You and I
are related under the same two parents somewhere back in history.
Think about it. Everyone alive on Earth today including you and I
had to have two parents. Your parents had to have parents, which
means you had to have four grandparents and eight
great-grandparents. Every set of parents doubles exponentially,
16, 32, 64, 128, 256, 512, 1024, etc. As you go back in time, at
some point, the doubling of total parents required to keep your
family tree and my family tree separate becomes greater than the
number of people on Earth at that time. (It only takes 33
generations to surpass 8 billion.) If it's greater by even a
single person, we must share at least that one ancestor.
Let's suppose that ancestor is female. If you go back another
generation, it would require double the number of people on Earth
to keep us from also having a common male ancestor, then
quadruple, then eight times, 16 times, 32, 64, etc. You can see
how mathematically necessary it is for everyone alive today,
including you and I, to be related under the same male ancestor
and the same female ancestor somewhere back in history. In fact,
you and I are statistically likely to have many thousands of
ancestors in common throughout history. Everyone alive on Earth
today is literally family.

Think about that the next time you insult someone's lineage.
You're insulting your own family member. You're insulting
your own lineage.

Let's approach the math slightly differently. Suppose there
are 7,000,000,000 people alive on Earth today. That would
immediately require 14,000,000,000 parents to keep everyone
separate, which is impossible, so we know many people on Earth
are immediately brothers and sisters. Every previous generation
requires double the previous number to keep people out of the
same family. That's 28,000,000,000; 56,000,000,000;
112,000,000,000; etc. Since those numbers are increasingly
impossible, it forces greater and greater numbers of people alive
today to be in the same family. Also, as you go further back, the
fewer and fewer people were actually alive on Earth at any time.
You can see that the exponentially increasing impossible numbers
of parents required to keep us separate and the decreasing actual
population on Earth requires that we are all related.

quote and format by Raxin