The_root_of_all_evil said:
Although the white baby born to Nigerian parents was interesting. [http://www.thisdayonline.com/nview.php?id=178835] Pity it's only in the Sun/Mail, so we can't be sure if it's correct.
Yay! A chance for me to get my old Genetics notes out! If you don't care about the science of it, skip to the bottom.
Now, that actually occurs more often than you'd think. See, it works like this. Say both of the parents have at least one white ancestor (perhaps a white explorer had sex with their ancestors in Nigeria? Or someone who had a white gene had sex with their ancestors?). The genes of the white person remain in them forever.
Now, when the two people who both have those white genes give birth, they have a chance that it will be mulatto, white or black, depending on how far back those white genes were introduced (if it was a long time ago, it is more likely it will be black, but you never know). This is what we call X-Linked Inheritance in Genetics, and the chances are portrayed through the Punnett Square. This applies to all biological things: plants, animals and humans, and in all aspects of the biology as well: height, eye/hair/skin colour, blood type, Rhesus factor, deafness, blindness, hemophilia, even the ability to curl one's tongue, everything; You want a pink flower? Breed a white and a red. You want a black sheep? Breed two whites. You want a blue chicken (Yes, they exist!)? Breed a black rooster and a white hen. Humans are obviously more difficult to predict, as our genes are, for the most part, unknown to us, and much more complicated than animals.
Let's go with the sheep example. White wool (B) is the dominant allele, and black wool (b) is the recessive. According to Mendel's first law of Genetics, the Principle of Dominance: the dominant allele is always expressed. So, we know that if it has a "B" in it, it cannot be black. A heterozygous white sheep is classified as Bb. Cross this with another heterozygous white sheep (Bb) Bb x Bb. The offspring will be: 1 BB (homozygous white), 2 Bb (heterozygous white) and 1 bb (homozygous black), so the chances are 1:2:1 that you will get a black sheep out of two white sheep, or 25%.
In my family, we have a history of achrondoplasia, a special kind of dwarfism that is characterized by shorter-than-average limbs, and malignant hypothermia, which kills you by shutting down your muscles (including your heart) if they take too much stress, especially in the heat. Both of these are dominant alleles with a 50% chance of getting either one (dwarfism on my father's side, and MH on my mother's.). I have both... *sadness*
tl;dr: Yes, very possible for two black people to have a white baby.
(Sorry, I didn't mean to rant. I just really enjoy the study of genetics, is all.)
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