Changes of chromosomal polymorphism in experimental cage populations of Drosophila subobscura

✍ Scribed by R. Frutos

• Publisher: Springer Netherlands
• Year: 1978
• Tongue: English
• Weight: 797 KB
• Volume: 49
• Category: Article
• ISSN: 0016-6707
• DOI: 10.1007/bf00120559

✦ Synopsis

We have analysed the evolution of chromosomal polymorphism in ten cage populations of Drosophila subobscura established with wild flies from five different natural populations. Periodic chromosomal analysis of the cages showed that the chromosomes of D. subobscura follow two different types of behaviour. In chromosomes A and J, there were erratic fluctuations in the frequencies, with oscillations more or less concentrated around the initial values. In chromosomes U, E and O, one arrangement increased (U1 +z+8, Est, and Ost , respectively) resulting in a decrease in the rest of the structural types forming the different polymorphic systems. We discuss these results in relation to the two types of polymorphisms (flexible or rigid) proposed by Dobzhansky (1962) based on the capacity of response of a potymorphic system to environmental changes.