Megan McCoy

Before having any biology classes, I would have thought of fitness as working out and staying in shape. If someone had great fitness, that just meant to me that they were in great shape. But now after having many years of biology, I know the second meaning of fitness relating to the evolution/biology aspects. In simple terms, fitness in evolution means reproductive success and how well an organism adapts to its environment. If the species is no longer reproducing, that means they are no longer evolutionary fit. To measure fitness in a natural population, you would measure the organism's ability to create offspring. This determine the amount of genetic material the organism has contributed to the population and next generation. Some organisms are more fit than other depending on the environment and habitat they live in. When I think of fitness, I begin to think about the organisms that have gone extinct. One that comes to mind is the Woolly Mammoth. This organism was once fit for it...

Microevolution is something that was easier for me to understand and follow compared to the other ideas from Darwin. Microevolution is the evolutionary change within a species over a short amount of time. I think microevolution relates to natural selection in the sense that natural selections drives the changes within the species that shows the differences over the shorter period of time. Microevolution can take place over one generation, where macroevolution takes place over a much longer period of time.  I researched about the various sparrow sizes throughout the United States to see what differences there were and how that related to microevolution. By taking a quick glance at the picture I attached above, it is apparent that sparrows have evolved different characteristics depending on their environment and location. We see that on the west coast, sparrows are a lot smaller in size compared to the ones up north and east. Sparrow populations that are bigger up north are due to na...