Evolution in action: new plant species

Evolution is not "progression towards increasing complexity." It's "progression towards better fitting with the environment." Therefore, it doesn't matter whether organisms are losing or gaining traits; what matters is whether those traits help the organism survive in its environment.

As far as examples of organisms losing traits (because they did not confer an evolutionary advantage), there are species of fish with no eyes (whose ancestors had eyes), and I believe that some species of insect "lost" its wings for a period of time because its environment did not favor them. But these are all examples of evolution, just as examples of gaining traits are.
 
rwald said:
Evolution is not "progression towards increasing complexity."
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I realize that does not -- necessarily -- support environmental selection.

Yet, that seems to be the way things went, and continue to go. Do we know if loss of eyesight was not overcompensated for by increased complexness: aural, tactile, and/or brain development?
 
rwald said:
Evolution is not "progression towards increasing complexity." It's "progression towards better fitting with the environment." Therefore, it doesn't matter whether organisms are losing or gaining traits; what matters is whether those traits help the organism survive in its environment.

As far as examples of organisms losing traits (because they did not confer an evolutionary advantage), there are species of fish with no eyes (whose ancestors had eyes), and I believe that some species of insect "lost" its wings for a period of time because its environment did not favor them. But these are all examples of evolution, just as examples of gaining traits are.
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There are species who have lost their tales. Now I have nothing to wag when I'm feeling friendly.
 
hammegk said:
...do current results in genetics have examples of species "de-evolving", that is losing overall complexness?
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In the context of what I think you mean, cetaceans (whales, dolphins, and porpoises) may be a good example. Moving back to the water certainly killed any chance of them discovering fire, or learning how to juggle.
 
I'm not sure I'm getting that the term "de-evolution" can be meaningful at all.

The morphological raw materials evolution has to work with at any point are always limited to those which were already present. In evolving to suit new conditions, any modification which served the new need better would look like "de-evolution" with regard to the old need.

Even what looked like backing straight down a developmental path would have to confer some advantage, be it greater fecundity or whatever; and again the new purpose would be served, and again the old purpose would suffer.

(I hate having to use the word "purpose" in this context, but I have to formulate my thoughts using the language resources available).
 
De-evolution is a handy concept for sci-fi plots, and produced a great name for a band. The term has no more value for this discussion than teleportation.
 
Oso said:
In the context of what I think you mean, cetaceans (whales, dolphins, and porpoises) may be a good example. Moving back to the water certainly killed any chance of them discovering fire, or learning how to juggle.
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Well, I didn't discover fire & can't juggle either. ;)

However, I suggest cetaceans traded legs & land for a less crowded niche that by all appearances has resulted in intelligence that may even rival homo saps. I'd call that increased complexity.

Dear fishbob


The band I believe is Devo (Devolution), not to be confused with the concept -- which I contend is never demonstrated -- of evolution resulting in "less complex" species-kinds-critters ( i.e.De-evolution).

I'm not sure why this is not suitable for "Evolution in action".

Dymanic said:
In evolving to suit new conditions, any modification which served the new need better would look like "de-evolution" with regard to the old need.

Even what looked like backing straight down a developmental path would have to confer some advantage, be it greater fecundity or whatever; and again the new purpose would be served, and again the old purpose would suffer.
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The key is overall loss of complexity.

(I hate having to use the word "purpose" in this context, but I have to formulate my thoughts using the language resources available).
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Yeah, I understand. "Purpose" is something an idealist can consider as probable -- answering "why" -- rather than a dirty word for materialist/atheist evolutionists.
 
I'll say it again: there is no reason for evolution to move towards increased complexity. It moves towards fitting with the environment. If the environment doesn't demand a very complex form, than the organism won't evolve into a more complex form. If an organism is already relatively complex (because it became so in a different environment), it could easily lose overall complexity. Yes, some new traits would evolve to deal with the new environment, but it is possible that more traits would be lost than gained. There's nothing stopping evolution from losing traits; evolution, being non-teleological, doesn't care about "complexity."

And are you trying to suggest that dolphins are more intelligent because they don't have legs? If you wanted to argue that they're more intelligent because their environment happened to be more suitable for intelligence, that's at least a reasonable claim, but saying that "since they lost complexity in their legs, they had to gain it in their intelligence" makes no sense whatsoever.
 
the concept -- which I contend is never demonstrated -- of evolution resulting in "less complex" species-kinds-critters ( i.e.De-evolution).
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I just realized what's so ironic about this quote. Hammegk is arguing that de-evolution doesn't exist. So are we!
 
rwald said:
There's nothing stopping evolution from losing traits; evolution, being non-teleological, doesn't care about "complexity."
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Hammegk is arguing that de-evolution doesn't exist. So are we!
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Er, ok. As I originally asked, can we cite a few (or even one) good example where complexity is lost?

And are you trying to suggest that dolphins are more intelligent because they don't have legs?
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No, I didn't suggest that. I pointed out that the cetacean example appears to result in "higher complexity-intelligence in particular" not lesser complexity.

And it is a point materialist/atheist evolutionists might consider.

"Why would mutation & natural selection (probably) always select for increasingly complex lifeforms"?
 
We've already cited humans losing tails, fish losing eyes, insects losing wings, and aquatic mammals losing legs. What else do you want?

And don't say "oh, but they always gain more complexity than they lose." Can you show that flippers are "more complex" than legs? When aquatic mammals lost their legs, did the complexity they gained outweight the complexity they lost? And if so, than what about the first land animals, which must have lost their flippers (or fins) for legs. In evolution, just as with entropy, you've got to use the word "complex" very carefully.
 
Genes that encode a product that is no longer required for the survival of a bacterial species are deleted from the genome over time. The duplication of other genes or generation of new genes/products by mutation, etc, is not required to 'balance' this loss. So-called useless genes are lost because the effort involved in making unnecessary proteins is a disadvantage. This isn't 'de-evolution' - it's evolution that may result in a less complex genome (ie: fewer genes).
 
Because it takes time to develop fancy equipment and time to learn how to use it, animals whose competitive edge is reliant on special eyes, wings, legs, etc., incur a cost in embryo development (and sometimes an investment in parental care) that limits the number of successful progeny they can produce. This strategy may pay off, however, if those progeny outperform others in competition for scarce resources. Should conditions change, and resources become plentiful, streamlining the design so as to enable production of greater numbers of offspring -- even less fancy offspring -- might give better numbers, and the population could move back toward the 'simpler' form. However, it is of course very unlikely that any such streamlining would constitute an exact reversal of the design path that produced the (now) over-equipped form.

Very often in any design process, simplifying a design increases efficiency, and has to be considered an improvement, rather than the degradation that a term like 'de-evolution' would seem to imply. But an increase in efficiency does not necessarily equal an increase in 'complexity' (assuming that we all understand what that means, whether we can define it or not).

If the advantage gained was fecundity, it's hard to regard that as an increase in complexity of the design specs for the organism; it's just about cranking out more babies -- really seems more like an emergent property of the organism in interaction with its environment.
 
We've long wondered about loss of eyes in cave-dwelling critters....Recent (2002) studies cited in Science 298(5595):953-955 found that one set of genes affects jaws and teeth--and--eye development. The expression of big jaws, more teeth is favored in subterranean environments, whereas expression of sight but small jaws fewer teeth is favored at the surface. So a lot of variation arises from the ways genes are regulated during development.
 
If forced to pronounce one organism more complex than another, it would be hard to decide whether to look at the level of the genotype or the phenotype. It's not hard to imagine one organism having more genes than another, yet having fewer expressed, resulting in simpler morphological structure.
 
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