Chapter 16 Question 15 Case Study What can fish color tell

Chapter 16 Question 15 - Case Study

What can fish color tell us about human pigmentation?

Skin color is often one of the first traits people notice in each other. Studies in zebra fish uncovered a mutation that altered a transport protein and resulted in light-colored fish. This discovery led to the finding that the same gene in humans has a strong influence on skin pigmentation in many populations.

Part A

The allele of the human transport protein associated with light skin is found almost exclusively in Europeans. The other common allele, which appears to be the ancestral allele, is found in Africans. Explain how you think the allele present in Europeans came to be so common in this population.

Select all that apply.

1. A mutation must have occurred in the population ancestral to modern Europeans after their migration to Europe.

2. A mutation must have occurred in the population ancestral to modern Europeans before their migration to Europe.

3. This mutation gave a reproductive advantage to people who carried it in the environments of Europe. So, over generations, the allele became more and more frequent until it predominated in this population.

4. A mutation must have occurred in the population ancestral to modern Europeans either before or after their migration to Europe.

5. This mutation was dominant. For this reason, over generations, the allele became more and more frequent.

6. The same mutations have occurred very often, so the allele became more and more frequent until it predominated in this population.

Chapter 1 Question 15 Case Study What can fish color tell us about human pigmentation? Skin color is often one of the first traits people notice in each other. Studies in zebra fish uncovered a ion that altered a transport protein and resulted in light-colored fish. This discovery led to the finding that the same gere in humans has a strong nnuerice on skin pigmerilation irl arly popula Part A Thc allok of the human transport protcin associated with light skin is found almost exclusivchy in Europeans. The other common allolo. appears to be the ancostral alkolc, is found in Africans. Explain how you think the allcle prcsent in Europeans which came to be so common in this population. Select all that apply. A mutation must have occurred in the population ancestral to modern Europeans atter their migration to Europe A mutation must have occurred in the population ancestral to modern Furopeans betore their migration to Europe This mutation gave a reproductive advantage to people who carried it in the environments of Europe So, over generations the allele became more and more frequent until it predominated in this population A mutation must have occurred in the population ancestral to modern Europeans either before or after their migration to Europe. This mutation was dominant. For this reason, over generations, the allele became more and more frequent The same mulalions have curred very orlen, so lhe allele became more and rnore requeril urili il predolmiinated in this population. Submit My Answers Give Up incorrect Try Again; 4 attempts remaining

Solution

* A mutation must have occurred in the population ancestral to modern Europeans either before or after their migration to Europe.

* This mutation gave a reproductive advantage to people who carried it in the environments of Europe. So, over generations, the allele became more and more frequent untill it predominated in this population.

When humans started migrating out of Africa, some of them settle in colder, darker climates of Europes. In the climatic conditions of Africa which has more sun-light, dark skin was an advantage since melanin responsible for dark skin controlsthe UV radiation that penetrates the skin.

However, in the darker regions of Europe, the radiation is too little to enable the body to synthesize vitamin D. As a result, people who had mutation that led to less melanin, which allowed them to absorb more UV light. This might have enabled them to synthesize vitamin D better than those who had dark skin. Thus, people with light skin had increased reproductive success in their sun-poor environments.