a virus inserted some of its DNA into a host gamete. I think I would fire a builder who was so careless in his designs. Thousands of locations in the humane genome contain Endogenous Retroviral Sequences. It is almost unthinkable to imagine a virus inserting itself into exactly the same spot in an entire population of a species while simultaneously inserting itself into the exact same locale in entire populations of many other species. You have not thought this argument through. Why do "all" Asians have jet black hair? Why do they "all" have brown eyes? The answer is simple. A small population of individuals separated from the rest of man and made his home in Asia. This group had these traits, either all of the members had these traits or the majority did and the other traits were lost by selection or drift. The event that you are calling "very unlickely" has already occurred many times. A very similar occurrence produced a population that all have the same endogenous retroviral sequences. There are hundreds of examples where an entire small isolated population has DNA sequences that have no conceivable advantage or disadvantage that the rest of the world does not have. It doesn't take a great imagination to see that if this were the only population to survive that all of the members of that species would have that DNA sequence and all of species that evolved from it would to, unless of course it was lost by the same means. Misinterpretation of the chart. DNA all has the same handedness. Finding the ERV's does not require searching the DNA with a fine-tooth-comb. Trying to imagine an ancient virus completely different than today's is a little farfetched.

I don't think we can always make an absolute distinction between instinctual and learned behavior. I believe that almost everything has some kind of genetic component and there are usually learned behavioral aspects as well. I imagine that kissing leans towards the learned behavior side of things. I’m guessing that there were a few tribes that didn’t kiss. Were Eskimos one of them?