The hitchhiker's guide to altruism -- Study explains how costly traits evolve

Jan 19, 2007

Darwin explained how beneficial traits accumulate in natural populations, but how do costly traits evolve? In the past, two theories have addressed this problem.

The theory of hitchhiking suggests that genes that confer a cost to their bearer can become common in natural populations when they "hitch a ride" with fitter genes that are being favored by natural selection. Conversely, the theory of kin selection suggests that costly traits can be favored if they lead to benefits for relatives of the bearer, who also carry the gene.

"Animal traits are not always independent. For example, people with blond hair are more likely to have blue eyes," explains Andy Gardner (Oxford University). "This is a nuisance for natural selection, which could not, for instance, favor blond hair without also indirectly favoring blue eyes, and this is the idea of genetic hitchhiking."

Kin selection is similar, but here the genetic associations are between different individuals: "If I have a gene that makes me more altruistic, then I can also expect my relatives to carry it. So while the immediate effect of the gene is costly for me, I would benefit by receiving altruism from my relatives, and so the gene is ultimately favored," Gardner explains.

New research carried out at the University of Edinburgh and Queen's University, Canada shows that both processes are governed by the same equations. This reveals that kin selection can be seen as a special form of genetic hitchhiking, explain Gardner and his coauthors Stuart West and Nick Barton (University of Edinburgh) in the February issue of The American Naturalist.

The researchers built on a general framework for modeling hitchhiking first proposed by Barton and colleagues, showing how it can be used to describe social evolution and recovering the classical results of kin selection theory. This insight raises the possibility of using the tools of hitchhiking theory to explore social problems that have so far been too complicated to analyze using traditional kin selection techniques.

Source: University of Chicago

Explore further: Untangling DNA with a droplet of water, a pipet and a polymer

add to favorites email to friend print save as pdf

Related Stories

Neighboring birds sing 'out of tune'

Feb 18, 2015

Great tits living next to each other may sing their songs at significantly different rates, more or less frequently, as compared to non-neighboring birds, according to a study published February 18, 2015 in the open-access ...

A gene that shaped the evolution of Darwin's finches

Feb 11, 2015

Researchers from Princeton University and Uppsala University in Sweden have identified a gene in the Galápagos finches studied by English naturalist Charles Darwin that influences beak shape and that played ...

Blind beetles show extraordinary signs of sight

Jan 28, 2015

University of Adelaide researchers have made a surprising discovery in the aquifers beneath the Western Australian desert, which challenges the traditional Darwinian view of evolution.

Recommended for you

A molecular compass for bird navigation

1 hour ago

Each year, the Arctic Tern travels over 40,000 miles, migrating nearly from pole to pole and back again. Other birds make similar (though shorter) journeys in search of warmer climes. How do these birds manage ...

Salish Sea seagull populations halved since 1980s

2 hours ago

The number of seagulls in the Strait of Georgia is down by 50 per cent from the 1980s and University of British Columbia researchers say the decline reflects changes in the availability of food.

Cultivation of microalgae via an innovative technology

2 hours ago

Preliminary laboratory scale studies have shown consistent biomass production and weekly a thick microalgal biofilm could be harvested. A new and innovative harvesting device has been developed for ALGADISK able to directly ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.