False ideas about evolution
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20-09-2011, 04:27 PM
 
RE: False ideas about evolution
(05-05-2011 08:14 AM)TheBeardedDude Wrote:  I'll start.
"If we evolved from monkeys then why are there still monkeys?"
Pretty common and I am sure this has been addressed on this site before but we did not evolve from monkeys. We share a common ancestor.
What else you guys got?

I LOVE this one. When i hear this stated as a fact. I begin to act.
I use my most sincere look of suprise and amazement and say "Oh my, i am blown away, you really have read Origins of Species cover to cover..so what was your favorite part or the part that upset you the most..and while you are at it, please share with me the chapter about where we come from apes as i have stupidly forgot it".

Then they do the Xtian shuffle...and the point is made that they have no idea what they are saying and know they are talkign out their ass! A usual reply is "Well, my preacher, sunday school teacher or pal told me so".

The world is more literate than anytime in history, but somehow its littered with the dumbest of people. Jeesh!

D
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21-09-2011, 08:57 AM
RE: False ideas about evolution
Perpetuation of false ideas. This is a misconception that seems to have persisted ever since Darwin hypothesized a common ancestor between ape and man. Instead of actually reading the material they pass along this erroneous information to others without providing any evidence for why it is or is not correct.

“Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.”
—Thomas Henry Huxley
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21-09-2011, 02:10 PM
RE: False ideas about evolution
I'll admit, I know very little (practically nothing) about biology and evolution. My specializations are in ancient history, anglo-saxon literature, and nuclear physics.

I have a question about evolution that I do not understand: why is it that an exterior stress causes a mutation in the first place? What is the catalyst?

For instance, let's say there are butterflies that live in and around yellow flowers. They are yellow to blend in to the flowers, and this protects them. Then, the flowers begin to change color to red (over a period of time). The butterflies, in response, turn red and thus adapt and survive.

But why? Why the specific change to the specific stress? Why don't the butterflies turn blue or purple or pink? Yes, turning red is more beneficial, but so what? Shouldn't the odds of each specific mutation be exactly the same? And while turning red is a beneficial mutation, how could it occur on a large enough scale, fast enough, to save this butterfly species? Shouldn't they all just end up extinct because they can no longer blend into their surroundings?

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21-09-2011, 03:20 PM
RE: False ideas about evolution
This example would only work if the population was already comprised of 2 different colors of butterfly and flower. A mutation would not occur in either population to randomly change the flower from one color to the next nor the butterfly. There is a good example in nature of this occurring (more or less). In England, prior to the Industrial Revolution and the burning of massive amounts of coal, there was a species of moth with 2 dominant phenotypes. 1 phenotype was a lighter color and the other was more speckled and darker. The trees at the time that these moths commonly landed on were light in color. As a result, birds could more easily pick out the dark moths. The result was a population dominated by mostly light colored moths and very few dark colored moths. The dark colored moths are not eliminated from the population, only diminished. Mathematically it is very difficult to cause it to approach 0, with the main emphasis being on how the color is genetically coded for. A moth can be a carrier for a particular color, but because of dominant and recessive genes not display it. Turn on the industrial revolution and cover the trees in black soot. Now the white moth stands out and the dark moth blends in. There is not a mutation that occurs, but instead natural selection begins to select against the light colored moth (i.e. predation by the birds). The population would not randomly change color without it already being in the population. (side note: with the current green initiatives and cleaning regimens, the trees are becoming lighter in color again and this trend is reversing).

Another good example would be spots, stripes and no spots/or stripes at all. We now have cats (big mean ones) with one of these variations. It appears that the earliest form of camouflage was what leopards have (the roundish spots that are multiple colors). Through successive generations natural selection favored individuals who had markings more similar to spots, those with markings more similar to stripes and those with very few markings. Add in a few more thousand generations and we see that as this continues we have distinctly different camouflage types. Once again it is not a mutation that causes it per say, but natural variation that is selected for or against. Perhaps prey detected the spots easier in tall grass type settings and those with fewer spots were more successful, and so on and so forth.

Did that make any sense? Or was I just rambling?

“Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.”
—Thomas Henry Huxley
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21-09-2011, 08:12 PM
RE: False ideas about evolution
(21-09-2011 03:20 PM)TheBeardedDude Wrote:  Did that make any sense? Or was I just rambling?

No, that absolutely made sense, thank you.

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22-09-2011, 07:21 PM
RE: False ideas about evolution
(21-09-2011 02:10 PM)17thknight Wrote:  I'll admit, I know very little (practically nothing) about biology and evolution. My specializations are in ancient history, anglo-saxon literature, and nuclear physics.

I have a question about evolution that I do not understand: why is it that an exterior stress causes a mutation in the first place? What is the catalyst?

For instance, let's say there are butterflies that live in and around yellow flowers. They are yellow to blend in to the flowers, and this protects them. Then, the flowers begin to change color to red (over a period of time). The butterflies, in response, turn red and thus adapt and survive.

But why? Why the specific change to the specific stress? Why don't the butterflies turn blue or purple or pink? Yes, turning red is more beneficial, but so what? Shouldn't the odds of each specific mutation be exactly the same? And while turning red is a beneficial mutation, how could it occur on a large enough scale, fast enough, to save this butterfly species? Shouldn't they all just end up extinct because they can no longer blend into their surroundings?
Please correct me, those who know more more than I do about this, but in my understanding the answer to your question about the random mutation is good, but the answer is that the butterflys DO turn blue and purple and pink. Over a long period of time, the ones that randomly mutate to yellow have a distict advantage over the rest. The odds of the mutation is just as you say, in general equal, but that's not the determining factor, in the long term survival rates. The advantage of those who do randomly mutate to yellow is much higher, as they are less "obvious" to predators, and AFTER their random mutation gives them an advantage, they "run with it". It's not that the color is CAUSED by the environmental pressure, but the random mutation gives them an advantage IN that environment. Am I wrong ?
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Those who were seen dancing were thought to be insane by those who could not hear the music - Friedrich Nietzsche
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22-09-2011, 08:14 PM
RE: False ideas about evolution
A mutation causing a change in color in a single generation is highly unlikely. The genotype for that color would need to already be in the population. Mutations are mainly a mechanism for "scrambling" up the information. Essentially mutations help randomize genetic information, but most mutations cause no phenotypic change and very rarely do they cause a noticeable effect. Deleterious mutations can kill but average mutations are more or less just noise in the genetic sequence. Mutations and back-mutations occur in a population simultaneously, so mutations do not have major influences, except over longer periods of time where they introduce new combinations of genes via the scrambling of the genetic sequences. These scrambling effects cause new combination possibilities that can result in small changes at the genetic of phenotypic level and compilations of these changes can result in noticeable morphological changes (i.e. macroevolution). And selection pressure is also thrown in, as well as sexual selection and environmental conditions.

“Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.”
—Thomas Henry Huxley
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22-09-2011, 09:26 PM
RE: False ideas about evolution
(22-09-2011 08:14 PM)TheBeardedDude Wrote:  A mutation causing a change in color in a single generation is highly unlikely. The genotype for that color would need to already be in the population. Mutations are mainly a mechanism for "scrambling" up the information. Essentially mutations help randomize genetic information, but most mutations cause no phenotypic change and very rarely do they cause a noticeable effect. Deleterious mutations can kill but average mutations are more or less just noise in the genetic sequence. Mutations and back-mutations occur in a population simultaneously, so mutations do not have major influences, except over longer periods of time where they introduce new combinations of genes via the scrambling of the genetic sequences. These scrambling effects cause new combination possibilities that can result in small changes at the genetic of phenotypic level and compilations of these changes can result in noticeable morphological changes (i.e. macroevolution). And selection pressure is also thrown in, as well as sexual selection and environmental conditions.

Why is it that I can grasp Kepler's laws of Planetary Motion in all of 5 minutes, I can recite the history of the entire Roman Empire from rote memory, and I've damn-near memorized Beowulf, but I can stare at this paragraph for an hour and just feel like I'm retarded Sad

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23-09-2011, 07:50 AM
 
RE: False ideas about evolution
(22-09-2011 09:26 PM)17thknight Wrote:  
(22-09-2011 08:14 PM)TheBeardedDude Wrote:  A mutation causing a change in color in a single generation is highly unlikely. The genotype for that color would need to already be in the population. Mutations are mainly a mechanism for "scrambling" up the information. Essentially mutations help randomize genetic information, but most mutations cause no phenotypic change and very rarely do they cause a noticeable effect. Deleterious mutations can kill but average mutations are more or less just noise in the genetic sequence. Mutations and back-mutations occur in a population simultaneously, so mutations do not have major influences, except over longer periods of time where they introduce new combinations of genes via the scrambling of the genetic sequences. These scrambling effects cause new combination possibilities that can result in small changes at the genetic of phenotypic level and compilations of these changes can result in noticeable morphological changes (i.e. macroevolution). And selection pressure is also thrown in, as well as sexual selection and environmental conditions.

Why is it that I can grasp Kepler's laws of Planetary Motion in all of 5 minutes, I can recite the history of the entire Roman Empire from rote memory, and I've damn-near memorized Beowulf, but I can stare at this paragraph for an hour and just feel like I'm retarded Sad

I've been in several of these Evolution type discussion with Xtian Fundies and what i always seem to take away from the conversation is that they want PROOF of damn near instantaneous evolution within their lifetime so they can SEE it...but then not need to see ANY proof whatsoever of their Sky Daddy and his creation.
They expect US to demonstrate Evolution that happens Fed-Ex-Fast and if not...will not accept it..but dont think twice about NOT looking at their holy book with an ounce, jot or tittle of critical thinking.

One of my dearest friends works at Focus on the Family and he's told me that he accepts Macro (or is it Micro) Evolution just not Darwins type of major evolution. This statement has had me at a loss for words more than once. I generally sit at amazement at such a claim.

D
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23-09-2011, 09:17 AM
RE: False ideas about evolution
My paragraph may be overly complex. This is not something I grasped with any immediacy either. I have had several classes dealing with evolution and one in particular devoted to it.

Let's start over with mutations. A mutation can be a simple (not sure I should say simple but you will get the point either way) change from one nucleic base to another nucleic base (changing from a Guanine to an Adenine). This mutation changes the genetic information, but may cause no noticeable effect. As a matter of fact some proteins (the nucleic bases code for proteins) can be coded for using multiple sequences of nucleic bases, so even though we mutated the gene sequence it may still produce the same protein. A detrimental mutation would be an instance where it codes for a different protein. In this case it may code for too much and cause cell dysfunction or death. These certainly happen but mutations with no effect are much more common. At the same time (in a population, always think about these processes occurring at the population level)back-mutations will be correcting these mutations. So, in one organism the base pair may change but in a later generation (or in the same) another mutation may reverse that original effect. Mutations and back-mutations keep the overall genetic sequence relatively stable. Add in a lot of time, and some new selection pressure (climate change, meteorite impact, Volcanic eruption [a really BIG one], etc) and decrease the size of the gene pool (kill off a lot of the organisms) and these new selection pressures plus our variable genome can begin to trend towards new adaptations. These could be selection pressures for lighter or darker colors that eventually breeds an all new together color, or perhaps a change in body size and/or shape.

The point of color is that a single mutation is highly unlikely to have any phenotypic (visible) effect on the organism. In order to select for a new color or body size or any other characteristic, you first need the genetic information to already be there and then a selection pressure that exploits it.

One of my favorite examples is Dragonflies. During the Permian, oxygen levels were elevated well above today's levels. The effect was an increase in terrestrial arthropod body size. The constraint on body size in arthropods is due to oxygen levels and gravity, not genetics. Since arthropods diffuse oxygen through their exoskeleton, they are not very efficient at obtaining oxygen, so you need a lot of it in order to increase metabolic rates. Gravity constrains their size mechanically. Ergo, if they get too big, they collapse under their own weight. And in the Permian we see very large arthropods, dragonflies with a wingspan the size of an EAGLE!. We do not see them anywhere near that big now, and it was not due to a mutation (then or now), but instead selection pressures from environmental conditions that fueled selection for bigger dragonflies. In order for selection to work, we need excess genetic information that is variable in a population. Organisms do not use all of the genetic information in their DNA sequence and mutations, sexual selection and natural selection effect the population by mixing up the combinations of genes.

“Science is simply common sense at its best, that is, rigidly accurate in observation, and merciless to fallacy in logic.”
—Thomas Henry Huxley
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