Nature as Teacher
The way organisms respond to shifts in their environments may hold clues for human resilience in the face of our own crises
Coral reefs are old. Really old. Scientists believe corals have lived in the shallows of Earth’s oceans for 160 million years, predating dinosaurs. They owe their longevity in large part to a symbiotic relationship with microscopic algae that live inside their tissues, absorbing sunlight and passing along vital nutrients that both feed corals and give them their vibrant coloration.
“It’s kind of like our microbiome inside of our gut,” says Sarah Davies, who researches coral adaptation. “Our body’s immune system allows it to persist, and it performs functional goodies for us. The algal symbiont does the same thing, and together, the symbiotic relationship fuels the ability for a coral to build that rock structure.”
The partnership keeps coral reefs healthy, vibrant, and teeming with marine life—not unlike massive underwater cities. “Everyone has their little duty in the city,” says Davies, an associate professor of biology and primary investigator of the Davies Marine Population Genomics Lab. “There are city workers that take care of the [problematic] turf algae—those are the damselfish. Maybe the sharks are the police. You can imagine that once you remove enough pieces, the whole city starts to break down and eventually leads to a cascade of degradation and loss of life.”
Davies, a seasoned diver who has been studying reefs for two decades, is still amazed by the “beauty of evolution” that caused coral and algae to team up and help each other grow quickly in shallow marine environments.
But reefs across the globe are under threat from warming oceans because of anthropogenic climate change. Davies researches how corals are evolving to survive—and sees lessons for humans in their tactics. She’s not the only CAS researcher learning about the ways some organisms and animals are responding to all kinds of changes in their environments. Researchers are gleaning lessons from orangutans’ adapting to the loss of their treetop habitats in Borneo, from vervet monkeys’ response to increased and prolonged droughts in South Africa, and from yellow-tailed woolly monkeys’ adjusting to living at higher elevations in Peru—all with the hope that these organisms can teach us how we can weather our own ecological storms.
“I think there are a lot of answers to problems that we have as humans—reducing fossil fuels, or reducing our impacts, or efficiency—that can come from studying how it was done by millions of years of evolution, Davies says. “We just need to listen to nature.”
“There are a lot of answers to problems that we have as humans…that can come from studying how it was done by millions of years of evolution.”
Delicate Ecosystems, Changing Behaviors
Human-caused climate change has affected virtually every square inch of the planet. Consider, again, coral. Warmer ocean temperatures mixing with the symbiotic algae inside corals produce a poisonous reactive oxygen species that forces an end to the partnership. Without its algae, the coral no longer gets the sugars it needs, and it loses its color. This bleaching is happening in every ocean on Earth, Davies says. Notably, in 2023, water temperatures in the Caribbean, southern Atlantic, and Gulf of Mexico reached record highs, resulting in bleaching conditions on nearly every reef and complete local extinctions of certain species of coral.
“When you get these years where there’s not a lot of hurricane activity, and you couple it with El Niño, where the winds lay off and the water temperatures are like a hot tub, we see bleaching of corals that we don’t tend to see bleach in normal years—the ones we think of as being really resilient,” Davies says. “A lot of them have recovered, but everybody took a hit.”
Human encroachment and exploitation also harm delicate ecosystems. Cheryl Knott has studied orangutans in Indonesia’s Gunung Palung National Park, on the island of Borneo, since 1992. She’s watched illegal logging operations reduce the number of orangutans to critically endangered levels, requiring massive conservation efforts, including her own, the Gunung Palung Orangutan Conservation Program/Yayasan Palung.
At the same time, Bornean orangutans are responding to a warming planet. The apes depend on an occurrence called mast fruiting, which happens unpredictably, every few years, when a large percentage of trees and plants fruit simultaneously throughout the rain forest. Knott, a professor of anthropology, biology, and women’s, gender and sexuality studies, says orangutan researchers are concerned that climate change may cause these mast fruiting events—which seem to be triggered by a drop in nighttime temperature—to occur less frequently or stop altogether.
“If we’re messing up the climate, then that could really have an impact on the flowering patterns of these forests,” she says. “That’s super important for orangutans and other species that live in these Southeast Asian rain forests, which have lower food availability than African or South American rain forests.”
And as temperatures rise globally, biologists are worried certain species may migrate to cooler, often higher-elevation regions, setting up conflicts with and displacement of species already there. Christopher Schmitt is researching whether yellow-tailed woolly monkeys in Peru—which currently live high in the Andes Mountains—would be able to acclimate to lower altitudes if they are displaced by lowland species seeking cooler climates.
“This could be a conservation concern because as lowland forests warm up, animals move up the elevation gradient when those habitats fall into the temperature range that they’re best suited for,” says Schmitt, an associate professor of anthropology and biology. “This also means that yellow-tailed woolly monkeys may have to move up, but of course there’sonly so high they can go.”
Resilient Organisms
These researchers have found that nature can be resilient, however. When their tree canopy was disturbed by loggers, orangutans in Borneo were able to adapt to the slightly degraded habitat or move into new areas of the rain forest without noticeable consequences. “Yes, they evolve in the primary rain forest, but they can live in these altered landscapes,” Knott says. Orangutan diets include upwards of 300 plants and fruits, a biodiversity that Knott says helps the primates survive when certain varieties are in low supply.
“As lowland forests warm up, animals move up the elevation gradient…but of course there’s only so high they can go.”
In addition to his work with Peruvian yellow-tailed woolly monkeys, Schmitt observed that some vervet monkeys living in captivity seemed predisposed to developing diabetes or becoming obese. He is studying whether wild vervet monkeys in South Africa have evolved to produce a gene in gestation that helps them permanently produce body fat quickly for survival during droughts—which have been increasing in number and severity in recent decades. If true, Schmitt says, “the mother is more or less preparing that infant for a starvation environment when they’re born. If they continue to live in a starvation environment, this is actually a very good thing.” Such an evolutionary protection could also become a liability, however. When a monkey with this thrifty genotype ends up in a calorie- and fat-rich environment “where food is limitless,” Schmitt says disease and obesity can follow—which could have implications for human metabolic disorders.
He says this suggests vervets with thrifty genotypes and phenotypes are “probably going to be more likely to survive, which is going to make the selective force on those all the stronger,” even amid more frequent droughts where they live. That’s not a guarantee, though. “It might also be that the severity and length of the droughts that are coming might just be too much,” Schmitt says.
Humans: A Special Responsibility
As humans, we also face the consequences of a changing climate, including a less biodiverse food supply, more frequent and devastating storms, and rising seas. The ability to study the ways corals and primates adapt and evolve gives humans a unique lens to apply those lessons to our own crises, like protecting a biodiverse food supply. Humans have another key advantage as we fight for our own existence on this planet that differentiates us from the individualistic orangutans Knott studies: “Cooperation is one of the essential things that made us human,” she says. Humans differ from some species in that we share food with each other and share in the raising of children, shortening birth intervals and raising survival rates—and allowing humans to “take over the planet,” she adds.
As the dominant species on Earth, Knott says, humans “have the ability to either protect or destroy. I think that gives us an incredible responsibility to try to protect the natural world.”
With humans, as with hungry vervets or corals, evolution itself may be the best hope for adaptation and survival in rapidly changing environments. When changes happen in a stable way, Schmitt says certain individuals will manage those changes better, and “hopefully that can be passed onto the next generation and lead to greater resiliency under the new conditions.”
Looking to nature for clues may hold implications for how we structure our economic systems as well. The capitalistic framework employed many places around the world may not always serve humans well in our struggle for survival, Davies says. Many things in nature have “evolved themselves into a dead end,” she says. “Capitalism is an evolutionary dead end. Biology tells us that you can’t have exponential growth without having a crash.” In contrast, coral reefs are colonial. When a section of a coral colony is not receiving enough sunlight to grow the anemone-like polyps that grow on its surface, Davies says, corals will translocate nutrients from polyps on the sunny side to the shady side in a sort of “socialism within a colony.”
“There’s so much that understanding the basic biology of organisms could do for humans,” Davies says. “But I also think it’s important to remember that, as we tackle this climate change crisis, it’s not a question of whether other things are going to survive. The Earth will continue, with or without humans. It’s a question of whether we live here with whatever else survives. Humans are resourceful, but I think we could use the organisms that are here to learn from them better, instead of just exploiting them.”