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filthy
SFN Die Hard
USA
14408 Posts |
 Posted - 03/20/2008 : 16:47:17 [Permalink]
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Interesting, interesting. But sometimes complexity can lead to odd-ball specialization that would be fatal to the species if something in it's environment were to radically change -- altered food chain, new predator, deteriorating climate, & so forth. An example might be the Kakapo, a flightless parrot native to NZ. These are no less complex than any other Psittaciforme, but it had the misfortune to end up in a virtually predator-less environment. Today, it has a total population of only 86, rigidly protected individuals. So complexity alone is not the answer to species immortality.
The fossil record is filled with complex species that ultimately couldn't make it -- the Megefauna come to mind, as do Triassic dinosaurs such as Stegosaurus and Diplodocus, The Trilobites of the Cambrian, one of the most successful crustations ever, were all but gone well before the Permian Extinction.
But as has been shown, a species can become less complex, as the Kakapo is starting to do and blind cave species, particularly eyeless fish, already have done, to an extent at least. This shows that small, pocket populations in special environments are much more likely to do this, and t'other way 'round. But as they are isolated, they cannot be used as an example of a species as a whole.
Darwin's Finches are particularly interesting in this regard. They are about as complex as any other finch, but have evolved into specialized niches in an isolated environment. The question is, have they become so specialized that they couldn't survive in their original habitat?
I really don't know where I'm going with this, so I'll hang it up now...
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist! 
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Jan
New Member
USA
5 Posts |
Posted - 03/20/2008 : 17:27:48 [Permalink]
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Originally posted by chaloobi
This is an interesting bit of research. In a nut shell, organisms tend to evolve toward greater complexity but almost never toward lesser complexity. Why would that be?
Life becomes more and more complex, evolution study finds Tue
WASHINGTON (AFP) - Life, as it evolves, becomes increasingly complex and rarely less so, a study of evolution by British and Canadian researchers has found.
In the study out Monday researchers looked back 550 million years in the fossil catalogue from today, checking several evolutionary branches of the crustacean family tree to see where animals evolved that became simpler than their ancestors.
But instead they found organisms that developed increasingly complicated structures and characteristics.
"If you start with the simplest possible animal body, then there's only one direction to evolve in, you have to become more complex," said Dr Matthew Wills from the Department of Biology & Biochemistry at the University of Bath who worked with colleagues Sarah Adamowicz from the University of Waterloo, Canada, and Andy Purvis from Imperial College London.
"Sooner or later, however, you reach a level of complexity where it's possible to go backwards and become simpler again," he said.
"What's astonishing is that hardly any crustaceans have taken this backwards route," added Wills. "Instead, almost all branches have evolved in the same direction, becoming more complex in parallel.
"This is the nearest thing to a pervasive evolutionary rule that's been found."
Adamowicz noted that "looking at many independent branches is similar to viewing multiple repeated runs of the tape of evolution.
"Our results apply to a group of animals with bodies made of repeated units. We must not forget that bacteria, very simple organisms, are among the most successful living things. Therefore, the trend towards complexity is compelling but does not describe the history of all life," she said. |
A couple thoughts:
#1. It seems like increased complexity is not necessarily the best way to go - doesn't more complexity mean more opportunities for things to go wrong? Shouldn't evolution prefer simplicity wherever possible?
#2. That said, the vast majority of organisms, like the trillion or so bacteria helping me digest my breakfast right now, are, and have remained for the history of life on Earth, very simple.
#3. But #2 isn't the same as going from simple to more complex back to simple again. They simply stayed fairly simple because increased complexity was not required for survival in perpetuity.
So does the increased complexity over decreased complexity rule stand? More research required? Assuming it does stand, anyone have any ideas why?
Link: http://news.yahoo.com/s/afp/20080318/sc_afp/usbiologycanadabritain_080318162118
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chaloobi
SFN Regular
1620 Posts |
Posted - 03/20/2008 : 19:25:57 [Permalink]
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| Jan? What's up? |
-Chaloobi
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chaloobi
SFN Regular
1620 Posts |
Posted - 03/20/2008 : 19:29:33 [Permalink]
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If you measure success by longevity before extinction, do complex species do better or worse than less complex?
EDIT: What's the most complex species known to exist today? |
-Chaloobi
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| Edited by - chaloobi on 03/20/2008 19:30:08 |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 03/20/2008 : 19:33:38 [Permalink]
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Originally posted by chaloobi
EDIT: What's the most complex species known to exist today? |
How do you define "complex?"
Some ferns have over 600 chromosomes, compared to our measly 46. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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chaloobi
SFN Regular
1620 Posts |
Posted - 03/20/2008 : 19:48:08 [Permalink]
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I don't know. Hasn't Filthy answered that yet?
Filthy: What is complex? |
-Chaloobi
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 03/20/2008 : 19:53:23 [Permalink]
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In this instance you have to use the author's supplied definition of "complex".
They are going with: (well, you can get the gist of it anyway)
"But instead they found organisms that developed increasingly complicated structures and characteristics."
So obviously they are not basing their "complexity" on total number of base pairs.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 03/21/2008 : 02:45:39 [Permalink]
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Originally posted by chaloobi
I don't know. Hasn't Filthy answered that yet?
Filthy: What is complex?
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Hell, I don't know, either -- as relating to what?
Back in the day, some 350 to 500 mya, this animal was about as complex as it got, and remains comparable in complexity to crabs today, albeit 'primitive' and quite different. But is it more or less 'complex' than a tiny Barnacle adhered to it's carapace?
What is 'Complex?' Thinking in mechanical terms, it might mean more moving parts to accomplish a certain task more efficiently -- a side-valve engine as opposed to one of equal displacement that uses an overhead camshaft; a sledge-hammer as opposed to a trip-hammer.
Does that hold true in biology? Well, yes & no. I would submit that Cetaceans are a lot more 'complex' than their terrestrial ancestors but yet, have fewer 'moving parts.'
I think that biological 'complexity' should refer to the survival & reproductive processes -- mechanical & chemical -- of species within their Orders, all outside factors a given. But don't ask me how to evaluate it.
I think I'm getting a migrain..... Why are you doing this to me?
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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chaloobi
SFN Regular
1620 Posts |
Posted - 03/21/2008 : 05:47:01 [Permalink]
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Originally posted by filthy
I think I'm getting a migrain..... Why are you doing this to me?
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It's Dave's fault. |
-Chaloobi
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Ricky
SFN Die Hard
USA
4907 Posts |
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 03/21/2008 : 12:02:52 [Permalink]
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Originally posted by Dude
In this instance you have to use the author's supplied definition of "complex".
They are going with: (well, you can get the gist of it anyway)
"But instead they found organisms that developed increasingly complicated structures and characteristics." |
Which is totally unhelpful of the Yahoo story since they don't publish the researchers' "complicated" metric. "Complicated" isn't exactly a strictly quantified biological term.| So obviously they are not basing their "complexity" on total number of base pairs. |
No, I just threw that out there as an indication of how complex the idea of complexity is.Originally posted by Ricky
In any case, I like the general idea of it... |
I do, too. Write it up and carry out some measurements. You've got four days (can't let it interfere with your chat hosting duties). By the way: enzymes are proteins. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Evolution Favors Complexity Over Time?
