In a population of birds, the climate becomes colder over time. Birds with larger bodies and thicker feathers survive better and produce more offspring than those with smaller bodies and thinner feathers. Which type of selection is occurring in this scenario? Stabilizing selection Disruptive selection Directional selection Frequency-dependent selection

40. Which of the following microevolutionary forces act upon existing variation within a breeding population?   gene flow and natural selection   natural selection and genetic drift   gene flow and mutation   genetic drift , gene flow, and mutation   natural selection, mutation, genetic drift, and gene flow

Which of the following is NOT true of stabilising selection a. it occurs when inidivuals with extreme trait values have lower fitness than those with intermediate trait values. b. it keeps the mean close (or moves it closer) to the optimum value c. it can result from opposing directional selection, such as when early flowering makes flowers susceptible to herbivores, but late flowering reduces the availability of pollinators. d. it does not improve the fitness of the population to the environment. e. it decreases the range of variation in the population

A farmer wants to make a better corn plant that produces more and bigger kernels. In the chart, information is provided on two ways organisms can change over time. Natural Selection Selective Breeding Humans are not involved in the evolution process Human intervention is involved More generations are involved in natural selection, so it is a slower process Selective breeding is a faster process Survival of the fittest increases species' chance for survival Adaptations may not necessarily improve survival Mutations that result in natural selection occur randomly The desirable charactenstics are artificially chosen What is the best way for the farmer to improve his crop and why? Use evidence from the table to support your reasoning. Please write in complete sentences.

In each experiment, what was the variable that differed??

In which population is evolution by natural selection most clearly demonstrated? Group of answer choices A virus sweeps through a population and makes everyone ill.  A virus sweeps through a population and kills 10% of infants. It is not clear why some die and some don't. A virus sweeps through a population and kills 20% of the population. It is not clear why some die and some don't. A virus sweeps through a population and permanently sterilizes the 10% of the population that has allele hx25c.

Imagine a group of adventurous people board a boat and leave for another continent. When they get there, they began to prosper and grow in size. After a few generations, some of the families experience an abnormally high number of birth defects, of the same type. This population is probably experiencing: O Kin Selection Founder Effect O Natural Selection O Post-Zygotic Isolation

60)The figure below shows the average horn size of male big horn sheep in Alberta over a period of 35 years. This population is subject to a legal trophy hunt. Given the available information, what would be the most reasonable evolutionary hypothesis explaining the observed trend? Trophy hunting caused stabilizing selection.   Trophy hunting caused disruptive selection.   Trophy hunting caused frequency dependent selection.   Trophy hunting caused directional selection.

Two males are fighting for territory that will increase the probability of mating success. Which term best describes this activity? O Intrasexual selection Intersexual selection Artificial selection O Mutation

Which of the following are accurate descriptions of natural selection? Select all that apply. •It selects for traits that increased the complexity of the organism . ���It creates genetic variation. •It creates physical variation. •It selects for traits that helps organisms reproduce most successfully.