Saturday, November 20, 2010

Laws of Biology

As is well known, there are no laws in biology as in physics, which is the reason I called an idea of mine the First Axiom of Biology. Recently, however, I noted that there are in the recent literature four laws of biology. One paper is titled The three laws of biology by Trevors and Saier. http://saier-14451.ucsd.edu/~saier/bimm122/reading122/TheThreeLaws.pdf

One book is titled Biology’s First Law by McShea and Brandon, which got a book review in this week’s Science magazine. http://www.sciencemag.org/content/330/6007/1048.full

Here are the three laws of biology according to Trevors and Saier:
The First Law of Biology: All living organisms obey the laws of physics and chemistry.
The Second Law of Biology: All living organisms consist of membrane encased cells.
The Third Law of Biology: All living organisms arose in an evolutionary process.

Here is Biology’s First Law, also called “Zero-Force Evolutionary Law” (ZFEL) according to McShea and Brandon:
ZFEL (special formulation): In any evolutionary system in which there is variation and heredity, in the absence of natural selection, other forces, and constraints acting on diversity or complexity, diversity and complexity will increase on average.

Here is what ZFEL supposed to mean:
Imagine a yard containing a number of trees, and imagine that the wind blows from each point of the compass with equal probability. Come autumn, the result will be an increase in the dispersal of the leaves over time. This, they suggest, is a zero-force state because there are no directional forces acting on the leaves. Yet there is a change over time (unlike the phenomenon described by the law of inertia in physics)—the leaves that were originally clustered about the trees become more dispersed. And if an evolutionary system is similarly in a zero-force state, it too will experience an increase in divergence over time.

If there are weaknesses to these laws, it would be formost in my opinion that they are all empirically based and not axioms or self evident. No one could have come up with these laws from priori reason without knowing a lot of biology details. But it seems that most fundamental laws should be simple and self evident. Newton's laws of mechanics are all self evident and Newton called them Axioms.

Second, a major flaw of ZEEL is that it equals random diversity with complexity. It fails to recognize my First Axiom of Construction or First Axiom of Biology that that random diversity must be suppressed in order for complexity/order to advance. Complexity means order which is intuitively obvious. The human brain is the most complex. It is also the most ordered as it is capable of tasks such as mathematics. Fallen leaves become more diverse with time but do not become more ordered or reach a higher level of complexity with higher degree of order. A junk yard become more diverse with time but do not become more ordered and complex. Evolution towards higher complexity is a process from disorder to order or a process of decreasing entropy. I have found that the entropy loss is reflected by the loss of randomness/mutations in the genetic building blocks.

Third, none of the Three Laws of Biology proposed by Trevors and Saier is necessarily true. It could be easily argued that it is realistically possible for exceptions to be found in the future. There may be already exceptions if we just take a look at the existing data from a different perspective and the popular perspective is based on assumptions rather than proven truth. We have not solved the mystery of evolution and the origin of life. What we know about life may look impressive in terms of amount of data but we really know very little about what they really mean.

Finally, these four laws fail as a scientific theory by the only standard that counts which is to explain facts and predict new experiments. For example, they all have nothing to say about molecular evolution phenomenon and cannot compet/replace the neutral theory. And yet the neutral theory is inadequate for macroevolution and fails to explain most key molecular macroevolution phenomenon. Without understanding evolution, one cannot understand biology. Without understanding molecular evolution, one cannot understand evolution. For a law of biology to have little to say about molecular evolution, it can only be a trivial law.

Thus, it is safe for me to conclude that the first real fundamental law in biology is the First Axiom of Biology.

1 comment:

Peer Terborg said...

First and only law:

Nothing in biology makes sense except in the light of reproduction.