Question

directions: read each description, determine which type of genetic drift it is, and write be for bottleneck effect, gd for genetic drift, or fe for founder effect in the space provided. 1. when christopher columbus came to the americas, he randomly chose 3 chickens from spain to bring along. these 3 chickens were the only chickens to breed in the americas for hundreds of years. 2. in 2013, typhoon haiyan is estimated to have killed over 5,000 water buffalo in the philippines. water buffalo are used in the philippines to plow crops. many of the water buffalo that perished were concentrated near farms. these animals are more muscular than buffalo allowed to roam free. 3. during a hike a man accidentally steps on a population of beetles that were in the path. a majority of the beetles that died had a rare mutation made them red in color. the population size was not greatly affected. 4. a forest fire, accidentally set off by humans celebrating a gender reveal party, randomly kills ten tall hemlock trees. the left - over population of hemlocks is still large in population, but short in height. 5. the afrikaner population of dutch settlers in south africa is descended from a few colonists. today, the afrikaner population has an unusually high frequency of the gene for huntingtons disease. 6. drought causes a local lake to shrink drastically. the fish population eventually returns to its original numbers. 7. the gene pool is calculated for a small population of snakes over several generations. these snakes vary in length. the last generation has a different allele frequency due to random chance. 8. the galapagos islands were colonized thousands of years ago by a small population of finches. each island selected for different adaptations among the birds. however, all of the finches shared many characteristics. 9. the northern elephant seal population was reduced by over hunting to 20 individuals in the 1890s. although the population had rebounded to over 30,000 individuals by 1974, the genetic diversity is still low within the current population. 10. the american bison was hunted to near extinction and even today as the population has recovered, the result is a population of bison with little genetic variation. 11. a small population of lizards moves to a new region that isnt inhabited by any reptiles. the population quickly grows in size, but the genetic diversity stays low. 12. a population of monkeys is separated by a river. both populations of monkeys live in the same type of environment, have the same predators, and food sources. one of the populations randomly evolves into a new species. 13. green eyes are a recessive gene. the last green - eyed person in a small - town dies, leaving only brown - eyed and blue - eyed people. with the green eye gene gone, people only have brown or blue eyes in the town, with brown being more dominant. 14. in a population of mallards with red and orange bills, only offspring with orange bills are born by chance. the very last red - billed mallard dies, leaving only orange - billed mallard populations behind. 15. an original population of flowers has both blue and yellow flowers. a mudslide kills a large portion of blue flowers on a hill leaving only yellow flowers.

Explanation:

1. Founder effect as a small group of chickens was the starting population for a new area.
2. Bottleneck effect due to a large - scale reduction in the water buffalo population.
3. Genetic drift as a random event affected a sub - population with a rare trait.
4. Genetic drift as a random event (forest fire) changed the trait (height) distribution.
5. Founder effect as the Afrikaner population descended from a small group of colonists.
6. Bottleneck effect as the lake shrinking reduced the fish population size.
7. Genetic drift as allele frequencies changed randomly in a small snake population.
8. Founder effect as a small group of finches colonized the Galapagos islands.
9. Bottleneck effect as over - hunting reduced the northern elephant seal population.
10. Bottleneck effect as the American Bison was hunted to near extinction.
11. Founder effect as a small lizard population moved to a new area.
12. Genetic drift as one monkey population randomly evolved into a new species.
13. Genetic drift as the green - eyed gene was lost randomly.
14. Genetic drift as the red - billed trait was lost randomly.
15. Genetic drift as a mudslide randomly killed a large portion of blue flowers.

Answer:

1. FE
2. BE
3. GD
4. GD
5. FE
6. BE
7. GD
8. FE
9. BE
10. BE
11. FE
12. GD
13. GD
14. GD
15. GD