Question

Please answer to every single question!!!

Include all the information below about comparison between Hair textures (Afro-texture vs. East Asian): ?

What is the trait called colloquially and scientifically? What are the hallmarks or characteristics? ?

What mutation(s) causes the trait in your population of interest? Name of allele? Gene?

Type of mutation? ?

What are the differences in frequencies of your trait between the two populations, or, which alleles are characteristic of each population? ?

Are there aspects of this trait that could alter the fitness of the population?

Was the trait selected for or against?

What about the environment caused this selection? ?

Did migration, bottlenecking, or the founder effect play pivotal roles in the prevalence of your trait? ?

Were there any types of selective breeding that contributed to the difference in frequency between populations. ?

Is there evidence that interactions with other, pre-existing genes, played a role in the emergence or extinction of your trait within each population?

Answer 1

1)

• Hair trait is controlled by several genes and it is called as polygenic inheritance , genetically meaning multiple genes are involved in the inheritance.
• For particular hair texture which is a single character , many genes are involved to produce a particular trait in the individual.

2)

• Genes like EDAR and FGFR2 are involved in asian ancestory which determine the hair texture.
• KRT71 is involved in african popultion for their hair structure.
• Small nuclear polymorphism is responsible for the hair texture in both ancesteries.

3)

• SNPs in the alleles of trichohyalin and EDAR is responsible for asian hair structure .
• 7 different SNPs in KRT1 allele is responsible for african structure.

4)

• Yes , in hot an dry areas , curly hairs like african texture are highly adaptive .
• This is because , thic curly hairs regulate body temperatures by not allowing the heat to enter through head . This acts like barrier from the hot environment.
• It also doesnot respond to sweat and stic to the scalp like asian hairs .
• Thus the population in dry areas with curly hairs are more fit compared to thin hairs.
• Similarly, Asian population with thin hairs are more fit compared to curly hairs due to the environmental conditions.

5)

• Yes , environment plays a central role in hair texture selection.

6)

• Phenotypical characters like hair texture and skin color doesnot undergo bottle neck , founder effects.

7)

• Ancestors of humans are from africa. So definetely there must be change in the genotype for different races to evolve.o,
• So, the mutations in different genes causes different hair structures in humans.
• For eg autosomal mutation in DSG4, LIPH . Wooly hair mutation in DSP, DSC2 .