The Problem of Species in Oenothera
| Autor: | Ralph E. Cleland |
|---|---|
| Rok vydání: | 1944 |
| Předmět: | |
| Zdroj: | The American Naturalist. 78:5-28 |
| ISSN: | 1537-5323 0003-0147 |
| DOI: | 10.1086/281163 |
| Popis: | Except for those forms growing in the southwestern portion of the United States and contiguous areas, the North American euoenotheras do not show a clear-cut segregation into readily recognizable species. Instead, the population consists of a multitude of geographical races which because of balanced lethals breed true, and because of a self-pollinating habit maintain a considerable degree of isolation from each other. Each race is a complex-heterozygote, whose two complexes differ from each other both in segmental arrangement and in genic composition. These races are of hybrid origin, owing their origin to the infrequent occasions upon which the reproductive barriers have been transgressed; or they have been derived from such hybrids through subsequent alteration in segmental arrangement or in genetic composition. One complex in a race often masks the phenotypic effect of the other complex, so that the presence of the latter, and the relationships which this race bears through the latter, can only be show... |
| Databáze: | OpenAIRE |
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