the_Nothing

Does anyone here have a good understanding of the life cycle of the HIV virus? I have a question that is pretty specific... I actually joined the forum to ask it, but the more I think about it the less I think I'll get a response... anyways, here goes. My understanding is that when the HIV virion spills its contents into the host cell those contents consist of the following: RNA genome Reverse transcriptase Integrase Protease The reverse transcriptase transcribes the RNA into DNA; the integrase splices the DNA into the host genome; when the host cell begins its reproductive phase it transcribes the HIV DNA into mRNA; the mRNA is translated into HIV precursor proteins; and then the HIV protease (that was first dumped into the cell) comes around and cleaves these precursor proteins into active proteins that construct the HIV virus and causes it to bud off the cell back into the blood stream. My question is: How does the protease find the HIV precursors? Isn't there a period of time before the cell reproduces before HIV DNA is even transcribed? How does the protease persist in the intracellular environment? Does it somehow stick around the area where the HIV DNA is going to be transcribed? Otherwise how could it possibly be effective at such a low concentration? I was trying to write a description of the HIV life cycle and I realized that I had no idea what was going on with the protease, and I think these questions are reasonable unless I'm missing something? Just putting it out there, thanks to anyone who can provide some insight!

My sense is that most people who ask this question are thinking of a scenario where there is no selective pressure and almost everyone survives to pass on their genes. So there are no "bad" genes anymore and we don't "evolve". However, in this case there would be no possible way for evolution to end! In a theoretical situation where no genes give a reproductive advantage then evolution will be dominated by genetic drift. Which basically just means randomness. Some alleles will eventually dominate the population until they are displaced by other alleles - which are generated randomly by old-fashioned mutation, and then eventually - by chance - some other allele will rise up to dominance. This is a mathematical certainty given no selective pressure and the fact that mutation is possible. (In this scenario, if mutation did not exist then we would eventually lose all diversity and become genetic clones of each other. One female clone and one male. That would end evolution I imagine.) The strange truth is that - because of the genetic drift scenario above - the only way that our population will maintain the same frequency of alleles over time (and we are therefore not evolving according to our definition) is IF there is some kind of selective pressure that is weeding out new genes. Furthermore this selective pressure would have to be constant and unchanging so any deviation from the genetic norm would give that person a poorer chance of reproducing and eventually those genes would get weeded out. This scenario isn't necessarily impossible - we see many species that have maintained the same apparent body shapes over millions of years. It just implies that humans haven't yet escaped the restrictions that nature places on us. So when will human evolution end? When we can artificially control the frequency of all alleles in the human population. And we don't decide to change them. Please let me know if I missed something important!!