ISSN:
1573-5117
Schlagwort(e):
Arctic
;
adaptation
;
copper
;
distribution limit
;
genetics
;
geographic cline
;
Macoma balthica
;
stress sensitivity
;
survival in air
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract The stress sensitivity, determined in copper exposureexperiments and in survival in air tests, and thegenetic structure, measured by means of isoenzymeelectrophoresis, were assessed in populations of theBaltic clam Macoma balthica (L.) from itssouthern to its northern distribution limit, in orderto test the hypotheses that near the distributionlimit the clams would be more stress sensitive andwould have a lower genetic variability. Thepopulations in west and north Europe show a stronggenetic resemblance. The populations in the sub-ArcticWhite Sea are genetically slightly different, and showa low stress sensitivity. The populations in theArctic Pechora Sea are genetically very distant fromthe other populations, and show the lowest stresssensitivity. Near the southern distribution limit, inagreement with the hypotheses, genetic variability islow and stress sensitivity high. On the other hand, incontrast to expectation, near the northerndistribution limit, in the populations of the PechoraSea, the genetic variability was higher, thus notreduced, and the stress sensitivity was low comparedto all other populations. Yet, it remains a questionif such is due to gradual physiologicalacclimatization (and ongoing differential selection)or to genetic adaptation.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1003009524563
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