Fisher stated that a sex ratio of 50:50 (males: females) is an Evolutionary Stable Strategy because it is a system that auto-balances maintaining equilibrium in mating success of the population. Dawkins states that the best strategy for an individual depends on what the majority of the population are doing (Dawkins, 69). If there is a mechanism that induces a sex bias, decreasing the mating success of the population, it would not evolve, and would not be an ESS.
Cytoplasmic elements won't be 50:50 because they all of different jobs within the cell that they have to accomplish. With all of the elements having different jobs, they would never encounter themselves so their won't be a bias. When it comes to sex chromosomes and autosomal chromosomes, I'm not 100% positive on this but, I would like to think that sex chromosomes should favor bias sex ratios and autosomal chromosomes should favor equal ratios. Sex chromosomes favor uneven bias because they determine whether an individual is going to be XY or YY. By doing this the determine the sex needed to achieve maximum reproductive success. Autosomal chromosomes should favor equal sex ratios because they are chromosomes that everyone needs so there is no competition. They are also there so that good genes are passed on to both males and females.
Monday, September 28, 2009
Sunday, September 20, 2009
Mayhew and Dawkins
According to Dawkins replicators were molecule that were able to make copies of themselves but with many replications come errors. According to Dawkins with errors come improvements which is essential to the progression of life. DNA acts in the same way creating copies of itself. DNa is disturbed among cells and thousands of cells make a human body. With this I believe Dawkins was thinking that cells just automatically replicated by theirselves and created multicellular organisms.
Mayhew however believed something didn't, he believed in autotrophic organisms. it was believed that early cell membanes probably weren't able to transport large molecules. The origin of photosynthesis provided a new energy source, light, for the world's ecosystems that would increase its potential productivity (Mayhew, 27). I believe this is the best scenario because light provided the energy for the cells to transport larger molecules throughout them. Dawkins believes the energy that a cell needs to function is automatically provided. It seems more logical to believe that this energy was provided by light because light is always there.
Mayhew however believed something didn't, he believed in autotrophic organisms. it was believed that early cell membanes probably weren't able to transport large molecules. The origin of photosynthesis provided a new energy source, light, for the world's ecosystems that would increase its potential productivity (Mayhew, 27). I believe this is the best scenario because light provided the energy for the cells to transport larger molecules throughout them. Dawkins believes the energy that a cell needs to function is automatically provided. It seems more logical to believe that this energy was provided by light because light is always there.
Monday, September 14, 2009
Blog #1
Darwin states that by crossing a few aboriginal species we can only come up with the intermediate of the parents. This is true because of genes. When you cross two different species you get half of the genes from one species and half from the other to create a new breed of animal. They have similarities to the parents but are not exactly the same. If it was possible to cross to different animals and come up with the same animal that you started with the species would eventually die out.
Dawkin rephrases “survival of the fittest” to “survival of the stable”. He states that a stable thing is “a collection of atoms that is permanent enough or common enough to deserve a name” (Dawkin, 12). Everything surviving today, that we find we must name, is stable and made of atoms. The survival of stable objects is so much bigger than just saying that the fittest survive when objects are made of atoms and molecules that house DNA that control life.
Ecology plays a role in the domestication of the dog because it helps with behavior. If a dog has a lot of competition for food in the environment it is more likely to have an aggressive behavior. If there is a lack of food in the environment, the dog would have to find other means of acquiring it, such as interacting with humans for scrapes of food. This interaction with humans could have lead to the domestication of the dog because the dogs would have to become tamer around the humans to get food they needed.
Dawkin rephrases “survival of the fittest” to “survival of the stable”. He states that a stable thing is “a collection of atoms that is permanent enough or common enough to deserve a name” (Dawkin, 12). Everything surviving today, that we find we must name, is stable and made of atoms. The survival of stable objects is so much bigger than just saying that the fittest survive when objects are made of atoms and molecules that house DNA that control life.
Ecology plays a role in the domestication of the dog because it helps with behavior. If a dog has a lot of competition for food in the environment it is more likely to have an aggressive behavior. If there is a lack of food in the environment, the dog would have to find other means of acquiring it, such as interacting with humans for scrapes of food. This interaction with humans could have lead to the domestication of the dog because the dogs would have to become tamer around the humans to get food they needed.
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