Neo-Darwinist theory is just a theory incorporating current scientific advances in science related to the evolution and biology, as the Laws of Mendel, but continues to deny the influence of the environment or the internal development of living beings in the load of genetic information.
Other theories of evolution and human origin are Synthetic Theory (Dobzhansky, Mayr and Simpson), Punctuated Equilibrium Theory (Eldredge and Gould) and Neutralism Theory.
The Modern Evolutionary Synthesis has incorporated the latest advances of science in biology and genetics. If the Neo-Darwinism or neo-Darwinian Theory explicitly incorporated the random variations or mutations within the population, the Synthetic Theory of evolution incorporates the random variations or mutations of the genetic information and accepts this mechanism as part of the evolution that, together with the mechanism of the natural selection, produce evolution as a whole.
The Synthetic Theory of evolution or Modern Synthetic emerged around the middle of the 20th century from the ideas of three authors specialized in different branches of the evolution: Theodosius Dobzhansky in genetics, Ernst Mayr in the species of living beings and George G. Simpson in the great categories of the organisms.
The diversification emerges slowly, usually through gradual changes, and originates in the specialization. Therefore, it is part of the Gradualism trend as the initial Theory of Darwin.
We can summarize the important differences of the Modern Synthetic Theory of evolution with the Theory of Darwin in the following:
- It incorporates Mendel's Laws.
- Variations in the population due to genetic variability.
- It assumes that the specialization is due to the cumulative changes in the genetic information in addition to the mechanism of natural selection.
In short, the synthetic theory greatly moved evolution of living, to the evolution of its internal component beings, while maintaining the same emergentist philosophy.
Concerning the evolutionary leaps and Modern Synthetic Theory, the controversy is currently present because of the fossil registry, about which there is not a clear position within the scientific community.
The opposite movement would be Saltationism.
It consists of the old attitudes defended by the geneticist Richard Goldschmidt and the paleontologist Otto Schindewolf of evolution in leaps. On the same line, more recently, the Theory of Punctuated Equilibrium or Punctualism appeared due to the contributions from the paleontology of Niles Eldredge and Stephen Jay Gould in 1972; the latter incorporates the selection between species to the Darwinian selection between individuals.
Although the Theory of Darwin is close to Gradualism, it could be compatible with Saltationism; both Theory of Punctuated Equilibrium or Punctualism and Modern Synthetic Theory belong to the Neo-Darwinism.
It is necessary to bear in mind that the General Theory of Conditional Evolution of Life is a fully scientific and evolutionary theory based on the assumptions that all life has an intrinsic tendency to widen the sphere of freedom using evolution within environmental and logical conditions, which indirectly imply an intelligent design. It means something little it working since the origin of life.
Definition, characteristics and main conclusions of the evolutionary theory are in title V of this online book.
Regarding Saltationism and Gradualism, the GTCEL accept small and gradual changes while explaining the evolutionary jumps as quick and big changes of the genetic structure to allow a much bigger development, like the origin of new species. In other words, the evolutionary leaps are a logical consequence of the evolution of vital impulse systems.
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