Nav: Home

To warn or to hide from predators?: New computer simulation provides answers

April 17, 2020

Scientists have understood quite well why so many poisonous or distasteful animals have brightly colored bodies - the colors send a message to the predators: "don't eat me, or you'll get sick and die." These permanent warning signals became textbook examples of "aposematism": use of conspicuous signals to warn predators. But not all animals show their warning colors all the time. Some toxic animals actually hide the warning colors, showing them only at the very last moment when they are about to be attacked (thus called "switchable aposematism"). Also, some other prey animals never advertise their distastefulness and defend themselves after attack only by chemicals creating a perception of bad taste in the predators. Scientists do not fully understand the reasons for such a diversity of prey behaviors.

In a recent report in , a Korean-Polish team composed of Woncheol Song and Piotr Jablonski from the Seoul National University and Polish Academy of Sciences, and Sang-im Lee from DGIST, has presented the first comprehensive computer simulation (ApoSim) to understand the evolution of the diversity of warning signals. The ApoSim model interface was built within a user friendly NetLogo framework and it can be used by anyone interested in simulation of
According to Dr. Woncheol Song, evolutionary biologists have paid disproportionate attention to the permanent aposematism. "It is relatively easy to understand why poison dart frogs have yellow color, giant hornets have bright orange-and-black stripes, etc. These animals gain the benefits of constantly warning the predators to avoid being eaten, but also increase the chance of detection by predators that are not deterred by the poison. However, when prey have choices to either show or hide the warning signal and of when to do it, it is not a simple matter. You need to weigh the costs and benefits of how and when to present the warning signals," points out Dr. Song.

The integration of the extremely diverse forms of animal behavior into one framework was not easy. "A praying mantis posturing to strike, a rattlesnake producing the alarm sound, a ladybug releasing foul-odored hemolymph, a cuttlefish flashing like a neon-sign, and a skunk raising its striped tail - their messages are all the same, to tell you stay away from them. But they are also different from each other in countless ways. However, if you want to conduct theoretical studies with them, you have to put them in the same formula. It is like doing sums of apples and oranges while convincing other scientists that it is a good idea," Dr. Song recalls the difficulty of model-building process. The researchers considered energy costs, timing, anatomy and physiology, detectability, memorability, and many other properties of prey aposematic behaviors, as well as predators' learning processes. Finally, the authors successfully created a simplified artificial digital world that reasonably captures the diversity of permanent and switchable aposematism, and can be used by anybody without prior programming experience.

The model was run over 88 thousand times in order to find out which aposematic behavior is the best depending on how fast the predators are learning, how high is the proportion of predators that have not yet learned to avoid the defended prey, how easy it is to detect a prey, how easy it is to detect a prey after the warning is displayed and the signal intensity is increased, how hard it is for the prey to develop and keep the ability to switch signals. The outcome of the simulations brought new discoveries as well as confirmed some of the already existing ideas. For example, one may argue that there are multiple types of predators in the ecosystem. If some predators are not deterred by the warning and attack the prey anyway, the prey may be better protected by withholding the warning to avoid detection by those predators. This is but one simple example that can be visualized and understood by using the new model.

"We have not only demonstrated that the predator mix can drive the evolution of switchable aposematism, but we have also evaluated several other equally-compelling hypotheses, all of them interacting in a five-dimensional parameter space defined by properties of prey and predators. There have been many ideas published since the time of Darwin, but only a few of them have been thoroughly examined. Now, each of them can be explored in the digital world provided in this model, and the model results can be integrated with findings made in nature, like the recent studies conducted by us on the spotted lanternfly [;]," Dr. Piotr Jablonski commented when asked about the importance of the new "ApoSim" model's availability to the research community. "The model will also serve as a new educational tool in teaching evolution," added Dr. Sang-im Lee, whose experience in undergraduate teaching of evolution in -end-

Laboratory of Behavioral Ecology and Evolution at Seoul National University

Related Diversity Articles:

Insect diversity boosted by combination of crop diversity and semi-natural habitats
To enhance the number of beneficial insect species in agricultural land, preserving semi-natural habitats and promoting crop diversity are both needed, according to new research published in the British Ecological Society's Journal of Applied of Ecology.
Ethnolinguistic diversity slows down urban growth
Where various ethnic groups live together, cities grow at a slower rate.
Protecting scientific diversity
The COVID-19 pandemic means that scientists face great challenges because they have to reorient, interrupt or even cancel research and teaching.
Cultural diversity in chimpanzees
Termite fishing by chimpanzees was thought to occur in only two forms with one or multiple tools, from either above-ground or underground termite nests.
Bursts of diversity in the gut microbiota
The diversity of bacteria in the human gut is an important biomarker of health, influences multiple diseases, such as obesity and inflammatory bowel diseases and affects various treatments.
Underestimated chemical diversity
An international team of researchers has conducted a global review of all registered industrial chemicals: some 350,000 different substances are produced and traded around the world -- well in excess of the 100,000 reached in previous estimates.
New world map of fish genetic diversity
An international research team from ETH Zurich and French universities has studied genetic diversity among fish around the world for the first time.
Biological diversity as a factor of production
Can the biodiversity of ecosystems be considered a factor of production?
Fungal diversity and its relationship to the future of forests
Stanford researchers predict that climate change will reduce the diversity of symbiotic fungi that help trees grow.
Brain diseases with molecular diversity
Parkinson's and multisystem atrophy (MSA) - both of them neurodegenerative diseases - are associated with the accumulation of alpha-synuclein proteins in the brain.
More Diversity News and Diversity Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at