Questions about Darwinism.

[simple]

I just read

 

http://www.catholic.net/rcc/Periodicals/Issues/Darwin.html

 

I believe in evolution... but this has some good points... it is kind of bias... but the scientific stuff it puts in there makes sense... what do you guys think.

 

The part that talks about eyes forming... how did they... why did an autotrophic organism decide to eat another... how were those channges gradual. how did they evolve to do that.

 

I do not believe in the genesis (which sounds like a fairy tale to me), but this makes me question some parts of evolution... So I wish to gather more information on this topic.

 

Any input, facts, or ideas you have would help my mind, allowing it to rest on one opinion rather than lugging between them.

[Hellbender]

The part that talks about eyes forming... how did they... why did an autotrophic organism decide to eat another... how were those channges gradual. how did they evolve to do that.

 

Eyes didn't simply pop out of nowhere, and no one proposed that they have. Eyes probably started out as simple light-sensitive clusters of cells, which would be advantageous to the organism in every stage of their development. See the eyes of a planaria. As for autotophic organisms eating one another, it wasn't a conscious effort for the organism, but likely the result of some gradual mutations, ending with the first heterotrophs. There are some carnivorous organisms today that have autotrophic ancestors, like venus fly traps, for example.

 

I do not believe in the genesis (which sounds like a fairy tale to me), but this makes me question some parts of evolution... So I wish to gather more information on this topic..

 

Why does a story in the bible make you question evolution?

 

Some critique (some, meaing "I don't have all night to correct every lie and misconception in this article")

 

"The crux of the issue is not evolution, but teleology. Either life forms came about by blind chance or they did not"

 

To my knowledge, this is no longer an issue, and hasn't been since Darwin proposed natural selection. There are some random elements to evolution, but we know that it is not totally random.

 

"With no direct empirical evidence, Darwin claimed that over long periods of time these micro-changes could result in macro-evolution, which consists of really big jumps-from amoeba to reptile to mammal, for example. This is where his theory runs into problems which are still not resolved in the minds of many scientists today."

 

This is simply a lie. Darwin may not have had empirical evidence at the time, but we now have lots of evidence for macroevolution.

See here: http://www.talkorigins.org/faqs/comdesc/section1.html#pred4

 

I'd expect an article like this to come from some fundamentalist site, not a Catholic site. As I recall, the previous pope publicly admitted the validity of evolution. Oh well....

[Hellbender]

May I add that "Darwinism" simply no longer exists. Darwinism is pretty much evolution, but with natural selection being the only known mechanism. We have since discovered more mechanisms, such as genetic drift and gene flow. "Darwinism" is now updated as "biological evolution". New discovery doesn't overturn a theory; it adds to it. It should behoove an article that critiques it so to know this.......

[swansont]

Either life forms came about by blind chance or they did not.

 

As Hellbender said, this isn't the case. It is a false dilemma, which underscores a debating tactic of someone that is either dishonest or ill-informed. The article appears to be rife with similar statements.

 

The correct information is available, so to perpetuate falsehoods, and so many of them, is either intellectually dishonest or willfully dishonest.

[simple]

if found this website... which clears it up a good amount... http://www.talkorigins.org/faqs/faq-misconceptions.html

 

and when i said "I do not believe in the genesis (which sounds like a fairy tale to me), but this makes me question some parts of evolution..." i meant those as two separate thoughts.... i should have added the genesis part at the end... i was speaking about the article... I am saying that I am questioning darwinism... not saying that i am either between darwinism or creationism... I just would like some things to be cleared up.

 

thx

[Hellbender]

...not saying that i am either between darwinism or creationism... I just would like some things to be cleared up.

 

okay, what else would like to be cleared up then?

[simple]

well... i was wondering this... most chinese people have a fold of skin above the eye... i think the term is epicantal folds or something like that... anyway, I do not see how the lack of these folds would reduce reproduction... i understand that it may be beneficial... but it does not decide life or death...

[Hellbender]

well... i was wondering this... most chinese people have a fold of skin above the eye... i think the term is epicantal folds or something like that... anyway, I do not see how the lack of these folds would reduce reproduction... i understand that it may be beneficial... but it does not decide life or death...

 

Epicathantic folds, yes. In truth, I have also wondered why Mongoloids (Asians) have this feature. You are thinking in terms of only natural/sexual selection, but it very well could have been the result of a genetic bottleneck. I will have to look more into this, though, my bioanthropology class didn't say why, and I never thought to ask.

[simple]

i guess ill ask my bio teacher about that. and sorry... what is a genetic bottleneck?

 

is that saying that there may have been a small group who had the eye fold... which i believe to be possible... but i do not understand how it became dominant, and then reproduced separately... and therefore only had the eyefold? or am I wrong about what that means.

[AzurePhoenix]

No, the eye-flap thingy diverging would be genetic drift (and maybe divergence). A bottleneck occurs when a population is reduced to a tiny number of it's original number. An example would be when cheetahs were nearly wiped out in some unknown disaster, leaving only a handful of surviving animals (some have theorized even a single female and several males), from which all modern cheetahs are descended

 

I think the eye-flap thing evolved as a sort of natural goggle against wind-blown sand. I'd say keeping your eyesight would be a major survival benefit.

[Hellbender]

I think the eye-flap thing evolved as a sort of natural goggle against wind-blown sand. I'd say keeping your eyesight would be a major survival benefit.

 

you know I never thought about that, Mongolian desert and all.

[Mokele]

Eyes didn't simply pop out of nowhere, and no one proposed that they have. Eyes probably started out as simple light-sensitive clusters of cells, which would be advantageous to the organism in every stage of their development. See the eyes of a planaria.

 

The numerous stages can actually be seen today, in polychaete worms:

 

(on a side note, I'm fairly sure I got that image from another poster on this board, but I don't recall the primary source, so anyone who knows, please PM me.)

 

if found this website... which clears it up a good amount... http://www.talkorigins.org/faqs/faq-misconceptions.html

 

Talkorigins is just plain spectacular, IMHO. Their FAQs and articles are stellar, and I've learned quite a lot from them (more than from my upper-level evolution course).

 

I think the eye-flap thing evolved as a sort of natural goggle against wind-blown sand. I'd say keeping your eyesight would be a major survival benefit.

 

It might also simply be a neutral trait (not good or bad) that drifted to fixation, or might be linked to another, different but very advantageous trait in development.

 

Mokele

[simple]

This is simply a lie. Darwin may not have had empirical evidence at the time' date=' but we now have lots of evidence for macroevolution.

See here: http://www.talkorigins.org/faqs/comdesc/section1.html#pred4

[/quote']

 

It all makes sense and should work... but what I cannot grasp are the steps... the change from the reptile to a bird... why were feathers advantageous... what is the midpoint between flying and gliding... is there anywhere that shows different possible steps... did it start with jumping high... the lighter you are the higher you jump... then possibly to gliding... then to flying? i understand this happened over thousands of generations, but it is still quite hard to completely get.

[-Demosthenes-]

There are some carnivorous organisms today that have autotrophic ancestors, like venus fly traps, for example.

Hate to nit pick, but venus fly traps get their energy from photosynthisis. All of its "food" is sugar from spliting water with evergy from the sun, they are autotrophs. The insects they "consume" are only for nitrogen, because it's not in the marsh soil that they live in.

 

But the first cells were autotrophs weren't they? So all carnivoirs would have evolved from autotrouphs!

[AzurePhoenix]

Simple;

 

Go to this thread. We talked a bit about feathers, wings, and flight.

 

http://www.scienceforums.net/forums/showthread.php?t=6434&highlight=microraptor

[Sayonara]

The key element here is that when someone starts trying to disprove "Darwinism", laugh at how quaint they are and then leave.

[Radical Edward]

The part that talks about eyes forming... how did they...

eyes formed principally from neural cells which fire when they absorb light as a byproduct of their normal function. there are actually two different sorts of these cells' date=' and our rods and cones are derived from just one sort. other organisms have derived their eyes from the other sort. The basic evolution of the pinhole-camera eye is quite simple really and starts off with a patch of these brain cells getting closer to the surface. since the organisms we are talking about at this stage are probably very basal chordates and translucent like a worm this is quite plausible. localisation of the cells under the skin would increase the efficacy of the primitive eyes. this would be attached to responsive behaviours (inevitable when neurons fire) for example moving when a shadow passes over (predator maybe) or travelling towards or away from a light source. a rim around the eye patch would create a slight amount of directionality since there would be a shadow, and an increased rim provides better shadow and so on. the rim continues to grow forming a cup and then a dome over the eye, and then blurred image formation occurs, eventually resulting in a pinhole. this can also occur in addition to variations in the refractive index of the filler material, resulting in a crude lens. not hard really.

why did an autotrophic organism decide to eat another.

they didn't decide, any more than a bacteria decides anything. those that did things that enabled their improved reproduction rate prospered at the expense of those that didn't.

.. how were those channges gradual. how did they evolve to do that.

easily answered, see above.

I do not believe in the genesis (which sounds like a fairy tale to me), but this makes me question some parts of evolution... So I wish to gather more information on this topic.

genesis is more closely related to abiogenesis anyway, which is a separate topic from evolution.

[simple]

all i was saying was that i was not a creationist.... but that helps a lot. I guess time is something much larger than I could comprehend

[swansont]

Epicathantic folds, yes. In truth, I have also wondered why Mongoloids (Asians) have this feature. You are thinking in terms of only natural/sexual selection, but it very well could have been the result of a genetic bottleneck.

 

Why couldn't it be both a bottleneck and sexual selection? Or one followed by the other?

[atinymonkey]

i guess ill ask my bio teacher about that. and sorry... what is a genetic bottleneck?

 

is that saying that there may have been a small group who had the eye fold... which i believe to be possible... but i do not understand how it became dominant' date=' and then reproduced separately... and therefore only had the eyefold? or am I wrong about what that means.[/quote']

A genetic bottleneck is where you can trace the gene pool back to a specific person or family. All the diversity stems from that point. For instance one in 100 men of European origin can trace their origin to Genghis Kahn, and in Asia the percentage is much higher than that. That's a genetic bottleneck, any dominant traits that Mr Kahn happened to have will have a higher change of appearing in the general population.

 

Epicanthic folds in Asia are dominant due to the Feudal system in place that placed a few people in positions with many concubines, then the borders of china were sealed for over 1000 years. The was no influx of genetic diversity, so the Asian community enhanced it's own dominant traits through cultural inbreeding.

[Hellbender]

Hate to nit pick, but venus fly traps get their energy from photosynthisis. All of its "food" is sugar from spliting water with evergy from the sun, they are autotrophs. The insects they "consume" are only for nitrogen, because it's not in the marsh soil that they live in.

 

cool. I used this example in response to simple's question to try and show that it is possible for a heterotroph to evolve from autotrophs, I knew that venus fly traps are not full heterotrophs, just that they display heterotrophic tendencies.

[Hellbender]

Why couldn't it be both a bottleneck and sexual selection? Or one followed by the other?

 

I was speculating, It certainly could be both of these.

[-Demosthenes-]

cool. I used this example in response to simple's question to try and show that it is possible for a heterotroph to evolve from autotrophs, I knew that venus fly traps are not full heterotrophs, just that they display heterotrophic tendencies.

Very true, just wanted to clear it up, and make myslef look smart

[Hellbender]

Very true, just wanted to clear it up, and make myslef look smart

 

LOL nothin' wrong with that.

[Kleptin]

I just joined this forum and read the thingie, forgive me if i'm a bit late

 

That article was surrounded by catholic this and that, and I know that micro/macro evolution has been a very big obstacle for supporters of darwin...but...

 

Can't you guys imagine what the follow up to that article might be? It would probably be along the lines of

 

"so...since I have brought darwinism into question, I would like to propose that an unexplicable supernatural deitiy plopped humans, animals, and all forms of life, down on the earth, in the form that they have today."