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Evolution, a theory on the theory

Double_R
Posts: 4,886
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4/30/2016 3:16:54 PM
Posted: 7 months ago
The explanation for the diversity of live through evolution has largely been explained via natural selection, the idea that traits more favorable to survival are more likely to survive and thus more likely to produce offspring, which results in the population shifting towards these traits over time.

I do however find it hard to fathom how this factor alone can account for much of what we see. Since I was much younger I have always believed (just from my own tuition) that how we live our lives has some sort of impact on the genes we pass down. For example someone who is very physically active will have a much lower BMI, which I have always believed would have a very small yet statistically significant impact on the traits inherited by their offspring. This to me explains so much more about evolution than natural selection alone.

My question is, is there evidence for or against this idea? Is this something already heavily studied, or an idea largely unexplored?
user13579
Posts: 822
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4/30/2016 3:55:47 PM
Posted: 7 months ago
At 4/30/2016 3:16:54 PM, Double_R wrote:
The explanation for the diversity of live through evolution has largely been explained via natural selection, the idea that traits more favorable to survival are more likely to survive and thus more likely to produce offspring, which results in the population shifting towards these traits over time.

I do however find it hard to fathom how this factor alone can account for much of what we see. Since I was much younger I have always believed (just from my own tuition) that how we live our lives has some sort of impact on the genes we pass down. For example someone who is very physically active will have a much lower BMI, which I have always believed would have a very small yet statistically significant impact on the traits inherited by their offspring. This to me explains so much more about evolution than natural selection alone.

My question is, is there evidence for or against this idea? Is this something already heavily studied, or an idea largely unexplored?

Is that person more likely to be "physically active" because of genetics?
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Double_R
Posts: 4,886
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4/30/2016 4:07:28 PM
Posted: 7 months ago
At 4/30/2016 3:55:47 PM, user13579 wrote:
At 4/30/2016 3:16:54 PM, Double_R wrote:
The explanation for the diversity of live through evolution has largely been explained via natural selection, the idea that traits more favorable to survival are more likely to survive and thus more likely to produce offspring, which results in the population shifting towards these traits over time.

I do however find it hard to fathom how this factor alone can account for much of what we see. Since I was much younger I have always believed (just from my own tuition) that how we live our lives has some sort of impact on the genes we pass down. For example someone who is very physically active will have a much lower BMI, which I have always believed would have a very small yet statistically significant impact on the traits inherited by their offspring. This to me explains so much more about evolution than natural selection alone.

My question is, is there evidence for or against this idea? Is this something already heavily studied, or an idea largely unexplored?

Is that person more likely to be "physically active" because of genetics?

I would say so, but I don't see how that addresses the question. Imagine an extreme example where a civilization goes from playing sports and weightlifting as "the things to do" when not earning a living, then all of a sudden computer technology comes and within one generation everyone get's real lazy. No one knows what sports are anymore and weightlifting becomes an ancient activity. After say 1000 years, assuming natural selection played no part in which couples produced offspring, would the traits inherited by the offspring be any different had the civilization remained active?
keithprosser
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4/30/2016 4:50:36 PM
Posted: 7 months ago
What you are describing is close to something called 'Lamarckism', which is a teory of evolution that somewhat predates Darwinism. Lamarckism has a good article in Wikipedia so I suggest you look there for more information.

The problem with Lamarckism is no matter how much you, say, work out in a gym your DNA does not change. This is perhaps as well, because while the bigger muscles you acquire might be good to pass on, most of the changes to a body are injuries. If you have you leg amputated, you would not want to pass on having one leg to your offspring!

There probably has been evolution due to civilisation and it can be seen as a sort of natural selection. Conditions in a big industrial city are not the same as in a small crofting village. If a society relies on self-sufficient farming the the sort of person who can go on to thrive and raise a family is not the same as the sort of person who can raise a family in a modern city. The 'average human' long ago was probably a little different from the 'average' modern human, but civilastion has not existed long enough for a radical change.

That is to say the 'average person' now and long ago may be different if you do a mathematical analysis, but you may not see much subjective difference if you had a time machine because there would still be tall and short people, fat and thin people and so on. Persumably there'd be fewer total wimps in a primitive society but that's about it. Most of the difference between ancient people and us can be put down to nongenetic post-natal effects such as bad nutrition and untreatable disease being more common then than now.
janesix
Posts: 3,460
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4/30/2016 7:32:18 PM
Posted: 7 months ago
At 4/30/2016 3:16:54 PM, Double_R wrote:
The explanation for the diversity of live through evolution has largely been explained via natural selection, the idea that traits more favorable to survival are more likely to survive and thus more likely to produce offspring, which results in the population shifting towards these traits over time.

I do however find it hard to fathom how this factor alone can account for much of what we see. Since I was much younger I have always believed (just from my own tuition) that how we live our lives has some sort of impact on the genes we pass down. For example someone who is very physically active will have a much lower BMI, which I have always believed would have a very small yet statistically significant impact on the traits inherited by their offspring. This to me explains so much more about evolution than natural selection alone.

My question is, is there evidence for or against this idea? Is this something already heavily studied, or an idea largely unexplored?

Some acquired traits have been shown to be passed down to decendants of a species.
http://www.scientificamerican.com...

This is the only study I've seen. However, I suppose something else could be going on.
Ramshutu
Posts: 4,063
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5/1/2016 12:59:57 AM
Posted: 7 months ago
At 4/30/2016 3:16:54 PM, Double_R wrote:
The explanation for the diversity of live through evolution has largely been explained via natural selection, the idea that traits more favorable to survival are more likely to survive and thus more likely to produce offspring, which results in the population shifting towards these traits over time.

I do however find it hard to fathom how this factor alone can account for much of what we see. Since I was much younger I have always believed (just from my own tuition) that how we live our lives has some sort of impact on the genes we pass down. For example someone who is very physically active will have a much lower BMI, which I have always believed would have a very small yet statistically significant impact on the traits inherited by their offspring. This to me explains so much more about evolution than natural selection alone.

My question is, is there evidence for or against this idea? Is this something already heavily studied, or an idea largely unexplored?

There are many, many factors that have an impact here.

Using your example, for example. The person in question (as mentioned) may pass down a gene they have that feeds into their low BMI and willingness to exercise.

When that person is bringing up their child, the fact that they exercise all the time may have a developmental impact on that child; either through nutrition, or psychologically through upbringing to have a positive attitude towards exercise or food; for example.

With much of the genome in many ways most genes generally give a "propensity towards X" rather than "definitely X", as quite often other situations and factors have to come in to play.

An example are genes for athletic ability. With training, you'll be a far better athlete than someone who doesn't train, regardless of whether they have that gene or not; but if you both train excessively that person is likely to be better! (It's the old 10,000 hours can make anyone an expert idiom).

There is, also, an increasing amount of evidence for Epigenetics; in that there are some changes that can be acquired after you're born that can be passed down. Unfortunately, I don't know enough about this (and I don't think anyone does) to be able to fully detail the significance or impact of this.

In essence, what you're suggesting likely happens to some degree, but how much of a degree is currently unknown; and it's very difficult to be able to actually tell.

We do, however, know that a number of key changes in our body from a common ancestor, are definitely genetic in nature; specifically skull shape and brain development.

But it's a very interesting question, and one I would highly suggest you try (and me, if I get the time) to do some more reading on; it's a very interesting question and one that I don't think has been fully answered yet.
imperialchimp
Posts: 234
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5/1/2016 1:52:50 AM
Posted: 7 months ago
At 4/30/2016 3:16:54 PM, Double_R wrote:
The explanation for the diversity of live through evolution has largely been explained via natural selection, the idea that traits more favorable to survival are more likely to survive and thus more likely to produce offspring, which results in the population shifting towards these traits over time.

I do however find it hard to fathom how this factor alone can account for much of what we see. Since I was much younger I have always believed (just from my own tuition) that how we live our lives has some sort of impact on the genes we pass down. For example someone who is very physically active will have a much lower BMI, which I have always believed would have a very small yet statistically significant impact on the traits inherited by their offspring. This to me explains so much more about evolution than natural selection alone.

My question is, is there evidence for or against this idea? Is this something already heavily studied, or an idea largely unexplored?

Training/exercising i believe only affects your phenotype. It doesn't affect your genes. A healthy mother will probably have a healthy baby mainly because she feeds the fetus with healthy stuff.
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Axonly
Posts: 1,802
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5/1/2016 3:44:49 AM
Posted: 7 months ago
At 4/30/2016 3:16:54 PM, Double_R wrote:
The explanation for the diversity of live through evolution has largely been explained via natural selection, the idea that traits more favorable to survival are more likely to survive and thus more likely to produce offspring, which results in the population shifting towards these traits over time.

I do however find it hard to fathom how this factor alone can account for much of what we see. Since I was much younger I have always believed (just from my own tuition) that how we live our lives has some sort of impact on the genes we pass down. For example someone who is very physically active will have a much lower BMI, which I have always believed would have a very small yet statistically significant impact on the traits inherited by their offspring. This to me explains so much more about evolution than natural selection alone.

My question is, is there evidence for or against this idea? Is this something already heavily studied, or an idea largely unexplored?

Sounds like you are thinking of Lamarckian evolution
Meh!
Ramshutu
Posts: 4,063
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5/1/2016 4:17:34 AM
Posted: 7 months ago
At 5/1/2016 1:52:50 AM, imperialchimp wrote:
At 4/30/2016 3:16:54 PM, Double_R wrote:
The explanation for the diversity of live through evolution has largely been explained via natural selection, the idea that traits more favorable to survival are more likely to survive and thus more likely to produce offspring, which results in the population shifting towards these traits over time.

I do however find it hard to fathom how this factor alone can account for much of what we see. Since I was much younger I have always believed (just from my own tuition) that how we live our lives has some sort of impact on the genes we pass down. For example someone who is very physically active will have a much lower BMI, which I have always believed would have a very small yet statistically significant impact on the traits inherited by their offspring. This to me explains so much more about evolution than natural selection alone.

My question is, is there evidence for or against this idea? Is this something already heavily studied, or an idea largely unexplored?

Training/exercising i believe only affects your phenotype. It doesn't affect your genes. A healthy mother will probably have a healthy baby mainly because she feeds the fetus with healthy stuff.

I know I'm replying to you; and this isn't really directed to you, but any Creationist listening!

I was about to write a post correcting you on your use of the word Phenotype; as I was given to believe that Phenotype was the visible expression of your geneotype.

However, I wrote a neat little reply, but just to make sure I wasn't wrong, I looked up the definition of the word, and read a wikipedia article on "Phenotype", and it seems that the Phenotype is the observable traits of the organism which is affected by a great deal of things.

So, rather than simply assume that my understanding was correct and you were wrong, I actually double checked and realized that I wasn't correct, and now better understand a scientific term.

So, always having a little bit of doubt as to whether I'm correct, has given me the ability to correct my understanding.

I know this doesn't really have any effect on what you just said, but I felt it very worthwhile pointing out that it's okay to be wrong, and in fact, thinking that you could be wrong is a good way of improving faults in your knowledge!
Mhykiel
Posts: 5,987
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5/1/2016 5:19:40 AM
Posted: 7 months ago
At 4/30/2016 3:16:54 PM, Double_R wrote:
The explanation for the diversity of live through evolution has largely been explained via natural selection, the idea that traits more favorable to survival are more likely to survive and thus more likely to produce offspring, which results in the population shifting towards these traits over time.

I do however find it hard to fathom how this factor alone can account for much of what we see. Since I was much younger I have always believed (just from my own tuition) that how we live our lives has some sort of impact on the genes we pass down. For example someone who is very physically active will have a much lower BMI, which I have always believed would have a very small yet statistically significant impact on the traits inherited by their offspring. This to me explains so much more about evolution than natural selection alone.

My question is, is there evidence for or against this idea? Is this something already heavily studied, or an idea largely unexplored?

Natural Selection and Genetic mutation attempt to explain the emergence of new, potentially beneficial features. The mutations happen in the gonads.

There have been some theories using epigenetics as a way the environment directly effects evolution.

Some studies suggest stress increases the mutation rate in the gonads, slowing DNA correcting mechanisms. Stress from starvation or trouble finding a mate. This is in the testes.

As for the woman, tho the causes are not well known, genetic disorders increase as a woman gets older.
keithprosser
Posts: 1,983
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5/1/2016 5:52:06 AM
Posted: 7 months ago
In the spirit of nit-picking over terms,

There is, also, an increasing amount of evidence for Epigenetics; in that there are some changes that can be acquired after you're born that can be passed down. Unfortunately, I don't know enough about this (and I don't think anyone does) to be able to fully detail the significance or impact of this.

'Epigenetic' in this context means it involves genes are switched on and off, not the genes themselves. Something like fear results in physiological changes such as elevated hormone levels and gamete cells are affected by that change in their environment. That change does affect the phenotype offspring, but the change is not neccessarily adaptive.

In the experient refered to above, http://www.scientificamerican.com...
the affect looks a bit like an adaptive change, but it is probably just a co-incidence. The offspring of scared mouse mothers could just as easily be more prone to having kinked tails. Such effects are known to occur but go largely unremarked because they aren't very exciting. Where - by co-incidence - the effect resembles an adaptive it change its signficance tends to be over-stated.

If you dose yourself up with, say, testoterone you will affect your gametes, but what effect that will have on your offspring is essentially down to random chance. It might make them more manly, but it probably won't and may just as easily have the opposite affect to that desired, just as it did in the experiment referred to where scared mice had offspring that were even more easily scared.

Practising the piano 12 hours a day will result in your children having no musical abiliyu whatsoever. That is probably false, but its just as likely as the idea that it will make your offspring better pianiststs.