Rename OP to Prince Pancake IMO.
Evolution
- Thread starter Princey
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Rename OP to Prince Pancake IMO.
It isn't an entity, it doesn't 'decide'.
Assuming there was an evolutionary branch of those without eyebrows, chances are they would have damaged their eyes, reducing their life span, usefulness (hunting, gathering etc.) and reducing their chances of breeding.
As such the gene for having no eyebrows isn't passed on and dies out, with the odd genetic mutation such as alopecia.
Well someone over the age of 12 who doesn't understand evolution and isn't a religious nut? It's unlikely enough to make you look like a troll.
No, somebody that posts something that's either purposefully stupid or inflamatory to evoke a reaction, this is both of those things. Whether it was purposeful or not is another thing
Fail.
You assume that evolution has an aim or a purpose. It doesn't.
The key is in the following:
Evolution through natural selection.
EDIT:
Pick yourself up a copy of The Blind Watchmaker.
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Caporegime
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No it's extremely common.
Wow, what's with all the nastiness in this thread?
The guy asked a genuine question, and all he gets is people giving him grief for it.
So maybe he really doesn't know how evolution works, instead of being a **** about it, point him in the right direction, and stop being so arrogant!
The guy asked a genuine question, and all he gets is people giving him grief for it.
So maybe he really doesn't know how evolution works, instead of being a **** about it, point him in the right direction, and stop being so arrogant!
Basically random mutations in DNA cause a difference, if this difference is favourable to the conditions (mating, feeding etc) then that living thing has more of a chance to pass on this mutation to its offspring as it lives longer or mates more frequently.
This over millions of years is how we randomly got eyebrows pretty much.
There's a short explanation of the principle, hopefully
This over millions of years is how we randomly got eyebrows pretty much.
There's a short explanation of the principle, hopefully
Caporegime
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Self-elevation by condescension is rife in here.
It doesn't. That's the whole point. Random mutations produce diversity within a population: darker/lighter skin, longer legs, bigger jaws, a tendency to run from wolves, etc. There is no direction to this process, differences just turn up.
But some traits give an organism an advantage or disadvantage: maybe it can hide better, attract mates more easily or hunt better. These organisms are slightly more likely to pass on their genes to the next generation so the next generation will tend to resemble the successful slightly more than the unsuccessful. This is natural selection
Over generations of time this process can produce radical changes in organisms.
Growth of hair is under the control of a suite of genes. These control the density of hair folicles on the skin, the kind of hair produced and the length of that hair. In fact, of course, eyelashes evolved long before humans, but, in these animals, the selective advantage to have the genes produce eyelashes was - as you say - it kept particles and (probably more importantly) sweat out of the eyes. Eyebrows were retained, rather than added, because hair is continuous in the organisms we evolved from, so what happened there was that the increasing pattern of baldness left those particular patches with hair.
The irony is delightful. And now with this post, we're going deeper!
dun dun dun dun dun dun dun BAAAAAAAAA BAAAAAAA
This book is quality.
http://en.wikipedia.org/wiki/The_Greatest_Show_on_Earth:_The_Evidence_for_Evolution
http://en.wikipedia.org/wiki/The_Greatest_Show_on_Earth:_The_Evidence_for_Evolution
To put it in extremely simple terms, via exposure to environmental conditions and organisms which threaten the lifeform. This has been observed with e.coli bacteria which where grown on a minimal glycerol + citrate medium for many many years upto the 17,000th generation or something where they then started using citrate as a carbon source. This was done only using the progeny of the original e.coli smear from 2 decades prior. I'll try dig up the source as its interesting reading (plus will correct the mistakes I've made above due to receiting it from memory lol)
Rightly or wrongly, I think it's getting people's backs up because it's a fairly simple question that could have been answered by fairly quick google.
However, a lot of threads in GD could have been answered/prevented if the OP did a quick google so it's not really anything new
I sort of understand what he means, at what point did the chameleon start to adapt to have the ability it does, or how some moths have patterns on their wings to that of tree bark? If they didn't before, obviously it isn't an overnight change or change in offspring, it takes thousands and thousands/millions of years to change slowly.
To change into something visually it would have to have been observed, no? Then passed down, over many, many, many unfathomable generations until it was good enough to be of any use.
It's intriguing but then it gets even more complicated when you talk about plants and how they evolve. D:
To change into something visually it would have to have been observed, no? Then passed down, over many, many, many unfathomable generations until it was good enough to be of any use.
It's intriguing but then it gets even more complicated when you talk about plants and how they evolve. D:
I, for one, will welcome our new, Triffid overlords.
Just be sure to avoid watching any solar events and you'll have a much better chance of suvival!
Man of Honour
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It might be worth doing a search on the dual criteria of username Nitefly and evolution as the subject criteria - he's written a number of useful posts on this particular topic.
However it's worth again affirming that evolution isn't directed (or at least not in any discernable way that we can tell yet) so there are what are effectively random mutations - if these are beneficial then they're more likely to be passed on because they convey some form of advantage to the individual. Remember there have probably been millions of previous iterations of almost any given species and many of the characteristics won't have been passed on because they didn't give enough of a benefit or last long enough to be passed on.
However it's worth again affirming that evolution isn't directed (or at least not in any discernable way that we can tell yet) so there are what are effectively random mutations - if these are beneficial then they're more likely to be passed on because they convey some form of advantage to the individual. Remember there have probably been millions of previous iterations of almost any given species and many of the characteristics won't have been passed on because they didn't give enough of a benefit or last long enough to be passed on.
The OP has asked some pretty massive questions really, I'm not really sure why any hostility was needed. It is completely mind boggling and if the OP wants to discuss it, he should discuss it.
The best way to think about it is that when DNA is duplicated or copied by a life form, the enzymes that carry out this process occasionally make mistakes. These variations, or alleles as they are technically called, may have a positive effect on an organism, a negative effect, or a neutral effect. There are two ways to be 'positive' - either by increasing the ability of an organism to survive, or by increasing the sexual success of that organism (more offspring, more attractive etc).
So if a variation has a positive effect, the organism will produce offspring that are equally more successful than their 'peers'. After a long period of time, you would expect to see a higher frequency of individuals expressing this characteristic (a characteristic is technically called a phenotype).
So, with the eyebrow example, there was a period of our ancestry where the genes relating to eyebrows were non-randomly selected for. This could either be because it confers some sort of sexual advantage relating to attractiveness, but I honestly don't know. The fact that they remain is evidence that they are either 'useful', or that they are somehow immune to genetic drift (the process whereby characteristics are lost or changed over time because the genes that relate to that characteristic are neither selected for or against). If you saw someone without eyebrows I would imagine that you thought they looked rather odd (I would), so it may well be natural for us to see eyebrows and relate that image to one of a human being. Over time, the eye brows may go.
I struggle to understand how evolution has developed complex animal and plant interactions all the time. If you don't find it confusing or think that it's 'simple', then you probably don't know much about it
I hope that has been somewhat helpful.
The best way to think about it is that when DNA is duplicated or copied by a life form, the enzymes that carry out this process occasionally make mistakes. These variations, or alleles as they are technically called, may have a positive effect on an organism, a negative effect, or a neutral effect. There are two ways to be 'positive' - either by increasing the ability of an organism to survive, or by increasing the sexual success of that organism (more offspring, more attractive etc).
So if a variation has a positive effect, the organism will produce offspring that are equally more successful than their 'peers'. After a long period of time, you would expect to see a higher frequency of individuals expressing this characteristic (a characteristic is technically called a phenotype).
So, with the eyebrow example, there was a period of our ancestry where the genes relating to eyebrows were non-randomly selected for. This could either be because it confers some sort of sexual advantage relating to attractiveness, but I honestly don't know. The fact that they remain is evidence that they are either 'useful', or that they are somehow immune to genetic drift (the process whereby characteristics are lost or changed over time because the genes that relate to that characteristic are neither selected for or against). If you saw someone without eyebrows I would imagine that you thought they looked rather odd (I would), so it may well be natural for us to see eyebrows and relate that image to one of a human being. Over time, the eye brows may go.
I struggle to understand how evolution has developed complex animal and plant interactions all the time. If you don't find it confusing or think that it's 'simple', then you probably don't know much about it
I hope that has been somewhat helpful.