
The grandmother factor: Why do only humans and whales live long past menopause? - alexandros
http://www.scientificamerican.com/blog/post.cfm?id=the-grandmother-factor-why-do-only-2010-06-30
======
nkurz
It's an interesting article, but surprisingly light on details, even for
Scientific American.

Here's the actual paper:
[http://rspb.royalsocietypublishing.org/content/early/2010/06...](http://rspb.royalsocietypublishing.org/content/early/2010/06/24/rspb.2010.0988.full)

And here's a delightful book that hits this topic and more:
[http://www.amazon.com/Mothers-Others-Evolutionary-Origins-
Un...](http://www.amazon.com/Mothers-Others-Evolutionary-Origins-
Understanding/dp/0674032993)

Sarah Hrdy is one of the absolute best popular science writers out there. This
and her earlier book "Mother Nature" are two of the best unsung biology books
I know of. I've given multiple copies as gifts.

Edit: Having now read more of the referenced paper, my opinion of the
Scientific American article drops further. The key detail left out of the SA
summary is that the paper describes an interesting mathematical model, rather
than yet another 'just so' story. Read the paper, skip the summary.

------
harshpotatoes
And now we cicumvent all evolutionary purposes, by moving across the country,
and having children in our 30's, making it very hard for the elder generation
to become involved with our children's lives.

~~~
Gormo
Of course, the ease of moving across the country has been facilitated by
advancements in transportation and communication, and the trend of people
having children in their 30s is likely correlated with the simultaneous
increases in average lifespan, so this is really a self-correcting problem.

Evolution is a process that is always at work in all circumstances, not
something that we can circumvent.

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devinj
Humans and dolphins. None of the "whales" mentioned (orcas and pilot whales)
are actually whales, they're both dolphins.

~~~
jacksoncarter
This kind of response is part of why hackers have such a difficult time in
social groups. That it is upvoted 7 times really drives the point home. The
article isn't at all about whale nomenclature. It's about an observation of
the world around us and a discovery that may explain it.

Yet, this comment has nothing to do with that discovery and only "nitpicks"
some superficial detail wholey irrelevant to the discussion. It throws
everyone off track with something that doesn't matter -- at all.

It's a semantic debate and it detracts from the conversation. It's annoying
and it's why "normals" don't like to talk with hackers.

For the record, _some_ people believe dolphins are whales, and some don't:

<http://www.ftexploring.com/askdrg/askdrgalapagos4.html>

~~~
roqetman
I agree, but the article didn't contain any actual research figures, just a
few suppositions (which made the inaccuracy stand out).

------
Jun8
How can this be right? I know that elephants society is formed around
matriarchs that may be quite old.

~~~
Shorel
Based on both the article data and your data I can deduce that old matriarch
elephants are still fertile.

------
reasonattlm
A couple more reference links on the topic:

[http://www.fightaging.org/archives/2009/02/why-are-humans-
lo...](http://www.fightaging.org/archives/2009/02/why-are-humans-
longlived.php)

[http://www.fightaging.org/archives/2005/04/evolution-
longe-1...](http://www.fightaging.org/archives/2005/04/evolution-longe-1.php)

Evolutionary histories and their effects on life span are still a rich area
for research. New and interesting theories are still being developed. For
example, see the recent thoughts on crowding as a path to longevity in some
species:

[http://www.fightaging.org/archives/2008/01/ouroboros-on-
the-...](http://www.fightaging.org/archives/2008/01/ouroboros-on-the-
evolution-of-extreme-longevity.php)

------
kbutler
Because Scientific American forgets about elephants?

------
forinti
This is a relatively recent development in human life. Roman women didn't
usually live past 30. And it wasn't until the XX century that average life
expectancy exceeded 40 years.

EDIT: And 50% of Roman women died giving birth. So there weren't many
grandmothers around.

~~~
LeBleu
This is a common misconception caused by quoting mean life expectancy at
birth, when the distribution is highly asymmetrical. High infant death rates
cause low life expectancy at birth, but the life expectancy if you live to age
5 can be massively longer.

A 5 year old ancient Roman was expected to live to 48. About 35% of the
ancient Roman population was over 30 years old. The highest listed age is 76,
which is the life expectancy of a 70 year old, an age that about 1 in 50
ancient Romans achieved.
<http://www.utexas.edu/depts/classics/documents/Life.html>

[http://en.wikipedia.org/wiki/Life_expectancy#The_Popular_Mis...](http://en.wikipedia.org/wiki/Life_expectancy#The_Popular_Misconception)

~~~
forinti
Excellent point. But that still doesn't leave many grandmothers around (1 in 3
at best?). And they didn't have many years beyond their reproductive age.

~~~
blahedo
Um, think about your numbers a bit more. 1 in 3 what? If 1/3 of the population
was over 30 and the average lifespan of people living past infancy was 48,
there were probably a _lot_ of grandmothers around. Especially if women were
having their first children in their late teens, which is just a guess but
seems likely.

