A discussion on the dynamics of natural populations - Adaptation and ecotypic components

• Published in: Proceedings of the Royal Society of London. Series B, Biological sciences Biological sciences, 1956-07, Vol.145 (920), p.333-337
• Main Author: Gregor, J. W.
• Format: Article
• Language: English
• ISSN: 0080-4649; 2053-9193
• DOI: 10.1098/rspb.1956.0045

At the present time botanical ecotypic investigations are still concerned mainly with amplifying the records of ecotypically differentiated populations and defining their patterns, and only incidentally with the processes of ecotypic fractionation. That ‘strictly specialized ecotypes are frequently very uniform populations and practically homozygous in respect of many characters’ was the opinion of Sinskaia and other earlier workers in this field. However, the concept of the ecotype unit has been undergoing modification, and to get an impression of the evolution of ideas it is only necessary to examine the changes in the language by means of which the results of ecotypic studies have been recorded. The appearance of the terms deme* and ecocline is but a reflexion of the difficulty of describing the intricate patterns of variation in terms of discrete ecotypes. An ecotype is by definition the product arising as a result of the genotypical response of an ecospecies to a particular habitat. To establish an ecotypic relationship it is virtually essential to demonstrate that variational changes follow some recognizable habitat gradient. Thus established ecotypic variation will almost inevitably be recorded as ecoclinal.