[InfiniteNow]

Originally Posted by C1ay

Actually some of us, at least one anyhow, have watched it. I particularly liked Richard's "Stork Theory of Reproduction" vs the "Sex Theory" and kind of wondered if someone might want to debate that in another thread...

Indeed.

And that, class, is today's lesson in chemistry. Let us all take our lunch break and return for today's alchemy lesson. Also, it appears tomorrow's astronomy professor has taken ill, so we will be sending the astrology substitute to fill his place.

[HydrogenBond]

Evolution creates the impression of a continuous flow of progress based on adaptability and selective advantage, with genes progressing. One of the problems with this are changes in the environment, can also result in genetics going backwards using selective advantage.

For example, let us start with an open forest with the deer competing for mating. The big 12-point buck is the dominant one and wins all the time. According to the evolutionary theory he has the advanced genetics. Next, we have a fire due to lightning, and the herd is driven into the thicket. Our Darwinian top dog finds it hard to move around because his 12 point rack keeps getting stuck in the thicket. He become food for wolves. Selective advantage now goes to the males that weren't good specimens in the forest because their antlers never grew to the same stature.

Here is the question. Does the fact that the #5 genetics, which are now better suited to the thicket, i.e., selective advantage, automatically imply his genes are now more evolved? In other words, by merely changing the environment can selective advantage allow #5 genes to evolve to #1 genes, overnight, by default. Or do we use the old scale and say it retains it original genetic placement based on the older environment. Or does evolution always have to go forward, so we automatically bump #5 to #1 to make it consistent with theory, so it always appears right?

This is one my problems. There is no objective way to determine whether a change in the environment that promotes new selective advantage implies overall genetic advancement. It could be based on one fluke. The theory works better when the environment stays the same or barely changes, but drastic change are common.

For example, we have a flood and all the male deer are caught in the flood, because they are fighting to decide the new #1 in the thicket and are not paying attention. One sickly male deer sitting on the sidelines, gets swept by a tree flowing in the flood and is the only male survivor. The twist of fate gave him selective advantage. Does he now have #1 genes, by default, so evolution is always right? Or do we say the herd has just de-evolved due to selective advantage?

Selective advantage is a relative concept that can do either way in terms of the sum total of the genes. One good gene may offer selective advantage but that could be the only good gene that critter has. For example, a bunch of men start a club. The head of the club is the biggest guy. He is the current leader out of intimidation. A new person trying to join the club and become the leader is just out of graduate school and is an expert. The big guy is well connected due to intimidation and gets everyone to vote for him out of fear. That ability to intimidate gives him selective advantage since now he is able to call the agenda of the club and slant it to just what it knows. Does this mean he has the most evolutionary genetics to be consistent with theory? Or does it mean a couple of genes is all that was needed to gain selective advantage. The smart guy who has more evolved total genes, but because it lacks a couple of key big-mean genes, is he less evolved since what he has, did not create selective advantage?

[C1ay]

Originally Posted by HydrogenBond

Evolution creates the impression of a continuous flow of progress based on adaptability and selective advantage, with genes progressing. One of the problems with this are changes in the environment, can also result in genetics going backwards using selective advantage.

Funny you should bring that up since the news story I posted this morning is about the despeciation of two species due to recent ecological changes...

[Ahmabeliever]

I watched the whole thing I always watch before I type. The speakers were excellent and the format of two worked very well.

On the storks - What, all those birds didn't have to die to prevent babies???? Damn, spent all my money on ammo too.

[Biochemist]

Originally Posted by InfiniteNow

So, yeah. Evolution is fact.

Well, given that

1) the definition and usage of "evolution" itself changes over time,
2) The definition changes to comply with the most recent dogma

then asserting that "evolution is a fact" is essentially a syllogism

Originally Posted by IN

Has anyone posting here actually watched the entire dialog I posted?

I did. I thought it was demeaning that two objectively smart men make fun of others. I don't really know why two academics engage in the public debate at this level. Their critique in this video is certainly not "science". "Screed" would be closer.

[Biochemist]

Originally Posted by ughaibu

I dont see any reason to assume there was an original common ancestor, is there any reason that various forms of proto-life leading to distinct ancestral lines should be ruled out?

This is an interesting question. I don't think that anyone has ruled out the notion that multiple ancestors are possible. But that would imply that the common architecture of life (exactly 4 DNA bases, exactly 20 amino acids, uniform tools for energy management, etc) appeared de novo in parallel identically. Given that it is problematic to demonstrate how it happened at all in a mere 500 million years, it is even more so to suggest it happened more than once, and happened identically.

Make sense?

[InfiniteNow]

Originally Posted by Biochemist

I don't think that anyone has ruled out the notion that multiple ancestors are possible. But that would imply that the common architecture of life (exactly 4 DNA bases, exactly 20 amino acids, uniform tools for energy management, etc) appeared de novo in parallel identically.

No, it wouldn't. It simply implies that IF there are multiple ancestors then, at some point, they merged.

Originally Posted by Biochemist

Given that it is problematic to demonstrate how it happened at all in a mere 500 million years, it is even more so to suggest it happened more than once, and happened identically.

Make sense?

No. You assume it has to be identical, and then go on to argue against the likelihood of that assumption (or, you will soon enough if you claim not to above). I challenge your premise... erm... assumption as completely baseless and not rooted in reality.

[Biochemist]

Originally Posted by InfiniteNow

No, it wouldn't. It simply implies that IF there are multiple ancestors then, at some point, they merged.

Huh? Tell me how ancestors (of different genetic character) "merge"?

Originally Posted by IN

No. You assume it has to be identical, and then go on to argue against the likelihood of that assumption (or, you will soon enough if you claim not to above). I challenge your premise... erm... assumption as completely baseless and not rooted in reality.

The caustic tone in not appreciated. I assume that any alternative biogenetic events were either identical, or they died out (because we have not found any). How is that "baseless"? Or were you going to argue the statistical point that the probability of an event happening twice is lower than the event happening once?

[C1ay]

Originally Posted by Biochemist

Huh? Tell me how ancestors (of different genetic character) "merge"?

Oddly enough the story I posted a few days ago was about two species of bacteria found to be merging. I realize this is not as genetically diverse as what you are discussing but it does show that despeciation can and does occur. Who knows what the limits are.

[maikeru]

Originally Posted by kcl0341

Further evidents to prove the Theory : Evolution occurs whenever a new species of bacterium evolves a resistance to an antibiotic which previously was lethal to that bacterium. Evolution is the observation that biological organisms evolve. In other words, descendants are seen to have gone through a type of genetic modification process when compared to their ancestors. The modification is most often the result of natural genetic synthesis, and the differential traits manifested may be translated into changes in the genetic composition of the population. As the populations of organisms change over time, the organisms are often observed to be well suited to their environments, and many different species of organisms resembling each other closely, are indicative of evolution

Sketchy microbiology. Evolution in action, yes, but the rest of your details and argument are a little murky. Resistance to an antibiotic does not a new bacterial species make. A bacterium can pick up resistance to an antibiotic if it picks up a gene that grants resistance, say, on a plasmid or through genetic material transfer (such as transformation, IIRC) and incorporation into its own genetic material. Let's say that one individual of a bacterium of one species such as E. coli picks up a resistance plasmid and another one doesn't. The gain of a plasmid in one and the lack in the other doesn't automatically separate them into different species. It probably doesn't separate them into different strains, either. Plasmids are touchy things. If so, you might as well consider every individual bacterium that has a mutation or two different than its neighbor to be a different "species." Actually, classification of bacteria is a little hard...

I'd put evolution a little more simply and directly like this: Evolution is the change in inherited traits in a population from generation to generation. Key components of evolution are natural selection and genetic drift. Reproduction and survival, key to passing on and maximizing genes/alleles and their frequencies, are the "end goals" because what does not reproduce will ultimately not survive. (From what I know, evolution has no purpose or end goals. It is "blind" to purpose.) This is where adapation comes into play, because natural selection provides for traits that benefit reproductivity and survival. It's not about progress--it's about survival. (Don't take this as the final word on evolution, but considering the time of night, it's the best I can summarize my view and thoughts on evolution at the moment.)