* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download review
Survey
Document related concepts
Gene expression programming wikipedia , lookup
Kin selection wikipedia , lookup
The Selfish Gene wikipedia , lookup
Saltation (biology) wikipedia , lookup
Sexual selection wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Koinophilia wikipedia , lookup
Sociobiology wikipedia , lookup
Evolutionary landscape wikipedia , lookup
Genetics and the Origin of Species wikipedia , lookup
Microbial cooperation wikipedia , lookup
Transcript
Name _____________________________ Assignment # ______ Natural Selection Worksheet 1. Read the following situations below and identify the key concepts of Darwin’s natural selection. There are 3 types of polar bears: ones with thick coats, ones with thin coats and ones with medium coats. It is fall, soon to be winter. The temperatures are dropping rapidly and the bears must be kept warm, or they will freeze to death. Many of the bears have had ~2 cubs each but due to the extreme temperatures, many mothers only have one cub left. Which polar bear will not benefit from natural selection? ______________________________________________ Identify the type of variation in the polar population. __________________________________________________ Who is the most fit in her environment? ____________________________________________________________ Predict how the gene pool (the alleles) will change over time. ___________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ 2. Below is a series of pictures representing changes in a population of cacti over many generations. Why would a deer be more likely to eat the left cactus than the right cactus? _______________________________ ____________________________________________________________________________________________ In figure 3, the right cactus has flowers, but the cactus that has been eaten by the deer is too damaged to make flowers. Figure 4 shows the situation several months later. What has happened? ____________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ Do you think that evolution by natural selection is occurring in this cactus population? Explain why or why not. _____________________________________________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ What adaptation seems to increase the fitness of the cacti on the right? How do you think this adaptation increases the ability of cacti on the right to survive and reproduce? _____________________________________________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ 3. There are two types of rabbits: those that strictly eat grass and those that strictly eat berries and flowers. A drought occurs one year, and the plants have difficulty producing any extras (flowers, berries, etc.).They can only try and keep themselves green. The rabbits have had babies all year long but many are eaten by foxes or hawks. Due to the drought, many have starved to death. Which rabbit will not benefit from natural selection? _________________________________________________ Identify the type of variation in the rabbit population. _________________________________________________ Who is the most fit in their environment? ___________________________________________________________ Predict how the gene pool (the alleles) will change over time. ___________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________ 4. Bob believes that giraffes have long necks because they have stretched their necks to try and reach food that is high in trees. Since the parent had stretched its neck, it passed the long neck on to its offspring. Ryan believes that giraffes have long necks because the ones with long necks were able to reach the food, and those with short necks could not and died. The long necked giraffes reproduced, and soon all of the giraffes had long necks. Who thinks like Lamarck? ___________________________________ Who thinks like Darwin? ____________________________________ Explain two potential environment factors that may have led to the change in the giraffee population. ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ ______________________________________________________________________________________ 5. A more complete definition of fitness is the ability to survive and produce offspring who can also survive and reproduce. Below are descriptions of four male lions. Name George Dwayne Spot Tyrone Age at death 13 years 16 years 12 years 10 years # cubs fathered 19 25 20 20 # cubs surviving to adulthood 15 14 14 19 Size 10 feet 8.5 feet 9 feet 9 feet (Adapted from Michigan State University, Occasional Paper No. 91, Evolution by Natural Selection: A Teaching Module by Beth Bishop and Charles Anderson, 1986) According to this definition of fitness, which lion would biologists consider the “fittest”? Explain why.__________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ Suppose that Tyrone had genes that he passed on to his cubs that helped his cubs to resist infections, so they were more likely to survive to adulthood. Explain in some detail what would you expect to happen to the population of lions over the next two thousand years? _____________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________