Posted by: Dan | November 11, 2008

A Biological Law of Everything

Medium Image“The articulation of truly great ideas, of the laws of nature, begins with simple premises that all of us see every day. From simple beginnings, ideas like these extend to explain the really big stuff, like the movement of the stars or the workings of time. In that spirit, I can share with you one true law that all of us can agree upon. This law is so profound that most of us take it completely for granted . Yet it is the starting point for almost everything we do in paleontology, developmental biology, and genetics.

“This biological ‘law of everything’ is that every living thing on the planet has parents.

“Every person you’ve ever known has biological parents, as does every bird, salamander, or shark you have ever seen. Technology may change this, thanks to cloning or some yet-to-be-invented method, but so far the law holds. To put it in a more precise form: every living thing sprang from some parental genetic information.

“The extension of this law is where its power comes in. Here it is, in all its beauty: all of us are modified descendents of our parents or parental genetic information.”

– Neil Shubin, Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body (page 174)



While mentioning the ‘Biological Law of Everything,’ I might as well mention the basic inferences behind the theory of Natural Selection. Darwin’s theory consists of three inferences based on five facts derived in part from population ecology and in part from phenomena of inheritance.

Fact 1: All species have such great potential fertility that their population size would increase exponentially if all individuals that are born would again reproduce successfully.

Fact 2: Except for minor annual fluctuations and occasional major fluctuations, populations normally display stability.

Fact 3: Natural resources are limited. In a stable environment they remain relatively constant.

Inference 1: Since more individuals are produced than can be supported by the available resources but population size remains stable, it means that there must be a fierce struggle for existence among individuals of a population, resulting in the survival of a part, often a very small part, of the progeny of each generation.

Fact 4: No two individuals are exactly the same; rather, every population displays enormous variability.

Fact 5: Much of this variation is heritable.

Inference 2: Survival in the struggle for existence is not random but depends in part on the hereditary constitution of the surviving individuals. This unequal survival constitutes a process of natural selection.

Inference 3: Over the generations this process of natural selection will lead to a continuing gradual change of populations, that is, to evolution and to the production of new species.

Can you believe that there are still people that don’t understand these really basic concepts, called Creationists?


Responses

  1. As an afterthought, readers might want to check out Larry Moran’s article of yore, What is evolution.


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