Re: News at <http://longevity-science.org/>

In sci.life-extension Leonid Gavrilov <[EMAIL PROTECTED]> wrote or quoted:
> Tim Tyler <[EMAIL PROTECTED]>  wrote in message news:<[EMAIL PROTECTED]>...
>> Leonid Gavrilov <[EMAIL PROTECTED]> wrote or quoted:

>> > "Does Exceptional Human Longevity Come With High Cost of Infertility?
>> > Testing the Evolutionary Theories of Aging"
>> > http://longevity-science.org/IABG-Gavrilova.html
>> 
>> I enjoyed this one - my thoughts:
>> 
>> The paper says:
>> 
>> ``What is really important is that the chances of being childless do not
>>   demonstrate any increase for long-lived women (lifespan 90+ years).''
>> 
>> From the graph, it /does/ seem like there is an increase in the > 80 yo
>> groups - though its significance is not clear.
> 
> *** The error bars provided at this graph indicate that there is no
> any statistical significance in this small fluke.

A more conventional way of presenting such a result would be to write:

``What is really important is that the chances of being childless do not
  demonstrate any significant increase for long-lived women [...]''

>> My other thought is that it would be nice to have data for other
>> population areas.
>> 
>> The idea that there is a trade-off between reproductive success and
>> longevity is largely based on allocation of limited resources.
>> 
>> Ladies in european aristocratic families may be relatively less
>> likely to experience resource shortages as a result of expenditure
>> on children - and so might avoid much of the resulting impact on
>> their lifespans - by being better equipped financially than most
>> members of the population.
>> 
>> The other obvious bias in the sampling is the one towards females.
> 
> *** Please elaborate in more detail, where have you found an obvious
> bias towards females in our study.

Only women were sampled:

``The dataset is comprised of 3,723 married women born in 1500-1875 and
  belonging to the upper European nobility. Every case of childlessness
  was cross-checked using at least two different sources. Data analyses
  were based on logistic regression model using childlessness as a
  dependent (outcome) variable, and woman lifespan, calendar year of
  birth, age at marriage, husband's age at marriage and husband's lifespan
  as dependent (predictor) variables. We found that woman's exceptional
  longevity does not increase her chances to be infertile.''
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