People are getting taller

[JarodRussell]

http://www.ourworldindata.org/data/food-agriculture/human-height/

I am wondering... what's the evolutionary reason to grow taller? Humans basically removed natural selection from the equation. So it's no longer important if you're small or tall to survive. But what about the actual fact of people getting taller? Is that a random mutation in the genes of the next generation based on the nutrition and health care of the previous generation?

 

[Tosk]

Improved nutrition, I assume? Or maybe because ceilings are getting higher and someone has to change the lightbulb.

 

[Melakon]

Better nutrition and improvements in medicine might have something to do with it. I noticed teenagers were getting taller within 5 years of my getting out of high school.

 

[RoJoHen]

Is that a random mutation in the genes of the next generation based on the nutrition and health care of the previous generation?

I wouldn't really call it a mutation. Better health and nutrition simply allows teenagers to get taller during their growth spurts.

 

[Mary Ann]

What everyone else said, though genetics left me at 156cm, not bad health or poor nutrition.

 

[Tom Hendricks]

I'm 6'6" tall and my wife is 6' tall, so I wonder how my kids are going to turn out.

 

[PlixTixiplik]

I agree with everyone saying nutrition, but the OP's statement that natural selection has basically been removed in human evolution definitely isn't true just because we're not at risk of being eaten by a lion on the savanna. I could easily come up with selective pressure for taller human height, given that taller people (at least men, and presumably to a point) are viewed as more attractive, height affects career success and income (which are also related to perceptions of attractiveness), etc. On that basis, there could be a statistical relationship between height and reproductive fitness, and that's all you need for natural selection. Of course, whether such a relationship actually played a role in recent human height increases (or if it even exists beyond a hypothesis) isn't clear, to me at least.

 

[MacLeod]

But don't some studies say Shorter men make better partners.

http://www.bbc.co.uk/news/magazine-29464446


Sure in the past being tall might have been an advantage but is that really true today? But if we are talking dating/procreation does heightims exist being on the short side I would say it does. I've tried the online dating things and you come across profiles like Must be over 5' 10". Sure we all have preferrences but if I wrote Must have Green eyes and be a Red Head, I would quite rightly be called on it. Really at the end of the day if two people get on does their relative size to each other matter?

 

[Robert Maxwell]

Nutrition surely helps a lot, but mate selection must play a role, too.

I suspect no one reads studies to determine what kind of partner they should seek out, though.

 

[Jedi_Master]

How certain can you be that two tall partners will conceive a tall child?
So any "selective breeding" would have to take place over several generations and still would have a decent chance of failure, as far I as I understand.

 

[PlixTixiplik]

That study says that marriages involving shorter men are more likely to last longer (and be happier), but that doesn't necessarily mean that those marriages produce more children, especially since the study also points out that shorter men are more likely to get married later in life. A longer relationship would certainly seem to help, but what's really needed to test the idea is data on average number of children in relation to parental height. I don't know if such data exists (it's not a field that I'm particularly familiar with), to see if taller parents have more children on average.

Height is a heritable trait, and from what I read something like 90% of children fall within 10 cm of the mid-parental heights (the average of father and mother), although with a regression towards the mean for especially short or tall parents. So, yes, tall parents have on average tall children, although I'm not aware of any quantitative estimates on the strength of selective pressure from a hypothetical relationship between height and offspring number.

 

[MacLeod]

Yes but then the question is why do shorter men tend to marry later in life? What factors are invovled in this.

 

[Santaman]

Improved nutrition, I assume? Or maybe because ceilings are getting higher and someone has to change the lightbulb.

Might be that you're right, Kodiak bears are exeptionally large compared to other Grizzly bears it could be that this is because there's a lot of food available to them.

I'r rather short for a Dutchman only 1.73m tall (short) at my school there was a poor guy who was about 2.18m tall and the school building wasn't really suitable for his hight.. you name it and he bumped his head onto it.

 

[Mary Ann]

I'm Dutch as well, Santaman, and come from a family of short people from Roermond. I always feel extra-small when I go back to the Mother Country.

 

[Santaman]

^^ I'm from the wild east of the country, I've been to the UK and there people were shorter than back home in any case.

 

[Mary Ann]

Which bit of the wild east? I have extended family all over the country.

 

[MacLeod]

I'r rather short for a Dutchman only 1.73m tall (short) at my school there was a poor guy who was about 2.18m tall and the school building wasn't really suitable for his hight.. you name it and he bumped his head onto it.

Still taller than me.

 

[ebusinesstutor]

Could be the steroids in the beef.

I think diet change is the biggest part of our increase in height not evolution.

 

[MacLeod]

^Sure diet might be a part, but there can be wide variation in height amongest siblings.

 

[Mary Ann]

It can't be generalised either way. Improved diet and medical care have lead to people being taller regarding stunted growth due to poor health and malnutrition, but genetics still determines what your maximum height is going to be.