Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deception fuels domestic bliss

21.11.2001


Happy families: heartwarming domestic scene or symphony of self interest?
© Photodisc


Evolution may make men ignorant and gullible.

Gentlemen: ignorance is bliss and gullibility is the best policy. A new mathematical analysis suggests that evolution favours babies who don’t much resemble their fathers, and males who believe their partner when she says a child looks just like him.

Anonymous-looking newborns make for uncertain fathers. But they also allow men to father children through undetected adultery, Paola Bressan of the University of Padova calculates1. The assertion - common across many cultures - that babies are the spit of their dad, is a way to get men to care for their offspring despite their uncertainty, she adds.



Mummy, daddy and baby might look like a heartwarming scene of family togetherness. But evolutionary biologists have no truck with such sentimental nonsense: to them, each of the trio is pursuing its own, often competing, interests.

The wild card is adultery. A baby comes into the world unsure of whether the male providing for it is its biological father. Being rumbled could mean neglect, or worse - infanticide. It’s easy to see how, in an evolutionary sense, babies might not want to resemble anyone in particular.

Whether fathers benefit from having recognizable babies is trickier. If dads pass on some genetic badge that allows them to identify their children, they could avoid raising another man’s child. But they will not be able to sneak any offspring into other families.

Bressan proposes that these two forces cancel each other out. Having anonymous babies stops fathers mistakenly rejecting their own children, which, in a slowly reproducing species such as humans, is probably a cost greater than that of raising someone else’s child. When the interests of babies and mothers are also taken into account, genes for anonymous babies should spread.

Human babies certainly seem to be masters of disguise. Neutral observers asked to match infants to their fathers do only slightly better than chance.

In fact, some of newborns’ features seem designed to enhance anonymity, says evolutionary biologist Mark Pagel, of the University of Reading. He points to the blue eyes and blond hair of many newborn Europeans, which result from genes being switched off at birth.

Could evolution mark babies with their father’s identity? Pagel thinks so: "There’s a lot of genetic variation to play with, and all sorts of things that are very easy to produce developmentally," he says.

Mother’s instinct

So everybody’s happy? Not quite: if all babies are anonymous and fathers are uncertain, males would invest less in kids whether they sired them or not.

A mother’s strategy to counteract this, says Bressan, could be to remark on the baby’s likeness to his father. Her mathematical model shows it can benefit a father to believe these assertions and increase his care for the child, as long as the chance that he is being deceived is slim enough.

Denson McLain, a behavioural ecologist at Georgia Southern University likes this idea. "The harm to a father of being sceptical towards is own children is greater than the cost of rearing someone else’s child," he says.

McLain has found that mothers remark more on their baby’s resemblance to their partner if he or his relatives are there to hear her than if he is absent.

Pagel, however, doubts that evolution would favour trusting males. The warm glow that dads get from hearing that junior has their nose might simply be "good old-fashioned vanity", he suggests.

References

  1. Bressan, P. Why babies look like their daddies: paternity uncertainty and the evolution of self-deception in evaluating family resemblance. Acta Ethologica, in the press (2001).

JOHN WHITFIELD | © Nature News Service
Further information:
http://www.nature.com/nsu/011122/011122-9.html

More articles from Life Sciences:

nachricht Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung

nachricht Algae Have Land Genes
13.07.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Research finds new molecular structures in boron-based nanoclusters

13.07.2018 | Materials Sciences

Algae Have Land Genes

13.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>