Identical Twins

[tossup]

Gosh, I was searching for information and I came across the question and answer regarding identical twins, and if they had identical fingerprints.

Having identical fingerprints may be the case for identical twins; BUT there is another type of identical twins. They are called mirror-image twins. The egg splits very late; making the twins identical -- but one is left-handed and the other is right-handed. If one twin has a birthmark on the left side, the other will have it on his right side, etc., etc.

So -- my twins, being mirror-image DO NOT have identical fingerprints.

ETA: Link to column: http://www.straightdope.com/columns/...t-fingerprints --Rico

[Sarabellum1976]

Identical twins are "identical" to different degrees depending on how many days into conception that the "split" took place.

A friend of mine has 21-year old identical twins that look similar in the face but not 100% carbon copies. One twin has much more hair, the other is several inches taller and skinnier, one is gay, the other straight. You really wouldn't know for certain that they were identical except that they did a DNA test to confirm because they were concerned that one twin had Marfans and wanted to know if they needed to worry about both boys. (No Marfans, thankfully.).

They were deemed "day one" identicals, since they likely split soon after conception and thus had more time in utero to differentiate themselves, if that makes sense.

Mirror twins most likely had their "split" several days later and are more "identical-looking" than other identical twins, except for that mirror effect.

If the split occurs even later, conjoined twins can be the result.

[Sarabellum1976]

Also, identical twins are purported to have *similar* fingerprint patterns, but they can be differentiated by a fingerprint test.

[Tim R. Mortiss]

Originally Posted by Sarabellum1976

.......A friend of mine has 21-year old identical twins that look similar in the face but not 100% carbon copies. One twin has much more hair, the other is several inches taller and skinnier, one is gay, the other straight. You really wouldn't know for certain that they were identical except that they did a DNA test to confirm because they were concerned that one twin had Marfans and wanted to know if they needed to worry about both boys. (No Marfans, thankfully.). .....

Wait a minute; identical twins, one gay, one straight? I don't want to turn this into a Great Debate or anything, but doesn't that invalidate the whole "born this way" argument?

[Babale]

Originally Posted by Tim R. Mortiss

Wait a minute; identical twins, one gay, one straight? I don't want to turn this into a Great Debate or anything, but doesn't that invalidate the whole "born this way" argument?

No. It's possible that they we're exposed to different hormones and/or chemicals while in the womb and developed differently.

[Tim R. Mortiss]

Originally Posted by Babale

No. It's possible that they we're exposed to different hormones and/or chemicals while in the womb and developed differently.

Riiiigghhht. Same womb, but different hormones and different chemicals. Thanks for clearing that up, Captain Rationalization.

[Inner Stickler]

If it weren't possible for the same womb to provide different hormones to two different fetuses, it would be impossible for fraternal twins of differing genders to exist.

[jackdavinci]

Originally Posted by Tim R. Mortiss

Riiiigghhht. Same womb, but different hormones and different chemicals. Thanks for clearing that up, Captain Rationalization.

Not all physical attributes have a direct consistent genetic input output relationship. And not all non physical attributes are mutable.

In any case, you'd be hard pressed to find many heterosexuals who consciously chose to have opposite sex desires.

[karen4180]

Originally Posted by Inner Stickler

If it weren't possible for the same womb to provide different hormones to two different fetuses, it would be impossible for fraternal twins of differing genders to exist.

Gender is determined by the sperm. The same hormones pass between mother/child regardless of gender. In fact, the excess of estrogen from the mother can cause the breasts of both girl AND boy babies to be swollen for a few weeks after birth.

[John W. Kennedy]

Nevertheless, the general point is quite correct. Identical twins are never absolutely and utterly identical, and can often be fairly distinguishable at sight. (Back in high school, I knew one pair that could be distinguished by face, though not easily, and who graduated in two different years.)

[Sarabellum1976]

I have to add, that my friend with the 21-year-old identicals... told me something that I found fascinating, when it comes to the whole gay/straight, born this way, nature/nurture argument.

She claims to have known early on, with a fair amount of certainty, that the gay twin was gay - and that she first noticed when he was SIX MONTHS OLD.

As she explained it to me, the boys were having their first finger food (a mashed banana) at about that age, and she noticed that one of the boys was thrilled to squash his food and smear it around and make a mess. The other boy seemed very upset that his fingers were messy, wanted to keep his hands clean, and wanted to be fed with a spoon.

I'm not sure how exactly that tipped off her gaydar, but apparently she was correct, LOL.

[ELVISMIRROR]

Check your history. Elvis was Jewish. His Birth Marks are on his hands. His SON'S Face Perfectly backwards. But the fingerprints & birthmarks are the same. I'm a LEFTY

[Czarcasm]

Originally Posted by ELVISMIRROR

Check your history. Elvis was Jewish. His Birth Marks are on his hands. His SON'S Face Perfectly backwards. But the fingerprints & birthmarks are the same. I'm a LEFTY

Cite, please.