genetic roll of the dice

[novapsyche]

Black and white twins: Brothers from the same mother -- Odds are "one in a million," but it seems to be happening a lot in the last handful of years. What I think would be amazing would be to have fraternal twins, opposite sex, different skin tone, hair type & eye color. That would be a sight to see.

Edit: Actually, I was thinking a little deeper than I'd originally stated. I'm imagining an egg that splits in two before fertilization and the two are fertilized by different sperm cells (the polar body phenomenon).

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In other news: 'Yeti hair' to get DNA analysis

Comments

[guppiecat]

There are 133,000,000 people born every year. Of these, about 7,000,000 of them should be twins. Given that two thirds of twins are fraternal, that gives us 4,666,666.7 fraternal twins each year, or 2,333,333.3 pregnancies. (I am assuming that three tenths of a fraternal twin pregnancy reflects the number that extend past the end of the year, rather than Siamese twinning.)

Thus, we should see about two of these events each year.

We cite sources. ('cause we went to Grinnell :)

[novapsyche.livejournal.com]

Thank you for the sources and analysis. :)