What is the more powerful evolutionary force?

a. genetic drift

b. mutations

c. natural selection

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

Approximately 90% of all cases of polycystic kidney disease are inherited in an autosomal dominant fashion. the disease is typically related to mutations to genes (pkd1 and pkd2). pkd genes can be found on chromosome 16. the disease occurs in approximately 1: 800 to 1: 1000 people. here is a hypothetical example. the dominant allele d will cause the development of pkd. the recessive allele is known as d. what genotypes would correspond to suffering from pkd? dd, dd what genotypes would correspond to being normal (not suffering from pkd)? dd consider that 1: 1,000 people have pkd in your population of 325million. consider that pkd is inherited in an autosomal dominant fashion. show you math for all of the following questions: what is the genotypic frequency for dd? what is the genotypic frequency for dd? what is the genotypic frequency for dd? what is p? what is q? how many people in your population would have pkd?

When is your respiration rate likely to change? a. when your intestines are digesting b. when your cells have too much glucose c. when your cells need more oxygen d. when your liver is working after a meal