Stickleback Fish Lab Report

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If a lake is cut from the ocean and has no large fish as predators (only dragonflies), then the sticklebacks will have a better chance at surviving and reproducing because the sticklebacks will be better adapted to the environment (presence/absence of a pelvic bone) and have little to no predators. The hypothesis was supported.
Before the experiment started, background knowledge was collected to better the knowledge of the lakes. Bear Paw Lake is an enclosed lake, meaning no predators could get into the lake. However, Frog Lake is connected to a water system by a small stream, thus allowing predators such as salmon to enter the lake. Twenty fish were collected from each lake and then put into a solution that stains the fish's bones. This makes …show more content…

Natural selection is the process by which evolution occurs where organisms that are better suited to the environment (‘fittest’) survive and pass on favorable traits to the offspring. Organisms must adapt to the environment in order to survive. The stickleback fish adapted to the environment by keeping/removing the pelvic structures. For example, in Frog Lake, the all of the sticklebacks had complete pelvic structures because the lake was connected to a system of streams that allowed predators into the lake. The sticklebacks in Bear Paw Lake had reduced or absent pelvic structures because little/no predators are present in the lake. The pelvic structures on the fish are similar to the legs of four-legged vertebrates. With this said, the pelvic structures are a very important to the survival/defense of a stickleback. The stickleback fish experiment was well designed for many reasons. First, the experiment contained all the variables of a well-designed experiment. The independent variable is the water source (lake) and the dependent variable being the amount of complete, reduced, or absent pelvic structures found in the fish. Also, the experiment contained a constant: the number of fish collected per lake (20). Secondly, the experiment contained lots of data and is