Featured Research

from universities, journals, and other organizations

The genes tell crows to choose partners that look like themselves

Date:
June 19, 2014
Source:
Uppsala University
Summary:
Crows like to select mates that look alike. In a large-scale genomic study a team of researchers found that this behavior might be rooted in their genetic make-up, revealing a likely common evolutionary path that allows for separating populations into novel species.

All-black carrion crow nestlings from a German population west of the hybrid zone. When crossing the zone, plumage colouration changes rapidly to the grey-coated hooded type.
Credit: Jochen Wolf

Crows like to select mates that look like themselves. In a large-scale genomic study, published in Science today, a team of researchers led by Uppsala University found that this behaviour might be rooted in their genetic make-up, revealing a likely common evolutionary path that allows for separating populations into novel species.

What is the driving engine behind biodiversity? One and a half centuries years ago, Charles Darwin recognized that species are subject to evolutionary change. Now, we know that all aspects defining an organism are encoded in its genome. Yet, how new species emerge from slight genetic changes remains unanswered. Crows, for example, are all black or grey coated, and they exhibit a strong tendency to select partners that look like themselves.

The researchers identified an avian system -- crows and ravens of the genus Corvus -- that they used as an evolutionary model to decipher the genetic underpinnings of speciation. Central to this system is the independent recurrence of a pied colour-pattern in several species of the genus that stands in contrasts to the predominant all-black plumage in the clade.

In this study the researchers focused on the young end of the evolutionary spectrum investigating the genetic architecture of divergence between all black carrion crows (Corvus [corone] corone) and grey coated hooded crows (C. [c.] cornix) that still hybridize along a hybrid zone stretching across Europe and Asia.

Hybrid zones are natural evolutionary experiments where early processes of speciation can be studied. Where black and grey morphs come into contact, they form a well-known hybrid zone that is astonishingly narrow (15-150 km) and apart from minor shifts has been stably maintained over at least 100 years.

Previous small scale genetic analysis showed hardly any genetic differentiation between carrion and hooded crow across the entire species range that would exceed the level of differentiation between populations of the same taxon, leave alone justify species status.

In this study the researchers set out to find the decisive differences that stabilize the hybrid zone and eventually keep carrion and hooded crows apart using a plethora of approaches: they generated a genome backbone, performed population genetic analyses of whole genome data of many individuals, raised young crows to measure gene expression under controlled conditions and conducted functional histological characterization of growing feather follicles to have a closer look at melanocytes, the cells where color is made.

Consistent with the hypothesis of color-mediated isolation, we found that gene expression differed almost exclusively in growing feather follicles at the stage where color is deposited into the feathers. Genes involved in coloration were constitutively expressed higher in black crow than in their grey counterparts.

Screens of the more than 1 billion base pairs in the genome revealed very little difference between the two. Only 82 base pairs were diagnosticly different and 81 of them were concentrated in one genomic region coding for genes involved in coloration and visual perception.

"This finding suggests the exciting possibility that a mate-choice relevant trait, like coloration, might be genetically coupled to its perception which could be common one evolutionary path allowing for separating populations into novel species. Such a mechanism could be common for many other species with visually oriented mate choice," says Jochen Wolf, one of the lead authors of the study.


Story Source:

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


Journal Reference:

  1. Jochen Wolf et al. The genomic landscape underlying phenotypic integrity in the face of gene flow in crows. Science, 2014

Cite This Page:

Uppsala University. "The genes tell crows to choose partners that look like themselves." ScienceDaily. ScienceDaily, 19 June 2014. <www.sciencedaily.com/releases/2014/06/140619142212.htm>.
Uppsala University. (2014, June 19). The genes tell crows to choose partners that look like themselves. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2014/06/140619142212.htm
Uppsala University. "The genes tell crows to choose partners that look like themselves." ScienceDaily. www.sciencedaily.com/releases/2014/06/140619142212.htm (accessed September 30, 2014).

Share This



More Plants & Animals News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com
Argentina Worries Over Decline of Soybean Prices

Argentina Worries Over Decline of Soybean Prices

AFP (Sep. 27, 2014) The drop in price of soy on the international market is a cause for concern in Argentina, as soybean exports are a major source of income for Latin America's third largest economy. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com
Mama Bear, Cubs Hang out in California Backyard

Mama Bear, Cubs Hang out in California Backyard

Reuters - US Online Video (Sep. 27, 2014) A mama bear and her two cubs climb trees, wrestle and take naps in the backyard of a Monrovia, California home. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com
'Crazy' Climate Forces Colombian Farmers to Adapt

'Crazy' Climate Forces Colombian Farmers to Adapt

AFP (Sep. 26, 2014) Once upon a time, farming was a blissfully low-tech business on Colombia's northern plains. Duration: 02:05 Video provided by AFP
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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