Energy and Human Ambitions on a Finite Planet, 2021a

D.6 Too Smart to Succeed? 411
D.6.1 Evolution’s Biggest Blunder?
As a brief follow-on, we framed evolution as a mistake-machine, sometimes
accidentally producing functionally advantageous incremental
improvements. Countless species adapt in ways that are not able to
survive long term, <strong>and</strong> die off. So those “blunders” are inconsequential
failed experiments. Evolution is indifferent to failure, being a mechanism
rather than a sentient entity.
But most of the time, these failures are isolated, bearing little consequence
on the wider world. Did anybody notice the three-dotted bark slug 70
disappear? If the human species turns out to be another of evolution’s
failed experiments—having made a creature too smart to stay within
the lanes of nature—is it just another inconsequential blunder?
70: ...totally made up
Unfortunately, it may turn out to be a rather costly blunder, if the failed
species creates a mass extinction as part of its own failure. By changing
the climate <strong>and</strong> habitat on the planet, we have already terminated or
imperiled a number of species, <strong>and</strong> are nowhere near finished yet. Mass
extinctions have happened many times through history, but seldom due
to an evolutionary blunder. We may yet distinguish ourselves!
It is true that cyanobacteria transformed the climate starting about
2.5 billion years ago by pumping oxygen into the atmosphere. Called
the Great Oxygenation Event, this precipitated the first-known mass
extinction on the planet—essentially poisoning the simple anaerobic
lifeforms that existed until that time. But we would hesitate to call it an
unmitigated disaster, as it paved the way for multi-cellular life 71 in all the
richness we see today. So accidental? Yes. Blunder? Okay. Disastrous?
Let’s say no, on balance. 72
The most recent mass extinction, 65 Myr ago, was caused by an asteroid
impact, <strong>and</strong> the two before that appear to be connected to volcanic
activity. The two prior to these are mixed: the first appears to have been
caused by geological processes, <strong>and</strong> the next by a changing climate likely
connected to diversification of l<strong>and</strong>-based plants. And that’s it, since the
much earlier cyanobacteria oxygenation event. Only one of the five is
likely attributable to evolution itself—<strong>and</strong> in this case not the fault of a
single species.
71: . . . although it took over a billion years
to get there: no instant gratification
72: The anaerobic life would disagree, but
when do we ever listen to them anymore?
In any case, the result was tremendous biodiversity,
which ultimately may be a decent
figure of merit for value in this world.
A human-caused mass extinction could pave the way to whole new
modes of lifeforms. But it was much easier in the early days to break new
ground. It seems much less likely that a human-induced mass extinction
will unleash a fantastic evolutionary richness hitherto unexplored. That
leaves only downside, <strong>and</strong> the ignominious distinction of being the one
species that evolution would most regret, if ever it could.
Please, please, please—let this tragic fate not come to pass!
© 2021 T. W. Murphy, Jr.; Creative Commons Attribution-NonCommercial 4.0 International Lic.;
Freely available at: https://escholarship.org/uc/energy_ambitions.