Chris D Thomas is causing a stir by suggesting that changing biodiversity represents the way nature is coping, and calls for a rethink on conservation practice. Chris Seekings meets the author of Inheritors of the Earth to find out more
Scientists agree we are living through a troubling period of mass extinction, with human overpopulation and overconsumption responsible for a biological annihilation of wildlife in recent decades.
Earlier this year, a study revealed that 32% of known vertebrate species are decreasing, along with 40% of mammals and 45% of insects, while approximately 68% of evaluated plant types are also threatened with extinction.
In addition, experts believe species are dying out at 1,000 to 10,000 times faster than they would if it were not for the influence of human activity, with dozens becoming extinct every day, instead of the ‘normal’ rate of one to five per year.
Yet despite this profound loss of life, one university professor is causing a stir by shining a light on the vast myriad of species emerging as a result of human behaviour.
Chris D Thomas’s new book, Inheritors of the Earth, challenges the general narrative of declining biodiversity, arguing that nature is actually thriving through this age of extinction.
Loss and gain
I catch up with Thomas amid a backdrop of media attention surrounding his first book, and am keen to ask why scientists seem so pessimistic about life on earth, if it is in fact thriving like he says. “There is this feeling that there is a way nature ought to be, and that the world is all going wrong under the influence of humans,” he explains. “But there are actually many biological gains taking place, and I think it is important to understand and appreciate that, so we obtain a balanced view of how the world is changing.”
It was the lack of reporting on these gains that motivated Thomas to write his book. He argues the gains have been both ecological and evolutionary, with the former demonstrated by organisms living in places they wouldn’t have existed before humans came along, and the latter resulting in entirely new species evolving because of our impact.
“If you can get away from the idea that anything new is bad, and that everything old is good, those changes represent biological gains,” he explains.
Thomas offers the example of the Oxford Ragwort – one of the UK’s most common urban plants – explaining how it originated as a hybrid on Mount Etna, and was moved by plant collectors to Oxford. It was then transported all around the railway network, with its seeds sucked airborne behind trains to the majority of the country’s towns and cities. In some places, it then hybridised with other plants, and the new hybrids became distinct species. “So we now have this bizarre scenario in Britain where more plant species have come into existence through hybridisation in the past 300 years than have actually died out in the whole of Europe, as best we know.”
Although Thomas concedes the number of species in existence around the world has decreased in the human era, he says it is important to consider different ways of measuring biodiversity of life. For example, he points out that there are some 2,000 new species living in Britain as a result of humans altering the landscape and bringing species in, while the number of different plants on Oceanic islands has doubled. “Our perception of nature is seen through the lens of human values. Do you regret the losses more than you enjoy the gains?” he ponders. “The question of what we care about most ultimately becomes a social issue for humanity as a whole to consider.”
Challenging conservation
Thomas is also keen to point out that, throughout the entirety of life on earth, it has been the norm for species to die out or move to new geographical locations, arguing that the changes we often see today represent “the way nature is coping, rather than a symbol of how bad everything is”.
Indeed, in his book, he explains how nature has come back from mass extinction before, and that an increasing variety of life seems likely for hundreds of millions of years to come.
So if much of the change we see today is a natural result of the earth ‘coping’, I ask if the efforts of conservationists are likely to be in vain? “There is a lot of effort, but there are only limited resources available,” Thomas says. “Given the climate is changing, given that species are moving around the world in the wake of humans, species are bound to continue changing where they live. The positions that many people are defending – the status quo – are in many cases indefensible.”
Thomas explains that these conservationists may have some success over a number of decades, but that “ultimately, they are going to lose” and fail to reach their long-term goal. “So I am very anxious that we try and transfer resources as far as possible to things that are going to make a difference in the long run, rather than expend all our efforts on temporary successes,” he adds.
Instead, Thomas argues that if a population of a particular species looks like it is going to die out – for example, if it is disappearing from one country – conservationists should perhaps ask if the species as a whole is likely to be endangered. “If the answer is no, then does it really matter if that one species disappears from your country, if it has been replaced by two other species that arrive from somewhere else?” he asks rhetorically.
This reminds me of one animal that has had a significant amount of resources put into its protection – the giant panda. So have these efforts been a waste of time? “Although the ecosystems could probably manage without having pandas roaming around in them, it is a conservation symbol, and has been a really important driver for protecting substantial areas of forest,” Thomas explains. “A huge amount of biodiversity has been protected as a side-benefit of keeping panda populations alive – so I don’t think it is a species to give up on.”
He is also keen to stress that if a species seems endangered from a global perspective, it may represent a long-term source of concern, and the need for intervention. He points out that species are the “building blocks” of all past, present and future biological communities. “So if we lose lots of species at the global level, in some sense the world has lost some of its ecological flexibility and number of biological ‘spare parts’ we have available,” he adds.
It is not that Thomas is against conservation efforts, far from it, but he advocates much “broader thinking” about what needs protecting, and a change in how success is measured.
No silver bullet
Thomas concedes that conservation is context-dependent, but argues that any approach should have the future very much in mind. “Unfortunately, neither I nor anyone else has a silver bullet,” he admits. “But if new ecosystems and species come into existence because another becomes extinct, and those new biological communities will be appreciated in 100 or 150 years into the future, then essentially we are fighting a battle that we don’t need to fight.”
I put it to Thomas that it is far easier for conservationists to focus on saving species in our own countries now than trying to predict what might come in their place in hundreds of years. “But it is not beyond the wit of man or woman to devise other metrics,” he replies. Thomas argues that in Britain for example, conservationists could decide to put all of their efforts into saving globally endangered species, rather than the majority that are nationally and locally under threat. “That would be prioritising the global bottom line rather than trying to save whichever species happen to be rare in a particular area at a particular time in our history.”
He also suggests that, as the climate shifts, we must allow animals and plants to move around, and may need to assist this. For example, species like the polar bear that are restricted to cold environments may have nowhere cooler to go, while those on top of tropical mountains will have a similar problem. “We might be able to save some of them by moving species, although many will disappear if the climate changes a lot,” he adds.
However, moving species runs counter to many rules and regulations designed to prevent invasive species, something that Thomas believes should be re-examined. “We have 2,000 non-native species living in Britain and, as far as we know, no single native species has become extinct as a consequence. The chances of species being exterminated by moving them to new areas are extremely low in most parts of the world.”
Inevitable inheritors
Thomas conjures up an image of the future in which many of the animals we are familiar with seeing in certain geographic locations could instead be found in vastly different terrains.
This is not a bad thing, he argues. “Keeping the world as it was is not realistic in the Anthropocene epoch of environmental change – things changing is how biological diversity survives in the long run.”
He continues: “We have to work out how we are going to adapt in the context of that change, rather than cling to some sort of hope that it won’t happen.” He wants conservationists to celebrate the resilient and dynamic nature of the world’s animals and plants, rather than just mourn the losses.
In his book, Thomas suggests that instead of swimming against the tide of ecological and evolutionary change, it is important to remember that “old was once new”, arguing that the story of life is one of diversification and renewal.
“Perhaps my bottom-line message is that no change is simply not an option that is on the table. Instead, we need to discuss the sort of change that we would most like to see.”
