Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Butterfly 'eyespots' add detail to the story of evolution

28.05.2014

A new study of the colorful "eyespots" on the wings of some butterfly species is helping to address fundamental questions about evolution that are conceptually similar to the quandary Aristotle wrestled with about 330 B.C. – "which came first, the chicken or the egg?"

After consideration, Aristotle decided that both the egg and the chicken had always existed. That was not the right answer. The new Oregon State University research is providing a little more detail.


The eyespots on this squinting bush brown butterfly are helping researchers answer questions about fundamental evolution.

Credit: Photo by William Piel


When wings are closed, these eyespots serve as camouflage for a painted lady butterfly.

Credit: Photo by Jeffrey Oliver

The study, published today in Proceedings of the Royal Society B, actually attempts to explain the existence of what scientists call "serial homologues," or patterns in nature that are repetitive, serve a function and are so important they are often retained through millions of years and across vast numbers of species.

Repeated vertebra that form a spinal column, rows of teeth, and groups of eyespots on butterfly wings are all examples of serial homologues. Researchers have tracked the similarities and changes of these serial features through much time and many species, but it's remained a question about how they originally evolved.

... more about:
»attack »butterfly »chicken »eggs »function »individual »species »spinal

Put another way, it's easier to see how one breed of chicken evolved into a different breed of chicken, rather than where chickens – or their eggs - came from to begin with.

Butterfly wings are helping to answer that question. These eyespots, common to the butterfly family Nymphalidae, now serve many butterflies in dual roles of both predator avoidance and mate identification. One theory of their origin is that they evolved from simpler, single spots; another theory is that they evolved from a "band" of color which later separated into spots.

"What we basically conclude is that neither of the existing theories about butterfly eyespots is correct," said Jeffrey Oliver, a postdoctoral scholar in the Department of Integrative Biology of the OSU College of Science. "The evidence suggests that a few eyespots evolved as a group at about the same time, but behaved somewhat as individual entities."

Having appeared as a result of some genetic mutation, however, the eyespots then had the capability to move, acquire a function that had evolutionary value, and because of that value were retained by future generations of butterflies. And at all times, they retained the biological capacity for positional awareness – the eyespots formed in the same place until a new mutation came along.

"At first, it appears the eyespots helped this group of butterflies with one of the most basic aspects of survival value, which is avoiding predators," Oliver said.

On the side of the wing that predators saw when the wings were closed, the eyespots could have served as camouflage from a distance, and up close almost a "bulls-eye" for a predator to see and attack. But this directed the attack toward the tips of less-important wings, and not the more vulnerable head or body of the insect.

But just as important, Oliver said, the study indicates how through continued mutation these eyespots moved to a completely different place – the other side of the wing. There, they performed a completely different function – helping the butterfly to attract and be identified by optimal mates.

"If you take this same concept and apply it to other important features like vertebra and a spinal column, it suggests that some small number of bones would form through mutation, and eventually move, join and be perpetuated as they acquired a function with survival value," Oliver said.

"There would be a biological position in which they were supposed to form, and that would be retained," he said. "And over time, the vertebra might expand in number, and acquire other functions that had nothing to do with their original function, but which still had value."

The evolution of life has never been simple, as Aristotle and the other early philosophers found out. But one bone or butterfly eyespot at a time, the pieces continue to come together.

###

Editor's Note: Digital images of butterflies are available to illustrate this story.

Squinting bush brown, showing "eyespots": http://bit.ly/1jYtyKz

Painted lady: http://bit.ly/1hvwqJp

Jeffrey Oliver | Eurek Alert!

Further reports about: attack butterfly chicken eggs function individual species spinal

More articles from Life Sciences:

nachricht Fish Oil-Diet Benefits May be Mediated by Gut Microbes
28.08.2015 | University of Gothenburg

nachricht Bio-fabrication of Artificial Blood Vessels with Laser Light
28.08.2015 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

Im Focus: Self-healing landscape: landslides after earthquake

In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.

These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...

Im Focus: FIC Proteins Send Bacteria Into Hibernation

Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.

For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...

Im Focus: Fraunhofer IPA develops prototype of intelligent care cart

It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.

Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

Large agribusiness management strategies

19.08.2015 | Event News

 
Latest News

Interstellar seeds could create oases of life

28.08.2015 | Physics and Astronomy

An ounce of prevention: Research advances on 'scourge' of transplant wards

28.08.2015 | Health and Medicine

Fish Oil-Diet Benefits May be Mediated by Gut Microbes

28.08.2015 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>