Nav: Home

Social isolation: Animals that break away from the pack can influence evolution

July 17, 2018

For some animals -- such as beetles, ants, toads, and primates -- short-term social isolation can be just as vital as social interaction to development and long-term evolution. In a review published July 17 in the journal Trends in Ecology & Evolution, two evolutionary biologists describe approaches for testing how an animal's isolation might impact natural selection and evolution. This framework can help design more effective breeding, reintroduction, and conservation strategies.

Research on evolution typically focuses on the importance of social interactions, including parent-offspring bonding, competition for resources, and courtship and mating rituals. But Nathan Bailey at the University of St Andrews in Scotland and his colleague Allen Moore at the University of Georgia realized that isolation must then be an extreme condition worthy of equal attention.

"The environment an animal experiences can influence which genes it expresses, when, and how much, so conditions of social isolation might cause expression of different traits," says Bailey. "This in turn could affect responses to natural selection in terms of survival and reproduction, which has evolutionary consequences. For some species, it might even mean that temporary social isolation is favorable."

The invasive cane toad Rhinella marina of Australia, for instance, will venture off on its own to expand into new territory, but the isolation this causes drives an uncharacteristically strong attraction to members of the opposite sex upon the toad's return to a social environment. This boosts the likelihood of both communication and successful mating, which are necessary for survival as the toads expand into new regions. This means that social isolation itself provides the conditions for natural selection to favor adaptations to cope with it.

Likewise, when poisoned, the European ant Temnothorax unifasciatus secludes itself from its kin until death. This eliminates contact with its nestmates, protecting them from the infection, ensuring its relatives' survival, and overall lessening some of the costs associated with social living, such as spreading disease.

"Traits expressed during social interactions might exist because they've been shaped by selection, but at the same time, social interactions themselves represent a type of environment that can select and shape how individuals behave," says Bailey.

This duality of social interaction as both trait and environment merits further study, and Bailey and Moore propose gaining a more complete understanding of social isolation's effects using a measurement termed the "index of social isolation." The index would allow researchers to compare an animal's ideal amount of isolation with how much it is actually experiencing.

To do this, researchers must first measure the optimal balance of interaction and isolation by testing individuals with different levels of each to find the best possible outcome in terms of survival and reproduction. Comparing this ideal to real observations will help determine whether animals are more or less isolated than they should be and ultimately allow for more effective designs for conservation strategies, reintroduction models, and breeding programs.

"To understand how short-term social isolation experienced by individual animals translates into trans-generational evolutionary impacts for a larger population, we need a number, something measurable that we can compare across different species and contexts," says Bailey. "After all, isolation that has negative effects for one species could in fact be beneficial for another."
-end-
This research was funded by the Natural Environment Research Council and the National Science Foundation.

Trends in Ecology and Evolution, Bailey & Moore.: "Evolutionary Consequences of Social Isolation" https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(18)30120-4

Trends in Ecology & Evolution (@Trends_Ecol_Evo), published by Cell Press, is a monthly review journal that contains polished, concise and readable reviews, opinions and letters in all areas of ecology and evolutionary science. It aims to keep scientists informed of new developments and ideas across the full range of ecology and evolutionary biology--from the pure to the applied, and from molecular to global. Visit: http://www.cell.com/trends/ecology-evolution. To receive Cell Press media alerts, please contact press@cell.com.

Cell Press

Related Evolution Articles:

Prebiotic evolution: Hairpins help each other out
The evolution of cells and organisms is thought to have been preceded by a phase in which informational molecules like DNA could be replicated selectively.
How to be a winner in the game of evolution
A new study by University of Arizona biologists helps explain why different groups of animals differ dramatically in their number of species, and how this is related to differences in their body forms and ways of life.
The galloping evolution in seahorses
A genome project, comprising six evolutionary biologists from Professor Axel Meyer's research team from Konstanz and researchers from China and Singapore, sequenced and analyzed the genome of the tiger tail seahorse.
Fast evolution affects everyone, everywhere
Rapid evolution of other species happens all around us all the time -- and many of the most extreme examples are associated with human influences.
Landscape evolution and hazards
Landscapes are formed by a combination of uplift and erosion.
New insight into enzyme evolution
How enzymes -- the biological proteins that act as catalysts and help complex reactions occur -- are 'tuned' to work at a particular temperature is described in new research from groups in New Zealand and the UK, including the University of Bristol.
The evolution of Dark-fly
On Nov. 11, 1954, Syuiti Mori turned out the lights on a small group of fruit flies.
A look into the evolution of the eye
A team of researchers, among them a zoologist from the University of Cologne, has succeeded in reconstructing a 160 million year old compound eye of a fossil crustacean found in southeastern France visible.
Is evolution more intelligent than we thought?
Evolution may be more intelligent than we thought, according to a University of Southampton professor.
The evolution of antievolution policies
Organized opposition to the teaching of evolution in public schoolsin the United States began in the 1920s, leading to the famous Scopes Monkey trial.

Related Evolution Reading:

Evolution: The Human Story, 2nd Edition
by Dr. Alice Roberts (Author)

Why Evolution Is True
by Jerry A. Coyne (Author)

Evolution
by Douglas J. Futuyma (Author), Mark Kirkpatrick (Author)

Darwin Devolves: The New Science About DNA That Challenges Evolution
by Michael J. Behe (Author)

Grandmother Fish: A Child's First Book of Evolution
by Jonathan Tweet (Author), Karen Lewis (Illustrator)

Evolution (Second Edition)
by Carl T. Bergstrom (Author), Lee Alan Dugatkin (Author)

Understanding Evolution
by Kostas Kampourakis (Author)

Theistic Evolution: A Scientific, Philosophical, and Theological Critique
by J. P. Moreland (Editor), Stephen C. Meyer (Editor), Christopher Shaw (Editor), Ann K. Gauger (Editor), Wayne Grudem (Editor), Steve Fuller (Editor), Douglas Axe (Editor), C. John Collins (Editor), John D. Currid (Editor), Guy Prentiss Waters (Editor), Gregg R. Allison (Editor), Fred G. Zaspel (Editor), Matti Leisola (Editor), James M. Tour (Editor), Winston Ewert (Editor), Jonathan Wells (Editor), Sheena Tyler (Editor), Günter Bechly (Editor), Casey Luskin (Editor), Paul A. Nelson (Editor), Ola Hössjer (Editor), Colin R. Reeves (Editor), Stephen Dilley (Editor), Garrett J. DeWeese (Editor), Tapio Puolimatka (Editor), John G. West (Editor)

Evolution: Making Sense of Life
by Carl Zimmer (Author), Douglas J. Emlen (Author)

Sydney Brenner's 10-on-10: The Chronicles of Evolution
by Sydney Brenner (Author), Shuzhen Sim (Editor), Benjamin Seet (Editor)

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#513 Dinosaur Tails
This week: dinosaurs! We're discussing dinosaur tails, bipedalism, paleontology public outreach, dinosaur MOOCs, and other neat dinosaur related things with Dr. Scott Persons from the University of Alberta, who is also the author of the book "Dinosaurs of the Alberta Badlands".