Peez

:rolling:
That looks like environmental variance to me.

Peez

Peez

No honey, I was just thinking about the postman.

Peez

premjan

I think therefore it is.

Claudia

What I want to say is that I have often seen
"This trait has high heritability, hence genetics has more influence on it than environment".

I have read it (approximately) on this board, too.

And it is false.
Of course, it can be true in some cases, but it is not the meaning of heritability which mainly deals with variations around the mean, which can be a lot lower than variations of the mean itself between parents / children groups

It is obvious
A genetic component, yes. But it seems that nutrition has a lot more importance than what was thought previously.

Tall parents will usually det tall children, small parents usually get small children. But average height of the parents can be lower than average heigth of children due to nutrition improvements (at least in some areas)

Peez

Yup.This is the part that I do not follow.

Peez

squozebrain

When speaking about heritable traits, can we refer to a quantity of "average Baptistness"? Does "being a Baptist" have to be a binary classification, or can it be fixed to a more informative continuous scale?

travc

My fun Chinese history prof (who thought that historians who didn't use statistics were weaklings) had us demonstrate that increasing mean height within a population is a good stand in for increasing quallity of food and real income (as an assignment). Turns out that height data is avalable in the historic record in lots of interesting places. China, of course, had a great census dating back almost a couple of thousand years. But even more interesting to me was the the average British soilder in the American Revoluiton was 4 inches shorter than his American counterpart. Turns out that the military was a frequent option to the destitute in the UK who would have otherwise starved or at least been dirt poor... and childhood food quality had a big effect on adult height. So we had, by and large, poor uneducated lower class Brits sent to fight strapping farm-lads who had a much higher quality of life.

Sorry for the complete aside...

travc

Back on topic:

Heritability in a nutshell:

How much variation in a trait amoung offspring is accounted for by the variation amoung the parents.

It is all about variance. If a trait is environmentally constrained (such that it does not vary), it is not necissarially devoid of heritability, but you can't measure heritability of that trait either.

God Fearing Atheist

That would depend on what you mean by "more influence."

If you mean genes play a greater role in trait variance, then no, it would be perfectly accurate.

Claudia

In variance within a group, yes.
In total value of the trait, no.