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 BigH1 -- The key histone for male fertility
14.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Guardians of the Gate
14.12.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>