Combining phylogenetic, geographic and macro-ecological data to determine niche evolution and biogeography of the marine green algal genus Halimeda
Tyberghein, L. (2008). Combining phylogenetic, geographic and macro-ecological data to determine niche evolution and biogeography of the marine green algal genus Halimeda. MSc Thesis. Universiteit Gent; MARELAC: Gent. 29 pp.
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| Available in | Author |
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Document type: Dissertation
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| Keywords |
Biological phenomena > Evolution
Geography > Biogeography
Modelling
Niches (ecological)
Species composition
Species diversity
Marine/Coastal |
| Abstract |
Marine benthic macro algae are important primary producers and provide both food and habitat for numerous other organisms. Although phylogenetic relationships between and within algal genera are increasingly characterized, macro-evolutionary processes remain relatively poorly addressed. We present an approach based on a combination of niche modeling techniques, molecular phylogenetics and ancestral state estimation to elucidate evolutionary niche dynamics and biogeographical patterns of the marine green algal genus Halimeda. Species’ niches were globally predicted using environmental characteristics associated with point localities for a given species. A nearly comprehensive molecular phylogeny was inferred from a six-locus dataset. Our study confirms the utility of recently developed methodology for species distribution modeling in evolutionary research, but also show the sensitivity of these methods when applied to correlated macro-ecological datasets. A newly developed niche similarity statistic implied a high degree of niche conservatism among Halimeda species and confirmed the pronounced tropical character of the genus. A comparative model test indicated directional trends in evolution of macro-ecological traits. Further we showed high predicted niche similarity between Atlantic and Indo-Pacific Halimeda species, leading to the conclusion that the genus Halimeda was strongly influenced by vicariance events and is presently unable to disperse between ocean basins. Niche modeling also identified several geographical hotspots where undiscovered species may occur in the East-Pacific Ocean. |
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