Hope for Pitman's Statistics

Well, not really. Sean was keen to show that a guy with a simple
statistical idea could overturn the entire field of evolutionary
biology. Not very likely, especially with a very bad statistical idea.
A recent article in Science does, however, basically set a whole little
field on its heels with a simple statistical idea that had been
overlooked (Nee et al [2005] The illusion of invariant quantities in
life histories. Science 309:1236-1239).

A mini-field had grown up over the past 10 years trying to understand
"invariant quantities" in life histories. These invariant quantites
were things like the ratio of age at sexual maturity to average
lifespan or of weaning weight to maternal weight. These dimensionless
ratios were allegedly conserved across many taxa and over many orders
of magnitude and the correlation coefficients and R squared values
between, say, weight at weaning and maternal weight, were remarkably
good for biology, up in the 0.90-0.97 range. A bunch of papers were
published trying to figure out the deep unifying principles of biology
that accounted for these dimensionless constants in life histories.

The authors of the new Science paper, however, noticed a simple
statistical point. All the ratios are constraned to the range 0-1,
while the original values (age or weight or what have you) vary over
several orders of magnitude. It was pretty easy to show that under
those circumstances you inevitably get a very high R squared value,
even if the ratios are randomly distributed between 0 and 1. It's
pretty clear that the whole "invariance" in life histories was a simple
statistical artifact.

Not that this is much comfort to Sean, but it does show that a bunch of
smart people can be led down the primrose path because they overlook a
relatively simple issue in statistics.

.

Relevant Pages

  • Re: Hope for Pitmans Statistics
    ... Sean was keen to show that a guy with a simple ... >lifespan or of weaning weight to maternal weight. ... >good for biology, ... But the problem with Sean wasn't so much his statistics ...
    (talk.origins)
  • Re: Hope for Pitmans Statistics
    ... Sean was keen to show that a guy with a simple ... >>> A recent article in Science does, however, basically set a whole little ... >>> lifespan or of weaning weight to maternal weight. ... >>> relatively simple issue in statistics. ...
    (talk.origins)
  • Re: Hope for Pitmans Statistics
    ... > "invariant quantities" in life histories. ... > lifespan or of weaning weight to maternal weight. ... All the ratios are constraned to the range 0-1, ... > relatively simple issue in statistics. ...
    (talk.origins)
  • Re: Hope for Pitmans Statistics
    ... Sean was keen to show that a guy with a simple ... >> lifespan or of weaning weight to maternal weight. ... All the ratios are constraned to the range 0-1, ... >> relatively simple issue in statistics. ...
    (talk.origins)
  • Re: Hope for Pitmans Statistics
    ... Sean was keen to show that a guy with a simple ... > lifespan or of weaning weight to maternal weight. ... All the ratios are constraned to the range 0-1, ... > relatively simple issue in statistics. ...
    (talk.origins)
Loading