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Jenn Sunday BSc Honors 2002
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Thesis Title: Differential Resource Use of Haploid and Diploid Phases of the Alga, Mazzaella splendens (Gigartinales, Rhodophyta) |
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ecological explanation for the evolution of diplo-haplontic life cycles
requires that the haploid and diploid phases utilize resources
differently. In the
isomorphic alga, Mazzaella splendens,
the relative abundance of haploids and diploids was measured in different
seasons in Barkley Sound, British Columbia, and a shift from haploid
dominance in the summer to diploid dominance in the winter is found.
A difference in nitrate uptake rate was found at a moderate nitrate
concentration (11µM) but not at a high concentration (30µM), which not
only hints at physiological differences between the phases, but may also
provide a mechanism for gametophyte dominance in early spring.
In addition, a difference in surface area to mass ratios between
the phases is detectable. This lends further support to the hypothesis
that there are differences between the life history phases despite their
apparent isomorphy, and supports an ecological basis for the evolution of
diplo-haplontic life cycles.
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