It’s a fact of life: Species die, get over it
The only reason to conserve biodiversity is to create a stable future for human beings, argues Alexander Pyron.
Near midnight, during an expedition to southwestern Ecuador in December 2013, I spotted a small green frog asleep on a leaf. It was a rio pescado stubfoot toad. Although a lone male had been spotted in 2011, no populations had been found since 1995, and it was thought to be extinct. But here it was.
We found several more that night and shipped them to an amphibian ark in Quito, where they are now breeding. But they will go extinct one day, and the world will be none the poorer for it. Eventually, they will be replaced by a dozen or a hundred new species that evolve later.
Mass extinctions periodically wipe out up to 95 per cent of all species in one fell swoop. These come every 50 million to 100m years, and scientists agree that we are now in the middle of the sixth such extinction, this one caused primarily by humans.
It is an ‘‘immense and hidden’’ tragedy to see creatures pushed out of existence by humans, lamented the Harvard entomologist EO Wilson, who coined the term ‘‘biodiversity’’ in 1985. A joint paper by several prominent researchers published by the National Academy of Sciences called it a ‘‘biological annihilation’’.
But the impulse to conserve for conservation’s sake has taken on an unthinking, unsupported and unnecessary urgency. Extinction is the engine of evolution, the mechanism by which natural selection prunes the poorly adapted and allows the hardiest to flourish.
Species constantly go extinct, and every species that is alive today will one day follow suit. There is no such thing as an ‘‘endangered species’’, except for all species. The only reason we should conserve biodiversity is for ourselves, to create a stable future for human beings.
Yes, we have altered the environment and, in doing so, hurt other species. This seems artificial because we, unlike other life forms, use sentience and agriculture and industry. But we are a part of the biosphere just like every other creature, and our actions are just as volitional, their consequences just as natural.
Conserving a species we have helped to kill off, but on which we are not directly dependent, discharges our own guilt, but little else.
Climate scientists worry about how we’ve altered our planet, and they have good reasons for apprehension: Will we be able to feed ourselves? Will our water supplies dry up? Will our homes wash away?
But unlike those concerns, extinction does not carry moral significance, even when we have caused it. And unless we somehow destroy every living cell on Earth, the sixth extinction will be followed by a recovery, and later a seventh extinction, and so on.
Yet we are obsessed with reviving the status quo ante. The Paris Accords aim to hold the temperature to under two degrees Celsius above preindustrial levels, even though the temperature has been at least 8C warmer within the past 65m years.
Whatever effort we make to maintain the current climate will eventually be overrun by the inexorable forces of space and geology. The animal kingdom will be just fine.
Within a few million years of the asteroid that killed the dinosaurs, the post-apocalyptic void had been filled by an explosion of diversity – modern mammals, birds and amphibians of all shapes and sizes.
This is how evolution proceeds – through extinction. The inevitability of death is the only constant in life, and 99.9 per cent of all species that have ever lived, as many as 50 billion, have already gone extinct. In 50m years, Europe will collide with Africa and form a new supercontinent, destroying species by irrevocably altering their habitats.
Extinctions of individual species, entire lineages and complete ecosystems are common occurrences in the history of life. The world is no better or worse for the absence of saber-toothed tigers and dodo birds and our neanderthal cousins, who died off as homo sapiens evolved.
Conserving biodiversity should not be an end in itself; diversity can even be hazardous to human health. Nobody donates to campaigns to save HIV, ebola, malaria, dengue and yellow fever, but these are components of microbial biodiversity, as unique as pandas and elephants.
Humans should feel less shame about moulding their environment to suit their survival needs.
There is no return to a prehuman Eden; the goals of species conservation have to be aligned with the acceptance that large numbers of animals will go extinct. Thirty to 40 per cent of species may be threatened with extinction in the near future and their loss may be inevitable.
If climate change and extinction present problems, the problems stem from the drastic effects they will have on us.
A billion climate refugees, widespread famines, collapsed global industries, and the pain and suffering of our kin demand attention to ecology and imbue conservation with a moral imperative.
A global temperature increase of 2C will supposedly raise seas by 0.2 to 0.4 meters, with no effect on vast segments of the continents and most terrestrial biodiversity. But this is enough to flood most coastal cities, and that matters.
The solution is simple: moderation. While we should feel no remorse about altering our environment, there is no need to clear-cut forests for mansions on six-hectare plots of grass. We should save whatever species and habitats can be easily rescued (once-endangered creatures such as bald eagles and peregrine falcons now flourish), refrain from polluting waterways, limit consumption of fossil fuels and rely more on low-impact renewable energy.
We should do this to create a stable, equitable future for the coming billions of people, not for the vanishing northern river shark. Conservation is needed for ourselves and only ourselves.
All those future people deserve a happy, safe life on an ecologically robust planet, regardless of the state of the natural world compared with its pre-human condition.
We cannot thrive without crops or pollinators, or along coastlines as sea levels rise and as storms and flooding intensify.
Yet that robust planet will still erase huge swathes of animal and plant life. Many creatures will die off, and alien species will disrupt formerly ‘‘pristine’’ native ecosystems.
The sixth extinction is ongoing and inevitable – and Earth’s longterm recovery is guaranteed by history (though the process will be slow). Invasion and extinction are the regenerative and rejuvenating mechanisms of evolution, the engines of biodiversity.
❚ Alexander Pyron is an associate professor of biology at George Washington University.