Can Twins have different colored skin and Why?
In the U.K., Amelia and Jasmine were born as identical twins but the doctors didn't need to mark them to tell them apart. This was stunning because it turns out that monozygotic twins can have different colored skin. This extremely rare case can be partially explained by scientists, however, there is still much speculation because of the lack of studies done. Due to the rarity. scientists say that this event most likely happened early in the developmental stage of the embryo. Variations in a DNA sequence known as Single Nucleotide Polymorphisms could be responsible. The variation likely occurs after the embryo splits into two. Alternatively, there is evidence that epigenetic controls can be responsible for the difference in skin color (Sommers, 2016). Epigenetics refers to heritable variations that are not caused by a change or changes in the DNA sequence in mitotic or meiotic cells (Delcuve, et al., 2009). Other explanations could be that there was a somatic mutation, which occurs after the embryo splits (Somers, 2016). Somatic mutations are mutations that occur in none sex cells or cells that go through mitotic division. Overall, the emphasis is placed on the early embryologic development stage because that is when cell differentiation occurs when cells change to a more specialized type. The occurrence of biracial looking identical twins is one in a million and studies are too few to understand it fully.
This amazing phenomenon is the result of probability. The probability of this is some astronomical number and because of it's rarity we cannot put a finger on what is actually happening. A phenotype that differs like this is absolutely stunning. How many people get to walk around and say they are identical twins and also have different colored skin.
Delcuve, Geneviève P, et al. “Epigenetic Control.” Journal of Cellular Physiology, U.S. National
Library of Medicine, May 2009, https://www.ncbi.nlm.nih.gov/pubmed/19127539.
Somers, Hannah. “Genetically Identical Twins Born with Different Eye and Skin Colour.”
BioNews, 28 Feb. 2016, https://www.bionews.org.uk/page_95408.