If you find a robber fly in Tenerife, you will be face to face with an insect that is found nowhere else – and whose evolution may be a direct consequence of the great wealth of species on the Canary Islands, according to new research.
Posted on 04/20/2005 5:17:33 PM PDT by PatrickHenry
A unique fly from the Canary Islands has helped shed light on one driving force behind the birth of new species, Nature magazine reports this week.
The robber fly is found nowhere else, and scientists speculate that the rich biodiversity on the islands may actually have led to its emergence.
The researchers think sharing an island with a myriad of other lifeforms may push one species to evolve into another.
This new theory adds fresh insight into how biodiversity arises.
"Why some areas contain greater species diversity than others has been a fundamental question in evolutionary ecology and conservation biology," said co-author Brent Emerson, of the University of East Anglia, UK.
Genetic drift
It is thought "speciation" -- the evolution of a new species -- can occur when two populations of the same species become isolated, allowing them to "grow apart" genetically over the course of many generations.
Eventually, the two populations become so different that if they were to meet again they would no longer be able to breed, meaning they had become separate species.
One species can also evolve into another if strong selective forces are placed upon it (where certain genes or genetic traits are favoured by natural selection), or if its population is small enough to allow for "genetic drift", which happens when certain traits are lost -- or become proportionately more common -- simply because the gene pool has shrunk.
But exactly what drives speciation is still not fully understood by scientists, and it is an area of intense research.
By carefully studying animals and plants in the Canary and Hawaiian Islands, Dr Emerson and his colleague Niclas Kolm were able to show an apparent link between biodiversity and the evolution of new species.
If you find a robber fly in Tenerife, you will be face to face with an insect that is found nowhere else – and whose evolution may be a direct consequence of the great wealth of species on the Canary Islands, according to new research.
They found that endemic species, such as the predatory robber fly (Promachus vexator), are more common in places that are bustling with many different species. Therefore, they speculate, new species are more likely to evolve if they are surrounded by an already rich biodiversity.
Species competition
"Imagine you have an island colonised 100 species and a similar island colonised by 10 species," explained Dr Emerson. "If you leave that for a period of evolutionary time, the percentage of entirely new forms will be higher on the island with 100 species on it."
The researchers can think of three reasons why this might be the case. First, species that are forced to share a space with a lot of other species usually have smaller population sizes. That means they are more susceptible to genetic drift, which can speed up speciation.
Secondly, islands with a rich biodiversity have more habitat complexity. In other words, instead of just one habitat -- say, grass -- there is, for example, grass, shrubs and trees. That means species are more likely to evolve new adaptations and, eventually, become different species.
Thirdly and, the researchers believe, most importantly, competition between species can encourage speciation.
"We think the islands with more species have an increased interaction effect - and that is the most significant thing," said Dr Emerson. "So the more species you have, the more, as an individual species, competitors and predators you are facing.
"And that puts pressure on you that can lead to your extinction or you can adapt to that pressure and survive and that would result in a new species forming."
Tropical diversity
This new research could help explain why islands in warm areas (which tend to start off with a richer biodiversity than colder areas), like Hawaii and the Canary Islands, tend to have a high proportion of totally unique species.
Professor Axel Meyer, of Konstanz University in Germany, who is eminent in the field of speciation, says the research is very interesting -- if it stands further scrutiny.
"It is very thought provoking," he told the BBC News website. "I'm sure it will have people rushing to their computers to see whether this pattern holds up and it will be interesting to see if it does hold up in other systems."
He also stressed that a rich biodiversity could not entirely explain a rich biodiversity because, of course, you had to start somewhere.
"They are saying that if you have biodiversity it will create more biodiversity - I can buy that. But it still doesn't explain the initial step: how do you get more biodiversity in the first place?"
Who could have made the world looking old. Last Thursday.
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Interesting reply. Not original, but interesting.
When I look at the Grand Canyon, I see what a lot of water did in a short period of time. You, forgive my assumption, see what a little bit of water did over a long period of time. So..could we table this topic of the earths age till later?
Please explain how all the items for evolution to occur occured first, in the correct sequence at second, the correct place and third, at the necessary time.
Could you translate that for us English speakers? I honestly have no idea what you were trying to say.
Can you explain this data point, by using the "Intelligent Design" hypothesis, and why it is a better fit to the factual information presented?
Please provide us with detailed reasoning on this important subject, that supports your hypothesis on this specific case.
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Nope. I decline to write a term paper for you.
What "factual information" are you talking about?
Please reread my first posting containing quotes from the original article.
Last Thursday already posted (and it was 9:00 AM PDT):
http://www.freerepublic.com/focus/f-news/1385996/posts?page=37#37
Clue to Starkers, the Grand Canyon is one one-millionth of your difficulties in trying to argue the universe is young. But you want a free pass on that to demand the broomsticks of ten thousand witches.
Please explain how all the items for evolution to occur occured first, in the correct sequence at second, the correct place and third, at the necessary time.
They can't happen in a truly out of sequence fashion where true dependencies exist, can they? Your premise has two problems. One, there are more scenarios than you are willing to learn in which the simple can evolve to the complex. Two, there is more time than you are willing to admit.
Things took as long as they took to get to here. Multiple lines of evidence support the mainstream science version of events regarding the history of life on Earth. Here's a link for you to ignore.
(They're not ready for the part about the Cat-Goddess yet. I'd suggest giving them time to absorb the basics.)
First, the sequence of events.
Second, the location.
Third, the timing.
1) A unique fly from the Canary Islands, the robber fly, is found nowhere else.
2) They found that endemic species, such as the predatory robber fly (Promachus vexator), are more common in places that are bustling with many different species.
Now, if new species are only created by "Intelligent Design", why would there be this association?
"...there are more scenarios than you are willing to learn..."
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You are starting to get mean. The conversation is over when you start personal attacks. The point is yours to make and you have failed. By attacking me you have demonstrated the weakness of your argument.
Factual information presented in this article:
1) A unique fly from the Canary Islands, the robber fly, is found nowhere else.
2) They found that endemic species, such as the predatory robber fly (Promachus vexator), are more common in places that are bustling with many different species.
Now, if new species are only created by "Intelligent Design", why would there be this association?
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A very good post. Sorry but I will have to answer tomorrow. Thank you.
Point goes to VadeRetro for using logic as an argument, instead of emotion.
When I look at the Grand Canyon, I see what a lot of water did in a short period of time.
This is selective absorption of data and nothing but.
The difficulties in ascribing the Grand Canyon to one big flood. (Fossilized features of tranquil surface life in layer after layer after layer.)
You are welcome Sir, and I look forward to your reply. As always, these debates are always interesting.
You: You are starting to get mean. The conversation is over when you start personal attacks.
Again, I wasn't making anything up. How Complex--Even Irreducibly Complex--Features Evolve.
Furthermore, by running off as you are doing, you reserve the right to show up back again trumpeting your same wilfully ignorant statements elsewhere, elsewhen. This is a key feature of creationism, as it is with any advocacy. One must be ineducable and incorrigible WRT the problems and failings of the Holy Cause.
Bingo! Evolution is a THEORY. You could give all of your belief system to evolution but it is by definition a THEORY. Creationism is also by definition, scientifically, a THEORY. ID is also by definition, scientifically, a THEORY. All three require a degree of FAITH so hence all are FAITH-BASED.
The comfortable assumptions made in this article, as you so astutely observed, are the building blocks of a THEORY.
Well at least that's my THEORY.
Now leave me alone while I try to figure out how to scientifically make something out of nothing (it will be a while.)
I'm glad to hear that, otherwise the Greenie Weenies would be after SlowBoat407 for introducing a xenobiotic species and we'd have to visit him in the Big House.
Hey, why all the ad hominems? That means you lose. Everything's a THEORY, man! Like, I mean, ID is a THEORY; creationism is a THEORY; even my colon is a THEORY. You science guys are really dumb!
</creationism mode>
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