You
are a winner. I'm not just saying that to garner your affection,
although I am not against that, but rather because it is the
truth. You are a winner because, to begin with your most recent amazing achievement, as a sperm you
beat out an estimated 300,000,000 other sperm for the coveted title of
being you. This race was long and arduous and, while other sperm made
fateful errors and turned the wrong direction at the fallopian tubes or
were ensnared by the vaginal mucous before even reaching the uterus, you
persevered and ended up fertilizing that egg. So you got that going
for you, which is nice.
Additionally,
even before you won the sperm race, you were descended from winners.
Your direct ancestors were all strong enough and fast enough to be able
to survive until it was time to mate, and when it was business time
they were attractive enough to actually get a mate. Had even one of
your ancestors been a bit of a dud with less than adequate skill in the
survival department you wouldn't be here now. You are the product of
over 3.8 billion years of evolution.
But
this planet of ours, where that evolutionary process happened and
continues to happen, seemed, at times, to be downright antagonistic to
the squishy things that were attempting to flourish on it. From
volcanos belching lava and tiny bacteria spewing forth nasty toxic gasses to meteors impacting the
surface and making life significantly more interesting than it already
had been, there have been times when it was incredibly difficult to be a
living thing.
Life,
and therefore your ancestors, almost come to an abrupt end on five
different occasions in the past. It was during these Mass Extinction
events that your ancestors survival skills were really put to the test.
The first of these occurred about 450 million years ago and wiped out
60-70% of all species. The second, around 370 million years ago,
resulted in the deaths of about 70% of all species. The third, the
Permian extinction event, is the subject of the rest of this post and
will be discussed in detail in a bit. The fourth occurred around 200
million years ago and wiped out 70-75% of all species including many of
the competitors of the dinosaurs, helping them rule the land for another
140 million years or so. The fifth happened about 65 million years ago
and is the one most people know about. It was responsible for not only
the deaths of all of the non-avian (not birdlike) dinosaurs but also
the extinctions of around 75% of all species.
The
third event, the Permian extinction, occurred around 250 million years
ago and is known as the Great Dying due to the fact that almost 95% of
all species went extinct. Your great-great-great (x140 million or so)
grandparents, the reptiles, had evolved only about 70 million years
prior and were attempting to make a go of it on this crazy death planet.
The reptiles almost immediately split into two main types, the
synapsids and the diapsids. These were sort of like sibling groups in
that while they were similar in a lot of ways, there were also some key
differences, the most obvious of which, assuming you have access to
these things, is the number of skull holes (or, should you wish to
impress people at a tea party, temporal fenestra) each had. As in all
sibling rivalries there was some competition, and there was a winner and
a loser. The winner, at first, were the synapsid reptiles which grew
to fairly decent sizes and were essentially the kings and queens of the
Permian period. Some, like Dimetrodon,
could reach 15 feet in length with a massive sail-like crest on its
back that allowed it to regulate its body temperature. These huge
reptiles are often mistaken for dinosaurs because of the large size and
scary teeth, but they predated dinosaurs by around 70 million years.
This
sibling rivalry lasted, with the synapsids in the ascendency, until the
Permian Extinction event. The synapsids, and indeed almost everything
else, were basically wiped out during this time, and this opened up the
door to their rivals, the diapsids. The diapsids had bided their time
while their synapsid relatives dominated, staying small and
inconspicuous. After the Great Dying the diapsid reptiles began their
dominance, leaving the synapsids to the fate of small stature and
inconspicuity, assuming that is even a word. Spell check doesn’t have a
problem with it so I am leaving it in.
The
diapsid reptiles eventually went on to evolve into such hit animals as
the pterosaurs, crocodiles, dinosaurs and, eventually, birds. The
synapsids hung back and began the process of evolving to survive. They
stayed small and adapted to the cooler, darker night conditions. They
developed hair to insulate themselves and assist in temperature
regulation. They developed more refined jaw bones and modified ear
bones to aid in hearing. They began to produce milk from glands on
their stomach to feed their young, and when the time was right, roughly
65 million years ago after the Cretaceous mass extinction event, evolved
into all of the groups of mammals that we have today. Dogs, cats,
platypuses, squirrels, elephants, whales, primates and eventually you -
all of them descended from that one group of reptiles that refused to
die when almost everything else did.
And
that is why you are a winner. Your ancestors survived everything that
this cranky old Earth and solar system could throw at them and came out
on top. You are #1.
Or,
to put it like one of my college biology professors:
