Natural selection and Genetic Drift
Videohttp://www.youtube.com/watch?v=BgqVPFiMhA0
Summary
Earlier this year, we learned about variation in organisms due to mutations or crossing over in meiosis. Yet, neither of these things directly create a new species. In fact, natural selection and genetic drift are the main reasons for evolution. Natural selection is the process where individuals with inherited characteristics well-suited to the environment leave more offspring than other individuals. In the video, the well-suited inherited characteristic is a light colored fur coat, used as camouflage. In addition to this trait, natural selection can favor bigger beaks or bigger shells. If the trait suits the environment, it will give the animal an advantage. The rabbits with darker fur are easier to spot and therefore predators catch them more easily. As generations go by, more light furred individuals are spared by predators and end up passing on their genes. Eventually, almost all of the population has the favored trait through natural selection. In conclusion, natural selection is not random. It is based on how well-suited inherited characteristics are to the environment.
Genetic drift was also briefly mentioned in the video. Genetic drift is change in the gene pool of a population due to chance. In the video, there was genetic drift when random individuals died, simply because they were unlucky. For example, some are run over by a car, blown away in a hurricane, etc. In a way, genetic drift slows down evolution because it may take a beneficial mutation away from a population.
Relevance to Class
This unit is about evolution. More specifically we learned about natural selection, genetic drift, the founder effect and bottleneck effect. But out of those four, natural selection and genetic drift are the most important. As we have learned, they guide evolution to create different species that are more suited to their environment. For example, the process that caused the four legged animals to evolve into whales was natural selection. It created a species fit for the water and perfect for a specific niche. After all, even humans evolved from other organisms. In this way evolution is one of the most important biological processes.
Video Information
URL: http://www.youtube.com/watch?v=BgqVPFiMhA0
Date of Publication: May 6, 2012
Creator's Youtube username: vinniehirt
Can genetic drift help a certain population adapt to a poor environment?
ReplyDeleteYes, genetic drift can help a population adapt. For example it may get rid of a bad mutation in a population before the bad mutation is passed on. But, there is no certainty that genetic drift will be beneficial. It is just as likely that it may be harmful to a population.
ReplyDeleteIf a sudden change to the environment of a variety of organisms occurs, is it possible for the organisms less suited to the previous environment to thrive and be better suited in the new one?
ReplyDeleteYes this situation is possible. For example, if an invasive species is introduced that eats large seeds, then the birds with smaller beaks (who normally are less suited to environment) will be more-suited to the environment.
ReplyDeleteIF mules are able to reproduce then they and horses or donkeys breed with each other than deos that make a new species
ReplyDelete