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Genetic Stability in a Peripheral Isolate of STEPHANOMERIA EXIGUA Ssp. CORONARIA That Fluctuates in Population Size
1Department of Genetics, University of California, Davis 95616.
Abstract:
Allelic frequencies did not change at five polymorphic loci in seedlings grown from seeds collected in four consecutive years in a geographically peripheral population of the annual plant Stephanomeria exigua ssp. coronaria (Compositae), even though the population number fluctuated during this period by 50:1. Genetic stability is attributed to buffering effects provided by seed storage in the ground. Evidence described elsewhere suggests that this population was the recent progenitor of a new diploid species. The present result indicates that fluctuations in number of individuals in the parental population were probably not involved in the origin of the new species.
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