Asia Nelson
October 13, 2012
Professor Butler
Guppies Lab Re-write Guppies The guppy is a freshwater fish that was originally found in certain South American and
Caribbean locations, though it has since been introduced to areas all around the world. Its scientific name is Poecilia reticulata, while another name they are commonly known by is the millionfish. In my own words natural selection is when an animal or anything can go through process over and over again and become stronger. i also believe that if something tragic keeps happining to something or someone they would eventually change and adapt. What happened to the guppies is when we increased the predator; there were less colorful guppies, and more dull ones. The reason i mentioned the increased in pradator rate is because the predator has a lot to do with how the guppies adapt and evolve over time. Sexual selection is the process by which certain organisms produce more offspring by mating more frequently than other organisms of the same sex and thereby ensure the survival of more of their genetic traits. Sexual selection is a form of natural selection in which organisms are competing not for food or other resources in the environment but for mates.
The development of size difference between males and females in mammals and birds, in which the greater strength (and often aggressiveness) of larger males allows them to have greater success mating, is seen as a consequence of sexual selection. The development of secondary sex characteristics, such as colored feathers in male birds or large antlers in male deer, which are attractive to the opposite sex as signs of fitness but are not directly involved in reproduction is also attributed to sexual selection. These features are often disadvantageous to the organism's survivalthe colored feathers make the male bird more visible to predators, for instancebut can provide the organism with a competitive advantage over rivals in mating. The theory of sexual selection was first proposed by Charles Darwin in
The Origin of Species("sexual selection"). Natural Selections operates on guppies because the male guppies tend to have bright colors because they want to attract the female guppies. I also futhered my education by learning that female guppies do not have to be a certain shape or size to get noticed. Sexual selection operates on guppies as well because a female is not going to mate with a male if he do not have attractive colorful colors. My predictions for the simulations were that there would be mor female guppies than male guppies. The reason i have came up with are since mae guppies try to get attention from female guppies by showing off their bright colors they tend to also attract a lot of attention from predators. Another reason is since the female guppies do not need color to attract male guppies they tend to reproduce, adapt, and evolve to their enviroment. The simulation was done on the computer. As a class we all looked at how the predator only went after the bright color guppies. We all had a paper that went over what natural and sexual selection was. After going over that we all wacth as Dr.Bulter increased and decreased the amount of pradators. What happened when we were all wacthing the simulations was when the amount of predators were increased the population of all colorful guppies decreased and there were only dull guppies left. But when we decreased the pradotor rate , there where a little bit of colorful guppies but the dull population stayed the same. The colorful males did not have any chance when the pradator rate was increased. I believe that the male guppies were so focused on finding a female guppies they were not aware of the pradators. When the padator rate was decreased the male guppies showed a little bit of improvement , there was some colorful guppies but it was the draker colors like purple. The male guppies that were not colorful tend to also adapt , and evolve. They had a better change of surviving because they were not bright enough to show off for a female guppie. The female guppies were more camouflague than the males. The draker female guppies did not have any problems. the population for all female guppies where high. The reason the population was so high for female guppies is because they could mate with any guppie that they want to they just perfer to mate with a bright colored guppie.
Some of the female bright guppies died off , only because they were bright and could be notice as well as the bright male guppies. My prediction was correct. I predicted that there will be more female guppies than male guppies. My reason was because the pradator would go after anything bright and noticable. I dont know how it happened i just believe that it has something to do with evolution. I also believed that all of the guppies will eventually add on features that will make them all camoflauge