What are the numerical odds that two living people share the exact same DNA without being identical twins?

Question

What are the odds that two people have shared the same DNA without living in the same time frame? Since everyone was more or less tribal, all over the world until at least 1200 years ago, and there was and in some cases is a lot of local intermarriage, doesn't this beef up the odds of this happening? What about two people sharing the same DNA pattern without their recessive genes matching? I'm just wondering if we're really unique individuals or are we model numbers in a really vast number of models. If we do share genetic patterns with others, it seems likely that there are common models and uncommon ones and that the uncommon ones are most likely in U.S. cities. The common ones are in small rural villages and towns, worldwide.

Answer 1

The human genome contains 3 billion bases. Each position can contain 1 of the 4 bases A, C, G or T

Therefore, there are 4^3,000,000,000 possible DNA sequences - a VERY BIG number

Answer 2

without being identical twins, normally and naturally, people can't have the same DNA. as we live, as we reproduce, we also become diverse. during reproduction, exchanging of characteristics happen. as we reproduce, varying characteristics are being exchanged thus we become more unique as humans multiply and as time goes by. this is due to genetic recombination which shares and modifies characteristics during meiosis usually in fertilization.physical resemblance are possible but not the human genome of two people being exactly the same. it's just like our thumb prints..it's one of our characteristics that is unique..see the analogy?

Answer 3

about 1 in 6.5 billion

Answer 4

i would have to say maybe 1 in every 4 billion but who knows. maybe more

Answer 5

One in a million!

Answer 6

1 : 6,680,230,414