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 More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>