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The theorem was first formulated in Fisher's 1930 book The Genetical Theory of Natural Selection. [4] Fisher likened it to the law of entropy in physics, stating that "It is not a little instructive that so similar a law should hold the supreme position among the biological sciences".
The chance of fissioning on absorption of a thermal neutron is about 92%; the capture-to-fission ratio of 233 U, therefore, is about 1:12 – which is better than the corresponding capture vs. fission ratios of 235 U (about 1:6), or 239 Pu or 241 Pu (both about 1:3).
The theory of evolution is widely accepted among the scientific community, serving to link the diverse speciality areas of biology. [19] Evolution provides the field of biology with a solid scientific base.
Evolution without Selection: Form and Function by Autoevolution is a 1988 book on evolution by cytogeneticist A. Lima-de-Faria. The book argues that only physical and chemical processes are real and the modern neo-Darwinian population genetics approach to evolution is misguided.
Professor of biology Jerry Coyne sums up biological evolution succinctly: [3]. Life on Earth evolved gradually beginning with one primitive species – perhaps a self-replicating molecule – that lived more than 3.5 billion years ago; it then branched out over time, throwing off many new and diverse species; and the mechanism for most (but not all) of evolutionary change is natural selection.
Evolution is the change in the heritable characteristics of biological populations over successive generations. [1] [2] It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. [3]
In a nuclear reactor, the neutron population at any instant is a function of the rate of neutron production (due to fission processes) and the rate of neutron losses (due to non-fission absorption mechanisms and leakage from the system). When a reactor's neutron population remains steady from one generation to the next (creating as many new ...
Two useful introductions to the fundamental theory underlying the unit of selection issue and debate, which also present examples of multi-level selection from the entire range of the biological hierarchy (typically with entities at level N-1 competing for increased representation, i.e., higher frequency, at the immediately higher level N, e.g., organisms in populations or cell lineages in ...