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It was interesting to see them mention shared environments between closely related persons, which was something I hadn't thought about before as another sort of

It was interesting to see them mention shared environments between closely related persons, which was something I hadn't thought about before as another sort of "heritability". (Where "shared environments" could be things like multi-generational poverty or a dangerous family profession or living somewhere with a long history of excess carcinogenic pollution. You get it from your parent and share it with your siblings, but it's not genetic.)

wutbrodo 8y ago
This is pretty much the central problem in distinguishing genetic and environmental factors: those that are most closely genetically related also tend to share much of their environment (hence the utility of things like twin and adoption studies).
tony_cannistra 8y ago
Well, being precise here (sorry, biologist talking)––the whole point of this article is that the "shared environments between closely related persons" is precisely not heritability. The issue at stake here is that genetics play a far lesser role in determining longevity than other non-genetic inheritable factors (like the "shared environment" examples you give); e.g. the heritability of longevity is considerably lower than previously thought.
- saalweachter 8y ago
  Firstly I will admit that the article was a bit much for me to process as a non-biologist, and that it didn't register that that was the entire point of the article until you said so :-) But to be a little defensive, yeah, I know shared environmental factors aren't really "heritable", I'm just saying that it honestly hadn't occurred to me before reading this article that they would be confused for heritable genetic factors, even though it does kind of seem obvious once it's pointed out.
  - tony_cannistra 8y ago
    Yeah, that's the important takeaway regardless of the pedantic terminology of genetics for certain.
- User23 8y ago
  The heritability of traits increases as the environment improves. For example historically height wasn't very heritable, it depended mostly on environment, which is to say nutrition. Now in countries where adequate nutrition is widely available, height is much more heritable. Could the same effect apply to longevity? I don't really know, because I don't even know what environmental factors improve longevity, except for the grossly obvious ones.
dsfyu404ed 8y ago
>Where "shared environments" could be things like multi-generational poverty or a dangerous family profession or living somewhere with a long history of excess carcinogenic pollution. You get it from your parent and share it with your siblings, but it's not genetic.) This is the key here. If you grew up poor with parents that weren't kind to their bodies and died young you'll probably do the same, marry someone who does the same and have kids who do the same.
- toasterlovin 8y ago
  > If you grew up poor with parents that weren't kind to their bodies and died young you'll probably do the same, marry someone who does the same and have kids who do the same. Considering that 90% of the population used to engage in manual labor on farms to provide for themselves, if your lineage never made the transition to non-manual labor like most of the developed world, genetics are probably a more likely explanation.

wutbrodo 8y ago

This is pretty much the central problem in distinguishing genetic and environmental factors: those that are most closely genetically related also tend to share much of their environment (hence the utility of things like twin and adoption studies).

tony_cannistra 8y ago

Well, being precise here (sorry, biologist talking)––the whole point of this article is that the "shared environments between closely related persons" is precisely not heritability. The issue at stake here is that genetics play a far lesser role in determining longevity than other non-genetic inheritable factors (like the "shared environment" examples you give); e.g. the heritability of longevity is considerably lower than previously thought.

saalweachter 8y ago
Firstly I will admit that the article was a bit much for me to process as a non-biologist, and that it didn't register that that was the entire point of the article until you said so :-) But to be a little defensive, yeah, I know shared environmental factors aren't really "heritable", I'm just saying that it honestly hadn't occurred to me before reading this article that they would be confused for heritable genetic factors, even though it does kind of seem obvious once it's pointed out.
- tony_cannistra 8y ago
  Yeah, that's the important takeaway regardless of the pedantic terminology of genetics for certain.
User23 8y ago
The heritability of traits increases as the environment improves. For example historically height wasn't very heritable, it depended mostly on environment, which is to say nutrition. Now in countries where adequate nutrition is widely available, height is much more heritable. Could the same effect apply to longevity? I don't really know, because I don't even know what environmental factors improve longevity, except for the grossly obvious ones.

dsfyu404ed 8y ago

>Where "shared environments" could be things like multi-generational poverty or a dangerous family profession or living somewhere with a long history of excess carcinogenic pollution. You get it from your parent and share it with your siblings, but it's not genetic.) This is the key here. If you grew up poor with parents that weren't kind to their bodies and died young you'll probably do the same, marry someone who does the same and have kids who do the same.

toasterlovin 8y ago
> If you grew up poor with parents that weren't kind to their bodies and died young you'll probably do the same, marry someone who does the same and have kids who do the same. Considering that 90% of the population used to engage in manual labor on farms to provide for themselves, if your lineage never made the transition to non-manual labor like most of the developed world, genetics are probably a more likely explanation.