Posted on 12/29/2013 12:13:31 PM PST by SeekAndFind
A new study has found that species living together are not forced to evolve differently to avoid competing with each other, challenging a theory that has held since Darwin's Origin of Species.
By focusing on ovenbirds, one of the most diverse bird families in the world, the Oxford University-led team conducted the most in-depth analysis yet of the processes causing species differences to evolve.
They found that although bird species occurring together were consistently more different than species living apart, this was simply an artefact of species being old by the time they meet. In fact, once variation in the age of species was accounted for, coexisting species were actually more similar than species evolving separately, opposite to Darwin's view which remains widely-held today.
'It's not so much a case of Darwin being wrong, as there is no shortage of evidence for competition driving divergent evolution in some very young lineages,' said Dr Joe Tobias of Oxford University's Department of Zoology, who led the study. 'But we found no evidence that this process explains differences across a much larger sample of species.
'The reason seems to be linked to the way new species originate in animals, which almost always requires a period of geographic separation. By using genetic techniques to establish the age of lineages, we found that most ovenbird species only meet their closest relatives several million years after they separated from a common ancestor. This gives them plenty of time to develop differences by evolving separately.'
The study, published in Nature, compared the beaks, legs and songs of over 90% of ovenbird species. To tackle the huge challenge of sequencing genes and taking measurements, Oxford University scientists were joined by colleagues at Lund University (Sweden), Louisiana State University, Tulane University (New Orleans) and the American Museum of Natural History (New York).
Although species living together had beaks and legs that were no more different than those of species living apart, the most surprising discovery was that they had songs that were more similar. This challenges some longstanding ideas because the standard view for the last century has been that bird species living together would need to evolve different songs to avoid confusion.
'Looking at the bigger picture, 'be different or die' doesn't appear to explain evolution,' said Dr Tobias. 'Ovenbird species use a wide variety of beaks, from long and hooked to short and straight, but these differences appear to evolve when living in isolation, suggesting that competition is not the major driving force producing species differences. Instead, it seems to have the opposite effect in promoting the evolution of similar songs.
'The reasons for this are difficult to explain and require further study, but they may have something to do with the advantages of using the same 'language' in terms of similar aggressive or territorial signals. For instance, individuals of two closely related species with similar songs may benefit because they are able to defend territories and avoid harmful territorial contests not only against rivals of their own species but those in other species coexisting in the same places and competing for similar resources.'
'The real novelty of this research is that it takes the evolutionary age of species into account,' said Dr Nathalie Seddon of Oxford University's Department of Zoology, co-author of the study. 'A first glance at our data suggests the same patterns that Darwin had expected. It is only when accounting for the fact that species vary in age, and then comparing between lineages of similar age, that the picture changes.'
'These insights are the result of a hugely collaborative venture, and a good example of standing on the shoulders of giants. It took almost a decade to compile genetic sequences and trait measurements from 350 lineages of ovenbird. The song recordings were made in over twenty countries by numerous tropical ornithologists, including ourselves, and the museum material was based on specimens collected by hundreds of individuals stretching back to the famous British naturalist Alfred Russell Wallace in the 1860s.'
The research was funded by the Oxford University John Fell Fund, Queens College, Oxford, The Royal Society and the United States National Science Foundation.
another effort to explain what evolution is because the facts don’t fit the theory.
>>another effort to explain what evolution is because the facts don’t fit the theory.<<
Additional clarification of TToE. There is nothing here that undermines the TToE, but rather puts a spotlight on some of the mechanics.
“A new study has found that species living together are not forced to evolve differently to avoid competing with each other, challenging a theory that has held since Darwin’s Origin of Species.”
Tell that to the people living with the animals in the inner cities.
Yes. Evolution is ipso facto. It can not be proven wrong.
LOL that is how I feel about pre-tribulation theology.
that’s okay I am not a pre-tribber
Hmm. We had an "ovenbird" for Thanksgiving...
>>It can not be proven wrong.<<
It can indeed.
But this isn’t that proof, nor has any been found to date.
If you found a modern horse skeleton at the Jurassic strata, that would fundamentally disprove it.
If you found a modern horse skeleton at the Jurassic strata, that would fundamentally disprove it.
______
I don’t think so. Answer these questions. 1) how would it disprove it? 2) what would replace it?
1) The same way Einsteinian Physics affected Newtonian.
2) I have no idea. The effect would be so fundamental it would take decades to unravel.
It won’t happen but it would meet the “falsifiable” criterion for a Scientific Theory.
1) The same way Einsteinian Physics affected Newtonian.
2) I have no idea. The effect would be so fundamental it would take decades to unravel.
It won’t happen but it would meet the “falsifiable” criterion for a Scientific Theory.
_________
That doesn’t make sense. Einsteinium physics did not disprove Newtonian physics.
If any analogous changes in biology are to happen it will be due to comparative genomics.
Is there any realistic result that could happen that can disprove evolution?
>>Is there any realistic result that could happen that can disprove evolution?<<
No, nothing realistic.
One cannot wave away billions of data points assembled over hundreds of years by thousands of scientists.
I just worry about declaring something ipso facto — it really is an unassailable Scientific Theory, probably the best understood one (as a Theory — the mechanics are still being worked out and will probably be refined forever) in all of science.
I think evolution is ipso facto. It’s a paradigm. It can’t be disproven.
Specific evolutionary theories can be, as this Nature article claims.
If there are no predictions that can be made about the coming comparative genomic information to test the theory, it’s not much of a theory, but a given.
Billions of data points?
No need to resort to hyperbole for effect.
>>Billions of data points?
No need to resort to hyperbole for effect.<<
How many fossils do think have been excavated in the last 200 years?
Billions, easily.
>>Specific evolutionary theories can be, as this Nature article claims.<<
I know we are on the same side here but you might want to tighten up your vocabulary.
TToE is a Scientific Theory (which is the highest level in science).
In this case the discussion is about the mechanics of one aspect of that theory.
It is falsifiable, but that falsification has yet to emerge (nor shall it).
This is a nice brief explanation but there are others in more depth: http://www.livescience.com/21491-what-is-a-scientific-theory-definition-of-theory.html
By definition conflicting paradigms are not reconciliable. Nor are they necessarily in conflict. Natural selection and creation selection are ultimately unknowables. There is no uncaused cause that can be delineated. Paradigms are a matter of faith, not reason.
>>By definition conflicting paradigms are not reconciliable.<<
Thus my eschewing the use of the term.
TToE is a Scientific Theory.
I am saying TToE, as you put it, is not a theory because it is not falsifiable.
Specific theories on the mechanics, as you put it, are testable.
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