The natural selection as defined by Darwin.?

Question

How did Darwin's theories differ from his predecessors? Have the theories proved to be correct?

Answer 1

The only real competitor in evolutionary theory came from Jean Baptiste Lamarck, who believed in the "use and disuse" concept, that a body part that was used extensively would become larger, stronger, and more complex, while unused parts wither away and die (thus the supposed origin of the giraffe's long neck).  Lamarck also was a firm believer in progress in evolution, the concept that all organisms have an innate drive towards greater complexity.  Virtually all of Lamarck's theories about evolution were replaced by Darwin's "descent with modofication" concept.  This theory has withstood the test of time, and is probably one of the most documented principles in biology (Read Steven J. Gould).

The complexity idea is particularly easy to debunk, since the simplest organisms, bacteria, are the most successful organisms on Earth.

Answer 2

Natural selection is the process by which favorable heritable traits become more common in successive generations of a population of reproducing organisms, and unfavorable heritable traits become less common, due to differential reproduction of genotypes. Natural selection acts on the phenotype, or the observable characteristics of an organism, such that individuals with favorable phenotypes are more likely to survive and reproduce than those with less favorable phenotypes. The phenotype's genetic basis, genotype associated with the favorable phenotype, will increase in frequency over the following generations. Over time, this process may result in adaptations that specialize organisms for particular ecological niches and may eventually result in the emergence of new species. In other words, natural selection is the mechanism by which evolution may take place in a population of a specific organism.

Answer 3

Natural selection is the process by which favorable heritable traits become more common in successive generations of a population of reproducing organisms, and unfavorable heritable traits become less common, due to differential reproduction of genotypes.

And YES! Darwin's theories are correct!