epigenetics

[YourCaptor]

To give a real-life example of where epigenetics has the potential to lead us:

There's a little girl I baby sat a great deal when she was younger. Small little Russian adoptee, beautiful, whip smart, and amazing in gymnastics. Her mom wants her to ride horses more, but she just loved gymnastics.

the doctors decided she was only going to grow to about 4'11". this would have been when she was around 10 or 11 I believe.

Her mother decided that was far too short and they put the girl on growth hormones to make her taller. A gangly stretched-out taller.

Morally, did her mother have this right? 4'11" is not a disabling height and many people that height or shorter get by fine! Furthermore it is an ideal height for gymnastic work! Although I can't help but think to myself, "yes, but Judges like the picture that a tall rider poses on a sporthorse!!"

A beautiful sprite of a child was turned into a scarecrow.

And now they want me to come visit... I'm already viscerally angry at the woman for some of her animal care decisions. I want to go visit the girl, but I'm deathly afraid I'll snap and go ballistic on her mother XD

I love the short ones. The x told to me her doctor said she was 5' but suspected he was trying to maker her fell better. Her body fit her perfectly though, I don't think anyone ever thought it weird, more hot. I called her fun sized, you know like the individual packed snacks.

The cell can't do so on its own, no, but it doesn't have to be spontaneous mutation either. There are a wide range of environmental factors and biochemical influences that could induce a change in a DNA line. I don't see why these couldn't affect a germ line. Obviously this wouldn't magically explain everything, but it does bump up your "chances".

It don't make sense. I think my brain is just wired against this kind of thinking. I remember spending hours just trying to figure out what the hell heritability meant. Even now I memorize the definition more than understand it. In a population, x% of variations in a trait is due to genetic variations, or some such.

 

[bhndblueyes88]

I love the short ones. The x told to me her doctor said she was 5' but suspected he was trying to maker her fell better. Her body fit her perfectly though, I don't think anyone ever thought it weird, more hot. I called her fun sized, you know like the individual packed snacks.

Lol yes fun-sized Although I prefer to think of her as an imp, as I had scars on my shins for many years from her temper tantrums

It don't make sense. I think my brain is just wired against this kind of thinking. I remember spending hours just trying to figure out what the hell heritability meant. Even now I memorize the definition more than understand it. In a population, x% of variations in a trait is due to genetic variations, or some such.

That's pretty much the definition. I don't understand why that's a problem for you to understand? There are two influences, genetic and environmental, and in lowly heritable traits, there are more environmental influences than genetic ones. Is it the potential impact of environmental factors that you can't wrap your mind around? If so, I have some excellent examples in my developmental pathology notes I could dig up for you

 

[teknight]

am so!

beef stew.

Uhhhh... you've yet to answer me. Don't make me get the anal hooks!!

@bhndblueyes:Good guess. Still doesn't elucidate me.

 

[bhndblueyes88]

Uhhhh... you've yet to answer me. Don't make me get the anal hooks!!

@bhndblueyes:Good guess. Still doesn't elucidate me.

It wasn't a guess, I had read the post and vaguely recalled it. Go back and read where he was referred to. You're the one who wants to know, not me

 

[where]

.....

 

[teknight]

I did say! beef stew!

I'll PM you his name.

Everything but the food comment!! Grrrr!!

http://www.stockroom.com/common/images/products/C152/C152.jpg

 

[lovebound]

No relevance to the current discussion, but I'm pretty sure most men were created dumb as a way of getting back at smart women.

At least that's the truth if my boyfriend is representative of the entire species.

 

[teknight]

No relevance to the current discussion, but I'm pretty sure most men were created dumb as a way of getting back at smart women.

At least that's the truth if my boyfriend is representative of the entire species.

Are you willing to accept that he might not, in fact, be representative of the whole species?

 

[lovebound]

Are you willing to accept that he might not, in fact, be representative of the whole species?

I don't know. It might take some convincing!

 

[YourCaptor]

That's pretty much the definition. I don't understand why that's a problem for you to understand? There are two influences, genetic and environmental, and in lowly heritable traits, there are more environmental influences than genetic ones. Is it the potential impact of environmental factors that you can't wrap your mind around? If so, I have some excellent examples in my developmental pathology notes I could dig up for you

Heritability does not express a, due to genetics vs due to environment ratio. The two aren't even separated. I think most simply it could be said that it expresses how much of a certain trait arise within a specific population.

No relevance to the current discussion, but I'm pretty sure most men were created dumb as a way of getting back at smart women.

At least that's the truth if my boyfriend is representative of the entire species.

Who is he getting back at? By the way, if he's spending a lot of time with another woman their may be something else going on, just helping you connect the dots.

 

[teknight]

What counts as proof?

 

[bhndblueyes88]

Heritability does not express a, due to genetics vs due to environment ratio. The two aren't even separated. I think most simply it could be said that it expresses how much of a certain trait arise within a specific population.

No I know that's not the definition of heritability, but the traits that are not highly heritable usually are not highly heritable due to environmental effects. It's a correlation, not a definition. I was just trying to figure out what was confusing you about heritability And that's not quite the definition of heritability either. At least, not according to what we were taught. However, I learned about heritability in a breeding course and not a genetics course, so they might have worded it differently to make it apply better to the course material. Unfortunately, I don't think I have those notes anymore, so I can't go look it up :[

 

[where]

No I know that's not the definition of heritability, but the traits that are not highly heritable usually are not highly heritable due to environmental effects. It's a correlation, not a definition. I was just trying to figure out what was confusing you about heritability And that's not quite the definition of heritability either. At least, not according to what we were taught. However, I learned about heritability in a breeding course and not a genetics course, so they might have worded it differently to make it apply better to the course material. Unfortunately, I don't think I have those notes anymore, so I can't go look it up :[

I'm coming into this a bit late... are you saying heritability isn't always down to genetics? just usually?

 

[bhndblueyes88]

I'm coming into this a bit late... are you saying heritability isn't always down to genetics? just usually?

Gah, I'm not explaining what I was trying to very well, I can see.

Okay, going back. YC said, "In a population, x% of variations in a trait is due to genetic variations, or some such." Now, this definition is correct, but it leaves out one crucial word. Phenotype. x% of phenotypic varations in a trait. Phenotype is determined by both genetics AND environment.

For example, in cattle. Red vs. Black in Angus Cattle is a highly heritable trait. It's hard for the environment to change it. However, weaning weight is lowly heritable. Weaning weight is influenced by many genes, and how the calf is raised.

The variations of color tend to be pretty set in stone by genetics. Most of the phenotypic variations in color are due to genetics. It has high heritability.

The variations of weaning weight tend to flux pretty easily, regardless of genetics. Most phenotypic variation is due to environment. It has a low heritability.

Does that make more sense? Heritability needs to be thought of in terms of PHENOTYPE, not genotype.

 

[teknight]

?
From my back in the day bio classes, phenotypes are what's expressed, "what you see," if you will. Since that is a result of external factors as well as genetics (internal factors), we can talk of the odds of seeing traits expressed. I guess, the external influence is what makes me question the outright notion of heritable phenotypes... Or am I missing something?

 

[where]

Gah, I'm not explaining what I was trying to very well, I can see.

Okay, going back. YC said, "In a population, x% of variations in a trait is due to genetic variations, or some such." Now, this definition is correct, but it leaves out one crucial word. Phenotype. x% of phenotypic varations in a trait. Phenotype is determined by both genetics AND environment.

For example, in cattle. Red vs. Black in Angus Cattle is a highly heritable trait. It's hard for the environment to change it. However, weaning weight is lowly heritable. Weaning weight is influenced by many genes, and how the calf is raised.

The variations of color tend to be pretty set in stone by genetics. Most of the phenotypic variations in color are due to genetics. It has high heritability.

The variations of weaning weight tend to flux pretty easily, regardless of genetics. Most phenotypic variation is due to environment. It has a low heritability.

Does that make more sense? Heritability needs to be thought of in terms of PHENOTYPE, not genotype.

a bit clearer. I don't think it's you, I think it's just me being dense.

 

[bhndblueyes88]

?
From my back in the day bio classes, phenotypes are what's expressed, "what you see," if you will. Since that is a result of external factors as well as genetics (internal factors), we can talk of the odds of seeing traits expressed. I guess, the external influence is what makes me question the outright notion of heritable phenotypes... Or am I missing something?

No you aren't.

Some phenotypes are more genetically heritable than others. That's whole idea behind heritability

From wikipedia: "Heritability analyses estimate the relative contributions of differences in genetic and non-genetic factors to the total phenotypic variance in a population."

So a heritability of 1 means that the phenotype will always be genetically inherited. A grey horse is genetically a grey horse and nothing in the environment changes whether he is a grey horse. A heritability of 0 means that there is no genetic influence on the phenotype what so ever. I can't think of a good example for this. Then you'll have traits that are more middle of the road. For example birth weight is pretty close to .5 (I don't know where the text is for this course, so I can't tell you for sure. Kind of moot toward the point, though). there are about equal environmental and genetic determinants for a calf's actual birth weight.

The biggest use for heritability is for breeders. It's easier to shape traits that are more heritable, and if you know which traits are more easily influenced by environment, it's easier to focus your management efforts.

 

[teknight]

No you aren't.
<snip>

Ah. Go wiki on me, will you?
That clears it up. Thank you.

 

[teknight]

Skin was the first organ to evolve That is, if you believe that evolution can happen.

 

[bhndblueyes88]

That makes sense. I believe the present theory is that biological membranes would have been first to form as well, due to the tendency of lipids to form vesicles on their own due to chemical forces. I think the theory was that the vesicles that spontaneously form would accidentally catch proteins. I wish I still had that video. It was really interesting to watch/listen to. Went in to talking about how some protein combinations would keep the vesicle "alive", and eventually as more advantageous proteins would combine, new functions would evolve in order to get more proteins in order to stay "alive" and so on and so forth.

Man I really wish I had it now. I think it'd be awesome to link in, even if it doesn't really relate to "epigenetics" specifically.

 

[teknight]

That makes sense. I believe the present theory is that biological membranes would have been first to form as well, due to the tendency of lipids to form vesicles on their own due to chemical forces. I think the theory was that the vesicles that spontaneously form would accidentally catch proteins. I wish I still had that video. It was really interesting to watch/listen to. Went in to talking about how some protein combinations would keep the vesicle "alive", and eventually as more advantageous proteins would combine, new functions would evolve in order to get more proteins in order to stay "alive" and so on and so forth.

Man I really wish I had it now. I think it'd be awesome to link in, even if it doesn't really relate to "epigenetics" specifically.

Well, to me this is the bio thread...so I posted here.

But, does this lipid vesicle assembly apply (unaltered) to unicellular and multicellular organisms? It seems like there are more factors in play, is what I'm saying.

 

[bhndblueyes88]

Well, to me this is the bio thread...so I posted here.

But, does this lipid vesicle assembly apply (unaltered) to unicellular and multicellular organisms? It seems like there are more factors in play, is what I'm saying.

Oh I'm sure it applies different between different types of organisms. It's just a theory as to how the first "organisms" might have arisen.

 

[where]

But, you've just turned the argument into: are the parents willing to accept abortion? I'm not saying they should, we've just deviated. At the same time, how disabled would a potential individual have to be before abortion started looking like an option? How much pain/suffering should a kid go through for a parent's decision?

the thing is, pre-natal screening is inextricably linked to abortion. here in the UK a cleft palate of a club foot is grounds enough for an at term abortion. I also think that you underestimate the will people have to live. so many people I know live with excrutiating pain daily, but have no wish to die. by the same token, I think that the lengths the medical establishment goes to to keep babies alive is beyond the pale and I think that if a parent wants to abort then they should be free to do so.


Do they come with authenticity stickers? Is it a popularity contest? Fine, they'd make a better face for the movement, but it's not a beauty pageant, is it?

you are being silly now.

Jeez, I'm all over the place here.


Do you know this for a fact? Oh, and, btw, I've fixed your spelling above.
Mind you, there are non-biological explanations for serious mental illness, so...

I spelled it right, fucker.

and I think yes, I'm pretty much accurate in saying most behaviour is social in origin and yes, there are non-bio explanations for some serious mental illness, but, as far as I understand it, there is some suggestion that things like schizophrenia can be inherited.


Unless I'm missing something, I believe this is the argument currently being made.

touche, touche. Although I will point out that not all ...ehh..."abnormality" leads to creative or artistic genius, nor is "normality" deathly boring and non intellectual.
quite true. but think of all the artistic and scientific genius we would have last if everyone was neurotypical

a) Who is Davis? What has he published? (not questioning your expertise nor..uhh..theirs, but, may I read some of this stuff?)
b) I don't follow what you're saying in green.

to follow the argument you need to understand the whole shebang and it's too big to go into unless you have prior understandings. which seems like a cop out, but it's too much right now.