Comment: There can be abysses behind all
table figures. The mental world of man is increasing in complexity every year.
As a consequence there is a proportionally increasing desire for clarity,
for guidelines, for understandability. We tend to listen to people who seem
to be able to break down the complexity to simple news like: "use my diet xyz
and you will stay healty. This is the result of a highly complex study based
on scientific results from 100,000 students". Not to speak of some politicians
that are lingering from press conference to press conference eagerly pretending
to be able to understand and even to solve the problems of the whole world.
Tables with well ordered, cleanly single cell imprisoned figures are consoling
in this chaotic situation and they look promising on our way to mental clarity.
But they can be elusive and deceptive as well. Why? Let's look at our tardigrade
tables once more:
The tardigrade enthusiast will possibly interprete the experiment in a different way:
a survival value of 0.0% would imply that less than one of thousand tardigrades
does survive after rehydration. But, as the 0.0% values in the table are based
on groups of 90, 92 or 36 individuals, at least the last digit of the result is
definitely overdone: in the case of 36 individuals one might state that
"less than 2%" of the tardigrades do survive, not 0.0 %. Remember,
one would need at least 1,000 individuals to confirm a 0.0 % survival
value. On a first sight one might think that this point of view might just
be a narrow-minded precision discussion. But, at second thought you will come
to the conclusion that it is not:
In nature there can be a tremendous difference between a value of 2 percent and
0.0 percent. It might be the difference between the survival of a population and
its death. Even a single female tardigrade might be sufficient to continue
the thread of life. We are all aware of the fact that "mother" nature
exerts tremendous brutality when generating individuals in high numbers and risking
at the same time that only a few of them will actually survive.
We call it selection or evolution. In fact it is some kind of life insurance
for life itself - shared among those many individuals which are desperately trying to
carry on - some lucky, many less lucky. Coming back to our percentages this means
that a difference between 0.0% and 0.1% percent might be much more decisive than
the rest of the scale between 0.1% and 100%. We live in a strange world anyway but
it tends to become even more strange when we are investigating the environment
of zero values on a linear scale. What if one out of a billion tardigrades
would be able to come back to life after 100 years? We would no be able to find
out in an experiment with 10,000 tardigrades but it might be possible. And we do have
no doubt that a billion of tardigrades are nothing when compared to
the world tardigrade population.
But, obviously, we will never be able to run an
experiment with a billion tardigrades. So Rebecchi's experiment gives a
reliable tendency but no one on earth will be able to actually tell whether it
provides safety in the 0.000 to 0.001% range.