NeoDarwinian Review

Neo-Darwinism is a term used to describe the synthesis of Charles Darwin's theory of evolution by natural selection with Gregor Mendel's theory of genetics. It arose in the early 20th century and became the dominant evolutionary theory by the mid-century. Homoplasy is the development of similar traits in unrelated organisms. This can occur through convergent evolution, when two or more unrelated species evolve similar traits in response to similar environmental pressures. For example, the wings of bats and birds are both adaptations for flight, but they evolved independently from each other. Here are 10 ways homoplasy challenges Neo-Darwinism: Homoplasy suggests that the environment plays a more important role in evolution than Neo-Darwinism allows for. In Neo-Darwinism, evolution is driven by natural selection, which is in turn driven by the physical environment. However, homoplasy suggests that the environment can also play a role in evolution by directing the cou...

Neo-Darwinism is the modern synthesis of Darwin's theory of evolution by natural selection and Mendelian genetics.  Gene duplication is a natural process in which a section of DNA is copied, resulting in two or more copies of the same gene. This can happen in a variety of ways, including errors during DNA replication, unequal crossing over during meiosis, and transposable elements. Gene duplication plays an important role in evolution. It can lead to the development of new genes, new gene functions, and increased gene expression. It can also allow genes to be subfunctionalized, where each copy of the gene takes on a different function. Neo-Darwinism explains the evolution of new genes and gene functions through the process of natural selection. However, gene duplication challenges Neo-Darwinism in a few ways: Gene duplication can lead to the evolution of new genes and gene functions without the need for natural selection. This is because the extra copy of the gene can m...

"Does evolutionary theory need a rethink?" Nature, October 9, 2014, Kevin Laland, et Al.  Introduction Evolutionary theory has been around since Darwin 170 years ago. It has challenged our understanding of the living world and has had a profound impact on many other fields of science. However, there is a growing body of evidence that suggests that our current understanding of evolution is incomplete. This has led some scientists to call for a rethink of evolutionary theory. The extended evolutionary synthesis One of the main challenges to traditional evolutionary theory comes from the field of epigenetics. Epigenetic changes are heritable changes in gene expression that do not involve changes in the DNA sequence itself as opposed to NeoDarwinism. Epigenetic changes can be caused by environmental factors, such as diet or stress. Traditional evolutionary theory has focused on natural selection as the primary driver of evolution. Natural selection is the differential...

The neutral theory of molecular evolution, proposed by Motoo Kimura in 1968, is a theory that explains the evolution of molecular variation at the population level by random genetic drift rather than by natural selection. Kimura argued that most mutations are neutral, meaning that they do not affect the fitness of the organism, and that the fate of these mutations is determined by chance. The neutral theory is based on the following assumptions: Mutations are random and occur at a constant rate. Most mutations are neutral, meaning that they do not affect the fitness of the organism. The effective population size is finite. Genetic drift is the primary force driving the evolution of neutral mutations. Under these assumptions, Kimura showed that neutral mutations can become fixed in a population by random chance. This is because in a finite population, some alleles will be lost by chance, regardless of their fitness. Over time, this process can lead to significant changes in ...

"All is for the best in this “best of all possible worlds." "It is impossible that things should be other than they are; for everything is right" - Dr Pangloss The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme by Stephen Jay Gould and Richard Lewontin is a seminal paper in evolutionary biology that challenges the adaptationist program of neodarwinism. The adaptationist program is a theoretical framework that views all organic form, function, and behavior as adaptations to the environment. Gould and Lewontin argue that the adaptationist program is too Panglossian, or overly optimistic, in its view of evolution. They use two metaphors to illustrate their point: the spandrels of San Marco and Dr. Pangloss. The spandrels of San Marco are the triangular spaces between the arches of St. Mark's Basilica in Venice, Italy. They are often decorated with beautiful mosaics, but these mosaics were not designed to f...

In her article "Symbiogenesis and the New Synthesis," Lynn Margulis argues that the theory of symbiogenesis, which proposes that new species can arise through the fusion of genomes from different organisms, challenges the central tenets of neo-Darwinism. Neo-Darwinism is the prevailing theory of evolution, which holds that all new species arise through the process of natural selection acting on random mutations. Margulis argued that symbiogenesis is a much more important mechanism of evolutionary change than neo-Darwinism allows for. One of the main ways in which symbiogenesis challenges neo-Darwinism is by providing a mechanism for the rapid emergence of new and complex traits. Neo-Darwinism holds that new traits can only arise gradually, through the accumulation of small, random mutations. However, symbiogenesis can allow for the sudden emergence of new traits by combining the genomes of two or more organisms. For example, the mitochondria and chloro...