I have a question about sexual selection. In Charles Darwin's book The Origin of Species, he talks about natural selection and sexual selection (and a bunch of other things, of course). However, all I ever hear about is "natural selection." So has sexual selection been found to not have an effect in evolution? Or do people simply not like talking about it?
Sexual Selection
Darwin did cover this concept in his book "The Descent of Man and Selection in Relation to Sex". If you read Darwin, you should remember that he did not understand Mendelian genetics, he believed in Lamark's ideas. Basically, Lamark believed that structures were inherited if you used them, and atrophied if you did not use them. Thus a fiddler crab had a large claw because it was used so often, but the small claw atrophied through the generations because it was not used often.
| Voodoocat wrote: |
| If you read Darwin, you should remember that he did not understand Mendelian genetics, he believed in Lamark's ideas. |
That's totally false. Darwin realized that some of the similarities between parents and children were heritable, though he didn't have a proposed mechanism for that heritability. Darwin knew that you could alter a parent without affecting the way its offspring looked -- that organisms carried some information that laid the foundation for their development, and that the effects of the environment built upon that foundation.
To answer aface's question, sexual selection is a really huge topic in biology, and it has been for a while. It doesn't get popularized as much as natural selection because it can be a little more complicated, but it's definitely not a subject that is avoided by scientists.
Darwin introduced the idea of sexual selection because he realized that it would be an important process if traits were heritable. His point in bringing it up is that sexual selection can cause traits to evolve that hurt the individuals chance of surviving (and are therefore acted against by natural selection). A good example is elk horns. They need the horns to secure mates (sexual selection) but large horns cost energy to produce, and can cause higher rates of mortality in the winter (natural selection). People are thinking a lot these days about how conflicting selective forces act on traits, and how sexual selection and other evolutionary forces interact.
Gagnar pretty much covered it.
Natural selection is the process by which traits evolve based on their ability to help an organism survive to be able to mate; those better able to survive (escape predators, acquire resources, fight off disease, etc etc) are more likely to pass on their genes than those less capable of surviving (given that those traits are heritable). This is your standard model of evolution.
Sexual selection, by contrast, is the process by which traits develop that have no effect upon survivorship, or even hinder it, but increase the chances of attracting a mate when they do survive. This form that hinders survivorship, but enhances their competitiveness in mating is generally driven by mate choice (usually the females selecting for more attractive males, but there are examples of the opposite) rather than by the ability to compete for survival.
Many great examples of this are found in many species of birds, some reptiles, mammals, insects, and of course, many other groups. Peafowl are a classic example; the females (peahens) are basically your standard chicken-like bird, mottled brown without superflously long feathers, very well camouflaged in their forest habitat and capable fliers; males (peacocks) by contrast are bright blue and green, with extremely long, decorative tail coverts (the fan)... the decoration means they cannot hide from predators as well as females, the extremely long and heavy fan hinders their ability to fly (and escape predation), and the complex structures of the long feathers, pigments and physical microstructure of the feathers to create the bright colours are very costly to produce... but those males that are more brightly coloured with larger, more impressive fans are more likely to mate with females, passing on their genes with more frequency than drabber males that may be able to compete better for survival, but not as well in the all important mating stage.
So really, there is evolutionary selection, which may be driven by a number of factors: natural selection is driven by organism vs. environment+competition for resources+predator avoidance; sexual selection is driven by the ability to compete with conspecifics in mating. There are a few other forms of selection that may come in to play, but these are the most common, with the least debate as to their validity; you may also encounter the concept of kin selection, in which related individuals help one another survive based on how closely related they are... but there's a lot of controversy over that. Social selection is a system by which social factors influence selection, which is only really a factor in species (such as ours) with complex social structures and factors like class determine which individuals are capable of mating, rather than more "natural" factors. There are a couple others as well.
Evolution is a fascinating subject
Natural selection is the process by which traits evolve based on their ability to help an organism survive to be able to mate; those better able to survive (escape predators, acquire resources, fight off disease, etc etc) are more likely to pass on their genes than those less capable of surviving (given that those traits are heritable). This is your standard model of evolution.
Sexual selection, by contrast, is the process by which traits develop that have no effect upon survivorship, or even hinder it, but increase the chances of attracting a mate when they do survive. This form that hinders survivorship, but enhances their competitiveness in mating is generally driven by mate choice (usually the females selecting for more attractive males, but there are examples of the opposite) rather than by the ability to compete for survival.
Many great examples of this are found in many species of birds, some reptiles, mammals, insects, and of course, many other groups. Peafowl are a classic example; the females (peahens) are basically your standard chicken-like bird, mottled brown without superflously long feathers, very well camouflaged in their forest habitat and capable fliers; males (peacocks) by contrast are bright blue and green, with extremely long, decorative tail coverts (the fan)... the decoration means they cannot hide from predators as well as females, the extremely long and heavy fan hinders their ability to fly (and escape predation), and the complex structures of the long feathers, pigments and physical microstructure of the feathers to create the bright colours are very costly to produce... but those males that are more brightly coloured with larger, more impressive fans are more likely to mate with females, passing on their genes with more frequency than drabber males that may be able to compete better for survival, but not as well in the all important mating stage.
So really, there is evolutionary selection, which may be driven by a number of factors: natural selection is driven by organism vs. environment+competition for resources+predator avoidance; sexual selection is driven by the ability to compete with conspecifics in mating. There are a few other forms of selection that may come in to play, but these are the most common, with the least debate as to their validity; you may also encounter the concept of kin selection, in which related individuals help one another survive based on how closely related they are... but there's a lot of controversy over that. Social selection is a system by which social factors influence selection, which is only really a factor in species (such as ours) with complex social structures and factors like class determine which individuals are capable of mating, rather than more "natural" factors. There are a couple others as well.
Evolution is a fascinating subject
| Gagnar The Unruly wrote: | ||
That's totally false. Darwin realized that some of the similarities between parents and children were heritable, though he didn't have a proposed mechanism for that heritability. Darwin knew that you could alter a parent without affecting the way its offspring looked -- that organisms carried some information that laid the foundation for their development, and that the effects of the environment built upon that foundation. To answer aface's question, sexual selection is a really huge topic in biology, and it has been for a while. It doesn't get popularized as much as natural selection because it can be a little more complicated, but it's definitely not a subject that is avoided by scientists. Darwin introduced the idea of sexual selection because he realized that it would be an important process if traits were heritable. His point in bringing it up is that sexual selection can cause traits to evolve that hurt the individuals chance of surviving (and are therefore acted against by natural selection). A good example is elk horns. They need the horns to secure mates (sexual selection) but large horns cost energy to produce, and can cause higher rates of mortality in the winter (natural selection). People are thinking a lot these days about how conflicting selective forces act on traits, and how sexual selection and other evolutionary forces interact. |
Thank your for the answer. I already completely understood sexual selection, I just didn't understand why I never heard anyone talk about it. I think that your answer is correct, it can get a lot more complicated than natural selection which is why it's not talked about as much (I never even learned about it in my introductory biology class that I took - I just learned about natural selection).
Well, sexual selection is a 'special case' of natural selection.
There is a nice section on the Berkeley Uni website which might be worth a read;
http://evolution.berkeley.edu/evosite/evo101/IIIE3Sexualselection.shtml
There is a nice section on the Berkeley Uni website which might be worth a read;
http://evolution.berkeley.edu/evosite/evo101/IIIE3Sexualselection.shtml
maybe sexual selection is just one of the effects of natural selection.
from a web,
from a web,
| Quote: |
|
Natural selection is the process by which favorable heritable traits become more common in successive generations of a population of reproducing organisms, and unfavorable heritable traits become less common, due to differential reproduction of genotypes. Natural selection acts on the phenotype, or the observable characteristics of an organism, such that individuals with favorable phenotypes are more likely to survive and reproduce than those with less favorable phenotypes. The phenotype's genetic basis, genotype associated with the favorable phenotype, will increase in frequency over the following generations. Over time, this process may result in adaptations that specialize organisms for particular ecological niches and may eventually result in the emergence of new species. In other words, natural selection is the mechanism by which evolution may take place in a population of a specific organism. Natural selection is one of the cornerstones of modern biology. The term was introduced by Charles Darwin in his groundbreaking 1859 book The Origin of Species[1] in which natural selection was described by analogy to artificial selection, a process by which animals with traits considered desirable by human breeders are systematically favored for reproduction. The concept of natural selection was originally developed in the absence of a valid theory of inheritance; at the time of Darwin's writing, nothing was known of modern genetics. Although Gregor Mendel, the father of modern genetics, was a contemporary of Darwin's, his work would lie in obscurity until the early 20th century. The union of traditional Darwinian evolution with subsequent discoveries in classical and molecular genetics is termed the modern evolutionary synthesis. Although other mechanisms of molecular evolution, such as the neutral theory advanced by Motoo Kimura, have been identified as important causes of genetic diversity, natural selection remains the single primary explanation for adaptive evolution. |
| Afaceinthematrix wrote: |
| Thank your for the answer. I already completely understood sexual selection, I just didn't understand why I never heard anyone talk about it. I think that your answer is correct, it can get a lot more complicated than natural selection which is why it's not talked about as much (I never even learned about it in my introductory biology class that I took - I just learned about natural selection). |
i avoid biology like it had the plague. But if you want to see sexual selection concepts tossed about in daily conversation, the psychology department is a good place to hang around. Sexual selection is a huge topic in evolutionary psychology. It's pretty much the whole field.
| knight_frost wrote: |
| maybe sexual selection is just one of the effects of natural selection. |
It's not an effect, it's a mechanism. Natural selection doesn't cause sexual selection, but sexual selection is one of the ways natural selection works.
It's kind of a fuzzy semantics issue, because even though sexual selection really is just a mode of natural selection, most biologists tend to talk about them as though they are two different things, for ease of communication. There's no good phrase for "anything that is natural selection other than sexual selection." Since scientists often explicitly compare the effects of sexual selection and "every other kind of natural selection," they tend to refer to "every other kind of natural selection" as "natural selection" for simplicity. The tendency I've observed is that people refer to "natural selection" + sexual selection as just "selection."
I did a little looking around, and there's a simple reason Darwin didn't say much about sexual selection:
1: His society at the time was very squeamish about any subject having to do with sex.
2: His work was very controversial already, so he didn't want to rock the boat more than he had to.
1: His society at the time was very squeamish about any subject having to do with sex.
2: His work was very controversial already, so he didn't want to rock the boat more than he had to.
Darwin actually wrote a lot about sexual selection. He needed to, because some traits that biologists knew about at the time couldn't be explained without it (like peacocks). If Darwin hadn't brought up sexual selection, his detractors could've used animals like peacocks against him and discredited his theory.
Yep, The Origin of Species is full of sexual selection, and uses artificial selection extensively as well as a vehicle explain the grander concepts of natural selection.
You are definitely correct in the fact that he didn't want to rock the boat more than necessary... in fact, if it weren't for Alfred Russel Wallace he quite probably never would have published "his theory". As it was, he revised The Origin after its initial publication to make it less controversial, going back on many (correct-ish) things he said in the original publication to appease the masses.
You are definitely correct in the fact that he didn't want to rock the boat more than necessary... in fact, if it weren't for Alfred Russel Wallace he quite probably never would have published "his theory". As it was, he revised The Origin after its initial publication to make it less controversial, going back on many (correct-ish) things he said in the original publication to appease the masses.
Mendel performed his experiments between 1856 and 1863. He read his paper in 1865 then published his findings in 1866; Darwin published On the Origin of Species in 1859. Since Darwin started working on his book in 1856 (and thought about it for many years before) then published it three years later Mendel did not influence Darwin.
Here is an interesting link from PBS: http://www.pbs.org/wgbh/evolution/library/06/1/l_061_01.html
Here is an interesting link from PBS: http://www.pbs.org/wgbh/evolution/library/06/1/l_061_01.html
Darwin's grand idea of evolution by natural selection is relatively simple but often misunderstood. To find out how it works, imagine a population of beetles:
1. There is variation in traits.
For example, some beetles are green and some are brown
2. There is differential reproduction.
Since the environment can't support unlimited population growth, not all individuals get to reproduce to their full potential. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do.
3.There is heredity.
The surviving brown beetles have brown baby beetles because this trait has a genetic basis.
End result:
The more advantageous trait, brown coloration, which allows the beetle to have more offspring, becomes more common in the population. If this process continues, eventually, all individuals in the population will be brown.
1. There is variation in traits.
For example, some beetles are green and some are brown
2. There is differential reproduction.
Since the environment can't support unlimited population growth, not all individuals get to reproduce to their full potential. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do.
3.There is heredity.
The surviving brown beetles have brown baby beetles because this trait has a genetic basis.
End result:
The more advantageous trait, brown coloration, which allows the beetle to have more offspring, becomes more common in the population. If this process continues, eventually, all individuals in the population will be brown.
Actually I would want all of you here to read this link
http://en.wikipedia.org/wiki/Assortative_mating
it is about
There are a lot of review on this and it almost the same as sexual selection in lay man terms
although I must say that is not exactly the same
I will continue on the topic if some one is interested
http://en.wikipedia.org/wiki/Assortative_mating
it is about
| Quote: |
| Assortative mating (also called assortative pairing) takes place when sexually reproducing organisms tend to mate with individuals that are like themselves in some respect (positive assortative mating) or dissimilar (negative assortative mating). In evolution, these two types of assortative mating have the effect, respectively, of reducing and increasing the range of variation, or trait variance, when the assorting is cued on heritable traits. |
There are a lot of review on this and it almost the same as sexual selection in lay man terms
although I must say that is not exactly the same
I will continue on the topic if some one is interested
| mshafiq wrote: |
| Darwin's grand idea of evolution by natural selection is relatively simple but often misunderstood. To find out how it works, imagine a population of beetles:
1. There is variation in traits. For example, some beetles are green and some are brown 2. There is differential reproduction. Since the environment can't support unlimited population growth, not all individuals get to reproduce to their full potential. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do. 3.There is heredity. The surviving brown beetles have brown baby beetles because this trait has a genetic basis. End result: The more advantageous trait, brown coloration, which allows the beetle to have more offspring, becomes more common in the population. If this process continues, eventually, all individuals in the population will be brown. |
The creationist objection to this, however, is that the brown and green traits had to be there beforehand. They will accept this as "microevolution", but will continue to reject "macroevolution" using the (flawed) argument that with this model, there will never be a pink beetle, because the pool of traits has only green and brown beetles.
Yeh nice post by Gagnar, that pretty much sums it up for me.
This posting will sound a bit crazy perhaps although I believe it is part of science and factual. I believe that our thinking vibes give off special frequencies that attract or repell what goes on around us. For example has anybody found that on any given day they seem to miss a bus, or any similar timing event, just by a fraction of seconds or minutes, and on that given day it happens to them exactly the same way with all their events? Though the next day everything seems to be perfectly in place, and appear as though by magic right in your moments all day long? One day everyone seems to be smiling at you, and the next you wonder what is eating them? I think we are transmitters, and the wavelengths from the transmitters in our bodies are largely dictated by what goes on in our heads, some of what we have no knowledge off, as they are subtle and part of our biological make-up. Perhaps because we are so involved in theories and processes?
And yes, the sexual thingie is part of natural selection. Agree with Indi. But for me the frequencies we give off are governed by the whole of our being and our minds and they are a major factor in attracting and repelling what is around us, including and perhaps because they are so instinctive, animals and small children. Why does a dog growl at one person or dog and not another for example?
And yes, the sexual thingie is part of natural selection. Agree with Indi. But for me the frequencies we give off are governed by the whole of our being and our minds and they are a major factor in attracting and repelling what is around us, including and perhaps because they are so instinctive, animals and small children. Why does a dog growl at one person or dog and not another for example?
| deanhills wrote: |
| This posting will sound a bit crazy perhaps although I believe it is part of science and factual. I believe that our thinking vibes give off special frequencies that attract or repell what goes on around us. For example has anybody found that on any given day they seem to miss a bus, or any similar timing event, just by a fraction of seconds or minutes, and on that given day it happens to them exactly the same way with all their events? Though the next day everything seems to be perfectly in place, and appear as though by magic right in your moments all day long? One day everyone seems to be smiling at you, and the next you wonder what is eating them? I think we are transmitters, and the wavelengths from the transmitters in our bodies are largely dictated by what goes on in our heads, some of what we have no knowledge off, as they are subtle and part of our biological make-up. Perhaps because we are so involved in theories and processes?
And yes, the sexual thingie is part of natural selection. Agree with Indi. But for me the frequencies we give off are governed by the whole of our being and our minds and they are a major factor in attracting and repelling what is around us, including and perhaps because they are so instinctive, animals and small children. Why does a dog growl at one person or dog and not another for example? |
This new age-style 'theory' is fairly typical of the genre. Most such 'theories' rely on 'vibrations', 'energies' and the like without ever explaining how these 'vibrations' actually work. The human brain does indeed transmit electromagnetic radiation, but at such low intensity that it barely gets past our skull. This can be detected by very sensitive equipment - which is how we perform EEG readings. These signals are of such low power that they could not possibly influence material bodies around us, let alone retard buses or similar macroscopic effects.
I think you will find that having a 'bad' day is common to everyone and has nothing to do with 'vibrations'. It would be astonishing if we didn't have the occasional day where everything seemed to go wrong - we live a lot of days and blind chance would dictate that some of them will be 'better' than others. I think you will also find that mental state has a lot to do with it. If you are feeling particularly pessimistic then you will tend to notice all the negative things and disregard the positives. The same thing applies the other way around.
As for dogs growling at some people - I have 4 dogs and I agree, they do. This is because of a combination of factors - pheromones, body position/stance etc. Some dogs growl at men and not women (our dog Max was an example, since he had previously been abused by a man, and it took a lot of time and effort to break him of the habit). Dogs are very sensitive to external signals which humans are less good at detecting, but those signals are entirely explicable and certainly not some strange 'vibrations'.
| Bikerman wrote: |
| Err...I think you need to have a sit down in a quiet place |
I generally do ...
But seriously. Has there been enough real research about the connection between human beings or for that matter all living beings able to communicate with one another? Generally it always seems to be put under the heading of psychiatry or psychology. But in the same way that they have fantastic microscopes to stretch our vision to planets beyond, one would hope that they could measure connection between one person and another by now? That connection is very real. I call it vibrations, but maybe it is something else in science lingo?
For example there are different intensities of connection, either by real communication, but also in thought, connecting people with one another. For example prayer. This seems to be put under the heading of religion, but strictly regarded scientifically, this is a focus by a number of minds on someone or something specific, stretching the link. A stronger and more powerful connection. Surely if someone did some real good research instead of frowning at it as something outside science, they would be able to measure this connection?
You are assuming that there IS a connection. The evidence for this is slim to none.
We communicate via non mystic means - body language, verbal and visual communication. The evidence for some mystic 'remote' communication is, to say the least, controversial.
Prayer doesn't connect people - that is not the aim. It is supposed to connect you to God. The evidence for this is...frankly bugger all.
You don't do science on some mythical idea - there is no point. First produce the evidence then the science will be done. To date every attempt to produce reliable evidence has failed. That is not a failure of science - it simply indicates that the phenomenon does not exist.
We communicate via non mystic means - body language, verbal and visual communication. The evidence for some mystic 'remote' communication is, to say the least, controversial.
Prayer doesn't connect people - that is not the aim. It is supposed to connect you to God. The evidence for this is...frankly bugger all.
You don't do science on some mythical idea - there is no point. First produce the evidence then the science will be done. To date every attempt to produce reliable evidence has failed. That is not a failure of science - it simply indicates that the phenomenon does not exist.
I'm not really seeing how these "vibrations" would be relevant to sexual selection.
Well, let me clarify; if they do exist (which, as mentioned there is next to no evidence, despite several ethological, sociological and psychological studies), I don't see how they would be any more relevant to sexual selection than to any other form of selection such that they would be a meaningful addition to the discussion rather than a background status quo concept.
Well, let me clarify; if they do exist (which, as mentioned there is next to no evidence, despite several ethological, sociological and psychological studies), I don't see how they would be any more relevant to sexual selection than to any other form of selection such that they would be a meaningful addition to the discussion rather than a background status quo concept.
| Bikerman wrote: |
| The evidence for some mystic 'remote' communication is, to say the least, controversial. |
Chris, I did not say the communication was mystic. For me the connection is real, and if enough time is spent on it, can be measured and analyzed with scientific methods. OK, maybe we need to replace prayer with meditation then. Look at it scientifically rather than with religious or mystic connotations. For me it would appear that science only wants to look at that what it can see, measure and count. Connection between one person and another is real. Connection between more than one person when they are focussed on one subject is also real. When one person looks at another and the other person looks at the one person there is a real connection.
| Ankhanu wrote: |
| I'm not really seeing how these "vibrations" would be relevant to sexual selection.
Well, let me clarify; if they do exist (which, as mentioned there is next to no evidence, despite several ethological, sociological and psychological studies), I don't see how they would be any more relevant to sexual selection than to any other form of selection such that they would be a meaningful addition to the discussion rather than a background status quo concept. |
You're in a crowd of people. I presume you are male. All of a sudden your eyes meet those of a particular female's and there is a connection between the two of you. She may look away or blush. For me that connection between two people, or more than two people is non-mystic and real.
| deanhills wrote: | ||
Chris, I did not say the communication was mystic. For me the connection is real, and if enough time is spent on it, can be measured and analyzed with scientific methods. OK, maybe we need to replace prayer with meditation then. Look at it scientifically rather than with religious or mystic connotations. For me it would appear that science only wants to look at that what it can see, measure and count. Connection between one person and another is real. Connection between more than one person when they are focussed on one subject is also real. When one person looks at another and the other person looks at the one person there is a real connection. |
You can't have it both ways. Yes, science is concerned with measurement. If, therefore, you cannot measure this 'connection', then it isn't science - it is pseudo-science or mysticism.
When you look at another person 'across a crowded room', you both receive all sorts of signals from body language, dress, appearance, situational clues and so on. There is nothing strange about this and it doesn't imply some 'connection'. Humans are pretty good at quickly evaluating another person but we often get it wrong - it is a biological and sociological short-cut, nothing more. If you look at a person from a different culture with different social cues and different body language then, I guarantee, you would be clueless.
| Bikerman wrote: |
| You can't have it both ways. Yes, science is concerned with measurement. If, therefore, you cannot measure this 'connection', then it isn't science - it is pseudo-science or mysticism. |
I guess for that reason we may never be able to agree on this. For me that connection exists and is real, and has nothing to do with other cultures. Depending on the other person, it could even be stronger with a person from another culture. Nothing to do with pseudo-science or mysticism. It is real. Perhaps still an area for science to explore, uncover, and then measure?
I think the major hang up here is almost ever post you've made, dean, involves the phrase for me... scientific principles are widely applicable and repeatable, they're not dependent upon one's perspective and beliefs. Your assertion that these vibrations are real relies heavily upon the inability to disprove their existence, rather than evidence to support that they're there... the toaster orbiting Mars concept.
In your example of locking eyes in a crowd, are you suggesting that there is some sort of antagonistic interplay in the vibrations that the female is selecting for in the male's vibrations (or vice versa) that increases his fitness while making other aspects of survival more difficult?
In your example of locking eyes in a crowd, are you suggesting that there is some sort of antagonistic interplay in the vibrations that the female is selecting for in the male's vibrations (or vice versa) that increases his fitness while making other aspects of survival more difficult?
| Ankhanu wrote: |
| In your example of locking eyes in a crowd, are you suggesting that there is some sort of antagonistic interplay in the vibrations that the female is selecting for in the male's vibrations (or vice versa) that increases his fitness while making other aspects of survival more difficult? |
It could be antagonistic. Or simply drawn to each other. A connection between the two of them along "awareness" lines.
| deanhills wrote: | ||
It could be antagonistic. Or simply drawn to each other. A connection between the two of them along "awareness" lines. |
Ok, so nothing to do with Sexual Selection (and thus the topic of the thread) then.
| Ankhanu wrote: | ||||
Ok, so nothing to do with Sexual Selection (and thus the topic of the thread) then. |
The sexual selection between male and female is natural and implicit in the connection and awareness example I mentioned.
Mate selection and Sexual Selection are different concepts. There have been a few posts earlier in the thread describing what sexual selection is; they shouldn't be ignored.
| Ankhanu wrote: |
| Mate selection and Sexual Selection are different concepts. There have been a few posts earlier in the thread describing what sexual selection is; they shouldn't be ignored. |
Thanks Ankhanu. I did take note of those, as well as some interesting programmes by David Attenborough on the natural selection by birds. Think the learning that came from this thread that captivated me most was from Indi, i.e. Evolutionary Psychology. I found quite a detailed description of it with very interesting information in Wikipedia at the URL below:
http://en.wikipedia.org/wiki/Evolutionary_psychology
It describes the difference between natural and sexual selection in a table format. Closest description to where my unscientific mind had been wondering to, was by Richard Dawkins on Memetic Selection (under the heading of Evolutionary Psychology):
| Quote: |
| A meme (pronounced /miːm/) comprises a unit or element of cultural ideas, symbols or practices; such units or elements transmit from one mind to another through speech, gestures, rituals, or other imitable phenomena. The etymology of the term relates to the Greek word mimema for mimic.[1] Memes act as cultural analogues to genes in that they self-replicate and respond to selective pressures.[2]
Richard Dawkins coined the word "meme" as a neologism in his book The Selfish Gene (1976) to describe how one might extend evolutionary principles to explain the spread of ideas and cultural phenomena. He gave as examples melodies, catch-phrases, and beliefs (notably religious belief, clothing/fashion, and the technology of building arches).[3] Meme-theorists contend that memes evolve by natural selection (in a manner similar to that of biological evolution) through the processes of variation, mutation, competition, and inheritance influencing an individual entity's reproductive success. Memes spread through the behaviors that they generate in their hosts. Memes that propagate less prolifically may become extinct, while others may survive, spread, and (for better or for worse) mutate. Theorists point out that memes which replicate the most effectively spread best, and some memes may replicate effectively even when they prove detrimental to the welfare of their hosts.[4] A field of study called memetics arose in the 1990s exploring the concepts and transmission of memes in terms of an evolutionary model. Criticism from a variety of fronts has challenged the notion that scholarship can examine memes empirically. Some commentators question the idea that one can meaningfully categorize culture in terms of discrete units. |
This is an exerpt of Richard Dawkin's book "The Selfish Gene" Chapter 11, where he gives a good summary:
| Quote: |
| Examples of memes are tunes, ideas, catch-phrases, clothes fashions, ways of making pots or of building arches. Just as genes propagate themselves in the gene pool by leaping from body to body via sperms or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation. If a scientist hears, or reads about, a good idea, he passed it on to his colleagues and students. He mentions it in his articles and his lectures. If the idea catches on, it can be said to propagate itself, spreading from brain to brain. As my colleague N.K. Humphrey neatly summed up an earlier draft of this chapter: `... memes should be regarded as living structures, not just metaphorically but technically.(3) When you plant a fertile meme in my mind you literally parasitize my brain, turning it into a vehicle for the meme's propagation in just the way that a virus may parasitize the genetic mechanism of a host cell. And this isn't just a way of talking -- the meme for, say, "belief in life after death" is actually realized physically, millions of times over, as a structure in the nervous systems of individual men the world over.'
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URL: http://www.rubinghscience.org/memetics/dawkinsmemes.html
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