Question About Evolution

[Animore]

I know this is a stupid question, but bear with me here. This is not skepticism of any kind, but a mere question.

If a cause of natural selection is mutation, how would that work, if mutation is a random process? I'm stuck here. If natural selection is adaptation, then how could genetic mutation be a part in it if it's random? Thanks in advance.

 

[Shadow Wolf]

Mutations happen at the cellular level all the time. They are not necessarily good, or bad, and most go unnoticed. However, what natural selection states, is that those organisms that are best adapted to their environment have a higher chance of survival and passing their genes on, which means there is a chance the genetic traits that enhanced their survival will pass to the next generation.
This is not a definite thing though. Often times these beneficial mutations do not pass down, and sometimes maladaptive traits are passed down. It's random in the sense that it happens, on its own, as it does, with no outside interference.

 

[Sultan Of Swing]

I know this is a stupid question, but bear with me here. This is not skepticism of any kind, but a mere question.

If a cause of natural selection is mutation, how would that work, if mutation is a random process? I'm stuck here. If natural selection is adaptation, then how could genetic mutation be a part in it if it's random? Thanks in advance.

Mutations are not the 'cause' of natural selection. Natural selection is simply better adapted animals having more of a chance to live long enough to reproduce than their worse adapted brethren, with the good genes carrying onwards, survival of the fittest and all that.

Now the actual adaptations the animal develop are said to be due to mutation, at least that would likely be the main driving factor if I am understanding the theory correctly.

The mutations are indeed random and not necessarily beneficial, but that's not the point. If the mutation is beneficial, then natural selection will do the rest. If the mutation is not beneficial, the animal dies out.

A very simplified explanation, but I hope that helps.

 

[Animore]

Mutations happen at the cellular level all the time. They are not necessarily good, or bad, and most go unnoticed. However, what natural selection states, is that those organisms that are best adapted to their environment have a higher chance of survival and passing their genes on, which means there is a chance the genetic traits that enhanced their survival will pass to the next generation.
This is not a definite thing though. Often times these beneficial mutations do not pass down, and sometimes maladaptive traits are passed down. It's random in the sense that it happens, on its own, as it does, with no outside interference.

Thanks a bunch for the response! It had been nagging me for a while now.

 

[Animore]

Mutations are not the 'cause' of natural selection. Natural selection is simply better adapted animals having more of a chance to live long enough to reproduce than their worse adapted brethren, with the good genes carrying onwards, survival of the fittest and all that.

Now the actual adaptations the animal develop are said to be due to mutation, at least that would likely be the main driving factor if I am understanding the theory correctly.

The mutations are indeed random and not necessarily beneficial, but that's not the point. If the mutation is beneficial, then natural selection will do the rest. If the mutation is not beneficial, the animal dies out.

A very simplified explanation, but I hope that helps.

Thanks a bunch for the response!

 

[निताइ dasa]

Changes in allele frequencies (evolution) is driven actually not just by natural selection but by 4 evolutionary forces.

The first force is mutation, however it actually only has a very small effect. It has been theorized however that if given enough time, certain mutations will develop that will be selectively advantageous (because most mutations are actually disadvantageous in that they decrease fitness). The next evolutionary force is natural selection, and this force acts upon mutations and selects certain traits in an environment that are advantageous and drives the allele frequencies in that direction. The adaptive nature from natural selection comes from the environment, while mutations are simply one of the factors which cause variation and allow selection to act. The third force is called random genetic drift, and this force happens in all populations (because genes move randomally due to the nature of reproduction) resulting in a random nondirectional flow in alleles. Basically the smaller the population, the greater the effect of genetic drift The forth evolutionary force is called geneflow and occurs when populations migrate and introduce new alleles.

It is the combination of these 4 forces that drive evolution. However mutation is actually very minor (it only becomes influential when we observe a long period of time), and most of the evolutionary changes happen due to the other 3. However mutation is really the only evolutionary force that is capable of introducing new alleles into a species. And its interesting certain mutations may be disadvantageous in one regard, but totally advantageous in another.

For example, individuals with cystic fibrosis have the condition due to a mutation (inherited) which affects the functioning of chlorine channels in the cell membrane (which usually pump chlorine ions in and out). Because of this, the cell has trouble balancing chlorine content so it produces excessive mucous which degenerates to the point that it affects heart or lung function. However, this very mutation actually gives you an advantage against the disease cholera. Why? Because Cholera is a disease which enters your cells through those chlorine channels (which are affected and closed by the mutation so the Cholera pathogen cannot enter). So this mutation provides a resistance against cholera and in countries (usually 3rd world) where individuals die due to cholera infections (death by diarrhea) this mutation is maintained in those populations.

Another example is that of sickle cell anemia. Usually the mutation distorts your red blood cells so they cannot carry sufficient oxygen, but since certain diseases like malaria are bloodbourne, this mutation also produces an advantage against malaria and are maintains in malaria prevalent populations like Africa. So an disadvantage in a general context can be an advantage in specific contexts.

 

[Kirran]

There's a fifth - non-random mating as well. Mutation, migration, genetic drift, natural selection and non-random mating.

 

[निताइ dasa]

fifth - non-random mating

Hmm, we learnt that non-random mating is specifically not an evolutionary force, because it while it affects genotype frequencies, it doesn't affect allele frequencies. According to the Hardy Weinberg Equilbrium, in the absence of evolutionary forces, the allele frequency stays constant, regardless of whether the mating is random or not. (sorry to disagree...). Perhaps its maybe how my university defined evolutionary forces lol

 

[Valjean]

 

[Kirran]

Hmm, we learnt that non-random mating is specifically not an evolutionary force, because it while it affects genotype frequencies, it doesn't affect allele frequencies. According to the Hardy Weinberg Equilbrium, in the absence of evolutionary forces, the allele frequency stays constant, regardless of whether the mating is random or not. (sorry to disagree...). Perhaps its maybe how my university defined evolutionary forces lol

Yeah it is a little borderline, but as it impacts the proportion of homozygotes:heterozygotes (i.e. 2ab vs a^2 and b^2) we had it included!

 

[beenherebeforeagain]

Mutations are not the 'cause' of natural selection. Natural selection is simply better adapted animals having more of a chance to live long enough to reproduce than their worse adapted brethren, with the good genes carrying onwards, survival of the fittest and all that.

Now the actual adaptations the animal develop are said to be due to mutation, at least that would likely be the main driving factor if I am understanding the theory correctly.

The mutations are indeed random and not necessarily beneficial, but that's not the point. If the mutation is beneficial, then natural selection will do the rest. If the mutation is not beneficial, the animal dies out.

A very simplified explanation, but I hope that helps.

Actually, if a mutation is harmful, natural selection will also do the rest.

It's important to remember that evolution through natural selection occurs at the level of the population, not the individual.

 

[Sunstone]

If a cause of natural selection is mutation, how would that work, if mutation is a random process? I'm stuck here. If natural selection is adaptation, then how could genetic mutation be a part in it if it's random? Thanks in advance.

Good question, Animore! I find it sometimes helps to envision these things. If so, maybe this will help. First, imagine a wolf. Let's call her Jackie. Now let's suppose this particular wolf, Jackie, has an immune system that gives her a ninety percent chance of surviving an infection of pneumonia.

Now imagine a second wolf -- we'll call him Charlie. Charlie is the brother of our first wolf, Jackie, and he is very similar to Jackie genetically. But the DNA Charlie got from his mother had a mutation in it -- a mutation that was not in the DNA that Jackie got from the same mother (Charlie and Jackie, although from the same mother, are from different eggs).

Charlie's mutation gives him -- not a mere ninety percent chance -- but rather a ninety-five percent chance of fighting off an infection of pneumonia. Which means, all else being equal, Charlie is more likely to have more children than Jackie (because he's more likely to survive longer than Jackie). And any of Charlie's children that inherit his mutation will be more likely to survive to have more children of their own than any of Jackie's children, who will not inherit the mutation.

Over time, Charlie's mutation would probably become increasingly common among wolves until nearly all or all existing wolves would share it. That might take ages though.

Random mutation and natural selection aren't the only ways in which evolution works, but I hope that by presenting those two concepts in concrete terms I have helped you visualize how they could work together. By the way, I'm not a biologist and my understanding of evolution is rudimentary -- so if someone contradicts me, that might be because they know more than me.

 

[Animore]

Good question, Animore! I find it sometimes helps to envision these things. If so, maybe this will help. First, imagine a wolf. Let's call her Jackie. Now let's suppose this particular wolf, Jackie, has an immune system that gives her a ninety percent chance of surviving an infection of pneumonia.

Now imagine a second wolf -- we'll call him Charlie. Charlie is the brother of our first wolf, Jackie, and he is very similar to Jackie genetically. But the DNA Charlie got from his mother had a mutation in it -- a mutation that was not in the DNA that Jackie got from the same mother (Charlie and Jackie, although from the same mother, are from different eggs).

Charlie's mutation gives him -- not a mere ninety percent chance -- but rather a ninety-five percent chance of fighting off an infection of pneumonia. Which means, all else being equal, Charlie is more likely to have more children than Jackie (because he's more likely to survive longer than Jackie). And any of Charlie's children that inherit his mutation will be more likely to survive to have more children of their own than any of Jackie's children, who will not inherit the mutation.

Over time, Charlie's mutation would probably become increasingly common among wolves until nearly all or all existing wolves would share it. That might take ages though.

Random mutation and natural selection aren't the only ways in which evolution works, but I hope that by presenting those two concepts in concrete terms I have helped you visualize how they could work together. By the way, I'm not a biologist and my understanding of evolution is rudimentary -- so if someone contradicts me, that might be because they know more than me.

Thanks for the response! It makes a lot more sense now.

 

[Skwim]

Excellent presentation.


.

 

[kaoticprofit]

Mutations happen at the cellular level all the time. They are not necessarily good, or bad, and most go unnoticed. However, what natural selection states, is that those organisms that are best adapted to their environment have a higher chance of survival and passing their genes on, which means there is a chance the genetic traits that enhanced their survival will pass to the next generation.
This is not a definite thing though. Often times these beneficial mutations do not pass down, and sometimes maladaptive traits are passed down. It's random in the sense that it happens, on its own, as it does, with no outside interference.

My questions are...

Who made the things that mutate? Who made the environment they mutate in? It all had to start somewhere. Who made it all good enough where it would, "pass down its traits." If it was all random, why is it a cow only produces a cow and my burrito needed human intervention to make what's called a burrito and put ground beef into it?

 

[Shadow Wolf]

My questions are...

Who made the things that mutate? Who made the environment they mutate in? It all had to start somewhere. Who made it all good enough where it would, "pass down its traits." If it was all random, why is it a cow only produces a cow and my burrito needed human intervention to make what's called a burrito and put ground beef into it?

Who says there must be a "who?" And if there is a who, who or what created this who? God does not get a free pass on the "original/first cause" just because this character is allegedly god. Where did god come from? What started god?
A cow produces a cow because a cow can only produce a cow. But, where does the cow's ancestor begin and their predecessor begin? When it comes to evolution and specialization, it's more like a rainbow where we can see red, orange, yellow, green, blue, violet, and indigo, but it's very difficult to tell exactly where one begins and another ends because the colors blend together, creating a range of tertiary colors when closely examined.
And, a burrito obviously isn't living, and is a human food invention. They are inanimate, non living, and it's absurd to even ask why a human has to make them.

 

[Louis Morelli]

Animore, I think I got your problem, because it is my problem also. Environment is not static, it is changing, and not by random, the changes obeys the laws of Physics. So, will be adapted the mutation that follow laws, that walks and dance in syntony with the environment's movement. The academic official understanding of evolution is not the knowledge of the long chain of causes and effects that's coming and advancing since the Big Bang ( and since before it because there was an ex-machine chain producing the Big Bang). We can't know if is there evolution, or, for example, if we are watching a merely process of reproduction of the thing that was existing before the Big Bang. We are inside this chain, rolling with the chain, we have no view about where it came from and where it is going. As says the Godel's incompleteness theorem: " Nobody can knows the thru about a system standing inside it". Then, we have an academic official "theory" believing in evolution.

I think that natural selection selects what is naturally designed. Natural design is the force producing all mutations. A random mutation should be produced by something coming outside the long chain (which is nature itself), so, a non-natural force. I think that due the existence of another theory, which I think is more rational than the Modern Synthesis from Darwinian theory. It is called " The Universal Matrix of Natural Systems and Life's Cycles", or Matrix/DNA Theory, which is not known by the academic world.
Matrix/DNA built an astronomical model which is exactly equal an unity of information of the DNA - a base-pair of nucleotides. it is the theoretical model that should be the evolutionary ( or reproductive?) link between cosmological and biological evolution. So, if at 4 billion years ago occurred a mutation in the way that terrestrial atoms were doing their connections and producing water, rocks,air, and went to producing RNA, DNA... which already was existing 10 billion years ago at the astronomical system to which this planet belongs,...it was not atomic mutations by random, but, by natural design. If youare interested in seeing this theory, google it. Cheers,...

 

[Valjean]

My questions are...

Who made the things that mutate? Who made the environment they mutate in? It all had to start somewhere. Who made it all good enough where it would, "pass down its traits." If it was all random, why is it a cow only produces a cow and my burrito needed human intervention to make what's called a burrito and put ground beef into it?

Nature -- by the mechanisms you should have learned about in High School science classes.

 

[Ouroboros]

If a cause of natural selection is mutation, how would that work, if mutation is a random process? I'm stuck here. If natural selection is adaptation, then how could genetic mutation be a part in it if it's random? Thanks in advance.

Mutation isn't natural selection.

Mutation is the change of the gene.

Natural selection is the process of the survival of the best genes for reproduction.

Mutations are random while natural selection depends on the environment.

 

[beenherebeforeagain]

Mutation isn't natural selection.

Mutation is the change of the gene.

Natural selection is the process of the survival of the best genes for reproduction.

Mutations are random while natural selection depends on the environment.

And as the environment changes, the traits--whether mutations or not--become more or less able to contribute to reproduction into future generations.