22 Bio 3/14/2008 Study Question # 5 Q: G. F Gause conducted a series of experiments to find out exactly what the consequences of competition were. Gause placed small populations of two similar species of unicellular ponddwellers, Paramecium Caudatum and Paramecium Aurelia, in separate cultures. Both grew logistically. However, when places in the same culture this was not the case. Briefly describe what happened to each of the species, what this is called, and why this happens. Although competition is common, there are different effects, what is one example of species competing that resulted differently? A: When P. Caudatum and P. Aurelia were placed in the same culture the P. Aurelia grew logistically while the P. Caudatum was driven to extinction. This is called the competitive exclusion which principle, occurs when competition is asymmetric. Basically competition is asymmetric when a species has lower fitness when placed with another, and this is because their niches completely overlap. During niche overlap species are competing for resources vital for living, but one species usually has a certain trait that leads to higher fitness, therefore enabling them to steer their competition towards extinction (evolution by natural selection). A different outcome is seen in various species of the Galapagos Finches that inhabited the same area. Their niches did not completely overlap, which led to niche differentiation, meaning the competing species evolved traits (different beak sizes) that allowed them to take advantage of different resources (different seeds) and areas.