Nav: Home

Alternative explanations for the evolution of monogamy and sibling cooperation

May 03, 2016

The textbook "monogamy hypothesis" argues that monogamy favors the evolution of cooperation by increasing sibling relatedness, since helpers are as related to the full siblings that they care for as they are to their own offspring. So under certain circumstances helping can be as, or even more, successful in getting genes passed on as reproducing. But in an Opinion, published May 3 in Trends in Ecology & Evolution, two experts in social and reproductive behavior say that the proof isn't all there.

In their paper, Professor David Westneat and his graduate student Jacqueline Dillard--both at the University of Kentucky--present three alternative explanations:
  • Monogamy and sibling cooperation co-evolved, so that one trait increased the benefits of the other.
  • Ecological pressures selected for both monogamy and sibling cooperation simultaneously, so that one trait does not depend on the other.
  • The evolution of monogamy created new physiological and behavioral adaptations that may also be useful in sibling cooperation.

"This is a case study demonstrating the importance of not boiling organisms down to simple traits," says Dillard, who studies a socially monogamous group of Bess Beetles. She notes that the classic monogamy hypothesis considers a single link between the high occurrences of sibling cooperation in monogamous species, when a number of factors could be in play.

For example, from beetles to birds to humans, both monogamy and sibling cooperation tend to occur where the value of caring for young is high and the opportunities for mating are low, so environmental changes that increase the benefits of care, such as food scarcity, or reduce likelihood of reproducing, could promote both traits.

Physical and social adaptations, such as increases in the hormones oxytocin and vasopressin, that enable monogamy could also pre-adapt species to cooperation. "If you are living with a social partner, evolving to live in that environment requires a lot of tolerance; these sorts of things can come in handy later on when you want to cooperate with another individual," Dillard says.

Dillard is now developing comparative and experimental studies that can measure the relative contributions of these variables. However, Dillard and Westneat believe that a more systems-level approach to studying monogamy and cooperation will be necessary to answer longstanding questions about the evolution of these traits.
-end-
This review was supported by a National Science Foundation Graduate Research Fellowship, a National Science Foundation grant, and the University of Kentucky.

Trends in Ecology and Evolution, Dillard and Westneat: "Disentangling the correlated evolution of monogamy and cooperation" http://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(16)00088-4 / http://dx.doi.org/10.1016/j.tree.2016.03.009Trends in Ecology & Evolution (@Trends_Ecol_Evo), published by Cell Press, is a monthly 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:

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

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

Evolution: A Visual Record
by Robert Clark (Author)

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

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

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

Evolution: The Cutting-Edge Guide to Breaking Down Mental Walls and Building the Body You've Always Wanted
by Joe Manganiello (Author)

Evolutions: Fifteen Myths That Explain Our World
by Oren Harman (Author)

Improbable Destinies: Fate, Chance, and the Future of Evolution
by Jonathan B. Losos (Author)

Evolution: The Human Story
by DK Publishing (Author)

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Dying Well
Is there a way to talk about death candidly, without fear ... and even with humor? How can we best prepare for it with those we love? This hour, TED speakers explore the beauty of life ... and death. Guests include lawyer Jason Rosenthal, humorist Emily Levine, banker and travel blogger Michelle Knox, mortician Caitlin Doughty, and entrepreneur Lux Narayan.
Now Playing: Science for the People

#491 Frankenstein LIVES
Two hundred years ago, Mary Shelley gave us a legendary monster, shaping science fiction for good. Thanks to her, the name of Frankenstein is now famous world-wide. But who was the real monster here? The creation? Or the scientist that put him together? Tune in to a live show from Dragon Con 2018 in Atlanta, as we breakdown the science of Frankenstein, complete with grave robbing and rivers of maggots. Featuring Tina Saey, Lucas Hernandez, Travor Valle, and Nancy Miorelli. Moderated by our own Bethany Brookshire. Related links: Scientists successfully transplant lab-grown lungs into pigs, by Maria Temming on Science...