Evolution of complex organs

[Gnosital]

baznap wrote

i was wondering, say in a few thousand years when we are alot more advanced, do you think it will be possible for humans to genetically take other creatures best abilities and make one super being, for example, take the sense of smell from a dog, the speed of a cheetah, the radar of a bat, the color changes of a camelion, the brain of a human, the armour of a beetle, the jump of a grass hopper!!??
is evolution already taking us down this path?

Sadly, whatever survives in a few thousand years from now may not be creatures that have been selected for their technological advancements.

And remember, evolution has no goal. I pissed off a bunch of catholic students with dirty foreheads today in my physio class when I said that.


(heehee, besides, who would want to sleep with something that smelled like a dog, sqeaked a lot, had skin like a technicolor dung beetle and big green ugly legs. It would die out due to radical sexual NOT-selection!)

brad89 wrote

Oh I see now. I always DID view evolution through the individual, not the population, that is probably why it looked like it always got better through intelligence, not being random. But that definitely clears some things up.

Actually, the conventional view is that evolution acts on the genetic level, not the individual. Genes compete in a pool and are split up among individuals by crossing over in sexual reproduction.

As far as evolving complex organs, it is only necessary that every increased step gives the "owner" a greater survivability. The eye, for instance, developed because light-sensitive spots which can focus light better, and resolve light and color better, in general, are more adaptive. The same applies to brains. An organism which can better sense, anticipate, and respond to its environment has a significant advantage, especially when that organism depends heavily on such skills for its survival, such as in social predators like humans.

brad89 wrote

However, I still hold more faith that Jebus has a plan for our spirits when we die and that the holy spirit will design animals, yet pick favorites such as humans, to go to heaven and that Jebus has died for my sins and that I can repent with wavelengths that defy the laws of physics. I hope that someday, you too will see this for yourself.

:lol:

[Eva]

yes, scat.......today was ash wednesday.....remember when i used to get that crap....

we would check who had the biggest blotch on the forehead...some kind of weird catholic school status simbol, i guess....

i saw some people with the dirty foreheads today at costco....should have taken that as a sign to buy that new tv....the one we have is kicking the bucket....

[Gnosital]

Eva wrote

yes, scat.......today was ash wednesday.....remember when i used to get that crap....

we would check who had the biggest blotch on the forehead...some kind of weird catholic school status simbol, i guess....

i saw some people with the dirty foreheads today at costco....should have taken that as a sign to buy that new tv....the one we have is kicking the bucket....

AHH! I see, a status symbol... The one with the biggest blotch on his forehead was the one who asked me the question, "So what's the point of having the visual pathways crossed?" which led to my telling them that there is no goal to evolution. That seemed to be an entirely unsatisfying answer for them, I suppose it has something to do with their belief in an imaginary friend who's supposed to be in charge of directing evolution.

I also told them that if there were any IDers in the crowd, that the eye was not a very good example to use for that, since it is ass-backward and by any logic it isn't a very smart design at all. My 6 year old could figure out a better way to organize an eyeball.

I love saying that stuff in front of big classrooms full of people. Especially when they can't say anything because they're all graduating senoirs in that class and they need to pass.

You should have bought that TV, Eva! You really shouldn't ignore those signs from jeebus, you know. Then again, I'm sure you could find another sign tomorrow if you want to...

[Eva]

indeedy!
jeebus talks to me everyday. i see his glory and majesty all around me. don't you all? it is sooo obvious.

yeah, i'll see a sign tomorrow.

one ofthis days, when you are in a particularly nasty mood, tell them that for all practical matters, you are their God. and you can send them to hell.

hehehehe.

[calpurnpiso]

Eva wrote

yes, scat.......today was ash wednesday.....remember when i used to get that crap....

we would check who had the biggest blotch on the forehead...some kind of weird catholic school status simbol, i guess....

i saw some people with the dirty foreheads today at costco....should have taken that as a sign to buy that new tv....the one we have is kicking the bucket....

Now I know where the ash ceremony came from and why it was adopted, like many many pagan ceremonies, by the creators of Christianity.
The Lord and Savior, Redeemer, God, Head Priest (Archieros Megistos=Iessous Christos for short) Iulius Caesar was cremated ( later mistranslated to impale aka crucify), since he was view as a GOD, the faithful took as sacred relics the cinders and ashes from the funeral pyre, they also went to his official residence ( the palace of the Archieros Megistos) and stole furniture and objects as divine relics.

Ashes were extremely important specially originating from the cremation of a god. The spirit of this Iessous Christos was seen in the sky as the comet of 44 bce. When the temple of Divus Iulius was built in the forum and other temples to this new god, other temples were also built....in Athens, Alia Capitolina ( Jerusalem) and many other cities through out the Empire. In those temples the image of the god was displayed in a tropaeum ( a cross shape structure symbolic of victory) as it had been during his funeral. This cult of Caesar ( divus Iulius=divine Julius), was not given to him, but to his SPIRIT and the TITLE of Archieros megistos he had held. He truly became a god and his true mortal name of Gaius Iulius Caesar cremated with him! But his cult was NOT the ONLY one in Rome. The cults of the other gods REMAINED, till Constantinus I, begun to pave the way to make ALL of them ILLEGAL starting in 313 ce. He planted the seed but it was the Christ-psychotic Theodosius I, ( 5th Century) who truly stablish this vile intolerant, immoral and perverted psychosis. All of them when to the temple, now called church and sprinkled ashes on their head to commemorate the cremation of Iessous Christos......with time, cremation became crucifixion and the ashes are neatly placed on the forehead of the Christ-psychotic retards that are fond of ignorance and misinformation.

From: http://www.sfgate.com/cgi-bin/articl...VGU65ISIN1.DTL

"Theodosius I, the first Roman Emperor to really embrace Christianity with a vengeance, paved the way for Cyril's persecution of pagan intellectuals. "

Amazing, crazy Christians are not hit over their heads with a mini cross during "Cross hitting Wednesday" sporting a bump in their foreheads, as it ought to be if Christ had bee truly "crucified"...but nooo...they have to use ashes on the foreheads shaped as a cross and call it "Ash Wednesday'!!..Idiots!........:lol:

[a different tim]

whoneedscience wrote

Actually, the conventional view is that evolution acts on the genetic level, not the individual. Genes compete in a pool and are split up among individuals by crossing over in sexual reproduction.

You have to be a little careful....evolution has two components - generation of variety and selection. Generation of variety can happen at the genetic level via mutation or at the individual level through sexual reproduction, although really the latter only generates variety within a preexisting gene pool. Selection has been argued over - Dawkins argues that it takes place at the genetic level, as above, but Gould and others have argued that it takes place at individual, deme and even species level (for what it's worth, I think Gould is wrong, but the argument is still current). The effects of evolution are seen at population level: as a species is pushed by selection towards a new form, for example, animals at on end of the spectrum will be selected out, and the occasional favourable mutation will be selected in, so the balance of the population will shift. A lot of selection takes place through differential breeding success - variant A has a few more offspring on average than variant B, so over time variant A will come to dominate the population.

Mayr and Dawkins are very good and readable on basic principles of evolution, although Dawkins obviously goes for the gene selection position, and makes baby Jeebus cry.

[Sternwallow]

scathach wrote

I am afraid I am not well versed in dinosaur neuroanatomy, but it seems very likely to me that there might have been large caudal ganglia in a really big dinosaur. Are you saying that dinosaur tails had a mind of their own...?

There was a discussion of dinosaur brains in one of my old old old biology books that said roughly that the delay in nerve impulses to get from the tail to the head was relieved by having much of the specific muscle control and coordination near the tail and directed by rather higher-level impulses from the brain. Rather than twitch each muscle 50 feet away, the brain could just say "wag right" and the command would be outsourced to the neural lump in his butt.

[calpurnpiso]

Sternwallow wrote

There was a discussion of dinosaur brains in one of my old old old biology books that said roughly that the delay in nerve impulses to get from the tail to the head was relieved by having much of the specific muscle control and coordination near the tail and directed by rather higher-level impulses from the brain. Rather than twitch each muscle 50 feet away, the brain could just say "wag right" and the command would be outsourced to the neural lump in his butt.

Hmm..can you imagine if one had a mini brain in our butts?.....chobus would be out of business, since the butt could warn the body:..."penis-christ approaching, a creator rod is approaching....help, close the gate tighten the belt, stick to your pants, help a foreign joy stick is tearing pants......:lol:

[Choobus]

calpurnpiso wrote

Hmm..can you imagine if one had a mini brain in our butts?.....chobus would be out of business, since the butt could warn the body:..."penis-christ approaching, a creator rod is approaching....help, close the gate tighten the belt, stick to your pants, help a foreign joy stick is tearing pants......:lol:

I would just stick to going to Christian assholes. If you tel lthem it's for jesus they will let you do anything...

a different tim wrote

You have to be a little careful....evolution has two components - generation of variety and selection. Generation of variety can happen at the genetic level via mutation or at the individual level through sexual reproduction, although really the latter only generates variety within a preexisting gene pool. Selection has been argued over - Dawkins argues that it takes place at the genetic level, as above, but Gould and others have argued that it takes place at individual, deme and even species level (for what it's worth, I think Gould is wrong, but the argument is still current). The effects of evolution are seen at population level: as a species is pushed by selection towards a new form, for example, animals at on end of the spectrum will be selected out, and the occasional favourable mutation will be selected in, so the balance of the population will shift. A lot of selection takes place through differential breeding success - variant A has a few more offspring on average than variant B, so over time variant A will come to dominate the population.

Mayr and Dawkins are very good and readable on basic principles of evolution, although Dawkins obviously goes for the gene selection position, and makes baby Jeebus cry.

Yes, I've read much of Dawkins's work. I was trying to simplify a bit, but seeing as I was jumping in to be anal-retentive, I suppose it is fair that you did the same to me. My understanding, however, is that theories of group selection, and even individual selection to an extent, are unorthodox, apart from being extremely weak next to genetic-based arguments like those of Dawkins. It is the process of crossing over that separates the gene from the individual. In species that undergo direct cloning, natural selection has little to work with, as beneficial mutations depend entirely on the success of the line of individual descendents. In sexual species, however, new mutation has only to survive a few generations of being dependent on its "survival machine" before it is established, unless there are significant selection pressures against it, in the gene pool, among individuals of many diverse lines. I don't quite see how it makes sense to say that selection occurs at the individual level through sexual repreduction, then.

Oh, and may I add that anything that makes baby Jeebus cry is more than worthwhile to read.

[calpurnpiso]

Choobus wrote

I would just stick to going to Christian assholes. If you tel lthem it's for jesus they will let you do anything...

Yup..they'll open the gates of heavenly pleasures and receive penis-christ with gusto...:lol:

[a different tim]

whoneedsscience wrote

Yes, I've read much of Dawkins's work. I was trying to simplify a bit, but seeing as I was jumping in to be anal-retentive, I suppose it is fair that you did the same to me. My understanding, however, is that theories of group selection, and even individual selection to an extent, are unorthodox, apart from being extremely weak next to genetic-based arguments like those of Dawkins. It is the process of crossing over that separates the gene from the individual. In species that undergo direct cloning, natural selection has little to work with, as beneficial mutations depend entirely on the success of the line of individual descendents. In sexual species, however, new mutation has only to survive a few generations of being dependent on its "survival machine" before it is established, unless there are significant selection pressures against it, in the gene pool, among individuals of many diverse lines. I don't quite see how it makes sense to say that selection occurs at the individual level through sexual repreduction, then.

Oh, and may I add that anything that makes baby Jeebus cry is more than worthwhile to read.

I personally tend to go the Dawkins route. However selection acting on genes is a little dodgy. Genes aren't really visible to selective processes - it's individuals which get selected out or in, breed or fail to, etc.
Dawkins does quite a good metaphor in "SG" about genes being connected to phenotypes via bungee cords or similar, but the effect of genes is strongly modulated by environment, especially in the womb. I'm not sure about gene selection then, although personally I like the idea. It's interesting that Dawkins' next step is to try to blur the boundaries between phenotypes (in "extended phenotype") thus giving credence to his vision of phenotypes as the terrain on which genes compete. it's an interesting argument. Mayr comes out very strongly in favour of individuals as the prime targets of selection ("What Evolution Is", chapter six, has a strong refutation of gene selection).

Replication certainly takes place at gene level - genes are the only true replicators (even bacterial clones can be different phenotypically due to environmental factors and plasmid swapping, so I'm with you there). I don't follow your point about sexual species - selection doesn't take place with "a few generations later" in mind, although obviously the effects of selection can be concieved that way.

Species selection is something I don't go with, but I thought Brad should be aware that the theory is not quite dead - Gould makes an extensive (but flawed IMHO) case for species as Darwinian entities in "the structure of evolutionary theory". He argues that they are stable (remember Gould came up with punctuated eqilibrium), give birth to "daughter species" and that these daughter species inherit some of their traits, thus demonstrating heritability, and that species can die out due to environmental factors, thus demonstrating selection. The flaw is, I think, that the heritable characteristics and effects of selection are all on "individual level" charateristics not "species level" ones. The one example he gives of a species level characteristic is variability, which may well affect the chances of a species surviving a catastrophic event or not, but by definition is not in this case heritable as such catastrophes cause genetic bottlenecks. "Structure" is quite valuable though in that it shows that all Gould's ideas do in fact fit together and aren't the confused mish mash that Dawkins claimed they were in "Unweaving the Rainbow". Some of the ideas are pretty good, and Gould's take on history is valuable. Gould was in fact, I think, trying to create a Darwinian theory out of anti Darwinian components - catastrophism, PE instead of gradualism, contingency rather than survival of the fittest, and group selection. I suspect he did it out of pure contrariness, but since catastrophes did in fact happen, contingency seems about right, and a lot of fossil evidence supports PE, I'm kinda glad he made the effort.

PS Anal retentive? Me? Surely not.....

[Gnosital]

Eva wrote

indeedy!
jeebus talks to me everyday. i see his glory and majesty all around me. don't you all? it is sooo obvious.

yeah, i'll see a sign tomorrow.

one ofthis days, when you are in a particularly nasty mood, tell them that for all practical matters, you are their God. and you can send them to hell.

hehehehe.

Well, according to my parents, I was conceived immaculately!

[Gnosital]

Sternwallow wrote

There was a discussion of dinosaur brains in one of my old old old biology books that said roughly that the delay in nerve impulses to get from the tail to the head was relieved by having much of the specific muscle control and coordination near the tail and directed by rather higher-level impulses from the brain. Rather than twitch each muscle 50 feet away, the brain could just say "wag right" and the command would be outsourced to the neural lump in his butt.

It's a lot like cortical or reflex activation of spinal cord motor units in humans, then. I bet those dinosaurs had axons of friggin enormous diameters, otherwise they'd take forever to move.