7th Kiefer '23 Mechanisms and Patterns of Evolution

Master evolution: natural selection, gene flow, and speciation. Practice key concepts!

Matching: Type of Selections Match the following types of selections with the correct descriptions. Directional Occurs when an individuals at one phenotypic extreme are at a disadvantage compared to all other individuals. Stabilizing The middle is selected for natural selection. When both phenotypic extremes are deleted. Disruptive Extremes are selected for natural selection which creates two subpopulations​ Which type of natural selection would describe the following situation?Species: Tarantula SpiderTrait: SizeLarge and small sizes are selected for. Large spiders are able to scare away predators and the small spiders can hide from predators. Directional Disruptive Stabilizing Which type of natural selection would describe the following situation?Species: JellyfishTrait: venom potency (how poisonous it is)High potency is selected for. High potency of venom disables the prey more quickly. Directional Disruptive Stabilizing Which type of natural selection would describe the following situation?Species: Great White SharkTrait: length of teethMedium length teeth are selected for. Long teeth break off easily and short teeth cannot cut through the prey. Directional Disruptive Stabilizing Connect each term to the best description on the right. Gene flow exchange of genes with another population. Mutations how new alleles are produced for a trait Genetic Drift a change in gene pool of a population due to chance not natural selection. Bottleneck effect Disasters that drastically reduce population size thus reducing size of gene pool Gene pool all of the alleles of a population's genes Founder effect Individuals colonize isolated areas have less genetic makeup represented in the gene pool Within a decade of the introduction of a new insecticide, nearly all of the descendants of the target pests were immune to the usual-sized dose of the insecticide. The most likely explanation for this immunity to the insecticide is that eating the insecticide caused the bugs to become less resistant to it. the insects were already immune to the insecticide, survived, and reproduced. eating the insecticide caused the bugs to become resistant to it. it destroyed organisms that cause disease in insects, thus allowing them to live longer. Patterns of Evolution Select the correct term. divergent evolution A type of evolution in which organisms become more distinct over time artificial selection The process of breeding organisms for desired traits reproductive isolation Separation of species or populations so that they cannot interbreed and produce fertile offspring adaptive radiation The process by which a species evolves into a variety species to fit many diverse habitats speciation The evolutionary process in which new species form convergent evolution A type of evolution in which organisms become more similar over time gene pool Consists of all the alleles in all the individuals that make up a population. This is where genetic variation is stored.