Week 3 blog response ESS

Dawkins states that an ESS is the best strategy for an individual depending on what the majority of the population are doing. An ESS is most important because it is applicable wherever we find conflict of interest and that is everywhere! Fisher states that a sex ratio of 50:50 is an ESS. This is due to the fact that if at any point a single sex outnumbered the other, the mating numbers would be disproportionate. If males outnumbered females, the opportunity for each male to have a mate is thus decreased and vice-versa. If each individual is trying to maximize his "own" success, then there must be an equal sex ratio being the 50:50 half males half females.
Conversely if you were to look at sex ratios of autosomal nuclear genes are transmitted to offspring through both of the sexes, so the sex ratio that must be favored is a balance between producing male and female offspring a 50:50 ratio. One can argue however that due to the fact that male species cannot produce offspring themselves, they are not necessary which would discount the male altogether. In contrast, cytoplasmic genes are mainly inherited through the egg cytoplasm and thus transmitted to offspring only through females. This means there is a strong selective pressure for cytoplasmic genes that distort sex ratio toward female production placing the sex ratio to 100:0 in favor of the females. And as previously stated, the sex chromosomes favor the 50:50 ratio potentially solely for mating purposes.
Two of these sex ratios could be the same because of the passing of genetic information through both sex chromosomes and autosomal chromosomes(as long as males were not discounted for not having the ability to produce progeny). The sex ratio of cytoplastic elements is different because that is only passed on through the mother and the male can completely be discounted.

Blog response week 2

Reading both Mayhew and Dawkins, I tend to lean a bit more towards Dawkins in his primordial soup theory. This is the theory that I personally have been taught my entire life. I feel that Dawkins tends to agree more with Darwin in the theory of evolution by natural selection than maybe Mayhew expresses. Dawkins tells of the primordial soup which contained purines and pyrimidines, the "building blocks of DNA itself." Dawkins idea that, "the situation only had to arise once" appeals to my understanding because that is all nature really is, is chance meetings at the right place and right time. Dawkins view also holds that mistakes happen (that is why evolution happens) and that is how eventually the survival machines he speaks of came to exist. In order to protect themselves, the genes had to develop some sort of defense, then develop the capability to compete for resources, and later to pass on that information to future generations.



Mayhew on the other hand looks at an autotrophic origin of life which recently has re-emerged. his argument is that early life probably lacked protein enzymes to catalyze reactions, using RNA instead. The problem that I tend to have with this is that Dawkins idea of a primordial soup contained the precursors for DNA. And, laboratory experiments done on inorganic materials exposed to ultraviolet light and or "lightening" produced something along the order of amino acids. I do not think that Mayhew recognizes such studies have been performed.

It is obvious that not a single person was around at the time of creation and that we may never know what truly happened at the origin of life, but that is why scientist formulate hypothesis... educated guesses... We can only speculate and thus will be divided in theories.

In regard to Darwin's statement that, "The origin of most of our domesticated animals will probably forever remain vague", scientific advancements in genetic mapping may well have far exceeded his expectations. Molecular comparisons on canines have been a fairly recent phenomenon that have and continue to yield the answers to the origin, at least of the canine. If indeed, as Darwin stated, that "all our races of dogs have been produced by the crossing of a few aboriginal species" why was it that he concluded that pigeons were derived from one single species? The modes of reproduction are essentially the same as is the transfer of genetic materials to offspring...random. Where is the wild poodle, if in fact Darwin is correct about crossing a few aboriginal species? Darwin's theory of Evolution by Natural Selection could, in fact, account for one common ancestor which had attributes that made it strong enough to survive in a particular environment. I am not clear as to why that appeared to be lacking in his conclusion about the origin of the canine.

Unfortunately, Darwin overlooked Mendel's studies of inheritance. An example of this was when Darwin bred snap dragons for only one generation. His result was that the offspring were an average of its parents, which we well know is untrue today. People can select for specific traits in animals. If you look at the Labradoodle as an example, a Labrador and a poodle were bred. The resulting individuals were a mix of parents genetics. But if you breed them with another Labradoodle, the result will revert back to the parental type.

Dawkins looks at this from a different point of view. He states that,"a predominant quality to be expected in a successful gene is ruthless selfishness." Any species with altruistic qualities will eventually die out and the selfish ones will be the only ones to survive. Dawkins also states that the fundamental unit of selection, and therefore of self-interest, is the gene. You must compete to survive, and if the unit is stable then it will survive.

One possibility of domestication of the dog is that after ancient hunters had made a kill, the less fearful wolves, or aboriginal species, gathered around to scavenge the remains the humans left over. After repeated times of doing this, the wolves may have learned to follow the humans back to their homes and stick around in hopes of stealing food supplies, receiving hand outs, or even just a more sheltered area. If this happened, the hunters possibly gained companionship and potential protection from outside groups of more aggressive wolves or any other predators. If the more tame wolves began to eventually rely on humans, they possibly were more comfortable giving birth in close proximity to human living areas. And, if this were true, as the progeny grew, they would have been around humans from day one and perhaps would have been accustomed to even letting humans touch or harness them as long as they received something in return such as food or shelter.