Swans help explain evolutionary question

Jan 25, 2006

University of Oxford scientists say they have answered a longstanding evolutionary question involving mute swans.

The researchers tracked a colony of swans for more than 20 years, exploring whether the number of eggs laid by a female bird -- known as "clutch size" -- changes in accordance with natural selection.

Researcher Ann Charmantier say debate has focused on an evolutionary point of view: Why is clutch size not evolving despite significant heritability and directional selection?

Many long-term studies of avian clutch size have looked for -- but not seen -- an increase in the number of eggs laid. However, the 25-year study of the selection, inheritance, and evolution in the mute swan population of Abbotsbury, England, yielded data on clutch size consistent with the direction predicted by evolutionary theory.

The scientists say they found clutch size providing an illustration of microevolutionary process on a small time scale. They hypothesize a relaxation of food constraints and an increase in predator protection might have enabled the swans to evolve towards a new, larger clutch size.

The study is to be detailed in a future issue of The American Naturalist.

Copyright 2006 by United Press International

Explore further: Corporate interest is a problem for research into open-access publishing

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

New search planned for grave of Spanish poet Lorca

2 hours ago

Archeologists will start inspecting land in southern Spain near where the acclaimed poet Federico Garcia Lorca is believed to have been executed and buried at the start of the Spanish Civil War in 1936, officials said Friday.

Family financing is anything but foolish

4 hours ago

Borrowing money from a family member or friend to start a business is often considered dangerous, both financially and emotionally, however new research conducted by an entrepreneurial expert at the University of Adelaide ...

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.