There are Degenerates in the Gene Pool

by Stephen Heap

You are a frog

You are a dyeing poison-frog (Dendrobates tinctorius) of French Guiana, and birds are trying to eat you. You protect yourself by carrying toxic chemicals that make you taste like lye. But you prefer not to be bitten at all. So you also carry a sign that says: TOXIC – DO NOT EAT. That is, you have yellow stripes on a black background.


This is you. Credit: J. P. Lawrence

But predators must learn to read the sign before it works, and learning is all about association. A bird that tries to eat one of your kind notices two things. One: it tastes like crap. Two: it has yellow stripes. Birds are smart enough to associate the two, and avoid disturbing anything with the same colors.


Yellow-and-black is a common warning of toxic hazard. That’s you in the top-right.

The moment of destiny in a predator’s gaze

A bird looms overhead, and your fate is decided within a blink of its eye.

Nothing happens. You are safe. The bird has recognized your markings as a sign to stay away. It has learned not to eat your kind.

Ahead is another frog. But this one is different. It has white stripes. A predator’s blink, and the frog is in claws. He should have had a better warning. Yellow is the way to go.

Warning signals work best when they are easy to learn. It’s easy for predators to learn a common signal, but harder to learn a rare signal. If you want your warning signal to work, then don’t experiment with novelty.


It’s why no one reinvents these.

For the poison-frog in a predator’s gaze, the finger of selection pushes down on the moment. It’s all about being the best right now, and this comes down to the colors on its back. Yellow stripes are best at keeping the birds away.

So how come some frogs don’t have yellow stripes?

You are a signalling system


You are an abstract entity.

You are the signaling system of the poison-frogs. You emerge from the colors and behaviors of the frogs, and you contain all sorts of things. Things like the warning colors on their backs, and the movements they make to woo mates or threaten competitors. You are a collection of messages and the meanings attached to them. You evolve alongside the frogs.

The meanings of your signals change with the demands of the environment. Predators right now respond to yellow signals, but what about predators of the future? It’s uncertain what signals will work best.

Your capacity to change depends on the variety of your parts. For instance, back coloration comes in both yellow and white flavors. The greater the variety of parts in a signaling system, the greater its possibilities for change. This is because the system has more possible solutions at hand to deal with new challenges. It’s like when some maniac holds you hostage and forces you to complete random Lego instructions. You want a box with the biggest variety of parts because this allows you to complete the most instructions.

Back to the frogs. The frog with white stripes is part of a longer game. It’s the reflection of a signaling system that has the capacity for change over long periods of time.

You are degenerate

You contain a degenerate signal. A degenerate signal shares meaning with another signal, but looks different.

The white stripes are a degenerate signal. Like the yellow stripes, they mean that a frog carries toxins. But they are white and not yellow.

Degenerate signals aren’t bad for you as a signaling system. Actually, they’re good. They make you more resilient to change. This means that you are quick to adapt with new conditions, such as the arrival of a new predator.


The greater the variety, the greater the possibility for change. The arrival of a new predator that munches down only on yellow frogs does not extinguish the frog population. The diversity of their signals allows them to survive.

Degenerate signals also allow you to do more. A degenerate signal can evolve to have new meanings. For example, the white stripes may come to mean something about mate quality, or they may signal toxicity to a predator that responds more to white than yellow.


The meaning of the white signal overlaps with the yellow signal, but it can also get new meanings – like signaling toxicity to a different type of predator or signaling quality to a potential mate.

You are a human

You are a human and you exist in a matrix of systems within systems. You have the responsibility to navigate and design the systems that influence your life. But it can be difficult to even notice them, let alone understand what they do.

Life in nature is full of systems that we can learn from. Systems like the poison-frogs and their signals. We can observe life responding to the laws of nature to learn how systems work. The principles that we learn can guide our understanding of other systems.

You must decide: the best for now or the best for later

Nature seems chaotic, but there are general principles that apply to almost every challenge. One of these is the exploitation-exploration trade-off. It’s a choice: exploit what you know, or explore new options. Be the best right now, or seek a better future.

When it comes to the threats of the current day, the yellow frogs are being the best. But when it comes to an uncertain future, its good that some frogs have a different color. The key to adaptive change is in signal diversity.

Degenerate signals work because they exploit the same meaning as another signal. For the frogs, both yellow and white types taste bad. The signals have the same meaning, but the yellow type is more effective. In fact, the yellow signal is so strong that birds learn to generalize the meaning to the white signal as well. The white signal piggy-backs on the yellow.

But degenerate signals also work because they look different and allow the exploration of new meanings. There are populations of frogs where white is the norm, and this can offer an environment for new meanings to emerge. These populations may even evolve to become a new species. Degeneracy is all about providing the means for the generation of new forms of life.

Degeneracy lets you be good for now and good for later

You must identify when you face the dilemma of an exploration-exploitation trade-off. You must learn how to balance the demands of the current situation with the flexibility to change in the future. This dilemma is fundamental to nature, and you want to know how to strike the right balance.

These frogs teach us that degeneracy can resolve the tension between now and later. Degeneracy occurs when things that are different can do the same thing. It allows you to exploit something that works, whilst also exploring for new possibilities. Use the principle of degeneracy to be more resilient to change and broaden your horizons.

Do You Want to Know More?

Here are the articles that inspired this blog post:

J. P. Lawrence el al., “Weak warning signals can persist in the absence of gene flow,” PNAS (2019).

E.A. Hebets et al., “A systems approach to animal communication,” Proc R. Soc. B. 283 (2016).

Author biography: Stephen Heap is a Freelance Scholar, writing about your research so you don’t have to. His origins are in academia (University of Melbourne, University of Jyväskylä), where he studied sociobiology and behavioral ecology. Now he bridges science with popular culture (for fun) and performs technical writing (for profit). You can find out more at his website:

Image Credit: All images by Stephen Heap or licensed under creative commons, unless otherwise noted.