"NOOOOOOOOOOO" - Judge

[SAJ]

lol
You're good at sarcasm

Sarcasm ?
Dont mock me, heretic !

 

[Stigmata]

Virii mutate at a much higher rate than things like bacteria (in part because they lack the sorts of correction methods DNA based life has), but they aren't necessarily so different because of that. All sorts of creatures have different rates of mutation (for all sorts of different reasons).

Mutation is what drives the increase in variation amongst a breeding population. Mere mutation alone is as near random as anything and so really only does just increase differences. It's the selection seive of the environment that pushes the gene pool in one dierction or another.

So, in semi-layman's terms, evolution is genetic mutation in conjunction with natural selection, no?

[edit: I'm probably generalizing a bit too much for your tastes, but that's basically what I got from what you said.]

 

[Apos]

Evolution refers both to fact of history on the earth and a body of theory about the particular mechanism that made it happen (primarily natural selection). Not all evolutionary change is the result of natural selection, and natural selection would still go on without genetic mutation (though it might eventually run out of variation without some mechanism to expand it).

 

[Max35]

Intelligent design (ID) is an anti-evolution belief that asserts that naturalistic explanations of some biological entities are not possible and such entities can only be explained by intelligent causes.* Advocates of ID maintain that their belief is scientific and provides empirical proof for the existence of God or superintelligent aliens. They claim that intelligent design should be taught in the science classroom as an alternative to the science of evolution. ID is essentially a hoax, since evolution is consistent with a belief in an intelligent designer of the universe. The two are not contradictory and they are not competitors. ID is proposed mainly by people at the Discovery Institute and their allies, who feel science threatens their Biblical-based view of reality.

So, bascically, ID was a wall constructed by the Discovery Institute to keep society at large rooted in Christian beliefs. As the above quote suggests, they are not entirely separate ideas, and to take a theory from within a theory and stand it on its own is unnecessary.

 

[Flyingdebris]

oy vey, i am sick and tired of this ID crap. People end up thinking that if evolution was true then their spirituality would be rendered meaningless, and thusly they adopt this reactionary attitude against the theory of evolution.

You can be religious and still acknowledge that evolution is pretty much spot on.

Besides, you can pretty much prove evolution through a microscope just in the way that over the course of time in response to certain stimuli, species of bacteria will change and adapt. Evolution all a matter of stimulus,
mutation/variation , and successfulness in breeding, taken on the grand scale.

 

[gh0st]

Mere mutation alone is as near random as anything and so really only does just increase differences. It's the selection seive of the environment that pushes the gene pool in one dierction or another.

how does mutation compare to adaption? is mutation random, occurring X number of years, where adaption is a mutation which is caused by some kind of environmental stimulus? or is it entirely different? you seem to know this well enough.

 

[Hectic Glenn]

how does mutation compare to adaption? is mutation random, occurring X number of years, where adaption is a mutation which is caused by some kind of environmental stimulus? or is it entirely different? you seem to know this well enough.

Yes it is, although mutation can occur overnight from one parent to its offspring. If the mutation provides it with say a long neck in a giraffes case, it will be able to reach the branches all the others can, including the higher ones, so it will be more successful. Mutation is therefore still a kind of adaptation. (It can benefit or severely disadvantage the organism)
The other one you talked of, via environmental interaction happens more slowly yes, usually due to slow changes in the environment. e.g. vegetation, predators, climate change. Things like that.

The huge variety of organisms found on earth are mainly down to mutation, allowing some to thrive in different places. Like a Rhino to a Dog, very different animals. But further evolution is down to environmental changes, as they are only slight. Iguana > Marine Iguana (allows it to swim etc). And long term adaptation from a horse into the hairless water horse we know today as...the hippo.

 

[Apos]

how does mutation compare to adaption? is mutation random, occurring X number of years, where adaption is a mutation which is caused by some kind of environmental stimulus? or is it entirely different? you seem to know this well enough.

Mutation and adaptation are, in most cases, best thought of as entirely different things.

Mutation is random: not perfectly random (since we are still dealing with physical objects with all sorts of causal features that constrain the chanegs in particular ways), but as random as just about anything in nature. You can think of it as anything that results in an inexact copy of the DNA (or RNA). Anything from radiation to a simple breakdown of the "error-correction" mechanisms can be responsible. Sometimes a single base pair is got wrong (what's known as a opint mutation). Sometimes entire sections of the DNA are switched around backwards. Sometimes entire sections are dropped out. Sometimes an entire scetion is duplicated. In fact, that last happens quite a lot. There are actually things in our DNA, for instance, that can be thought of as "parasite" DNAs in that their only purpose is to duplicaet more copies of themselves in our DNA. For instance, a particular type of sequence called "alu" is present over a million times in our DNA: though different people will have some slight variation in different numbers in different places (which is often useful to track ancestry).
http://en.wikipedia.org/wiki/Alu_repeat

It's a real mess in there: more like the record of a battlefield than a neat little set of instructions. Mutations are common. However, most mutations have no effect on anything meaningful. Imagine a hard disk that's been passed around a lot. You've mostly wiped out all the previous data filling the disk. Well, the way that actually works is that the hard disk has a sort of map as to where bits of files are. Deleting files just deletes the map entries to those files: the data often remains until it is overwritten with something else. DNA is sort of like that (except that the "map" pointers are also scattered all around). If the disk is error prone, then the vast majority of these errors will affect the sections of the disk that have basically lost or non-functional data on them. Sometimes they will affect the remaining used files. By an large, these changes, however, will ALSO do little to affect the programs (this is where the analougy of the hard disk starts to break down: computer programs are a lot more exacting than biological ones, which tend to be sloppy with lots and lots of redundancies and flexibility).

Again, moving away from the hard disk analogy, remember that every single cell (well most) are like this in your body. Any of these cells can divide or accumulate mutations, and they do. But the only ones that matter to evolution are the "germ line" cells: the ones that go on to be sperm and eggs (at least in sexual life). Oftentimes, harmful mutations will cause the sperm or eggs to die before they even form, thus weeding out most of the really bad changes before they even get anywhere close to coming into being. Other bad mutations hinder the sperm and eggs enough that they are more easily beat out by their fellows in trying to impregnate each other. And still others will cause such gross malformations that developing embryos will fail and self-abort long before anyone realizes they were there (this is actually very common in human beings, such early miscarriages mostly just go unnoticed). Of the surviving beings that bare new genetic mutations, we still don't have much major differences. What we have are a collection of slight changes to this feature or that: usually very tiny effects (slightly shorter legs, sightly thicker skin, etc.). Are they beneficial? Harmful? Only the exact circumstance of the environment will tell (and remember that harmful/beneficial are used in very limited sense: solely as to what will help increase the prevalence of those genes in the NEXT generations, and so on)

That's why its best to separate mutation from adaptation. If you think of evolution as simply some creatures with short necks waiting around for a long neck mutation to arise all at once, you're probably thinking about it the wrong way. If such a thing ever happened, it'd be something called saltation.
http://en.wikipedia.org/wiki/Saltation
While not technically impossible, saltations are at the very least so exceedingly rare and unlikely that they cannot possibly be the mechanism for most evolutionary change. That's because of the nature of mutation: most big jumps are far far more likely to be non-functional garbage than anything still workable: let alone beneficial.

Instead, adaptation happens gradually: small steps by small steps (and this where the confusion about Gould comes in: the recognized form of Gould's theory of Punctuated Equilibrium was not saying that evolution does NOT happen by small steps, but rather that the changes that ultimate break out into different directions to cause speciation are uneven: the break outs happen quickly, and are often interspersed with periods in which equilibrium is mostly maintained aside from random drift). It also helps to remember that evolution happens to populations, not individuals. A single mutation just isn't going to do it even if it is beneficial: that one creature may die early for some other reason, or its new genes may be swamped out after a few generations. Or it might be so different that it is less successful in breeding with a mate, or so different that it has no one to breed with and so dies out despite being better suited for survival than everyone else!

Instead, think of adaptation as happening to entire populations. In each population there is a wide variance of traits: longer and shorter legs, thicker and softer skin, and so on. From this, a patricular non-random sampling is "selected" by the pressures of the environment to pass down more of their genes into the next generation. Each time this happens, some new variations are lost (even if they might have been beneficial in a different environment!), and the population as a whole shifts towards one type of trait or another (and this might happen for many different types of traits at once each generation).

In short, there's no immediate need to think of mutation happening at all to explain adaptation. Mutation does play an eventual role in adding back that successively lost amount of variation: it shakes things up again so that there are more possibilities in the long run to play with than steadily less and less. But it is rarely (we think) a direct and immediate player in the changes that happen to populations

That was really long-winded. but it's hella complicated, so it had to be, and that's only scratching the surface, simplifying many things, and so on.

 

[Flyingdebris]

nice job Apos, couldn't have said it better myself.