This entry is part 1 of 2 in the series RAINBOW

The Red Queen Hypothesis

Now, here, you see, it takes all the running you can do, to keep in the same place.

–Red Queen, Lewis Carroll, Through the Looking Glass

Undoubtedly, one of the greatest scientific revolutions transpired in the mid-1800s, as Charles Darwin and Alfred Wallace advanced the theory of evolution. Borne time and again by experiments and genetic examination, evolution explains the ever-adapting nature of species across the planet.

Natural selection, fitness, and mutations are now cornerstones of biology, but evolution remains technically a theory, as its exact mechanisms are complex and possibly unprovable. Since Darwin’s landmark 1859 work On the Origin of Species, scientists have worked to refine the mysteries of evolution.

In the 1970s, biologist Leigh Van Valen (fantastic name) tackled an interesting question regarding evolution.

Intuitively, it’s easy to think that the longer a species remains alive, the better its chances are of avoiding extinction. After all, if an adaptation allows a species to survive its surroundings, we could easily believe the species had become a better version of itself. Evolution, in this mode of thinking, could be viewed as a constant stream of refinement. Barring freak or external annihilation, constant improvement should lead to better and better odds of making it to the next generation.

Does the fossil record support this notion?

Van Valen dived into the data and discovered something unexpected. The probability of extinction did not decrease with the time a species survived; the data showed that the chances remained essentially constant over the eons. The likelihood that a species disappeared from Earth was the same for one that had been around for 1 million years or 25 million years. If the process of evolution was continually progressing the fitness of a species, what was happening?

This discovery that the probability of extinction for a species is constant over time, regardless of how long the species has already existed, became known as Van Valen’s Law.

Van Valen figured that other pressures, namely ecological niches and interplay with other species, must be the driving force in extinction rates and occurrences.

His conclusion can be reworded in several ways. First, extinctions can occur randomly over time, but nonrandomly on the ecological playing field. Or, when considering a non-evolving or homogenous organism, its survivability rate will decrease over time due to the ever-changing world. Van Valen likened the evolutionary battle royale to a zero-sum game between species in specific ecosystems. If one species becomes fitter, it isn’t a step on an evolutionary scale to perfection, but a direct detriment to a competitor or neighbor.

For example, in a two-species predator-prey situation, if the prey evolves to become faster to adapt to predation and the predator does not evolve, the predator will face immense pressure to evolve or perish. So, the predator cannot remain at its current fitness. If the predator becomes faster to catch the speedy prey, the target will then face increased survival stresses. This back-and-forth requires constant adaptations from the two species; if one ever “stands still,” it will face extinction.

In Van Valen’s notion, a species can never reach an evolutionary mesa of safety. It must continually adapt, but these improvements will not advance it to an end-game build. Instead, it must sprint just to remain in place!

Van Valen likened this reality to Lewis Carrol’s Red Queen in Through the Looking Glass. The royal tells Alice, “Now, here, you see, it takes all the running you can do, to keep in the same place.”

He named this framework the Red Queen hypothesis.

Various scientific experiments have shown the Red Queen hypothesis to, at least, be a part of the evolutionary process for many species in specific situations.

It also helps explain another mystery of evolution: sexual reproduction. Species that propagate sexually spend vastly more resources than those that reproduce asexually. Clones take less time, food, and energy than sexual babies.

Why has sexual reproduction become so common, then?

Variability!

Under the Red Queen hypothesis, an organism that remains unchanged, even if it is the beneficiary of millions of years of evolution, will likely perish as time moves forward. Sexual reproduction introduces a changing genome by default.

Certain species have allowed biologists to test both the Red Queen hypothesis and the benefits of sexual reproduction at the same time. The New Zealand mud snail can produce both sexual and asexual populations, often living next to each other. A parasite – the trematode worm – loves these mud snails. Experiments showed that when high pressure from the worms exists, sexual populations of the mud snail dominate; when stress is low, the asexual populations thrive. This fact seems to back up the Red Queen situation, where the sexual snails can evolve with genetic variation to keep up with the parasites.

Sometimes, the most absurd works of literature can have real-world correlations. Sometimes, we have to heed the advice of the Red Queen, hopping on the treadmill just to survive.

BONUS FACT: The Red Queen is often conflated with the Queen of Hearts from Carrol’s preceding work, Alice’s Adventures in Wonderland. Three of the most famous adaptations of the Alice world mixed the two characters into one. In Walt Disney’s Alice in Wonderland, the Queen of Hearts speaks Red Queen lines from Looking Glass. Tim Burton’s Alice in Wonderland blends both queens into one royal character. Jefferson Airplane’s famous song “White Rabbit” utilizes the lyric “and the Red Queen’s off with her head.” It was the Queen of Hearts who wanted Alice’s noggin.

Lewis Carroll recognized the confusion, stating:

“I pictured to myself the Queen of Hearts as a sort of embodiment of ungovernable passion – a blind and aimless Fury. The Red Queen I pictured as a Fury, but of another type; her passion must be cold and calm – she must be formal and strict, yet not unkindly; pedantic to the 10th degree, the concentrated essence of all governesses!”