Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Major mutations, not many small changes, might lead way to new species

13.11.2003


Hummingbirds visited nearly 70 times more often after scientists altered the color of a kind of monkeyflower from pink – beloved by bees but virtually ignored by hummingbirds – to a hummer-attractive yellow-orange.



Researchers writing in the Nov. 13 issue of Nature say perhaps it was a major change or two, such as petal color, that first forged the fork in the evolutionary road that led to today’s species of monkeyflowers that are attractive to and pollinated by hummingbirds and separate species of monkeyflowers that are pollinated by bees.

The color change is the result, it appears, of mutation in a single gene, according to H.D. "Toby" Bradshaw, a professor of biology at the University of Washington and lead author of the Nature piece. He says the resulting quick change in pollinator preferences adds to the debate over whether new species arise according to the classic, 150-year-old Darwin theory of evolution that says it may take a hundred small genetic changes, each with mounting effect, or might speciation be kick-started by a few mutations that cause large effects.


"It could be that the first adaptations require a few big changes, sort of like taking a watch that has stopped ticking and banging it a few times before making the small tweaks to restore its optimal performance," says Douglas Schemske, professor of plant biology at Michigan State University and co-author of the letter in Nature.

There are 123 species of monkeyflowers, a wildflower found around the world. Mimulus lewisii appeals to bees with forward-thrusting petals that serve as a landing platform and yellow nectar guides that contrast with the pale pink flowers. The closely related M. cardinalis, on the other hand, has a deep, tubular shape that excludes bees but is easily probed by the slender beaks of hummingbirds, and has red or deep yellow-orange petals, colors bees can’t see.

These and other differences make the species of monkeyflowers distinct and nearly eliminates crossbreeding in the wild.

In an experiment funded by the National Science Foundation, the researchers changed the region of a chromosome, thought to be a single gene, that affects the concentration of yellow pigment in petals of monkeyflowers. M. lewisii, the normal favorite of bees, responded with petals of yellow-orange instead of the usual pink. Although its other features – flower size, petal shape and amount of nectar – were unchanged, the resulting flowers were suddenly being visited 68 times more often by hummingbirds. The flowers were actually shunned by bees, probably because orange is in the spectrum of light they don’t see.

In another alteration as part of the experiment, M. cardinalis, usually favored by hummingbirds, responded with petals that were dark pink rather than deep red. These flowers appealed equally to hummingbirds and bees.

Bradshaw and Schemske say altering just the genetic region responsible for the concentration of yellow pigment is much like what might happen during a naturally occurring mutation.

"Perhaps a single mutation having to do with color changed the pollinator milieu back when there was only a single species," Bradshaw says. That one big evolutionary step may then have been followed by many smaller steps triggered by pollinator preferences that led ultimately to different species.

Monkeyflowers, so-called because someone once imagined the face of a monkey in the markings on the blossoms, have been used by researchers interested in ecology and evolution for more than 50 years. The plants readily reveal the effects of crossbreeding and can be planted in native settings so they are useful for experiments.

"A unique aspect of out work is that it combines ecological observations with molecular genetic techniques to elucidate the process of adaptation in natural populations," Schemske says.

Schemske, Bradshaw and researchers at Duke University, Clemson University, University of North Carolina and University of Montana recently received $5 million for the study of monkeyflowers and questions of how species arise. The money is part of the new Frontiers in Integrative Biological Research program .



For more information
Bradshaw, (206) 954-4392, toby@u.washington.edu (On Veterans Day, it will be best to call rather than use e-mail)
Schemske, (517) 432-5289, schem@msu.edu
Michigan State University media contact: Tom Oswald, (517) 432-0920, oswald@msu.edu
NSF’s Frontiers in Integrative Biological Research explores biology’s mysteries:
http://www.nsf.gov/od/lpa/news/03/pr03106.htm

Sandra Hines | EurekAlert!
Further information:
http://www.nsf.gov/od/lpa/news/03/pr03106.htm

More articles from Life Sciences:

nachricht Molecular microscopy illuminates molecular motor motion
26.07.2017 | Penn State

nachricht New virus discovered in migratory bird in Rio Grande do Sul, Brazil
26.07.2017 | Fundação de Amparo à Pesquisa do Estado de São Paulo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>