Temporal genetic stability and fitness responses to human-driven eutrophication in the water flea; Daphnia magna

Marshall, Hollie (2017). Temporal genetic stability and fitness responses to human-driven eutrophication in the water flea; Daphnia magna. University of Birmingham. M.Sc.

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Abstract

Climate change and anthropogenic impact affect natural environments driving species adaptation though migration, plasticity and genetic evolution. Investigation of multiple stressors is paramount to accurately represent the mosaic of stressors found in natural environments. The synergism between different stressors is not always predictable and further work is needed in this field. Resurrection ecology, the hatching of dormant life-stages of some species, pro- vides a powerful method to study species adaptive mechanisms through time to environmental stressors. In this thesis I examine a combination of stressors on Daphnia magna resurrected from the Lake Ring system and assess neutral genetic diversity through time in the same sediment core. Preliminary analysis suggests there are no differences in fitness responses between the sub-populations to combinations of stressors. As neutral genetic variation was also stable over time it is possible standing genetic variation, and possibly the buffering effect of resting egg banks, allow this species to adapt and evolve to strong environmental selection pressures. Further work investigating the mechanisms underpinning this adaptive ability will be done using whole genome and transcriptome sequencing. Finally it was also found hatched and unhatched sub-populations of Daphnia magna, from the same sediment core, show the same neutral genetic diversity and structure suggesting resting stages can be confidently used to represent dormant populations through time.

Type of Work:

Thesis (Masters by Research > M.Sc.)

Award Type:

Masters by Research > M.Sc.

Supervisor(s):