Featured Research

from universities, journals, and other organizations

'Be different or die' does not drive evolution, bird study finds

Date:
December 22, 2013
Source:
University of Oxford
Summary:
A new study has found that species living together are not forced to evolve differently to avoid competing with each other, challenging a theory that has held since Darwin's Origin of Species.

The Red-billed Scythebill (Campylorhamphus trochilirostris), a woodcreeper from the ovenbird family.
Credit: Joseph A. Tobias

A new study has found that species living together are not forced to evolve differently to avoid competing with each other, challenging a theory that has held since Darwin's Origin of Species.

By focusing on ovenbirds, one of the most diverse bird families in the world, the Oxford University-led team conducted the most in-depth analysis yet of the processes causing species differences to evolve.

They found that although bird species occurring together were consistently more different than species living apart, this was simply an artefact of species being old by the time they meet. In fact, once variation in the age of species was accounted for, coexisting species were actually more similar than species evolving separately, opposite to Darwin's view which remains widely-held today.

"It's not so much a case of Darwin being wrong, as there is no shortage of evidence for competition driving divergent evolution in some very young lineages," said Dr Joe Tobias of Oxford University's Department of Zoology, who led the study. "But we found no evidence that this process explains differences across a much larger sample of species.

"The reason seems to be linked to the way new species originate in animals, which almost always requires a period of geographic separation. By using genetic techniques to establish the age of lineages, we found that most ovenbird species only meet their closest relatives several million years after they separated from a common ancestor. This gives them plenty of time to develop differences by evolving separately."

The study, published in Nature, compared the beaks, legs and songs of over 90% of ovenbird species. To tackle the huge challenge of sequencing genes and taking measurements, Oxford University scientists were joined by colleagues at Lund University (Sweden), Louisiana State University, Tulane University (New Orleans) and the American Museum of Natural History (New York).

Although species living together had beaks and legs that were no more different than those of species living apart, the most surprising discovery was that they had songs that were more similar. This challenges some longstanding ideas because the standard view for the last century has been that bird species living together would need to evolve different songs to avoid confusion.

"Looking at the bigger picture, 'be different or die' doesn't appear to explain evolution," said Dr Tobias. "Ovenbird species use a wide variety of beaks, from long and hooked to short and straight, but these differences appear to evolve when living in isolation, suggesting that competition is not the major driving force producing species differences. Instead, it seems to have the opposite effect in promoting the evolution of similar songs.

"The reasons for this are difficult to explain and require further study, but they may have something to do with the advantages of using the same 'language' in terms of similar aggressive or territorial signals. For instance, individuals of two closely related species with similar songs may benefit because they are able to defend territories and avoid harmful territorial contests not only against rivals of their own species but those in other species coexisting in the same places and competing for similar resources."

"The real novelty of this research is that it takes the evolutionary age of species into account," said Dr Nathalie Seddon of Oxford University's Department of Zoology, co-author of the study. "A first glance at our data suggests the same patterns that Darwin had expected. It is only when accounting for the fact that species vary in age, and then comparing between lineages of similar age, that the picture changes."

"These insights are the result of a hugely collaborative venture, and a good example of standing on the shoulders of giants. It took almost a decade to compile genetic sequences and trait measurements from 350 lineages of ovenbird. The song recordings were made in over twenty countries by numerous tropical ornithologists, including ourselves, and the museum material was based on specimens collected by hundreds of individuals stretching back to the famous British naturalist Alfred Russell Wallace in the 1860s."


Story Source:

The above story is based on materials provided by University of Oxford. Note: Materials may be edited for content and length.


Journal Reference:

  1. Joseph A. Tobias, Charlie K. Cornwallis, Elizabeth P. Derryberry, Santiago Claramunt, Robb T. Brumfield, Nathalie Seddon. Species coexistence and the dynamics of phenotypic evolution in adaptive radiation. Nature, 2013; DOI: 10.1038/nature12874

Cite This Page:

University of Oxford. "'Be different or die' does not drive evolution, bird study finds." ScienceDaily. ScienceDaily, 22 December 2013. <www.sciencedaily.com/releases/2013/12/131222161809.htm>.
University of Oxford. (2013, December 22). 'Be different or die' does not drive evolution, bird study finds. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2013/12/131222161809.htm
University of Oxford. "'Be different or die' does not drive evolution, bird study finds." ScienceDaily. www.sciencedaily.com/releases/2013/12/131222161809.htm (accessed April 23, 2014).

Share This



More Plants & Animals News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Leopard Bites Man in India

Raw: Leopard Bites Man in India

AP (Apr. 22, 2014) A leopard caused panic in the city of Chandrapur on Monday when it sprung from the roof of a house and charged at rescue workers. (April 22) Video provided by AP
Powered by NewsLook.com
Iowa College Finds Beauty in Bulldogs

Iowa College Finds Beauty in Bulldogs

AP (Apr. 22, 2014) Drake University hosts 35th annual Beautiful Bulldog Contest. (April 21) Video provided by AP
Powered by NewsLook.com
805-Pound Shark Caught Off The Coast Of Florida

805-Pound Shark Caught Off The Coast Of Florida

Newsy (Apr. 22, 2014) One Florida fisherman caught a 805-pound shark off the coast of Florida earlier this month. Video provided by Newsy
Powered by NewsLook.com
Breakfast Foods Are Getting Pricier

Breakfast Foods Are Getting Pricier

AP (Apr. 21, 2014) Breakfast is now being served with a side of sticker shock. The cost of morning staples like bacon, coffee and orange juice is on the rise because of global supply problems. (April 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins