If we compare the DNA of any two people on Earth who are not related, we will discover that they only differ genetically by 0.1%. It may seem little, but it is a world. The reason we are unique is sex. When nature discovered 2,200 million years ago that shuffling the genes of two different individuals accelerated evolution, we gained individuality.
Not so identical twins
There will never be two subjects with an identical genetic heritage, except for twin brothers. Now even these are not that alike, at least if we put DNA aside. We have an example in Juan Barbachano and his twin sister Liana Hoemke. Juan was born as Juanita, although very soon he felt like a man enclosed in the body of a woman. After a sex change treatment, he is now a man. Considering what we have seen, the probability that there is someone just like us is zero.
