Is it "possible"....

[Trekker4747]

Say a man and woman had unlimited time, unlimited resources and that they wouldn't suffer any effects of time or age. (I.E. they don't age.)

Would it be possible for this couple to produce "twins" seperated by years of birth? I mean his DNA and her DNA can only combine so many ways, right? Now, granted, this number is likely in the thousands if not millions of different combinations but it is "possible" right?

 

[Robert Maxwell]

Remember that all heredity is chromosomal. You receive half your chromosomes from each parent: 23 from the father, 23 from the mother.

If I am thinking about this correctly, the number of possible combinations is 2^46 or about 70 trillion. And that's leaving out any crossover effects (partial chromosomal inheritance).

 

[RoJoHen]

I vote yes.

 

[Lindley]

I don't know, but I'm sure they'd have fun trying.

 

[RoJoHen]

I mean, I have friends who look almost identical to their siblings, so obviously they already have very similar pairings of chromosomes. I'm sure it would be possible to get two people with exactly the same combinations of chromosomes, even if it would be incredibly unlikely.

 

[Trekker4747]

Remember that all heredity is chromosomal. You receive half your chromosomes from each parent: 23 from the father, 23 from the mother.

If I am thinking about this correctly, the number of possible combinations is 2^46 or about 70 trillion. And that's leaving out any crossover effects (partial chromosomal inheritance).

So, as I suspected, it's "possible" but "mathematically unlikely."

It is, however, more possible to happen than it is to re-shuffle a deck of cards back into order. (8x10^67)

 

[farmkid]

So, as I suspected, it's "possible" but "mathematically unlikely."

It is, however, more possible to happen than it is to re-shuffle a deck of cards back into order. (8x10^67)

It's actually much less likely. During gamete production, there are multiple crossover events on each chromosome. So, to get two genetically identical offspring would require all of those crossover events to happen in exactly the same places along each chromosome. I suspect that even if you could analyze every sperm cell a man made during his entire life you would probably not find two with the exact same genetic makeup.

 

[jgalley]

it's possible without having unlimited time, life, etc...it's just EXTREMELY unlikely....but if they literally had unlimited EVERYTHING (as in the universe would NEVER end..nor the world..etc) then eventually it would.

 

[scotpens]

I mean, I have friends who look almost identical to their siblings, so obviously they already have very similar pairings of chromosomes. I'm sure it would be possible to get two people with exactly the same combinations of chromosomes, even if it would be incredibly unlikely.

About as likely as identical cousins.

What a crazy pair!

 

[ThankQ]

Well, also, Treker, while your odds are for ONE couple, remember, there have been/(presumably) will be billions of couples "trying". So it in fact could have already happend. Of course, the numbers are still beyond staggering.

 

[YellowSubmarine]

If they have infinite time, eventually they will. In fact, due to random mutations they will eventually have kids that are a twin of someone who doesn't carry their genetic traits, like William Shatner, and they will eventually give a birth to a non-human. That assumes that they keep making babies and the fact that the universe will end in 10^100 years doesn't concern them. The chance for all these events approaches 100% as the time approaches infinity.

As for possible, they are possible even after one attempt, just extremely unlikely.

 

[Lindley]

Well, there is the fact that women have a finite number of eggs. Also the fact that men have a finite bank account to pay for the education of these attempts.

 

[ThankQ]

^Perhaps its Bill Gates and Oprah doing the trying.

 

[JarodRussell]

Well there IS a possibility. And with all possibilities, it can happen now, or it can happen never (even if they had infinite time and infinite attempts, probability has nothing to do with the real outcome).

 

[RobertVA]

The odds would still be pretty slim despite a very large percentage of nuclear genes from both parents, or the entire human population for that matter, being a match. In other words, all four genes (two from each parent) for most characteristics are identical. These are the genes for things like basic biochemistry and anatomy. However there are still a large number of genes that are mismatched pairs and control things like (but certainly not limited to) blood type, complexion, hair and eye color and some of the facial details like nose and jaw shape.

Of course with the same mother any genetic material in the mitochondria are going to be essentially the same.

 

[ProtoAvatar]

Will they give birth to brothers very similar to each other (in appearance, behaviour, genes, etc)?
The chance of this happening is quite high.

Will they give birth to brothers with the exact same genetic make-up?
They'll have to work at it for cosmic time scales until they succeed - the chance of this happening is just so small.

 

[YellowSubmarine]

Well, there is the fact that women have a finite number of eggs. Also the fact that men have a finite bank account to pay for the education of these attempts.

Just clone the mother. She'll have different eggs each time. And that's the best way to make a human survive that long anyway.