Chris D. Thomas: Inheritors of the Earth - Six Key Ideas (Part 2: Sections IV-VI)

Chris D. Thomas (Photo: Allen Lane)

IV. Vive la bio-révolution!

According to Chris D. Thomas, we are today in the midst of a great global interchange; a biological coming together, facilitated by humanity, of previously separated species which will conceivably be "the greatest spur to evolution for a hundred or more million years" [169]. Speciation seems to be unfolding in front of us at a pace that Darwin would have found unimaginable, although, of course, the real proliferation of new species will come in a far-distant future.

In another crucially important passage, Thomas writes:

"These new connections are unlike any previous period in the Earth's history. The explosion that killed off the dinosaurs, and the other four major episodes of mass extinction in the last half-billion years, did not transport vast numbers of the survivors around the planet on a timescale of hundreds to thousands of years. There was no equivalent bringing together of species from different regions. ... Given the geographic distances and rapidity of connections that are taking place in the Anthropocene, there is no precedent since multi-cellular life forms colonized the land." [195-96]

He concludes:

"I find it difficult to imagine a period in the entire history of terrestrial life on Earth when the speed of origination of new evolutionary lineages could have been faster, as a result of  the combined forces of populations arriving in new locations and starting to diverge there, the previous residents becoming adapted to the new species that arrive, and new hybrids coming into existence as species meet up for the first time in new habitats and new geographic locations." [196]

In brief: the human era is undoubtedly a time of unusually rapid extinction. But, ultimately, the Anthropocene bio-revolution will almost certainly represent a bright new dawn.


V. On Translating Man Back into Nature

The idealistic separation of man from nature continues to this day, despite the fact that Darwin published his theory of evolution over 150 years ago. Even some philosophers and scientists who really should know better, still insist on the myth of human exceptionalism and regard human abilities and activity as, in some sense, either unnatural or transcendent. Thomas, to his credit, is having none of this:

"When we contemplate the biology and impacts of humans on the Earth, there is no doubting that Homo sapiens is an extremely unusual animal. But at what point in the unbroken sequence of generations should we decide that humans ceased to be part of nature ... There is no scientific or philosophical justification that could be used to separate this continuum of ape-then-human animals into two qualitatively different categories." [207]   

Evolution has been going on long enough so that humans and chimpanzees are recognisably different; but we are still primates, just like them, and whilst it is man who exercises dominion over the Earth, this is still essentially the planet of the apes. And everything that happens upon it - including art, agriculture and architecture - is absolutely natural and represents an "indirect product of evolution" [209]. 

Indeed, even our anthropocentrism has an evolutionary basis; for this will to species self-privileging is shared with other animals: lions, bison, and killer whales, for example, "respond strongly to other members of their own species for exactly the same reasons" [210] we do. When they see others of their own kind, they see potential mates, family members, collaborators, enemies, etc. "Every species is special to itself because the survival of each individual's genes depend on it." [210]

However, whilst evolutionary predisposition encourages us to develop ideas of human uniqueness, it's important to recognise that we are still just animals and that "everything we do ... is natural" [211].


VI. Welcome to Anthropocene Park

Finally, we arrive at the last chapter of Thomas's book, entitled 'Noah's Earth'. Here, and in the Epilogue that follows, he speculates on what we might do today and how the world might look one million years from now. Different, is the answer to the latter question. But difference and becoming isn't something that has been engineered by man. It's built into the very fabric of the universe, including biology.

What we need, therefore, is an environmental philosophy that is based on an acknowledgement of change and the further recognition that change is something beyond good and evil regardless of whether the consequences are beneficial or harmful to human well-being and survival (although, obviously, we will want things to turn out for the best and it's perfectly legitimate for man to attempt to direct life's unfolding in "a desired direction as effectively and efficiently as possible" [230], eradicating deadly new diseases, for example).

As part of this new philosophy, Thomas thinks it worth considering radical conservation projects that don't just try to save a limited number of endangered species in their present location, but dare to move them to new places where they might thrive, just like the yellow-crested cockatoo, for example, which is thriving in Hong Kong, even as it continues a rapid decline in its Indonesian homeland:

"All the many thousands of transported plants and animals that have established populations in new regions have demonstrated time and again that species may flourish outside their historical ranges. In doing so, they normally increase the total number of species that live in each region, they start to evolve into distinct forms and they sometimes hybridize and create new species. Eventually, they will increase the diversity of life on Earth." [235]

And, in the meantime, it means we might get to see African lions hunting in the USA and black rhinos stomping about in Europe. I'm all for that and all for thinking about the creation of new ecosystems and biological communities - including communities made up of deliberately engineered new species (or even extinct species resurrected).

Ultimately, I agree entirely with Professor Thomas that we shouldn't allow those who worry about Frankenstein science prevent us from using all available means to maintain and increase biological diversity in a variety ways that many puritans would regard as not only unconventional, but unnatural and immoral.

See: Chris D. Thomas, Inheritors of the Earth: How Nature is Thriving in an Age of Extinction, (Allen Lane, 2017). All the page numbers given above refer to this edition of the book. 

To read Part 1 of this post (Sections I-III) click here.

Chris D. Thomas: Inheritors of the Earth - Six Key Ideas (Part 1: Sections I - III)

I. Extinction isn't the End of the World and Change is the Only Constant

Professor Chris D. Thomas is an ecologist and evolutionary biologist at the University of York who has written a book that lends scientific support to Rupert Birkin's vision in Women in Love of a far-off future in which biological diversity is even greater than it is now and unimaginable new species of life will have unfolded. Of course, Thomas doesn't share Birkin's misanthropy and long for a world free of humanity, but he does affirm that evolution never ends and that there is thus an infinite array of lovely things still to come (after - but also out of - the Anthropocene period).

Thomas begins by setting out a familiar tale of woe concerning the negative effect that mankind is said to have had on the Earth. Whilst conceding the importance of recognising ways in which human activity threatens the existence of life, he quickly counters this doom-laden narrative of eco-apocalypse and suggests we take a broader view, considering all the evidence and not just those facts that reinforce the moral and political concerns of those who subscribe to a green philosophy based on a desire to save the planet.     

Essentially, Thomas is arguing that short-term ecological upheaval and species extinction pales into insignificance when seen from the perspective of evolution. Ultimately, no matter how great the losses, there will be winners; that is to say, species that will not only survive, but thrive; not only thrive, but diversify into an unimaginable variety of new species. Periods when the levels of extinction are high - as they are presently - obviously present setbacks; "but in the end they have provided new opportunities for enterprising creatures that have been able to exploit the new conditions" [7]. Come back in a million years, says Thomas, and you're likely to be astonished at what you'll find.  

We might not like it, but never-ending change is the only constant; the world is in a state of permanent flux. Futile attempts to conserve the world as it is - or, even more vainly, to restore it to some earlier, more pristine, more natural state - are not only untenable, but "implicitly dismiss as undesirable the continuing biological gains of the human epoch" [8]. Further, the logic of such a way of thinking can have ugly consequences, such as the call to eradicate alien arrivals and exterminate impure hybrids. Rather than "swim against the tide of ecological and evolutionary change" [9], writes Thomas, we should go with the flow and joyfully facilitate and accelerate biological processes.


II. The Future Walks Among Us

Just to be clear: Thomas isn't arguing that we shouldn't, for example, try to prevent unsustainable fishing and the dumping of plastic into the oceans. But, we need to open our eyes to the evolutionary reality of the world and acknowledge biological gains made. It can also be strangely comforting to realise that we can glimpse the future within the present; that the "inheritors of the future Earth are already among us today" [43], just as birds and mammals were coexistent with the dinosaurs for millions of years and did not "suddenly appear after the asteroid hit" [41] (an idea that greater knowledge of the fossil record plus revolutionary advances in molecular biology has shown to be false).

These inheritors, as Thomas calls them, might not be the wild and charismatic megafauna that most people worry about (tigers, gorillas, pandas, polar bears, etc.), but we should probably get over our sentimental privileging of such beasts and recognise that domestic animals and household pets - as well as cereal crops - have all been incredibly successful by taking advantage of "a gullible primate" [45] in order to ensure their survival and global proliferation.

It's a Lawrentian nightmare, but there are now about 1.5 billion cattle, 1.2 billion sheep, 1 billion pigs and an astonishing 22 billion chickens in the world, all being fed and cared for in addition to the 1 billion cats and dogs, by 7 billion human beings. In other words, "the present is not a dip in the total numbers or combined weight [biomass] of large animals ... it is a substantial increase" [47] and the Anthropocene remains "just as much an age of mammals and birds as it ever was" [47].

Thomas concludes that "it's time to stop yearning for a pristine, wild world ... [as] there is no longer any such thing as human-free nature" [53] and we cannot reverse time. Besides, many species of large non-domestic animal are recovering in number and returning to their former lands; bears, bison, wolves, deer, boar, etc. Such recoveries seem likely to become more widespread (albeit within human-managed spaces) and the chances are "there will be considerably more large wild mammals in existence one hundred years from now than there are today" [51].


III. On Accelerated Evolution

Ecological transformation is one thing; evolutionary change is something else - something, in the long run, far more fundamental. Evolution, as Thomas says, is how life on Earth responds to and recovers from natural disasters, including periods of mass extinction.

People often parrot the phrase sixth extinction and like to blame humanity for it. But perhaps we should also consider whether this will in turn trigger a new flourishing of life. Thomas certainly seems to think so. Further, he argues that new species are already "coming into existence with immodest haste, adapting to new conditions" [118] - such as the Italian sparrow.

In a crucial passage, he continues:

"Remarkable as it might seem, new plant species may be coming into existence faster today than at any time in the history of our planet. A new era has arrived in which we see an acceleration of evolutionary change and the genesis of new life-forms. Given that many of them would not exist but for humans, they challenge us to contemplate the relationship between humanity and nature." [118]

We should abandon our human (all too human) guilt about our place in the world and our influence upon it. We should abandon also our privileging of old species over new and the mad desire to save everything. Life doesn't need saving, it needs accelerating and diversifying and the rapid evolution taking place not just in plants, but in animals, fungi and microbes, is something to marvel at.

"Great replacements have frequently been at the heart of large-scale and long-term evolutionary change ..." [140] and rather than always try to conserve things and weeping over the creatures that disappear into the void, we might seek to "build new biological communities composed of compatible species so that future ecosystems are more robust than those that currently exist" [126].


See: Chris D. Thomas, Inheritors of the Earth: How Nature is Thriving in an Age of Extinction (Allen Lane, 2017). 

To read Part 2 of this post (Sections IV-VI) click here. 

Two Inconvenient Truths

Poster by Stanislav Petrov 

deviantart.com 

I: Habitat Heterogeneity Leads to Greater Biodiversity 

According to the ecologist and evolutionary biologist Chris D. Thomas, paradise hasn't been lost because we never had it to begin with: "The harmonious coexistence of humans and the rest of nature in the distant past is a romanticized and largely fictional notion" [59].

Thus it is that the relationship between man and nature remains an often violent one, involving environmental destruction and species extinction. Having said that, human beings have also (inadvertently perhaps) created a "world of new opportunities for those animals and plants capable of seizing them" [59].

Already I can hear the obvious objection from the green lobby: There were once huge areas of land covered by dense forest. Animals and plants wouldn't need new opportunities if only we conserved what remained of these primordial environments.

And, yes, it's true, ancient woodland does contain a great number of trees and many rare species.

However, it's only by converting it into a mixed landscape consisting of a patchwork of forest and various human-created habitats, that the number of species significantly increases: "This is because new species move into human-created habitats faster than the previous residents of the region die out." [67]

This, obviously, is an inconvenient truth for those who oppose all deforestation, for example, and dream of protecting pristine nature as they imagine it. But it's a truth, nevertheless, that if you want to maximise the number of animals and plants, then accelerating habitat heterogeneity is the way to go.


II: Life Prefers Warm and Wet

To say that the world's climate is getting hotter is to state a scientific fact. But to claim that global warming will prove catastrophic for life on Earth is a moral and ideological interpretation of that fact - and a misinterpretation too. For most animals and plants like it warm and wet and will exhibit enhanced physiological performance if the global thermostat is nudged up a degree or two.

Of course, there will be climate change casualties; "at least 10 per cent of all species that live on the land are expected to perish, and possibly double this number" [78]. But the rest - being naturally more dynamic and adaptable - are likely to survive and prosper by migrating, if necessary, to where the conditions best suit them.

Conservationists may not like it, but life is chaotic and in a state of constant flux. Nothing has ever stayed the same and as soon as you begin to think on grand timescales you realise that species are essentially nomadic: "Biological communities are transient. ... That is how species survive climate change. They move around. ... Any attempt by humans to keep things just as they are is utterly pointless." [84]

Thanks to human activity, it's going to get warmer. And wetter. Warmer and wetter than it has been for three million years. But, amazingly, around two-thirds of the species that researchers have studied in recent decades have already wised up to the fact and "shifted their distributions in response" [91].

At the present rate of movement, within just a few centuries we will have a "new biological world order" [92] as subtropical species, for example, move into the temperate zones and former inhabitants of the temperate region "try their luck in the polar world" [92-3]. And this will very likely increase biodiversity, even if the total number of species on Earth is likely to be lower.

I'm not trying to pick a fight with Al Gore or cause Vivienne Westwood to get her knickers in a twist by pointing out this inconvenient truth concerning global warming; I'm not even advocating that we should stop thinking seriously about climate change and its likely consequences.

I'm simply saying - in agreement with Chris Thomas - that we need to accept the reality of the world we live in and encourage the movement of so-called invasive species "because botanical and zoological world travellers will form the basis of the world's new ecosystems, just as they have when the climate has changed in the past" [94].

See: Chris D. Thomas, Inheritors of the Earth: How Nature is Thriving in an Age of Extinction (Allen Lane, 2017). All page numbers given in the text refer to this work. 

To read a related post to this one - on biodiversity in the Anthropocene - click here.  

On Biodiversity in the Anthropocene

The London Underground Mosquito (Culex molestus)

When you read reports about global warming, the destruction of the natural world and accelerated rates of extinction, it's easy to think that there are no winners other than ever-proliferating humanity and that even our malignant success as a species is unsustainable and will thus be relatively shortlived.

But, actually, there are other animals who are doing OK and might even be said to be thriving in this age that some term the Anthropocene ...

Mosquitos, for example, are well-adapted to life in cities; illegally dumped waste and poor sanitation means lots of stagnant water in which to breed; whilst millions of people and their pets all conveniently packed into one place means a constant supply of warm blood on which to feed.  

Other insects doing just fine thanks to human expansion and activity, include bedbugs and cockroaches. But it's not just creepy-crawlies that will enter the evolutionary future alongside man. Larger animals also find shelter, warmth and plentiful food in urban environments. It has been pointed out that if a rat was to design its own ideal home, it would pretty much resemble the system of sewers we've built for them.

And in the UK, thanks to current forestry practices and the eradication of natural predators, the number of deer is at its highest for a thousand years, with some one-and-a-half million frolicking in the woodlands and suburban gardens (just ask my sister about her plants).

Even when we poison the lakes and pollute the rivers, the cyanobacteria (or blue-green algae as they are commonly known) come up smiling; eagerly exploiting the increased nitrogen levels that result when fertilisers applied to farmland are washed into the waters. 

Finally, it's worth giving a big shout to the cephalopods; for species of squid, cuttlefish, and octopus are also making the most of present conditions. Whilst not entirely sure why their numbers are rising, scientists think it's likely due to the fact that the oceans are warming - thanks to human activity - and because we're significantly depleting the numbers of those animals that usually prey on the above.

In addition, celaphopods are natural suvivors; highly intelligent and extremely adaptable creatures who have been around for approximately 480 million years (cf. the pitiful 200,000 years chalked up by modern humans).  

In brief: although some like to imagine an apocalyptic future in which the earth is devoid of all life apart from human beings and their parasites, there is evidence to suggest that things won't be so grim; that large scale and drastic changes to the environment can, in fact, give evolution a real kick up the arse, resulting in new and more resilient species (often as the result of hybridization).

Of course, there probably aren't going to be any charismatic megafauna outside of zoos and conservation areas, but the process of natural selection will almost certainly ensure the survival of life at some level and in some form. Indeed, to return to our friend the mosquito, a sub-species has been discovered living in the London Underground of all places; while you mind the gap and worry about saving the whale, she pierces your skin and drinks ...    


Notes 

Those interested in this topic might like to see the recently published book by Professor Chris D. Thomas; Inheritors of the Earth: How Nature is Thriving in an Age of Extinction, (Allen Lane, 2017). 

For a fascinating interview with Prof. Thomas on the Vox news site (Dec 15, 2017) click here.