“We are hybridizing the planet,” author Jonathan Weiner writes of humanity’s impact on the natural world in his book The Beak of the Finch. In other words, Weiner is implying that modern humans have forever changed the face of the earth in many irrevocable ways. By exploring how human evolution, migration, and industrialization have impacted the natural world, the book suggests that because of humanity’s remarkable (yet often destructive) progress, the world’s plants and animals have come to a unique and critical point in their evolutionary processes. Ultimately, Weiner argues that humans have a responsibility to recognize and assume responsibility for the impact they’ve had on the natural world.
The book explores how humanity’s long journey toward industrialization has impacted the natural world. Humanity’s power to impact the natural world—and the evolution of species—is fact, not hypothesis. Author Jonathan Weiner cites an example from the height of the Industrial Revolution to underscore the realities of humanity’s impact on other species. In 1848, an English lepidopterist (the word for a person who studies butterflies and moths) noticed that, in the city of Manchester, a species of moth that had previously been whitish with small black spots was turning black. But moths of the same species in rural parts of the country weren’t changing. The “black mutants,” it turned out, were turning black in order to blend in with their increasingly grimy, soot-stained urban surroundings. This anecdote illustrates how the activities of the human species have the power to change the evolutionary patterns of insects, plants, and animals. Because, as the book also shows, nature’s ecosystems are delicately and profoundly interconnected, changing the behavior or appearance of even an animal as small as a moth has cascading consequences throughout the world’s bionetworks.
Climate change brought on by human industry is yet another way that humanity has impacted the natural world. Global warming, for instance, threatens the integrity of the current patterns of the oceans’ currents—currents that bring seasons to places like the Galápagos. Shifts in the weather patterns of the Galápagos will certainly impact the evolution of the animals that live on the island, or whether the islands cease to be habitable for those animals at all. Because of climate change, whole species could be eliminated—and because every ecosystem on earth is delicate and interconnected, whole species’ evolutionary patterns and relationships with other species could be wiped off the map.
The book suggests that because humans have forever changed the face of the planet—and because humans are the only species on earth with full consciousness of the correlation between action and consequence—humanity has a responsibility to invest itself in the preservation of nature. “Never before was such havoc caused by the expansion of a single species,” Weiner writes in The Beak of the Finch. “[And] never before was the leading actor aware of the action, concerned about the consequences, conscious of guilt.” Here, Weiner suggests that though humans have caused immense “havoc” on and damage to the planet and its many species, humanity is also unique in its ability to understand that it should feel some “guilt” about its actions. That guilt, the passage implies, should be a motivating force that compels humanity to take responsibility for its actions. Weiner goes on to observe that, “for better and for worse, this may be one of the most dramatic moments to observe evolution in action since evolution began.” Now that humanity has changed the face of the planet and pressurized certain selection and evolution events (such as in the case of the Manchester moths), it can absorb the gravity of its actions. Humans shouldn’t only feel guilt—they should marvel at the planet’s capacity to change, and work to take actions that will nurture positive selection and change rather than continuing to feign ignorance as to how human activity impacts the planet’s many species.
After Britain enacted clean-air legislation in the mid-20th century, the moths in Manchester began to morph back to their original forms—the frequency of the black mutant dropped from seven in ten months to fewer than one in ten. The Beak of the Finch makes the case that humanity has the power to assume responsibility for how its activities impact nature, and to ensure that we are conscious, careful, and deliberate in our actions.
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Nature and Humanity Quotes in The Beak of the Finch
A “web of complex relations” binds all of the living things in any region, Darwin writes. Adding or subtracting even a single species causes waves of change that race through the web,” onwards in ever-increasing circles of complexity.” The simple act of adding cats to an English village would reduce the number of field mice. Killing mice would benefit the bumblebees, whose nests and honeycombs the mice often devour. Increasing the number of bumblebees would benefit the heartsease and red clover, which are fertilized almost exclusively by bumblebees. So adding cats to the village could end by adding flowers.
The arrival of human beings means a new phase in the evolution of Darwin's finches, and its directions are still unclear. […] Rosemary and Peter do think they see something odd about the finches of Santa Cruz. The birds around the research station, and in the village, seem to be blurring together. The Grants have never made a systematic study of this: but to their eyes the species almost look as though they are fusing. "They just sort of run into each other," says Rosemary. There is no difference between the largest fortis and the smallest magnirostris.
You don't find situations that chaotic under natural conditions, but you do find them in the havoc that human beings bring in their train. […] Thus, our disturbances hybridize both the environment and the species.
We are hybridizing the planet.
A pesticide applies selection pressure as surely as a drought or flood. The poison selects against traits that make a species vulnerable to it, because the individuals that are most vulnerable are the ones that die first. The poison selects for any trait that makes the species less vulnerable, because the least vulnerable are the ones that survive longest and leave the most offspring. In this way the invention of pesticides in the twentieth century has driven waves of evolution in insects all over the planet.
In the world's oceans, Norwegian cod, chinook salmon, Atlantic salmon, red snapper, and red porgy are getting smaller, very likely through the selection pressures of the net. Fishermen are not happy with the trend toward small fish, any more than elephant poachers are pleased with the trend toward tusklessness. But both resistance movements are direct results of Darwinian law.
The black mutants swept up through the mort populations wherever the air was black with the soot of the industrial revolution. Their numbers did not rise in rural parts of Cornwall, Scotland, and Wales. In rural Kent, Darwin's adopted county the black form of the moth was not recorded during his lifetime; but by the middle of this century, nine out of ten Biston betularia were black in Bromley, and seven out of ten in Maidstone.
Manchester, of course, was one of the grimy hubs of the industrial revolution.
They rise, they are discovered by seeds and birds, they support Darwinian chains of action and reaction, and they sink again to the bottom of the sea, while new islands rise in their place. This rise and fall may have gone on here in the middle of the sea for as many as eighty or ninety million years. […] We know [that Daphne Major is] a place that was here before we came and will remain when we are gone. The very island will sink someday, and another will rise when it is drowned.
