this is a big question that is almost always framed incorrectly.
evolution and survival of the fittest is unquestionably true in short time frames and powered by genetic mutations and local conditions. eg agriculture has caused a lot of changes in humans over the last 5-10 thousand years. longer time frames and development of different species is a much fuzzier and less understood mechanism but still a very reasonable hypothesis.
the problem is that people confuse a natural tool, evolution, with the origin of life. evolution only works on pre-existing life forms, it does not cause them to come into existence.
the actual origin of the spark of life is unknowable at this time. I am all for teaching evolution in school, just dont pretend it has anything to do with the origin of life.
Actually, I am reserving origin of life for some future post....
Now, as for mutations....
I must point out that mutations only function to alter the adaptability of a particular extant species to its environment.
They don not cause large alterations, e.g.. producing new species.
1. Paleontologist Louis Agassiz knew the fossil record better than any man alive.
"He recognized that the problem with Darwinism was not the survival of the fittest, but rather the arrival of the fittest. Agassiz knew, as did most all animal and plant breeders both then and today, that
clear limits exist to variation and no known way exists to go beyond these limits in spite of 4,000 years of trying. .... all mutations known to us cannot even begin to produce the variety required for molecules to mankind evolution, but rather they create 'monstrosities, and the occurrence of these, under disturbing influences, areÂ…only additional evidence of the fixity of species. '"
Louis Agassiz: Anti-Darwinist Harvard Paleontology Professor
a."DarwinÂ’s theory of the development of living systems is
based on gradual accumulation of micromutations, i.e. mutations that lead to slight changes in the phenotype of organisms. Only long-term accumulation of these minor changes, as a consequence of the consistent action of natural selection, can lead to major evolutionary changes in the structure of organisms.."
Macromutations evolution | Frozen Evolution. Or, that?s not the way it is, Mr. Darwin. A Farewell to Selfish Gene.
b. "By
macro-mutation I mean a considerable hunk of DNA that contains more than one gene....All macro-mutations have drastic effects on development,
most are lethal. "
Genetic Dark Matter? Part 2 | | Richard C. Francis