Thomas, Inheritors of Earth, species survival and extinction

The Anthropocene epoch:

The politically and ideologically fraught debate over human ecological impacts receives some much needed context from Chris D. Thomas in "Inheritors of the Earth: How Nature is Thriving in an Age of Extinction."
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The vast majority of living creatures are robust enough not only to accommodate their changing environments but to take advantage of the human-created opportunities

Much of the losses are among creatures that had been living in protected niches suddenly exposed to new stresses, competition and predation.

There are real losses that Thomas does not minimize. However, the vast majority of living creatures are robust enough not only to accommodate their changing environments but to take advantage of the human-created opportunities to spread to new regions. In the process, they are adapting rapidly to new conditions, often hybridizing with closely related new contacts and even accelerating the long process of evolving new species.
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The Anthropocene epoch is the name given to the present period by many scientists. Thomas goes at length into the negative impacts on the creatures and plants that have not been able to cope or are otherwise endangered. Of those species that survive, "13 percent of bird species, 26 percent of mammals, 31 percent of cacti, 33 percent of reef-forming corals and 42 percent of amphibians are threatened."
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Much of the losses are among creatures that had been living in protected niches suddenly exposed to new stresses, competition and predation. Flightless birds provide primary examples of creatures that had become dependent on a protected environment for survival. Large mammals provide primary examples of creatures that had demonstrated their ability to prosper through millions of years of competition, predation and environmental change until hunted to extinction by man. Creatures dependent on disappearing forests or warming mountain tops are examples of those threatened by difficulty in moving to more suitable accommodations.
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Many Harlequin frog species in Central and South America have disappeared apparently due in part to diseases spread by the warming climate.

There are many examples of insects and small creatures that were once spread widely about the earth but that now survive only in protected niches.

Global warming threatens a wide variety of creatures. African hairy mountain geladas may be pushed ever higher up their mountain ranges by a warming climate. The Ethiopian wolf and the giant mole rats that they eat are also likely to be pushed ever higher. The mole rats do not thrive in warmer climes, and the wolves do not thrive among humans and their dogs, so the wolves must follow the rats ever higher up their mountain habitat.

"Animals confined to tropical mountains cannot descend to the lowlands and seek out colder mountain ranges thousands of kilometers away. Insects and plants that live only in moist ravines cannot cross deserts to reach new homes."

Will they be able to adapt? A survey of moths in Borneo revealed that certain creatures will indeed have trouble adapting to these types of stresses. Many Harlequin frog species in Central and South America have disappeared apparently due in part to diseases spread by the warming climate. Many are trapped. Their only hope may be human intervention to place them in more hospitable habitats.
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There are many examples of insects and small creatures that were once spread widely about the earth but that now survive only in protected niches. Thomas mentions a widespread ice-age dung beetle now found only at heights in Tibet. Other species of ice-age beetles now are found thousands of miles apart in places like the arctic or the Pyrenees or as far away as East Asia. Even relatives of the geladas were once widespread during ancient ice ages.
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"Biological communities are transient." Species are threatened only if they cannot move. All species are interlopers where they now exist.

Many creatures have demonstrated a surprising capacity to move in response to changing conditions. It is clear that "many species currently live in places where they happen to survive, rather than where they originally evolved." Indeed, "the biological world has been turned on its head repeatedly since the last ice age."

"Dynamism is the norm, not the exception. It is how species survive times when the world's climate changes."

"Biological communities are transient." Species are threatened only if they cannot move. All species are interlopers where they now exist. "Any attempt by humans to keep things just as they are is utterly pointless."
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The previous trickle of species successfully taking advantage of human-created opportunities is becoming a torrent. Thomas provides numerous illustrative examples. New species have been arriving at least as fast as previous occupants are disappearing.

At present, the gains to the diversity of life around the world far exceeds the losses. The previous trickle of species successfully taking advantage of human-created opportunities is becoming a torrent. Thomas provides numerous illustrative examples. New species have been arriving at least as fast as previous occupants are disappearing. Agricultural lands and urban areas still average about 60 per cent of the species that previously inhabited them while accommodating a variety of new arrivals..

"The original habitat is not so much destroyed as replaced by a new environment that still contains quite a lot of species."
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"When people have counted changes to the number of species of animals or plants in any given location over time, they usually find that local diversity has stayed about the same -- a conclusion that is based on the analysis of large volumes of data that have been collected over many decades. If anything, the average number of species is increasing slightly."

For example, California has lost its ice age giants and many others of the species preserved in the La Brea tar pits, but it has gained in the last four hundred years European rabbits, two species of squirrel, house mouse, two rats, Barbary sheep, fallow deer, wild boars, pheasant, turkey, starling, house sparrow, brown-headed cowbird, and numerous insects and slugs as well as domestic animals.
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Birder, plant and butterfly hunter counts imply that "the total number of species in a mixture of ecosystems is likely to be greater than if an entire area was covered by one type of vegetation."

Where there is a mixture of human altered habitat and preserved habitat, the species population may be considerably increased. Birder, plant and butterfly hunter counts imply that "the total number of species in a mixture of ecosystems is likely to be greater than if an entire area was covered by one type of vegetation." While this is not the case in the American Midwest or parts of Northern Europe, most agricultural areas around the world include a wide variety of current and former farmland and remaining and wild habitats.
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The Vale of York:

Thomas resides in the Vale of York, now dominated by industry and agriculture. Nevertheless it is alive with thriving wild creatures, many of which are recent arrivals.
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The biological community has been completely changed at least four times in the last fifteen thousand years and at least forty times in the last million years. Today, "new arrivals are turning up as the climate warms once more, changing the biological community again."

The Vale of York was previously occupied by a lake, then sand dunes, steppe, wetland, forest, and finally human farm land and field margins. The biological community has been completely changed at least four times in the last fifteen thousand years and at least forty times in the last million years. Today, "new arrivals are turning up as the climate warms once more, changing the biological community again."
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Man has vastly changed the environment, but the ordinary processes of life continue. Plants spread and grow, capturing energy from the sun to create the leaves that render the world green. Animals consume the plants and their seeds and in turn are eaten by other animals. Decomposing plants and animals and faeces are recycled as nutrients for future use. Among the recent arrivals are Asian harlequin ladybugs feasting on newly arrived greenflys, small-leaved Tasmanian pigmyweed, European poppies, and Kestrels that arrived to feast on the rodents revealed by the clearing of the forest. However, Thomas is not aware of any established residents that have disappeared.

"I have counted [on just two hectares or 5.5 acres] twenty-two butterfly species, fifteen types of dragonflies and damselflies, ninety-two bird species and nineteen different kinds of mammals living on the land, or at least visiting occasionally. For each of these groups, these numbers amount to between 30 and 40 per cent of all the species regularly found in Britain . - - - What is odd about this is that all these species are living in a thoroughly human-changed landscape that bears almost no resemblance to the pre-human habitats that used to be here."

Evolution in the human-altered environment:

There are numerous "opportunists" thriving in the Anthropocene. Few of these species would have lived in the original forest. It is the same in almost all the habitable parts of the Earth.

"Humans have created a cornucopia of new habitats, and have done so for millennia across six continents. This has created a world of new opportunities for those animals and plants capable of seizing them."

Even the Lake Maggiore region in the Swiss Alps has a record of massive ecological change.

Man has massively altered the environment everywhere. Thomas covers in some detail tropical forests, ancient agricultural regions, coastal forests, the realms of hunter-gatherers, agricultural prairies, all of which have experienced centuries and even millennia of human impacts. The transformations are both ancient and truly global. Even the Lake Maggiore region in the Swiss Alps has a record of massive ecological change. "It is a human-altered land" now hosting plants and animals from all over the world.

"Familiar creatures have taken the human-modified Earth by storm, be they talkative yellow-billed Indian myna birds that are now at home in Florida, Japan, Sumatra, Madagascar and Australia, agile mice that started life in Asia and then spread - - -, or Australian wattle trees and previously endangered California pines that are growing wild in Africa. They are joined by thousands of other mammals, birds and plants, as well as microbes, fungi, worms, snails, shrimps, insects, fish, toads and lizards."

Many species are thriving. Their existence somewhat counters the "paradigm of biological decline."

The vast majority of species manage to survive, resulting in an increase in diversity. With the exception of some small islands and isolated bits of land, "diversity has grown in nearly all regions of the world."

The processes of ecological change and species evolution have been accelerated, but are nothing new. While some species don't make it, others adapt to take advantage of new opportunities by evolving new capabilities. Many species are thriving. Their existence somewhat counters the "paradigm of biological decline."
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The geologically sudden connection between North and South America that saw the extinction of many species but an overall increase in the variety of species on both continents is an example used by Thomas. The ice age connection between the Americas and Asia is another. The creatures that arrived from the larger, most diverse region appear to have been the most successful in the competition that followed, but diversity increased overall.
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Thomas expends considerable ink speculating on the characteristics that distinguish the winners from the losers in these cases. He emphasizes that the vast majority of species manage to survive, resulting in an increase in diversity. With the exception of some small islands and isolated bits of land, "diversity has grown in nearly all regions of the world."
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Most new species arrivals do not displace any native species. The norm is that "immigration usually increases species diversity."

Humans have carried a wide variety of species to new environments, "from horses to hippos, pigeons to pythons, lobsters to lionfish." Indeed, most new species arrivals do not displace any native species. The norm is that "immigration usually increases species diversity." Is there "an evolutionary yang to the yin of human impacts?"

"Nature has come back from mass extinctions before and the variety of life has grown again. Could this happen once more?"

All creatures - including humans - are hybrids.

Animals transported to new environments are developing new characteristics that may eventually result in their evolution into new species. The evolutionary processes are on a much grander scale but quite similar to those on island archipelagos like the Hawaiian Islands or Darwin's Galapagos Islands. It is a new Great Global Interchange.

The process of hybridization and the often irrational response of conservationists to recent examples is covered at some length by Thomas. Indeed, all creatures - including humans - are hybrids, he emphasizes.
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Insects such as butterflies and crickets have spread to new regions around the world and evolved new ways of surviving, new animal and plant species are coming into existence. "In fact, the formation of new hybrid plant species in Europe and North America would appear to be faster already that the rate at which previously existing plants are becoming extinct."
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Animals transported to new environments are developing new characteristics that may eventually result in their evolution into new species. The evolutionary processes are on a much grander scale but quite similar to those on island archipelagos like the Hawaiian Islands or Darwin's Galapagos Islands. It is a new Great Global Interchange.

"We are watching the formation of a New Pangea, conceivably the greatest spur to evolution for a hundred or more million years. While some might think of the New Pangea as a single human-connected mega-continent, this new world is more akin to a Pangean archipelago. Each continent, and each region with a continent, each true island, represents a node in a global network of islands. Each species that arrives in a fresh location experiences the physical conditions there, meets species it has not previously encountered, and starts to evolve into something a bit different. This new global archipelago has the potential to deliver a torrent of evolutionary changes."

Size, physical characteristics such as dietary characteristics, birds beaks, and chromosomal arrangements have diverged with great rapidity in small rapidly breeding creatures.

The pace of species differentiation into new species is astounding. Thomas discusses the California star thistles and the Italian sparrow and the fruit flies and their predator fruit fly wasps. Size, physical characteristics such as dietary characteristics, birds beaks, and chromosomal arrangements have diverged with great rapidity in small rapidly breeding creatures. Hybridization remains possible but becomes increasingly difficult over time among such differentiating species.

"The broad geographical, ecological and evolutionary context reminds us that the biological world is in constant flux. Dynamic change means that we face an indefinite future of biological gains as well as losses - often with humans as the underlying cause."

Conservation confusion:

Conservationist efforts to keep things as unchanged as possible are untenable, Thomas asserts.
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The world already exists as a human altered environment. "We have to work with natural biological processes, not against them."

Oak, lime, beech and hornbeam trees were banished from the frigid European prairie but survived in hospitable southern European niche environments to become the dominant and invaluable species of today.

Useful medicinal products and chemicals have repeatedly been derived from obscure species of plants and fungi and microbes.

"Humans are a part of nature," he emphasizes. The world already exists as a human altered environment. "We have to work with natural biological processes, not against them."

"[W]e should not try to halt biological change. I would certainly advocate that we tackle the underlying causes of change: we should stabilize and then reduce the human population, minimize levels of harmful consumption, obtain our food in ways that reduce our footprint on the Earth, and minimize and when possible recycle the waste we produce. We should also reduce our greenhouse gas emissions. But we should not normally attempt to halt how the biological world responds to the consequences of humanity, except when those responses are directly and obviously injurious (we will, of course, want to control new human diseases, crop pests and pathogens that afflict our livestock)."

Many of the species most widespread and useful today narrowly escaped extinction during the last ice age by retreating to confined niches, Thomas points out. "Rare species becoming common and common species becoming rare is not a human-created phenomenon." Examples include the alpine clough and British dung beetle that were widespread in the frigid climate while oak, lime, beech and hornbeam trees were banished from the frigid European prairie but survived in hospitable southern European niche environments to become the dominant and invaluable species of today.

"The majority of species that have ever become really important contributors to the Earth's ecosystems have evolved in a relatively localized area first before they spread more widely, and then their numbers have waxed and waned as conditions have changed. - - - Most of our carbohydrates come from plants that are descended from a few species of grasses that were restricted to small parts of the world before people arrived: maize, rice, the ancestors of wheat, and so on."

Useful medicinal products and chemicals have repeatedly been derived from obscure species of plants and fungi and microbes.

"Keeping as many species as possible alive on our global Ark should still be a primary target for our conservation activities, however, because these species and those that evolve from them are the building blocks from which every future ecological system will be constructed."

"Why should we not aspire to a world where it is as legitimate to facilitate new gains as it is to avoid losses?"

There is no need to be shackled by the pessimism-laden, loss-only view currently dominating much of the environmental movement. "Why should we not aspire to a world where it is as legitimate to facilitate new gains as it is to avoid losses?" Among the numerous examples provided by Thomas are the Monterey pine trees endangered in coastal California and Australian blue gum trees originally confined to Tasmania and southern Australia. Both have been intentionally spread by man to a wide variety of suitable locations around the world where they now comprise important woodland resources.
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Thomas calls the sparrow "inheritor number one of the human-altered earth."

The human response to the sparrow amply demonstrates that conservation strategy lacks both consistency and logic.

The Bactrian sparrow of Asia provides a prime example of how human agricultural developments over the millennia followed by the spread of human buildings opened irresistible opportunities that enabled a wild creature to spread around the world. Thomas calls the sparrow "inheritor number one of the human-altered earth."
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The Asian sparrow merged with wild gray-headed sparrows to become the familiar house-sparrow that has long-since conquered the human world. It formed other hybrids like the Italian sparrow. Genetic analysis discloses that the Italian sparrow is a true hybrid of the Asian and Spanish sparrows. All of this is a result of the spread of human agriculture and dwellings.
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The sparrow has sometimes been viewed as a pest but has been favored at other times. Their nests can be a nuisance. They "block gutters, eat crops, leave their droppings in stored grain and on windowsills, carry avian diseases and oust other birds from their nesting holes, and they do sometimes peck their competitors to death." They kill some desirable bluebirds, but so do our pet cats and many other creatures. The Christmas Bird Counts show no connection between sparrow and bluebird populations.
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Sparrows were intentionally transported across the oceans to the Americas, Australia, New Zealand, South Africa and Zanzibar, but traveled as stowaways to other places including many remote islands. Sparrows are the quintessential "invasive" species, with many hundreds of millions all around the earth. However, a substantial population decline in England towards the end of the twentieth century led conservationists to support the spending of much time and money for their preservation.

"In the second Elizabethan age, it is illegal to kill or injure sparrows intentionally, or to remove any of their nests that are in active use."

The population decline in England apparently ended about 2000 and has been traced to changes in agricultural practices and modern building construction that impact their food sources and nesting sites. The sale of both sparrow traps and nesting boxes are profitable businesses in the United States. The human response to the sparrow amply demonstrates that conservation strategy lacks both consistency and logic.
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The spread of the "foreign" American ruddy duck to Europe was not intentional. It and its hybrids are viewed as a menace to the "native" European white-headed duck which is actually not "native" to Europe. Conservationists and their numerous august associations have declared war on the ruddy duck and its hybrids and have decreed that they must all be exterminated.
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Similarly, the arrival in New Zealand of black-and-white pied stilts from Australia - apparently on their own wings - is viewed as a threat to the "native" black stilts. The newcomers and their hybrids are being attacked by conservationists even though the primary threat to the black stilts seems to be the arrival of new predators that the foreign and hybrid stilts seem to be better at avoiding.
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Other diverse and successful species thriving in the Anthropocene include a variety of rodents, perching birds, lizards, frogs, fish, beetles, trees, grasses and lichens.
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The "mini-mass" extinction:

Conservationists seem to take a particularly dim view of biological success stories when "successful 'foreign' species have the temerity to interbreed with 'native' residents" that often themselves were alien transplants of previous times. The populations of each of these "foreign" species - whether mammal, insect, snail, mussel, worm or plant species - are now more widespread and numerous than before, but their success is seldom celebrated.
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The populations of each of these "foreign" species are now more widespread and numerous than before, but their success is seldom celebrated.

These successes are all just examples of the broad movement of life on earth coping with and adapting to the impacts of humanity, Thomas asserts. The world contains both winners and losers. "There is no correct state of nature." Why should humans act as referees and arbiters of how nature should be? Yet massive sums are now spent in the attempt to keep "invasive" species at bay and maintain existing species in their present locations.

"We have to accept that a world without change is not an available option, - - - We are confused because - - - species are neither all good nor all bad from a human perspective."

Fresh immigrants provide a counterbalance that results in an increase in plant and animal diversity in most major regions of the earth.

"The extinction crisis is real," Thomas affirms. However, fresh immigrants provide a counterbalance that results in an increase in plant and animal diversity in most major regions of the earth.
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Wherever in the world you may be, "you would once have been surrounded by an impressive array of staggeringly large animals." Only three of perhaps twenty separate elephant species survive. Survivors in Africa include just two elephant species, hippos, white rhinos, black rhinos, and four species of giraffe. No continent inhabited by man has been spared. Giant flightless birds have disappeared from New Zealand and giant marsupials have disappeared from Australia. The La Brea tar pits in Los Angeles demonstrate the losses in North America.
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It was stone-age ingenuity in weaponry and traps rather than brawn and daring that doomed many of the earth's largest mammals, Thomas points out.
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Flightless birds are not the only casualties among those that had existed in protected environments. Human hunters and the stowaway rats that accompanied them "drove perhaps a thousand bird species extinct from the Pacific Islands in little over three millennia," including a spectacularly large New Zealand eagle.
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The losses are not yet as great as during the five recognized mass extinction events of the past when more that three quarters of all then existing species disappeared.

The species that succeed tomorrow are already living among us.

This "mini mass extinction" is virtually instantaneous in terms of geological time. The losses are not yet as great as during the five recognized mass extinction events of the past when more that three quarters of all then existing species disappeared, but the losses directly attributable to the arrival of modern man are already quite extensive.
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However, the result of the last mass extinction that killed off the dinosaurs is that "the world now contains over ten thousand different kinds of birds and no reptiles weighing more than a tonne, other than a few crocodiles and their relatives." Many small mammals also survived and diversified to fill the voids and inherit the Earth. Similarly today, the species that succeed tomorrow are already living among us. "Those that succeed in the long run can only come through the ranks of the initial survivors."
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An unexpected beneficiary is the surviving game animals and birds that are no longer needed for food and are sometimes accorded protected status.

Once we stop killing them, large animals come back, rejoining the 90-plus percent of smaller ones that never disappeared in the first place."

The survivors of today include plants and animals found useful by man. There is a lengthening list of useful animals, plants and fungi that man protects or domesticates. They exist in staggering numbers and variety. It is "bonanza time" for animals that can consume human tended plants. Counting humans and their animals and birds, "the Anthropocene is just as much an age of mammals and birds as it ever was."
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An unexpected beneficiary is the surviving game animals and birds that are no longer needed for food and are sometimes accorded protected status. Wolves, bears, bison populations are up, and beaver, deer and wild-boar populations are exploding. Their predators - including wolves, bears, golden Jackel, wolverine and lynx - are repopulating Europe. Large birds and whales are also thriving. Many benefit from active conservation programs. "Once we stop killing them, large animals come back, rejoining the 90-plus percent of smaller ones that never disappeared in the first place."

"It seems that it is time to stop yearning for a pristine, wild world. We are living on a fundamentally altered planet, and there is no longer any such thing as human-free nature. - - - We should appreciate changes that are positive as much as we regret any losses."

Everything from moths to trees, amphibians, reptiles, and plants are on the move. Fish, marine plankton and shell fish are moving towards the polls. "Animals are moving towards the polls at about 17 kilometers a decade."

The movement of creatures about the earth is covered at some length by Thomas. He features a variety of butterflies, bees and birds now newly arrived in the Vale. Around the world, everything from moths to trees, amphibians, reptiles, and plants are on the move. Fish, marine plankton and shell fish are moving towards the polls. "Animals are moving towards the polls at about 17 kilometers a decade."

"Even those animals that are unaffected by temperature and rainfall directly are living in places where the vegetation they eat and the animals that prey on them have already changed."

At least two thirds of all species now live in new habitats. There are few truly "native" species.
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A warmer, wetter world should actually increase in biological diversity. "Foreign" species are a threat primarily in niche habitats. Species trapped in small niches may need human help to reach new habitats.

Water is the most obvious limiting factor. While a warming climate should be wetter overall, deserts and dry lands will expand in places. Coral reefs are threatened by acidic water as well as warmer water. Extinction events have been accelerated by the movement of 'invasive" species by or with man into previously protected habitats.
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However, a warmer, wetter world should actually increase in biological diversity. "Foreign" species are a threat primarily in niche habitats. Species trapped in small niches may need human help to reach new habitats.
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Killer conservationists:

New Zealand has a plethora of endangered species. New Zealand has undertaken extensive efforts to sustain them. They attempt to repress invasive and competing creatures and keep out others. There is considerable scientific interest in the threatened species and considerable public support for conservation efforts.
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Native creatures that live nowhere else include a variety of parrots and tuatara reptiles, native plants and "unreasonably large" snails and giant insects. The South Island takahe flightless bird has been moved to small islands where it has apparently never previously lived. European-origin grassland plants recently introduced to the islands are included in its diet, but alien predators and competitors have been cleared away. Rats, mice, feral dogs, possums, cats, stoats, weasels, and resident humans have been eliminated or removed.
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Shelter islands and mainland cages are too small to support viable populations, so protected creatures must be continuously moved back and forth to maintain reasonably sized populations. Such "unstable" ecological systems must be defended indefinitely.

"New Zealand conservationists have become world leaders in extermination." They are building predator-proof fences around some mainland areas and eliminating the predators and competitors within them. Civic organizations roam the land to poison and trap un-caged areas.
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However, invasive plants, insects and fungus remain, extinct creatures cannot be brought back to life, and protected species can exist only so long as the conservation effort is continued. Shelter islands and mainland cages are too small to support viable populations, so protected creatures must be continuously moved back and forth to maintain reasonably sized populations. Such "unstable" ecological systems must be defended indefinitely. Rats and mice, in particular, repeatedly arrive with shipping.
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"Foreign species hardly ever cause native species to become extinct from entire continents." Roughly just one in a thousand newly arrived species causes a real issue for native animals and plants. The importation of new species "almost always increases the numbers of species in any given location."

There are more different kinds of vertebrates in New Zealand today than before humans arrived, twice as many plants and hosts of imported insects, most of which are not going away. Thomas somewhat unrealistically suggests that instead of wasting efforts on New Zealand's losers, efforts might be better directed towards establishing hardy replacements using species from elsewhere. (This suggestion is unlikely to capture sympathy from the New Zealand public.)
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"Foreign species hardly ever cause native species to become extinct from entire continents." Roughly just one in a thousand newly arrived species causes a real issue for native animals and plants. The importation of new species "almost always increases the numbers of species in any given location." This is true even in New Zealand where there has been considerable loss of native species. Plant diversity has greatly increased in Great Britain and continental regions.
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Accelerated evolutionary divergence and speciation:

The world has become a "New Pangea," with man responsible for the mixing of plants and animals from all over the world. The survivors will include the very ordinary creatures that are today all around us. "Look out of your window and the chances are that you will be staring at the future."
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Thomas highlights the extraordinary pace of evolutionary changes in dogs and some species of butterfly. Fish are getting smaller and breeding faster. "Evolution is not necessarily a slow process." Unfortunately, flightless birds cannot evolve wings that work or change vestigial wings back to forelimbs.
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In response to the rapid pace of change in the human-impacted environment, "it follows that nearly all wild animals, plants and microbes must be evolving in response." Pathogens and other pests stay one step ahead of antibiotics and poisons. "Over 200 different weeds have overcome at least 150 herbicides." Rats and roaches remain evolutionary success stories. "Each gene for resistance in all these pathogens, plants, insects and mammals is its own biological success story." Even human pollution drives adaptive evolutionary changes.

"There is variation in almost everything that anyone can imagine. When the environment changes, some of these variants are almost bound to survive at least slightly better than others, such that the characteristics of the next generation will differ from those that went before. Given how much and how fast humans have changed the world, it is entirely credible that we are now living through the most rapid period of evolution since the after math of the extinction of the dinosaurs 66 million years ago."
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"Almost all countries, states and islands are now more biologically diverse than they used to be."

Human "artificial selection" can be seen in cattle, pigs, sheep, llama and horses as well as dogs and the domesticated rock dove (pigeon). Cabbage varieties now include turnips, Napa cabbage, rapini, field mustard, and mizuna. Peppers are another example of the extraordinary scope and speed of human-driven evolution. They all make use of vast genetic libraries.
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The capacity to digest milk is one change that is visibly now in midstream. The ability to digest starch, carbohydrates and fats varies with differences in human genetic makeup and territorial background.

Science writers and natural historians "report each new example" of rapid evolutionary adaptation "with a sense of shock and amazement." Scientists milk the discoveries for publicity, ecologists and conservationists "find it convenient to treat species as if they are fixed entities."

Humans, themselves, are evolving in response to human alterations in the environment. A variety of food "allergies" demonstrate the process and pace of evolutionary change. The capacity to digest milk is one change that is visibly now in midstream. The ability to digest starch, carbohydrates and fats varies with differences in human genetic makeup and territorial background. Differences in taste and tooth enamel exhibit human evolution in process.
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"There is no clear dividing line" between the processes of natural selection and "artificial selection." Animal preferences are just as capable of driving extraordinary evolutionary changes as human preferences. (See, Prum, "The Evolution of Beauty" on the impact of female bird breeding choice on male breeding conduct and plumage.)
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Yet science writers and natural historians "report each new example" of rapid evolutionary adaptation "with a sense of shock and amazement." Scientists milk the discoveries for publicity, ecologists and conservationists "find it convenient to treat species as if they are fixed entities."

"The Earth was not in some perfect or final state before humans pitched up. Life is a process, not a final product. So we need conservation philosophy that is based on natural change, with humans center stage: partly because we have already brought about so many changes to the world that cannot be ignored, and partly because humans evolved naturally and we are part the the natural system."

Those who view environmentalism as a convenient lever to be used against the capitalist system will not welcome Thomas' optimistic view. However, the burdens of environmental policies will always be rejected by electorates unless the economy is thriving, so Thomas' actually envisions a way forward for ecological concerns.

Life on Earth is a dynamic process. We must accept change, retain flexibility to respond to future change by preserving endangered species - - - and only rarely by waging war on interlopers.

Change is at the center of Thomas philosophy. Life on Earth is a dynamic process. We must accept change, retain flexibility to respond to future change by preserving endangered species often by relocation and only rarely by waging war on interlopers.
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We should accept that the changes wrought by humans are a part of the natural world, but also acknowledge that we "have to live within our planetary bounds."
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"We can let change happen." The "no-change-is-best framework for conservation" is untenable.
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