You have 23 pairs of chromosomes. Each pair comes half from one parent and one from the other, so there’s four possibilities for each pair.
That would mean 4^23 or about 70 trillion possible combinations. The probability of having two kids with identical genes is so small it might as well be zero, unless they are identical twins.
There’s an incredibly varied but ultimately finite number of ways that meiosis can go to produce sperm/eggs in either parent, so it’s possible (in the absolute most theoretical sense) to produce one that is identical to a previous one.
If you manage to do that in both parents *and* then bring these two together as well, you could end up with a child that is identical to a previous one.
But in reality, this is never ever ever going to happen.
Mathematically speaking, a finite number of definite objects can only be combined or selected from in a finite number of ways. This applies whether the discussion is genetics or pretty much a combination of anything.
But the combinations grow exponentially so anything past a fairly small number grows to an extent that it is for any (human) intents and purposes pretty much “infinite”. The simple example is shuffling a deck of cards. Only 52 cards but the number of different ways of arranging them is a number so large that if a different arrangement were made every second, it is likely that the time needed to do this would exceed the ultimate age of this universe.
The total number of kids you could actually have would be pretty small. Being generous at 50 years of fertility and 9 months per baby that’s 62 kids. The world record for multiple babies at once is 10. So even if we assume each pregnancy was a 10 pack that’s 620 kids. Way less then would be needed for a reasonable chance of a duplicate
Yes, but bear in mind, if God had started shuffling a 52 card deck at the Big Bang at a rate of 1 shuffle per millisecond he would still have a long way to go until it being guaranteed to have a duplicate deck order.
And that’s a 52 element set. Your and your wives’ dna has several orders of magnitude more elements so it would take orders of magnitude to the power of orders of magnitude longer.
In other words, even if all the people that ever existed and will ever exist until the sun goes supernova were all your children the chance of getting two identical children would still be infinitesimal.
Due to meiosis, the process by which gametes (sex cells – sperm and ova) form;
there is a 1 in 8388608 chance of getting the right sperm
1 in 8388608 chance of getting the right ovum
Multiplying these together gives a 1 in 70368744177664 chance of YOU being created (genetically as you rather than a sibling), so you’d need to have a lot of kids to be likely to get repetition.
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