It’s true
that “who was the first human” is a good question that any of us would do – and
probably did at some point. But this question is actually not applicable and
reveals our confusion regarding how life evolves and, mostly, about the
distinction between life as it is and the categorization that we do for study
purposes.
First,
about categorization. We classify things for a simple and obvious reason:
because it’s easier to study. It’s as simple as that. We classify living beings
in unicellular life, multicellular, plants, animals, mammals, primates, humans,
etc simply because this makes it easier to comprehend the different kinds of
life in the planet. But it’s a rough idealization of reality. Helpful, but
rough.
When we
enter the reality of biological life things are not that simple. There’s no
clear line that separates living beings into categories – and when talking about
the evolution of species things get even blurrier.
If we could
look back in time and follow retroactively the human evolution – or any species
for that matter – and how it came to be, it wouldn’t be possible to find a
point where, on one side we have a human being and in the other we have a
different species. It’s not how it works. There's no single mutation that end up creating a new
species because it tends to happen slowly, with little changes that, at first, doesn’t
change much at all. With luck, a “good” mutation (something that helps to
copulate and pass its genes ahead – carries on into the descendants, which
will be passed along with other mutations. No new species there. But, at some
point, the amount of new mutations differentiates a population so much from the
previous that it can be considered another species1 altogether.
But it’s not something that happens overnight nor it’s something that we can
possibly find an specific point in time from when it happened.
One
possible analogy is to compare with our own growth in life. Although a
human being can be classified roughly as child, teenager, adult and elder,
there’s no way to tell exactly when the person crossed the line and go from
children to teenager. We establish ages that helps creating frontiers but we
know that, in reality, a person doesn’t go to sleep an adult and wakes up the
other day as an elderly only because it’s his or her birthday. But when you least
expected, you’re already on the other side.
This is
more or less what happens with the evolution of species2: instead of “beginnings”
and “ends” what life does is more like a gradient that slowly transforms one
species into another. So, if you could divided any of our ancestor’s mutations
like it was a photograph, you wouldn’t be able to find a “first human”. You
would have to find a photo of one specie and, several photos later, you would find
a photo that you could definitely said, “this is a human”. But the in-between is
just a series of tiny changes, many so imperceptible that you couldn’t tell
what happened there. It may sound a little counterintuitive considering that we've spend a whole life learning to define frontiers to stuff, but nature isn’t
interested in frontiers at all.
The humans
and hominid fossils are classified as a way to gives us a reference point to
guide us in relation to how much in time and in what context of evolution these
fossils are. Again, because it helps the study and helps us to better interpret
the issue. The fossils doesn’t represent “thresholds” as if we could find, one
generation after, immediately another species.
In other
words, it’s better to stop trying to find a “missing link” between humans and
other primates. You won’t find one – not in the way most people think, at
least.
Rafael
Algures is a Bachelor of Philosophy specialized in Neurosciences of Language.
He is also a copywriter, content and science writer, and a comic book creator.
His latest work, “Gutter of Horror: Transition”, a short horror comic about
Philosophy and Artificial Intelligence are available at Amazon – digital and
paperback.
Further
reading: The Magic of Reality: How We Know What's Really True, by Richard
Dawkings
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1. There’s
also that thing where the species are not able to breed with each other or its
offspring is born sterile, but I won’t get into that.
2. But
remember, this is just an analogy; evolution is NOT biologically comparable to
becoming and adult.