Hi guys,
I think that Nature papers are a very big challenge to write. They are
necessarily very short and thereby could be misleading. I know Chuck
Fisher's group and can tell you that the sample contains about 500
individuals (which is very big for a study on deep-sea animals).
Unfortunately, things like statistics are not welcome in papers for Nature.
Ted Williams is a very good statistician and land ecologist, teaching at
PennState University. He retired about one year ago. I'm sure another
paper will be submitted soon with much more data analyses and other
data. The curves they applied are commonly used by people studying
growth in natural populations. In that sense, their study is serious.
It is true that "throughout their lives" is misleading. Actually, one should
refer to Fig. 2 legend to understand the meaning of that phrase. In the
legend, it is said that the maximum growth rate was estimated on the 10%
highest growth values for EACH SIZE CLASS. These are worms which
are considered as being in the best conditions and growing accordingly.
On these data, another curve can be adapted and we can thus calculate
the age of a worm which always grew at the highest growth rate and find
around 80 years. The fault is not really the authors' but Nature's format
where details of experiments and calculations are usually given in
Figures' legends ...
I agree, our growth is non-linear but also it stops after 20 years or so ...
These worms keep growing. Now, these results are only estimates (better
estimates than earlier ones published a few years ago !) and gave us an
interesting subject to discuss. The main interest is the difference or
growth between Riftia and these Gulf of Mexico Lamellibrachia. The life-
span of hydrothermal vents ranges from a few months to about 10 years
on the East Pacific Rise. The Gulf of Mexico seeps are probably stable
for thousands of years ... Adaptations to each environment are very
interesting to study and we have here two very good examples !
Although Nature can be criticized, I think that it is very good for us when
one of our favorite "pets" is the subject of a paper in this Journal.
Wormly, Stephane
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