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Chapter 19
Themes
Key
LitCharts assigns a color and icon to each theme in The Beak of the Finch, which you can use to track the themes throughout the work.
Natural Selection and Evolution as Ongoing Processes
Nature and Humanity
Evolution, the Modern Era, and Nature’s “Resistance Movement”
The Interconnectedness of Species and Ecosystems
Hybridization and Specialization
Summary
Analysis
Humanity has long struggled to understand why we, as a species, developed consciousness and self-awareness—and the consequences of how this development has set us apart from the other species with which we share the planet. Evolutionists still debate what led to this split in development. Crossbills, hinged jaws, and specialized talons help certain finches to survive, but those adaptations are smaller than the leap from ignorance to consciousness.
This passage shows that this chapter will investigate the “metaphysical crossbeak” humans have developed. In other words, this chapter is going to delve into the unique specializations that have allowed humanity to grow and expand into new niches. Even though consciousness is a different kind of trait than a special beak, Weiner is attempting to draw a parallel between humanity’s evolutionary advantages and the evolutionary advantages that appear in other species. Humanity must recognize that we, too, are only animals—and that we, too, are sensitive to the processes of evolutionary biology.
Themes
Humans walked upright for millions of years before our brains and skulls expanded in one of the most “dramatic evolutionary changes in the fossil record.” The human brain tripled in size after that development. We developed opposable thumbs and our hyoid bone changed shape, allowing for speech. And somewhere in this series of evolutions, consciousness heightened. And it is this trait that sets humanity apart from other species most profoundly—so much so that we consider ourselves in a different family from other primates. But in reality, humans are as genetically close to chimpanzees as ground finches are to tree finches. Neurobiologists are still looking for the origin of consciousness in the brain: our “metaphysical crossbeak.”
By drawing a connection between the “dramatic evolutionary changes” that humanity has gone through and the specialized “crossbeak” belonging to certain species of finches, Weiner is once again suggesting that humanity is more like the species that live all around us than we might like to think. He argues that our capacity for consciousness is not something divinely granted to us: it’s just another advantageous evolutionary adaptation that has allowed us to fill a particular social and ecological niche.
Themes
Humanity’s heightened consciousness has allowed us to carve out adaptive niches quite rapidly. But other species, too, are still evolving and learning: blue tit birds in England are learning to peck open holes in milk bottles left out overnight, monkeys in Japan are learning to wash their food before eating it, and octopi in Italy are able to observe one another’s mistakes and learn from them, so as not to repeat them.
Humanity was able to radiate in so many ways because of our ability to pass along knowledge to our contemporaries and our offspring. Now that other animals have been observed engaging in this behavior, naturalists and biologists are wondering what might happen if natural selection starts to favor various animals’ abilities to share knowledge with their own kind, and retain that knowledge from generation to generation.
Themes
Cultural evolution, these anecdotes show, is not unique to our kind. On Cocos Island in the Galápagos, where the finches are all one single species, they are not radiating into new variations. Neither is humankind—our environment has become too small. Humans are “specialized in our despecialization”—in other words, we aren’t hyperspecialized like, say, cactus finches, but that very despecialization has allowed us to thrive in a variety of environments. And as we fill more and more niches, we pass on our learning through collective memory.
This passage shows that humanity has indeed evolved to reach an adaptive peak. We’re different from the finches—but in many ways, we’re still living examples of natural selection and evolution’s power to force a species to evolve in a certain way. Humanity, the book suggests, must realize this in order to fulfill our responsibilities to the many species with which we share the planet.
Themes
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Many believe that humanity is static, immune to the pressures of selection. But individual humans are much more like finches than we’d like to think: we all start out as fledglings, then enter a phase of “wild experimentation,” then “narrow” our scope and seek trades in which we can successfully fill a niche. Humans are evolving, and, in the process, driving evolution around us. But a species that can only survive by causing such havoc is at risk of extinction—the whole planet, Weiner writes, is like a “twisted pinecone” we are trying to pry open.
By comparing humankind to Darwin’s finches, Weiner is highlighting that humanity isn’t necessarily special among the many life forms on Earth today. Humanity needs to learn in harmony with its fellow creatures in order to survive. By denying our own ongoing evolutionary processes—and by attempting to do things that create havoc for the rest of the planet, like expelling carbon into the atmosphere—humanity is dooming itself along with the Earth’s plants and animals.
Themes
Just as cactus finches on Daphne Major sometimes accidentally snip the reproductive organs of the cactus flower in the process of eating it—thus cutting off their only food sources’ ability to reproduce and nourish them—humanity is, in essence, “stealing from [our own] future[s].” Often, the needs of the individual clash with the needs of the flock. Yet Darwin optimistically called mankind “the wonder and glory of the universe.”
Weiner suggests that Darwin’s belief in humanity’s unique, innate “wonder and glory” is useful for modern people to consider and internalize. There is always the chance that humanity will wind up negating its own future chances for survival through the struggle for power or hubris. But hopefully, as humanity continues to grow and evolve, we can add to what the generations before us have learned for the better, as we were born to do.
Themes
