Buzz
Through evolution, the most adaptable creatures have survived. Often, multiple species find themselves evolving and competing within the same ecosystem. This can manifest as predator-prey dynamics, competition for resources, and many other forms of coevolution. Sometimes, organisms evolve together, each adjusting to outpace the other.
10. Caterpillars, Corn, & Wasps
When considering an evolutionary arms race, the relationship between corn, caterpillars, and wasps might not come to mind, but it’s exactly what's happening. When a caterpillar chooses to feast on corn, the plant releases a chemical compound called a 'terpenoid' from both its damaged and intact leaves. This chemical travels through the air and attracts a parasitic wasp species, Cotesia marginiventris, which sees the caterpillar as an ideal host to lay its eggs. The result is the untimely demise of the corn-eating caterpillar and the successful breeding of the wasp. Meanwhile, the corn continues to thrive, releasing terpenoids whenever it senses a threat, ensuring that its 'bodyguard' wasps are nearby to lay their eggs in any new invader.
Current victor: Both the corn and the wasps are prevailing over the caterpillars in this ongoing survival contest.
9. Fruit Flies & Mustard Plants
Insects and plants have waged a battle since the first insect landed on a leaf long ago. Plants, which remain rooted in place, have become both a source of nourishment and shelter for insects. In response, some plants have evolved defensive strategies such as thickened bark or producing enzymes that are unpleasant or even harmful to those that attempt to consume them.
In a tiny ecosystem consisting of just two species, a fruit fly and a mustard plant are locked in a battle for survival. While most fruit flies thrive on rotting fruit, one species—Scaptomyza flava—feeds almost exclusively on a type of mustard plant (Arabidopsis). The flies live out their entire life cycle on the plant, beginning as larvae that burrow into the leaves, feeding on the plant’s sap. The plant, however, has developed a defense mechanism. Arabidopsis produces a protein that disrupts the flies’ digestion. Consuming it either kills them or slows them down. As a result, the plants continue to survive, even while under attack by the parasitic flies.
Current victor: Arabidopsis has found a way to persist despite being continually consumed by flies. If the flies evolve to tolerate the plant’s proteins, the plants may increase their production, making the proteins even more toxic… and the evolutionary race will continue.
8. Greater Honeyguides & Greater Honeyguides
Yes, you read that right. The greater honeyguide is in an evolutionary arms race with its own kind. These birds practice a behavior called 'brood parasitism,' where they lay their eggs in the nests of other birds, specifically the underground nests of little bee-eaters (Merops pusillus). To successfully pull this off, honeyguides have evolved the ability to make their eggs resemble those of the bee-eaters. While you might think this is a tactic to deceive the little bee-eaters, it’s actually not. It turns out that little bee-eaters don’t care about the appearance of eggs in their nests—but other honeyguides certainly do.
When a honeyguide lays its eggs in a little bee-eater’s nest, it punctures the host eggs to eliminate the young. However, it can’t destroy all the eggs, as doing so might prompt the little bee-eaters to abandon the nest. The chicks that hatch are killed by the honeyguide chicks using their sharp, hooked beaks. If a honeyguide discovers that some of the eggs in the nest belong to another honeyguide, it will destroy those eggs without hesitation. This behavior suggests that the birds are competing for nest space. Thus, the honeyguide’s tactic of mimicking the eggs of little bee-eaters is not meant to deceive the foster parents, but rather to trick other honeyguides, ensuring that their own chicks have a better chance of survival against rival birds.
Current victor: There isn’t a clear winner. Since the greater honeyguide (Indicator indicator) is essentially competing against itself, it only causes harm to its own kind in the long run. The true losers in this scenario are the little bee-eaters, as their chicks suffer the most.
7. Cheetahs & Gazelles
Everyone knows that the cheetah (Acinonyx jubatus) holds the title of the fastest land animal, capable of reaching speeds of up to 120 kilometers per hour (75 mph). If it were a superhero, its emblem would surely be a lightning bolt on its chest. It’s also well-known that cheetahs often prey upon the graceful gazelle (Gazella).
These two species serve as prime examples of an evolutionary arms race, with each generation adapting to outsurvive the previous one. When a cheetah misses a catch, it risks not surviving, leaving the faster cheetahs to prey on the slower gazelles. Likewise, the slower gazelles are at a disadvantage, while the faster ones are more likely to survive. Over countless generations, the cheetah has evolved into the fastest predator on Earth, while the gazelle has adapted to become a swift and elusive target.
Current victor: The cheetah holds the lead in this evolutionary arms race, thanks to its unmatched ability to catch prey. Cheetahs are typically successful in catching anything that tries to flee, so until the gazelle develops a powerful defense, the cheetah is firmly in the lead.
6. Ant-Mimicking Spiders & Ants
Ant mimicry is a widespread adaptation seen in many species of jumping spiders across the globe. These spiders often live within ant colonies, blending in by mimicking ants through either social behaviors or chemical means (like scent). The spiders don’t typically prey on ants, as ants will aggressively swarm any perceived threats, even those they believe to be other ants. Most of the time, the spiders rely on the protection of the ants and coexist within the colony. However, one species of jumping spider found in New Guinea, Australia, and Micronesia has taken a bold turn and decided that ants make a tasty meal, disregarding the risks.
Cosmophasis bitaeniata enjoys spending time with the green tree ant (Oecophylla smaragdina) and hunting its larvae. This spider cleverly mimics the ants’ appearance, taking advantage of their poor eyesight, and uses a strategy called 'exploitative chemical mimicry.' By releasing a chemical compound, the spider cloaks its scent, blending in with the ants. When hunger strikes, the spider avoids the larger workers but targets the minor ones, snatching larvae directly from their mandibles. The ants mistakenly believe they are passing their brood to another worker, while the spider enjoys a quick snack before returning for more.
Current victor: For now, the jumping spider holds the upper hand in this contest. The ants are still unaware that the disappearance of their young might be tied to the increasing size of a strangely familiar 'ant' lurking among them.
5. Sierra Garter Snake & Sierra Newt
In cases where predator and prey evolve together, a distinct feature of one species often drives the adaptation process. In the case of the Sierra garter snake (Thamnophis sirtalis) and the Sierra newt (Taricha granulosa), the key factor is the deadly neurotoxin tetrodotoxin (TTX). This toxin, found in amphibians and certain fish like the pufferfish, is so potent that ingesting even a small amount from a newt can lead to death within 17 minutes. Symptoms include respiratory failure, hypotension, and coma. (Just a reminder: it’s a very bad idea to pick up newts and eat them!) The TTX makes the newts lethal to almost anything that tries to eat them.
The only species that appears to have cracked the TTX puzzle is the Sierra garter snake. In certain populations where these snakes coexist with the Sierra newt, they have evolved resistance to TTX, allowing them to safely consume the newts. This evolutionary adaptation enables the local snake population to prey on a species that would otherwise be untouchable.
Current victor: The Sierra garter snake holds the upper hand, as it successfully preys on the newt without any complications from the toxin. While the newt may evolve an even deadlier form of TTX in the future, for now, it takes second place in this evolutionary contest.
4. Sea Urchins & Sea Lilies
Sea urchins may not immediately come to mind as formidable predators that influence the evolution of their prey, but in reality, they have played a key role in shaping the sea lily’s development for over 200 million years. These spiny creatures forced sea lilies, or Mesozoic crinoids, to adapt by abandoning their stationary lifestyles and becoming mobile. This phenomenon is known as 'predator-induced macroevolution,' where a species undergoes significant mutation to survive against a persistent threat.
The sea lily, seeing the sea urchin approaching, recognized the need for mobility to survive. And so, it evolved to move, a change visible in the fossil record from the Mesozoic period. Fossils show signs of predation by sea urchins for hundreds of millions of years, indicating a long-standing predator-prey dynamic. By the time the dinosaurs vanished, Mesozoic crinoid species had diversified into mobile forms, while the stationary species began to dwindle.
Current champion: Sea lilies are currently ahead in this evolutionary battle, as the number of mobile species has outpaced the sea urchins. Though still preyed upon by sea urchins, sea lilies are no longer commonly found on the menu.
3. The Golden Poison Frog & Water Snake
The golden poison frog (Phyllobates terribilis) holds the title of the world’s most toxic creature. This seemingly innocent frog can produce enough poison from its skin to kill 22,000 mice. The toxin serves purely as a defense mechanism, and any predator foolish enough to try and eat one of these frogs would perish almost instantly—humans included. But there is one species that has evolved alongside the frog and can challenge its dominance in the ecosystem.
The water snake species Liophis epinephelus from South America is the only known animal capable of resisting the frog’s lethal toxin. While not entirely immune, the snake can consume the frog and survive the deadly poison. This adaptation makes the snake a unique predator in the frog’s environment. While the frog’s toxins would destroy any other animal daring to eat it, the water snake swallows the frog whole and continues to thrive, making it the victor in this evolutionary standoff.
Current leader: The water snake now takes the lead with its remarkable ability to consume the golden poison frog and slither away without harm.
2. The Malaysian Carpenter Ant & Weaver Ants
The Malaysian carpenter ant (Camponotus saundersi), also known as the ‘exploding ant,’ possesses an extraordinary survival mechanism. When under attack, an individual ant will self-sacrifice by exploding, releasing a sticky substance that adheres to its attacker. This prevents the predator from continuing its assault, forcing it to deal with the sticky substance before it can resume attacking. The ant achieves this through a specialized poison-filled mandibular gland that runs the length of its body. By contracting its abdomen, the ant forces the glands to rupture, unleashing a corrosive and irritating glue.
The primary predators of the Malaysian carpenter ant are weaver ants (Oecophylla smaragdina), also known as ‘green ants,’ despite their red color. These ants are extremely territorial and aggressive, making them natural enemies of the exploding ant. Over time, these two species have co-evolved, fighting for resources. However, carpenter ant colonies are usually protected from weaver ants because of their self-destructive defense. Even though one ant must perish to save the colony, the larger group benefits, allowing the colony to survive and continue to capture resources, outcompeting the weaver ants for space and food.
Current victor: The Malaysian carpenter ant takes the lead, as it can safeguard the majority of its colony with a single act of self-sacrifice.
1. Bats & Moths
A tiger moth (Carales arizonensis) native to Arizona has adapted a clever strategy to defend itself against local bats. Bats, which hunt primarily by night using echolocation, can easily track the distance and speed of their prey. This ability has made them incredibly effective predators, typically consuming around 600 insects per hour. However, the tiger moth is rarely a target on the menu.
To avoid becoming bat prey, the tiger moth employs two effective defense mechanisms. First, it releases a distasteful toxin that makes it unappealing to bats. Second, the moth uses a special organ known as the 'tymbal' to produce a series of high-pitched clicks, signaling to bats that it is a non-palatable meal. For this method to be successful, bats must first encounter and dislike the taste of the moth. Afterward, any bat that has had a bad experience with the moth will hear the warning clicks and move on to more appetizing prey.
Current victor: The tiger moth is in the lead for now, but if bats evolve a tolerance to the toxin, the moths may need to step up their defenses in this ongoing evolutionary battle.
