Featured Research

from universities, journals, and other organizations

Molecular methods are not sufficient in systematics and evolution

Date:
June 7, 2010
Source:
Laboratory of Behavioral Ecology and Evolution at Seoul National University
Summary:
Biologists studied mitochondrial DNA, plumage coloration and behavior of 10 subspecies of a Central and South American warbler the Slate-throated redstart, an inhabitant of montane forests. Mitochondrial DNA analyses indicated that evolution of these birds started over 70 millions years ago, in the Pleistocene, in northern and central areas of modern Mexico.

Modern evolutionary systematists often use molecular methods, such like mitochondrial DNA analysis, to differentiate between species and subspecies. These molecular methods are a flashy symbol of modern science cleverly exploited by media to draw interest of public and by laboratory scientists to draw attention of government funding agencies.

Related Articles


However, current research indicates that the picture painted by these methods may be false, and only a creative combination of classical field-based ecology, museum-based systematics and DNA-based phylogenetics, can lead to right conclusions. In the last issue of Ornithological Monographs (pages: 90-102), a team of biologists from the Universidad Central de Venezuela, Allegheny College in USA, Seoul National University in South Korea and Centre for Ecological Studies in Poland demonstrate how modern evolutionary biology needs the "old-style" biology in order to explain evolution and systematics of birds.

The team composed of Jorge Perez-Eman, Ronald Mumme, and Piotr Jablonski studied mitochondrial DNA, plumage coloration and behavior of 10 subspecies of a Central and South American warbler the Slate-throated redstart, an inhabitant of montane forests. Mitochondrial DNA analyses indicated that evolution of these birds started over 70 millions years ago, in the Pleistocene, in northern and central areas of modern Mexico. First, the birds rapidly expanded southwards to South America diversifying into several genetically and morphologically different subspecies. Second, about 40-70 million years ago, when today's montane forest types existed at lower elevations, a rapid expansion started producing several morphologically distinct subspecies that differ in the coloration of their bellies from yellow, orange, through red, and in the tail pattern from small to large white patches, but do not differ in the mitochondrial DNA. The researchers believe that during this rapid expansion of the populations, the genes responsible for these morphological traits have evolved rapidly due to adaptation to local habitats, while the mitochondrial genes often used in the phylogenetic research, remained unaffected by the evolutionary change.

Why would local conditions lead to rapid changes in the plumage pattern? The answer to this question can be found in the role of tail pattern in foraging of these warblers. The Slate-throated redstarts, as well as their relatives, the Painted Redstarts, use "flush-pursue foraging." The foraging birds look like butterflies when they spread their tails and wings in order to be conspicuously visible by the insects. Insects, such like treehoppers or flies, are scared by the sudden visual displays and are flushed away from their resting sites on leaves and branches.

The birds only wait for this to happen, and in elegant pursuits they catch the escaping insects in the air. Field experiments conducted by the research team with birds of the Costa Rican subspecies Myioborus miniatus comptus (see photo) and their key prey indicated that a contrasting black-and-white tail is critical to flush-pursuit foraging success, and that subspecific variation in the extent of white in the tail reflects evolutionary adaptation to regional prey or habitat characteristics that maximizes flush-pursuit foraging performance. Thus, even though the subspecies of the Central American clade are genetically homogeneous with respect to the mitochondrial genes, analysis of tail pattern and its effect on foraging performance suggests a recent adaptive evolutionary divergence, warranting the status of separate subspecies.

The researchers conclude: "Our findings serve as a reminder that mitochondrial DNA (mtDNA) gene trees will not always succeed in capturing all evolutionarily significant genetic change, and that manipulative field experiments can provide crucial information on the selective factors that lead to evolution of subspecies-specific morphological traits even in the absence of mtDNA diversification."


Story Source:

The above story is based on materials provided by Laboratory of Behavioral Ecology and Evolution at Seoul National University. Note: Materials may be edited for content and length.


Cite This Page:

Laboratory of Behavioral Ecology and Evolution at Seoul National University. "Molecular methods are not sufficient in systematics and evolution." ScienceDaily. ScienceDaily, 7 June 2010. <www.sciencedaily.com/releases/2010/06/100607122438.htm>.
Laboratory of Behavioral Ecology and Evolution at Seoul National University. (2010, June 7). Molecular methods are not sufficient in systematics and evolution. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/2010/06/100607122438.htm
Laboratory of Behavioral Ecology and Evolution at Seoul National University. "Molecular methods are not sufficient in systematics and evolution." ScienceDaily. www.sciencedaily.com/releases/2010/06/100607122438.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Buzz60 (Nov. 24, 2014) A Swedish Adventure racing team travels to try and win a world title, but comes home with something way better: a stray dog that joined the team for much of the grueling 430-mile race. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Red Panda Cubs Explore the Bratislava Zoo

Red Panda Cubs Explore the Bratislava Zoo

AFP (Nov. 24, 2014) Four-month old Red Panda twins Pim and Pam still rely on their mother for breast milk at the Bratislava Zoo in Slovakia, but the precocious cubs have begun to branch out to solid foods, as well. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) A new study links greater authority with increased depressive symptoms among women in the workplace. Video provided by Newsy
Powered by NewsLook.com
Winter Can Cause Depression — Here's How To Combat It

Winter Can Cause Depression — Here's How To Combat It

Newsy (Nov. 23, 2014) Millions of American suffer from seasonal depression every year. It can lead to adverse health effects, but there are ways to ease symptoms. Video provided by Newsy
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