8 In some types of cactus the total number of spines is a
Last updated: 12/14/2022
8 In some types of cactus the total number of spines is a heritable trait that can vary from very few to very many A population of Gymnocalycium kieslingii cactus initially shows the variation in spine number diagrammed below number of cactuses total number of spines You observe that cactuses with very few spines get eaten by peccary a pig like mammal and cactuses with many spines get eaten by parasitic insects that use the cactus spines as a defense against their own predators a 1 point On the graph above use a solid line to draw the frequency distribution of total number of spines in this population after many generations of the selective pressures described above b 2 points If the change in the distribution of this trait is the result of natural selection name the mode of selection c 2 points What is the overall effect of the mode you named in part b on genetic variation in this population d 2 points If a lightning strike starts a fire that eventually kills off 80 of the cactuses in this population which process of evolution has now occurred