Evolution. The part I hadn’t considered.
Posted: 18 December 2011 10:53 PM   [ Ignore ]
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I’m sorry in advanced because I’m going to do two things here. I’m going to confuse the hell out of you, and/or I’m going to show you just how ignorant I am about the full spectrum of how evolution works. I was under the impression that evolution involved single changes within a single species, but in fact, I’m coming around to believe that a single species could have multiple evolutionary changes within it within the same time period. Then all those evolutionary changes come together creating a stronger third species. Maybe I should read up on it more instead of expecting people to answer this for me on a forum, but I thought it would be interesting to get others input on this.

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Posted: 19 December 2011 05:05 AM   [ Ignore ]   [ # 1 ]
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ExMachina - 18 December 2011 10:53 PM

I’m sorry in advanced because I’m going to do two things here. I’m going to confuse the hell out of you, and/or I’m going to show you just how ignorant I am about the full spectrum of how evolution works. I was under the impression that evolution involved single changes within a single species, but in fact, I’m coming around to believe that a single species could have multiple evolutionary changes within it within the same time period. Then all those evolutionary changes come together creating a stronger third species. Maybe I should read up on it more instead of expecting people to answer this for me on a forum, but I thought it would be interesting to get others input on this.

Sure, it can, it all depends on the mutations and selection pressures. But I’d urge you not to think that evolution necessarily produces “stronger” species. What it tends to produce is better adapted species, i.e., species better adapted to their local niches. It does this by tending to weed out the members’ genetic inheritance that is less well adapted.

Strength has its own downside in high metabolism. If the strength is worth the metabolism it can be selected for. But if not, not.

In general, apart from the line about adaptation, evolution is undirected. It doesn’t tend to push in any particular direction. Some might say that it tends to produce in the direction of ‘complexity’, but this is only a byproduct of beginning with the least complex. There’s only one direction to go, which is up. (I think Dawkins has a good description of this somewhere in Selfish Gene).

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Posted: 19 December 2011 05:27 AM   [ Ignore ]   [ # 2 ]
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In general, apart from the line about adaptation, evolution is undirected. It doesn’t tend to push in any particular direction. Some might say that it tends to produce in the direction of ‘complexity’, but this is only a byproduct of beginning with the least complex. There’s only one direction to go, which is up. (I think Dawkins has a good description of this somewhere in Selfish Gene).

If you want a real hoot go backwards in the evolutionary system. Read Dawkins “The Ancestor’s Tale”. He begins in the present and works backwards to the original concestor. It’s a great way to learn about how the process worked and our place within it.


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Posted: 19 December 2011 06:36 AM   [ Ignore ]   [ # 3 ]
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ExMachina - 18 December 2011 10:53 PM

I’m sorry in advanced because I’m going to do two things here. I’m going to confuse the hell out of you, and/or I’m going to show you just how ignorant I am about the full spectrum of how evolution works. I was under the impression that evolution involved single changes within a single species, but in fact, I’m coming around to believe that a single species could have multiple evolutionary changes within it within the same time period. Then all those evolutionary changes come together creating a stronger third species. Maybe I should read up on it more instead of expecting people to answer this for me on a forum, but I thought it would be interesting to get others input on this.

I doubt it normally happens within the same period of time. Species evolve according to environmental changes and these will affect the whole population and steer it in one direction. I imagine it can happen, but the two new-to-be species would have to be separated by enough of geographical differences from each other (and from the original group) to make this possible. Maybe some major catastrophes can have this effect. There is also the generic drift which can complicate things, but we can leave that aside for now.

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Posted: 19 December 2011 07:11 AM   [ Ignore ]   [ # 4 ]
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ExMachina - 18 December 2011 10:53 PM

I’m sorry in advanced because I’m going to do two things here. I’m going to confuse the hell out of you, and/or I’m going to show you just how ignorant I am about the full spectrum of how evolution works. I was under the impression that evolution involved single changes within a single species, but in fact, I’m coming around to believe that a single species could have multiple evolutionary changes within it within the same time period. Then all those evolutionary changes come together creating a stronger third species. Maybe I should read up on it more instead of expecting people to answer this for me on a forum, but I thought it would be interesting to get others input on this.

Do you have an example. I’m not sure what you mean about a ‘third’ species

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Posted: 19 December 2011 02:31 PM   [ Ignore ]   [ # 5 ]
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Usually one or two positive mutations don’t really make a new species.  Just as different humans have different skin pigmentation, different eye colors, different blood types, etc., but are all one species, the same goes for others.  As I recall from a 1949 Zoology there’s a thing called (approx.) a rosencreist. There will be one species of bird with a few local variations in one larger area.  Next to it will be another area where the same species has the variations of that one local area plus another variation.  This will continue, area to area.  I Believe it was seen in the forest surrounding a mountain range.  The birds in any two adjacent species can mate (i.e., same species) but when one puts birds from the first location with birds from around the mountain, they can no longer mate, that is, they’ve become different species through the gradual addition of minor mutations. 

Similarly, Neanderthals and Cromagnons seem very different, but there’s evidence that they were able to mate and produce fertile offspring. 

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Posted: 27 December 2011 07:26 PM   [ Ignore ]   [ # 6 ]
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It seems evolutionary changes start small, and spread over a geometrically huge number of generations, yield new species.  Hawaiian rainforest birds are diverse, not able to interbreed, and allegedly started with a handful of the same birds blown to the islands by a storm. They adapted to utilize the unique Hawaiian flora. Although they evolved to fit the environment, most were unable to evolve rapidly enough to meet industrial revolution’s rigorous demands; that is, to compete with foreign species (avian, mammalian, biologic, and parasitic) which were introduced by other foreign species.

Additionally, you’re right, in that evolutionary changes are often multitudinal. As with Neanderthals mating with their close relatives, the Denisovans, our ancestral lineage helped Cro Magnons succeed - but other genes accompanied the enabling ones. These background genes may be foundational for susceptibility to some autoimmune diseases today. See, http://www.guardian.co.uk/science/blog/2011/aug/25/neanderthal-denisovan-genes-human-immunity.

Evolution can be progressive, in that “weaker” variants are eliminated, however there may be a price; post-industrial pressures/ factors need to be considered in the whole as well.

Yes, it’s multi-dimensionally complex.

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Posted: 28 December 2011 03:48 PM   [ Ignore ]   [ # 7 ]
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macgyver - 19 December 2011 07:11 AM
ExMachina - 18 December 2011 10:53 PM

I’m sorry in advanced because I’m going to do two things here. I’m going to confuse the hell out of you, and/or I’m going to show you just how ignorant I am about the full spectrum of how evolution works. I was under the impression that evolution involved single changes within a single species, but in fact, I’m coming around to believe that a single species could have multiple evolutionary changes within it within the same time period. Then all those evolutionary changes come together creating a stronger third species. Maybe I should read up on it more instead of expecting people to answer this for me on a forum, but I thought it would be interesting to get others input on this.

Do you have an example. I’m not sure what you mean about a ‘third’ species

Seconded.

Re Occam: here’s a link for what you’re describing: http://en.wikipedia.org/wiki/Ring_species

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Posted: 28 December 2011 04:59 PM   [ Ignore ]   [ # 8 ]
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What I find most interesting is that all species share identical genetic similarities. It seems that successful basic genetic codes are retained from the earliest organisms to the most evolved species. The differences mainly sprang from accidental mutations and modifications in the start/stop growth triggers.

About 60 percent of chicken genes correspond to a similar human gene. However, researchers uncovered more small sequence differences between corresponding pairs of chicken and human genes, which are 75 percent identical on average, than between rodent and human gene pairs, which are 88 percent identical on average.

The analysis also showed that genes conserved between human and chicken often are also conserved in fish. For example, 72 percent of the corresponding pairs of chicken and human genes also possess a counterpart in the genome of the puffer fish (Takifugu rubripes). According to the researchers, these genes are likely to be present in most vertebrates

http://health.dailynewscentral.com/content/view/197/62

[ Edited: 28 December 2011 05:08 PM by Write4U ]
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Posted: 28 December 2011 05:33 PM   [ Ignore ]   [ # 9 ]
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I believe we even share some genes with redwood trees and crab grass.

Occam

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Posted: 29 December 2011 02:16 AM   [ Ignore ]   [ # 10 ]
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Occam. - 28 December 2011 05:33 PM

I believe we even share some genes with redwood trees and crab grass.

Occam

Quite a few genes with them. They are are our brethren!!

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Posted: 29 December 2011 11:15 AM   [ Ignore ]   [ # 11 ]
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And I think some of my Libertarian friends have an excess of crab grass genes.  :lol:

Occam

(Afterthought.  Interesting that I can put up with Libertarians but refuse to associate with any evangelical Christians. :)  )

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Posted: 29 December 2011 05:14 PM   [ Ignore ]   [ # 12 ]
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Unlike the Christians, the Libertarians usually get their facts right, Occam. It’s the conclusions they derive from the facts that can be worrisome.

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Posted: 30 December 2011 01:13 PM   [ Ignore ]   [ # 13 ]
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You’re right, George.  They usually have accurate facts and decent logic.  The problem seems to be that they have a few basic premises they don’t even bother mentioning that are incorrect and which cause them to arrive at weird conclusions.

Occam

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