Neo-Darwinism
In evolutionary biology, neo-Darwinism is understood to be the system of theories developed by August Weismann and Alfred Russel Wallace around 1890 for the causal explanation of species change ( evolution ). Based on Charles Darwin's main work On the Origin of Species (1859), Weismann and Wallace made fundamental corrections and additions to classical Darwinism .
Darwin's mistakes and Weismann's corrections
The Neo-Darwinian theory , also called Neo-Darwinism (or Weismannism), is a variant of the Darwinian theory of descent formulated to a large extent by the German evolutionary researcher August Weismann (1834–1914). The Freiburg zoologist had recognized, among other things, that there is no inheritance of acquired physical characteristics in animals, as was mistakenly assumed by Charles Darwin in his major work published in 1859. Weismann also drew the conclusion that the cause of the variability in animal and plant populations, which Darwin (1859) tried to explain with his misguided Pangenesis hypothesis, is brought about by bisexual reproduction ( sexual reproduction ). Weismann also formulated the concept of the germline soma differentiation of the development of humans and animals, a model that could be confirmed by empirical facts. According to Weismann, variability arises through sexual processes (fertilization), whereby the offspring differ from the parents with regard to numerous characteristics. Dynamic natural selection (Darwin-Wallace principle) then determines the direction of species change, with slow environmental changes leading to adaptation (or extinction). An inheritance of acquired traits, such as B. was suspected by Jean B. de Lamarck (1809) and Darwin (1859), could be refuted experimentally (mouse-tail amputation attempts) as well as theoretically by Weismann. Independently of Weismann, Alfred Russel Wallace (1889) came to similar conclusions, so that he is recognized as a co-founder of the Neo-Darwinian theory.
Sex and Evolution: Neo-Darwinian Discussions 2016
The zoologist, cell biologist and geneticist August Weismann interpreted sexual reproduction as a "generator of variations" and thus started a discussion since 1892 that continues to this day. Countless empirical studies and theoretical models (computer simulations, etc.) have shown that "sex leads to variability". In mammals (including humans) it has also been shown that the males, due to a sex-specific, high germline mutation rate (numerous mitoses during spermatogenesis ), are a decisive factor in the variability within the progeny. This finding was summarized in the following sentence: "Men are generators of variations that are incapable of childbearing". Since only females can reproduce via egg cell production and a subsequent sex act, ie fertilization, the males are in principle unnecessary for maintaining the group - but according to Weismann they create biological diversity. In the event of environmental changes, the collective organisms, due to the diverse offspring, can be preserved with a high degree of probability, since in every generation some random variants arise that can survive and reproduce.
Confusion with the synthetic theory
Although Ernst Mayr and other evolutionary researchers and biology historians have repeatedly stated that Neo-Darwinian theory reflects our picture of the driving forces behind species change around 1900, neo-Darwinism is regularly confused with its further development, the " synthetic theory of biological evolution" . This system of statements for describing and explaining species change includes the evolutionary synthesis of the 1940s (including integration of Mendel's laws of inheritance and population genetics as components for explaining evolutionary events). At the end of the 1990s, the synthetic theory, which can be summarized in 6 central theses, which can be illustrated in illustrated schemes, was expanded to form the "expanded synthetic theory of biological evolution". This complex system of theory, which is to be equated with the scientific discipline "evolutionary biology", also includes symbiogenesis , epigenetics , and other sub-areas of bio and geosciences as integral components. Equating the Neodarwinian theory developed by Weismann (and Wallace) around 1890 with the scientific discipline evolutionary biology (or expanded synthesis) founded around 1950 is incorrect and should be avoided.
Misinterpretations of worldview
The term "neo-Darwinism" is occasionally used by creationists who are faithful to the Bible and secular opponents of evolution in order to discredit the scientific discipline evolutionary biology as a Darwinian "one-man ideology". This misuse of a technical term from biology historiography, as well as the associated devaluation of the achievements of the "sex researcher" August Weismann, is problematic. The word “neo-Darwinism” is only of historical significance today, as the core theses of Weismann (and Wallace) could be supplemented or refined and represent integral components of the scientific disciplines of evolutionary biology and anthropology .
Web links
Individual evidence
- ↑ Mayr, E. (1982) The Growth of Biological Thought. Diversity, Evolution, and Inheritance. Harvard University Press, Cambridge, Massachusetts.
- ↑ Mayr, E. (2001) What Evolution Is. Basic Books, New York.
- ↑ Junker, T. , Hoßfeld, U. (2009) The discovery of evolution. A revolutionary idea and its story. Scientific Book Society, Darmstadt. 2nd Edition.
- ↑ a b c Wrede, P., Wrede, S. (Ed.) (2013) Charles Darwin: The emergence of the species. Annotated and illustrated edition. Wiley-VCH, Weinheim.
- ↑ Kutschera, U. (2010) fact evolution. What Darwin couldn't know. 3. Edition. Deutscher Taschenbuch Verlag, Munich.
- ↑ a b c d e Kutschera, U. (2015) Evolutionary Biology. Origin and evolution of the organisms. 4th edition. Publishing house Eugen Ulmer, Stuttgart.
- ^ Futuyma, DJ (1998) Evolutionary Biology. Third edition. Sinauer Associates, Inc., Sunderland, Massachusetts.
- ↑ Kutschera, U. (2013) Evolution. In: Maloy, S., Hughes, K. (eds.), Brenner's Encyclopedia of Genetics, Vol. 2, pp. 541-544. Elsevier, New York.
- ^ Kutschera, U. (2011) Darwiniana Nova. Hidden art forms of nature. LIT publishing house, Berlin.
- ↑ a b c d Kutschera, U. (2013) Design Errors in Nature. Alfred Russel Wallace and Godless Evolution. LIT publishing house, Berlin.
- ↑ a b c d Ulrich Kutschera : The gender paradox. Man and woman as evolved types of people . LIT , Berlin 2016, ISBN 978-3-643-13297-0 .
- ↑ Blancke, S., Hjermitslev, HH, Kjaergaard, PC (Eds.) (2014) Creationism in Europe. Johns Hopkins University Press, Baltimore.
- ↑ Höxtermann, E., Hilger, H. (Ed.) (2007) Lebenswissen. An introduction to the history of biology. Publishing house Natur & Text, Rangsdorf.
- ↑ Hoßfeld, U. (2016) History of biological anthropology in Germany. From the beginning until the post-war period. 2nd Edition. Franz Steiner Verlag, Stuttgart.