Piero Scaruffi(Copyright © 2013 Piero Scaruffi | Legal restrictions )
These are excerpts and elaborations from my book "The Nature of Consciousness"
The Origin of Evolution
Fundamental to Gregor Mendel's theory is the distinction between the appearance of an organism (its "phenotype"), which turns out to be a blend of the appearances of its parents, and the physical state of the factors inherited from each parent (the "genotype"), which remain unmixed. The physiology of development fuses, at the level of the whole organism, the information of heredity, which is still kept separated at the genetic level. The two fundamental laws of heredity are that, first, the factors that are passed from parent to offspring (which today we call "genes") maintain their individuality despite their interaction with other genes in the development of the organism, and that, second, gene segregation allows for the reappearance of a variation in later generations of offspring. From these considerations Mendel had the intuition that heredity is based on a discrete (rather than continuous) entity, just like Physics is based on elementary particles. That entity was the gene. What is truly inherited is not the "traits": it is the genes.
(Darwin, incidentally, believed that traits were transmitted from parent to offspring through blood).
Mendel also found that new variation will not be diluted by the process of mating but will always be available for selection, a fact that explains why a population variation is not immediately destroyed by selection itself. The antithetical properties of heredity and variation are dual aspects of the same process: the actual variation among members of the same generation explains the transmission of similarity across generations.
In our century, population genetics showed that Darwin's theory (that change occurred by the natural selection of many minute variations) and Mendel's theory (that change occurred suddenly, by mutation) were complementary: changes occur in the frequencies of genes.
Modern evolutionary genetics stems from the merging of those two traditions, the Darwinian and the Mendelian, both of which take variation as the crucial aspect of life. The Darwinian view can be summarized as "evolution is the conversion of variation between individuals into variation between species".
The paradox is that Mendelian theory dictates the frequencies of genotypes as the appropriate genetic description of a population, whereas variation is much more important. As the US biologist Richard Lewontin put it, "what we can measure is uninteresting and what we are interested in is unmeasurable".
Back to the beginning of the chapter "The Evolution of Life: Of Designers and Design" | Back to the index of all chapters