... It does however miss neutral theory so I would prefer
Curiously I don't see it being
excluded ...
quote:
The neutral theory of molecular evolution holds that at the molecular level most evolutionary changes and most of the variation within and between species is not caused by natural selection but by genetic drift of mutant alleles that are neutral. A neutral mutation is one that does not affect an organism's ability to survive and reproduce. The neutral theory allows for the possibility that most mutations are deleterious, but holds that because these are rapidly removed by natural selection, they do not make significant contributions to variation within and between species at the molecular level. Mutations that are not deleterious are assumed to be mostly neutral rather than beneficial. In addition to assuming the primacy of neutral mutations, the theory also assumes that the fate of neutral mutations is determined by the sampling processes described by specific models of random genetic drift.[1]
Surviving a stochastic catastrophe does not depend on fitness so much as luck, and I see that falling under challenge to the breeding population, and an opportunity for the survivors for growth, development, survival and reproductive success in changing or different habitats. It also changes the frequency of hereditary trait distribution.
quote:
The unified neutral theory of biodiversity and biogeography (here "Unified Theory" or "UNTB") is a hypothesis and the title of a monograph by ecologist Stephen Hubbell.[1] The hypothesis aims to explain the diversity and relative abundance of species in ecological communities, although like other neutral theories of ecology, Hubbell's hypothesis assumes that the differences between members of an ecological community of trophically similar species are "neutral," or irrelevant to their success. This implies that biodiversity arises at random, as each species follows a random walk.[2] The hypothesis has sparked controversy,[3][4][5] and some authors consider it a more complex version of other null models that fit the data better.[6]
Examples would be hair and eye color variations, when not subject to sexual selection or survival fitness, as they could propagate randomly in the breeding population ... ie they are
selection neutral.
What I see neutral genetic mutations and selection neutral phenotype traits contributing, is a reserve of increased diversity within the population so that it has a ready arsenal should selection suddenly become an issue, and it also provides a "scaffold/structure" for further mutation, trait alteration, that
could be beneficial but that couldn't occur on its own. An example is the e.coli citrate experiment, where the first mutation is neutral, but without it the second one doesn't happen.
A neutral mutation or trait is neutral until it becomes incorporated into a useful or deleterious mutation\trait, and that can depend on ecological and climate changes.
[Biological] evolution is heritable change in a population over time.
While very simple and direct, I find this --and the standard "change in the frequency of alleles" definition -- fail to incorporate the contribution and effect of the ecological habitat, it's at too molecular level for me.
Take an organism and clone it and put them in different habitats and they will evolve differently because the ecological effect will be different. This is how you get branching lineages of descent.
So you could say that my definition is more of an
ecological definition of (the word) evolution.
Enjoy