From genes to phenotype: dynamical systems and evolvability
Autor: | Pere Alberch |
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Rok vydání: | 1991 |
Předmět: |
Genotype
Dynamical systems theory Population Zoology Plant Science Biology symbols.namesake Genotype-phenotype distinction Genetics Selection Genetic education Phylogeny education.field_of_study Human evolutionary genetics Chromosome Mapping Genetic Variation General Medicine Biological Evolution Phenotype Human genetics Evolvability Genes Evolutionary biology Insect Science Mendelian inheritance symbols Animal Science and Zoology Mathematics |
Zdroj: | Genetica. 84:5-11 |
ISSN: | 1573-6857 0016-6707 |
DOI: | 10.1007/bf00123979 |
Popis: | The advent of genetics as an autonomous field of inquiry is closely associated with the establishment of the concepts of genotype and phenotype (Sapp, 1983). Heritable variation is generated at the genotypic level. Mendelian laws specify how this variability is transmitted to the next generation while selection operates at the level of gene product, i.e., the phenotype, The definition of this conceptual genotype-phenotype dichotomy allowed, for example, the integration of Mendelian genetics and population dynamics; a powerful tool of analysis which has been at the core of the Neo-Darwinian Synthesis (e.g. Provine, 1971; Mayr & Provine, 1980). A consequence of the consolidation of this conceptual framework was the effective elimination of development from the corpus of theoretical evolutionary biology. In the theoretical scheme proposed by evolutionary genetics, development is the function that maps the genotype onto the phenotype. It is well known that, even at the lowest levels of protein transcription, the relationship genotype-phenotype is not one-to-one. At higher levels of interaction, such as morphological traits, the genotype-phenotype is more complex and non-linear. For such a reason, genetic theory has to postulate ad hoc properties, such as pleitropy, penetrance, covariance, etc. to deal with the non-linear interactions characteristic of developmental systems (Cheverud, 1984). This phenomenological treatment, although satisfactory when studying the dynamics of gene transmission and evolution, prevents the possibility of studying the role of development in evolution. These non-linear interactions at the molecular, cellular and tissue levels give a structure to developmental systems that may have important evolutionary consequences. In particular, I would like to review the mathematical properties of the genotype-phenotype mapping function, explore its emerging properties and relate them to the issue of opportunity and constraint in morphological evolution. I will conclude with a speculative hypothesis on the role of selection at the level of the dynamical properties of generative systems. |
Databáze: | OpenAIRE |
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