Uma visão de sistemas da assimilação genética de Waddington: Lamarck redivivus???

quinta-feira, novembro 24, 2016

International Journal of Bioinformatics & Biological Systems (IJBBS) IJBBS-01-102

A Systems View of Waddington’s Genetic Assimilation

Nair A1*, Dearden PK2

1 Arthritis & Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City 73104, Oklahoma, USA.

2 Laboratory for Evolution & Development, Biochemistry Department,University of Otago,Dunedin 9054, New Zealand.

*Corresponding Author

Ajay Nair
Arthritis & Clinical Immunology Research Program,
Oklahoma Medical Research Foundation,
Oklahoma City 73104, Oklahoma, USA.
Tel: 1 (405)985-6960
Email :

Received: January 11, 2016; Accepted: March 30, 2016; Published: April 13, 2016

Citation: Nair A, Dearden PK (2016) A Systems View of Waddington’s Genetic Assimilation. Int J Bioinform Biol Syst. 1(1), 10-17.

Copyright: Nair A© 2016. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.

Source/Fonte: UNC Chapel Hill


Lamarck believed that traits acquired during an organism’s lifetime could be passed onto the next generation. Although the idea of the inheritance of acquired characters was discarded due to lack of experimental evidence, Conrad H. Waddington realized its significance. In 1953, he showed that Drosophila melanogaster (wild-type) flies that were heat-shocked produced a Crossveinless (cve; disrupted posterior crossveins) trait. Through repeated selection of this trait with heat-shock, he not only increased its frequency in the population, but also found that individuals, from the untreated stock, showed the phenotype. This apparent inheritance of an acquired character is important to evolutionary theory, because it provides a mechanism whereby the environment may influence future evolutionary change. Despite the long history of this experiment, genetic assimilation remains elusive. The main aim of this work was to examine genetic assimilation and understand it as an evolutionary theory. Revisiting the experiment indicated that there is much that remains unclear. We have shown that production of cve is strain specific, with the white-eyed lines being vulnerable and the wild-type not. Though the frequency of the cve allele increased in every generation, there was a fitness cost for acquiring crossveinless. Assimilation of cve was found to be heritable but, unlike Waddington’s classic work, it did not tend towards fixation; appearing more like a transient, low penetrance effect.