“From the standpoint
of the world’s biota, global travel represents a radically new phenomenon and,
at the same time, a replay of the very old.
The drifting apart of the continents that Wegener deduced from the fossil
record is now being reversed—another way in which humans are running geologic
history backward and at high speed.
Think of it as a souped-up version of plate tectonics, minus the
plates.” (p. 208)
The latest reports of a discovery of yet another new species
of hominids, Homo neledi, is a
reminder of how our group of primates almost didn’t make it. It also makes me wonder what it is about us (Homo sapiens) that preserved us—perhaps it
is the madness gene that Kolbert speaks of.
But survived we have, and we continue to consider ourselves very clever
with our technology, cars, and spaceships. (I suppose we are clever.) While
cultivating our cleverness, humans have also become the taxi service of
biodiversity. While reading The Sixth
Extinction, I can’t help but think that while the phenomenon of mass extinction
clearly sounds horrific, there is also a sense that this is nothing new. Life
will go on, even though we are currently in a god-like position of deciding, at
least to some extent, how life will proceed. The species that will form the
evolutionary foundation of the recovery following the sixth mass extinction event—a
recovery that will require tens to hundreds of millions of years if the last
mass extinctions tell us anything—are currently being selected for by chance
and happenstance, as well as human whim.
Extinction is an old story, it’s just the characters have changed: It’s
Tony and Maria instead of Romeo and Juliet.
Both plays were good, and the new one even had music, which is arguably
an improvement in the situation. Maybe
things will be even better on New Pangea.
The New Pangea. It is
an intriguing idea. It doesn’t mean we
lose all diversity. Connected places can maintain high diversity because of
variation in the connected habitat (think about the life forms from Canada to
the tip of South America). But it does
mean that our introductions lead to new interactions with outcomes that are not
entirely clear. Species have always moved other species with themselves when
they travelled, although perhaps less consciously. It would be surprising if we
didn’t take other life forms with us by chance (parasites & pathogens, the
occasional seed stuck in our hair or on our trousers) or by planning (gotta
eat). I am intrigued by the tension in the book between what is natural and what
is unnatural in this telling of the troubles of the current times. If we were
scientific observers of the human species, I’m not sure we would cast the
biodiversity crisis in quite the same light (a moral dilemma). We are doing what individuals of any
population or species do—looking out for ourselves as well as those in our group,
since sociality has been selected for over our evolutionary history. Part of
looking out for ourselves should include the health and sustainability of our environmrent,
since failure to do so could be a game changer for us. But it’s hard to associate
our individual actions, many of which seem benign, with the cause of the real
and large problems facing life. Kolbert even incriminates us in the
biodiversity crisis in the very act of buying and reading her book—sincere
& high minded folks, we too are implicated. Damn it. And still, I would buy
this book again.
Redistributing biodiversity in our travels and trade is
arguably natural, but it is not without consequences. Kolbert offers many
examples of the outcomes of bringing continents together in our modern
way: White-nose syndrome in bats which
appears to have a European origin; amphibian chytrid fungus coming out of
Africa; the Asian long-horned beetle from China; the emerald ash borer from
Asia; chestnut blight from Japan; and the list goes on. The changes that happen
relatively quickly lead to us growing up thinking that a forest devoid of
chestnuts is normal, the ways it’s always been. So, the baseline has shifted—it
is shifting. We will inevitably find ourselves living with less diversity on
the New Pangea. Our insistence in transporting plants and animals half-way
around the world results in the movement of parasites and pathogens. Planting our yards with exotic species [like
most grass for starters!] dramatically alters many of the surrounding natural
ecosystems, often favoring exotics or “weedy” species like deer. Introduction
of exotic animals has led to collapses in diversity in some cases. Darwin would
have been so confused if the world’s diversity had been configured the way it
is today.
Speciation often occurs in isolation, and in a connected
world that is slowly becoming homogenized as species interactions play out, it
is hard to see how diversity will be maintained in a world overflowing with
people. Although, as Kolbert points out,
evidence suggests that the megafauna were vulnerable to small bands of people. So
maybe the success of humans 200,000 years ago set in motion this sixth extinction
event—maybe the fate of biodiversity was written long ago. But still, hope *is* the thing with feathers,
as both Emily Dickinson & Elizabeth Kolbert suggest. I am waiting for our
frontal lobes to lead the way. We have
the capacity to make things better, but how this unfolds is really anyone’s
guess.
PS I love this book.
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