For what it's worth department:
IF YOUR TWO parents hadn*t bonded just when they did—possibly to the
second, possibly to the nanosecond—you wouldn*t be here. And if their
parents hadn*t bonded in a precisely timely manner, you wouldn*t be here
either. And if their parents hadn*t done likewise, and their parents
before them, and so on, obviously and indefinitely, you wouldn*t be here.
Push backwards through time and these ancestral debts begin to add up. Go
back just eight generations to about the time that Charles Darwin and
Abraham Lincoln were born, and already there are over 250 people on whose
timely couplings your existence depends. Continue further, to the time of
Shakespeare and the Mayflower Pilgrims, and you have no fewer than 16,384
ancestors earnestly exchanging genetic material in a way that would,
eventually and miraculously, result in you.
At twenty generations ago, the number of people procreating on your behalf
has risen to 1,048,576. Five generations before that, and there are no
fewer than 33,554,432 men and women on whose devoted couplings your
existence depends. By thirty generations ago, your total number of
forebears—remember, these aren*t cousins and aunts and other incidental
relatives, but only parents and parents of parents in a line leading
ineluctably to you—is over one billion (1,073,741,824, to be precise). If
you go back sixty-four generations, to the time of the Romans, the number
of people on whose cooperative efforts your eventual existence depends has
risen to approximately 1,000,000,000,000,000,000, which is several thousand
times the total number of people who have ever lived.
Clearly something has gone wrong with our math here. The answer, it may
interest you to learn, is that your line is not pure. You couldn*t be here
without a little incest—actually quite a lot of incest—albeit at a
genetically discreet remove. With so many millions of ancestors in your
background, there will have been many occasions when a relative from your
mother*s side of the family procreated with some distant cousin from your
father*s side of the ledger. In fact, if you are in a partnership now with
someone from your own race and country, the chances are excellent that you
are at some level related. Indeed, if you look around you on a bus or in a
park or café or any crowded place, most of the people you see are very
probably relatives. When someone boasts to you that he is descended from
William the Conqueror or the Mayflower Pilgrims, you should answer at once:
“Me, too!* In the most literal and fundamental sense we are all family
We are also uncannily alike. Compare your genes with any other human
being*s and on average they will be about 99.9 percent the same. That is
what makes us a species. The tiny differences in that remaining 0.1
percent—”roughly one nucleotide base in every thousand,* to quote the
British geneticist and recent Nobel laureate John Sulston—are what endow us
with our individuality. Much has been made in recent years of the
unraveling of the human genome. In fact, there is no such thing as “the*
human genome. Every human genome is different Otherwise we would all be
identical. It is the endless recombinations of our genomes—each nearly
identical, but not quite—that make us what we are, both as individuals and
as a species." |
