Question

Indonesia is the fourth most populous country in the world. It is an island nation in southeast Asia. Half of the population lives on the largest island, Java, while the other half of the population is scattered among 13,000 smaller islands. Indonesia is a collection of several hundred unique ethnic/cultural groups, with each having their own language.

Determine which population genetics term best describes each of the hypothetical scenarios below:

1) In 1883, more than two thirds of Krakatoa island was obliterated by a large volcano eruption. The eruption almost completely sterilized the island (most living things killed). Since then, the biodiversity of the island has been steadily returning.

• Founder
• Effect
• Migration
• Population
• Bottleneck
• Eugenics
• Nonrandom Mating
• Positive Selection
• Negative Selection
• Mutation
• A small population of one spider species survived the eruption because they were protected by the rock caves where they were living. Now, 50% of this spider species population on the island is dark red while the other 50% is brown. However, on neighboring islands only 5% of the spiders are red and 95% are brown.
• Founder Effect
• Migration
• Population Bottleneck
• Eugenics
• Nonrandom Mating
• Positive Selection
• Negative Selection
• Mutation
• Cline
• Balanced Polymorphism
• Most of the trees on the island were killed. Over time, the island has been repopulated with new tree species due to tree seeds that wash up on the beach from neighboring islands and birds that visit the island and leave the seeds in their droppings.
• Founder Effect
• Migration Population
• Bottleneck Eugenics
• Nonrandom Mating
• Positive Selection
• Negative Selection
• Mutation
• Cline
• Balanced Polymorphism
• One species of grass on the islands has two phenotypes, short and tall. Since the eruption, tall grass has become more common than short grass. Genetic studies have found that the short phenotype is caused by an allele of a gene that causes a mineral in volcanic ash to be toxic to the grass.
• AnswerFounder EffectMigrationPopulation BottleneckEugenicsNonrandom MatingPositive SelectionNegative SelectionMutationClineBalanced Polymorphism
• On this island, one species of plants makes white, red, and blue flowers. The allele for blue flowers is not found anywhere else in the world, except on this island.

2) Blindness is ten times more common on one particular Indonesian island than the rest of Indonesia. Subsequently, it has been found that the blindness is an autosomal recessive disorder. The dominant allele is associated with normal vision. The recessive allele causes blindness.

• AnswerFounder EffectMigrationPopulation BottleneckEugenicsNonrandom MatingPositive SelectionNegative SelectionMutationClineBalanced Polymorphism
• At one time in recent history, religious leaders on the island decided that blindness was a sign of "evil spirits". They convinced members of their group to attempt to castrate all blind men on the island to prevent them from producing children that had the "evil spirits".
• AnswerFounder EffectMigrationPopulation BottleneckEugenicsNonrandom MatingPositive SelectionNegative SelectionMutationClineBalanced Polymorphism
• Geneticists have traced the occurrence of the allele that causes blindness to a small group of British colonists that became shipwrecked on the island in the 1800's. After being shipwrecked, the colonists remained on the island and raised their families. Over time, the colonists families became more integrated with the island and began to inter-marry with the indigenous people. Blindness remains most common in island families that trace their lineage back to the original colonists.
• Answer
• Founder Effect
• Migration
• Population
• Bottleneck Eugenics
• Nonrandom Mating
• Positive Selection
• Negative Selection
• Mutation
• Cline
• Balanced Polymorphism
• People on the island get all of their food through fishing, hunting, and foraging. Blindness seriously seriously affects their ability to obtain adequate nutrition. However, it has been found that people who are heterozygous for the blindness allele (have one allele for normal vision and one allele for blindness) have much better night vision than people who are homozygous for the dominant allele. This allows them to hunt much more effectively at night than other people on the island.
• Founder Effect
• Population
• Bottleneck Eugenics
• Nonrandom Mating
• Positive Selection
• Negative Selection
• Mutation
• Cline
• Balanced Polymorphism
• Geneticists have studied the frequency of the recessive allele in southeast Asia. On the island in question, it occurs at a frequency of 0.01. It occurs at a frequency of 0.0007 on an island twenty miles away. It occurs at a frequency of 0.00002 on an island 75 miles away. On the main island of Java, 200 miles away, it occurs at a frequency of 0.000006. In mainland China, 2000 miles away, it occurs at a frequency of 0.00000009.

Answer 1

1. A. Population bottleneck: It is a sharp reduction in the size of a population due to environmental events (such as famines, earthquakes, floods, fires, disease, or droughts) or human activities (such as genocide).

b.balanced polymorphism

c.migration: when alleles are brought in and out of population because of movement of individuals

d. Positive selection

e. Mutation

2.a. Non random mating

b. Negative selection

c.migration

d. Positive selection