   Reason for Sexual Beings?
  Has science come up with an explanation to why nature invented sexed life forms?What is the advantage of such a system?   
  I think the advantage is that the genes mix and spread more this way.   ;  And the desire to procreate even if you don't want any (more) kids.   ;Quote:Original post by LodeI think the advantage is that the genes mix and spread more this way.hmmmm.... could you elaborate a bit more?Quote:Original post by tstrimpAnd the desire to procreate even if you don't want any (more) kids.Ok, but I think you're mixing disire with ability. There are asexual beings that can procreate in the dozens, or thousands, and cant do it more often because of caloric limitations (development of the fetus or eggs takes a heavy toll on the progenitor).   ;Quote:Original post by Prozak[...]hmmmm.... could you elaborate a bit more?[...]Standard asexual reproduction has mutation, sut since only one individual is involved, there is no sharing of genes ('crossover'), thus genes from individual entities don't get mixed as much and you have what amounts to inbreeding (and thus genetic decay or whatever other problems that causes).By allowing genes to mutate (slightly - lots of code in DNA is to prevent excessive mutation iirc) AND mix between individuals, a local maximum can be reached in many fewer generations than would be the case with only mutation. Or so it appears in the greatly simplified representation of DNA we use for searching large spaces - Genetic Algorithms.As to why it didn't invent some kind of asexual reproduction that required multiple entities (ie making all members of a species hermaphrodites), perhaps it's because it creates too many vulnerabilities (two sets of vulnerable organs, more energy to support them both, etc) with too little gain (all members can share genes to make offspring vs one half with the other half).   ;Quote:Original post by ProzakQuote:Original post by tstrimpAnd the desire to procreate even if you don't want any (more) kids.Ok, but I think you're mixing disire with ability. There are asexual beings that can procreate in the dozens, or thousands, and cant do it more often because of caloric limitations (development of the fetus or eggs takes a heavy toll on the progenitor).Ah, I didn't read the OP correctly.   ;  Example of how sexual reproduction is useful:At each time, population has individuals with different beneficial mutations. For example, there may be mutation of one gene that gives larger brains and other gene that gives better hands and mutation of third gene that improves immune system against some disease, etc.Really many beneficial mutations enhancing survival/reproduction , scattered around the population.Without sexual reproduction (or bacterial conjugation for bacteria), eventually one "most useful" or rather "most lucky" is selected. Rest is irreversibly lost. Also, the "best" one will inevitably have many "bad" mutations in other genes.With sexual reproduction, all these mutant genes will increase in frequency in this population, so you will get them all.Better yet, we are diploid. And everyone carry two copies of each gene, often of different version. It is kind of long to explain all effects, but the point is that some information is preserved even if not visible in phenotype. It is overally good.Practically all life transfer genes; bacterias who don't do it sexually use bacterial conjugation instead.   ;  Take a look at the book The Red Queen for an in-depth discussion.The short answer is simple: parasites.The long answer is that asexual reproduction doesn't mix things up quickly enough to combat parasites.  Sexual reproduction no only does this, but it can help propogate immunities that would otherwise have to be "discovered" by individual bloodlines.  Sex is essentially adding a communications medium for genetic information.   ;  Ok, interesting replies. I've found sexed reproduction useful in my AI research, because the units developed mechanisms to inspect other unit's genes. In my simulation, a gene is a value that controls something in that unit's body or Neural Network. An easy example would be a JILP gene (jump into lava pit). This gene usually has a negative value (unit avoids jumping into lava pits), but if some sort of mutation occurs, and this gene turns into a positive value, then the unit might jump into a lava pit, if it finds one.So, in my current simulation, units have the ability to read each other's genes. This gives them a tool that enables them to compare themselfs to other units, and try to find a close match (a mate).Having problems in finding a mate might mean that that unit has a set of genes that are quite diferent from the norm, and is geting rejected.In the general population, this system of reproduction reenforces good genes, like the "lets search for food" gene, and starves off certain genes, like the JILP gene.I mean, if both mates have their JILP gene at a deep negative value, then their offspring will also have a negative JILP gene, it's a way of saying "if you think that is bad, and if I think that is bad, then we shouldnt pass that off onto our offspring".Over time, some behaviours will get ingrained onto their NN, for example, avoiding at all costs any contact with JILP gene-carrying units.I just wanted to know if the scientists of natural laws thought that the causes for the development of sexed beings where more or less in line with what I had just observed.(Note: All examples above where meant as ilustrations of my work, and the simulation is vastly more complex than anything described above).   ;Quote:Original post by ExtrariusQuote:Original post by Prozak[...]hmmmm.... could you elaborate a bit more?[...]Standard asexual reproduction has mutation, sut since only one individual is involved, there is no sharing of genes ('crossover'), thus genes from individual entities don't get mixed as much and you have what amounts to inbreeding (and thus genetic decay or whatever other problems that causes).By allowing genes to mutate (slightly - lots of code in DNA is to prevent excessive mutation iirc) AND mix between individuals, a local maximum can be reached in many fewer generations than would be the case with only mutation. Or so it appears in the greatly simplified representation of DNA we use for searching large spaces - Genetic Algorithms.As to why it didn't invent some kind of asexual reproduction that required multiple entities (ie making all members of a species hermaphrodites), perhaps it's because it creates too many vulnerabilities (two sets of vulnerable organs, more energy to support them both, etc) with too little gain (all members can share genes to make offspring vs one half with the other half).Explained in The Red Queen TheoryQuote:One possible explanation for the fact that nearly all vertebrates are sexual is that sex increases the rate at which adaptation can occur. This is for two reasons. First, if an advantageous mutation occurs in an asexual line, it is impossible for that mutation to spread without wiping out all other lines, which may have different advantageous mutations of their own. Second, it mixes up genes. Some genes might be advantageous only when paired with other genes, and sex increases the likelihood that such pairings will occur.