scale and biology

Questions to ask a biologist:

"What is the growth rate of hair in turns per second?"
and
"How big is the Human Genome in meters?"

For some odd reason, biology is not particularly good at quantities. Astrophysicists know about the distances between stars, and chemists know enthalpies of reactions but biologists? Some have accused this science of being nothing more than 'butterfly collection' - that is, naming and classifying objects.

In case you were wondering, the first question has the answer '10' (for a growth rate of 15cm a year), while the second is 1.2 meters.

See: bioarchitecture

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There seems to be some confusion from this node - both on my part and, naturally, on the part of pimephalis. I didn't say biologists can't do maths I said (or meant to say:

Scale is an important, and difficult to grasp, feature of biology.

I mean, the astrophysicist has to deal with very large things (say 10¹⁰m) and the nuclear physicist with very small things (say 10^-10m) but only the biologist has to consider structures with such a range (Ångstroms to meters).

So the problem is, biology has traditionally been a descriptive science and is only this century becoming a more quantitative one. What surprises me is the incomplete grasp of the scale of biological structures (how much bigger is a neuron than a water molecule? how many mitochondria could fit into a cheek cell?).

I hate to have to do this, but this node should really be more thoroughly explained as the concept of scale is integral to the science of biology, and particularly to ecologists. But, before I get on to that, I really have to reply to Alchemists' inference that the science of biology is nothing more than butterfly collection.

The criticisms that he levels at biologists in general are, in my opinion, unfair and misleading. Not that it is inappropriate to ask biologists the two kinds of questions listed above, but the fact that any working biologist may not be able to answer should not be taken as evidence of the poor scientific status of the field of biology. After stating that biologists are "not particularly good at quantities", he then contrasts these individuals with chemists and astrophysicists. The latter are able, apparently, to tell you, at the drop of a hat, about the distance between any two stars and the enthalpy of any reaction. I would claim that they would likely have to look up this information prior to responding, as a biologist would have to do in the prior cases.

Biologists can be particularly good at mathematics and numbers, if their work requires it. Anyone who doubts this should look at any recent publication from the journals of vegetation science (particularly strong in multivariate statistics) and evolution (very strong in mathematical modeling).

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Now, that being said, on with the node itself. The concept of scale is integral to modern ecologists, and has even an overriding paradigm: hierarchy theory.

Hierarchy theory is, essentially, the following list of concepts:

1. Everything is connected and inter-related.
2. Every ecological entity is referred to as a holon.
3. The speed at which a holon varies depends on its spatial scale and the scales of those holons that influence it most strongly.
4. The strength of the relationship between two is determined by their scales: the closer the scales, the stronger the relationship.

This concept allows ecologists to attack complex, hierarchical questions in an intelligent manner. Recent work I've seen uses hierarchy theory to create models of ecological function, and subsequently applies modern statistical and numerical approaches to determine the scales at which communities, populations and species vary.