Answer:
<em>A. Natural Selection</em>
Explanation:
The <em>TYR </em>gene is responsible for the production of the enzyme tyrosinase which is crucial in the production of melanin which is primarily responsible for skin pigmentation and for pigmentation of other organs. In albinism, there is mutation of the <em>TYR </em>gene therefore there will be no transcription of DNA to mRNA and no translation of mRNA to the enzyme tyrosinase leading to its deficiency. The deficiency of tyrosinase will eventually lead to the absence of melanin and ultimately, the absence of pigmentation in an organism.
I believe that a pair of homologous structures in this case is; Maple leaf and oak leaf. Homologous structures that have similar ancestries and common traits, however they may not have the same function in an organism. They appear in different animals or organisms, underlining anatomical commonalities demonstrating a descent from a common ancestor. Examples include the arm of a human, the wing of a bird or a bat, the leg of a dog and the flipper of a dolphin or whale.
4.6 million years ago the solar system was a cloud of dust and gas known as a solar nebula, other material that was most likely present was calcium and iron.