Putting the algal tree of life to use
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Transcript of Putting the algal tree of life to use
Putting the algal tree of life to useEvolutionary dynamics of ecological niches, physiology
and species’ diagnostic traits
Heroen Verbruggen School of Botany, University of Melbourne
Algal Diversity
• architecture
• functional traits
• life history
• physiology
Algal Tree of Life• systematics: species delimitation
and higher-level relationships
• phylogenies in evolutionary enquiry
• endosymbiosis events: patchwork of genes → accumulation of genomic features
• examples of phylogenetics applied in evolutionary questions
Talk contents
Systematics
Thermal Niche
Trace Elements
Thermal niche
van den Hoek. 1982. Biol. J. Linn. Soc. 18: 81-144 — Cambridge et al. 1984. Helgol. Meeresunt. 38: 349-363 — Eggert. 2012. In: Wiencke, C., Bischof, K. [Eds.] Seaweed Biology
Thermal niche
Map: T. Schils
Species diversity map
Codium
How does the thermal niche evolve?
How fast?
Which direction?
Pulsed or gradual?
Effect on biodiversity?
Are there covariates?
Exploration
Which direction?
Codium Dictyotales
Tropics
Temperate0.011
0.027Tropics
Temperate0.028
0.032
Are there covariates?sheltered exposed
HalimedaMarcelino et al. 2014. submitted
Pulsed or gradual?
Dictyota
Thermal niche & diversification
DictyotaTyberghein et al. unpublished
Thermal niche evolution• thermal niches evolve over geological timescales
• microhabitat preferences affect evolvability
• diversification relates to SST and its evolvability
• results are taxon-specific
• scale up to bigger datasets: more species
• harder questions: adaptation, interactions, timescales
Talk contents
Systematics
Thermal Niche
Trace Elements
Trace element utilization
Raven. 1999. Photosynthesis Research 60: 111-149
Thylakoid membrane with photosystems
Trace element utilization
Quigg et al. 2003. Nature 425: 291-294
Hypothesis
ExplorationCya
Eug
Cha
Stra
Din
Din
Gla
HapCry
Rho
Chltime(Ga) 00.511.5
Feutilization
low high
Hypothesis ⇒ Model
Cya
EugCha
Stra
Din
GlaHapCry
Rho
Chl
Cya
Eug
Cha
Stra
Din
Din
Gla
HapCry
Rho
Chl
Host phylogeny Plastid phylogeny
Parfrey, L.W., Grant, J., et al. 2010. Syst. Biol. 59: 518-533 — Baurain, D., Brinkmann, H., et al. 2010. Mol. Biol. Evol. 27: 1698-1709.
Results for Fe/P ratioPulsed Gradual
0 10.25
Nuclear Tree0.40 Plastid Tree
Relative rates
σ 2ENDO = 73.5
σ 2OTHER = 447.3
Nuclear tree
p = 0.09Relative rates
σ 2ENDO = 103.2
σ 2OTHER = 382.9
Plastid tree
Simulation study5.05!7.55!3.64!7.94!3.54!4.23!2.42!5.92!6.55!9.78!3.93!4.95!5.17!5.14!6.04!5.10!5.53!4.29!3.76!5.05!2.98!9.28!3.49!2.07!5.67!7.11!6.07!6.05!7.95!3.36!3.95!0.12!3.80!4.02!5.63!4.57!5.22!7.35!5.55
non-ES rate ES rate
1
100
0.01
1
100
0.01
Power analysis
Trace element utilization
• results are inconclusive
• support for existing hypotheses is limited
• power to detect differential evolution of continuous traits is low
• limited effect of increase in taxon sampling
• metalloproteomics approaches
Talk contents
Systematics
Thermal Niche
Trace Elements
Role of ToL in Systematics
Simulation: extrapolate what we know about trait evolution
A
B
C
Problem: Cryptic Diversity
Zuccarello, G.C., West, J.A. 2003. J. Phycol. 39: 948-959. — Photo: J. West
How big is the problem?
Pseudochlorodesmis
Verbruggen, H. et al. 2009. J. Phycol. 45: 726-731 — Photo: H. Verbruggen
Is it more of a problem in simple organisms?
Complexity and diagnosability
Verbruggen, H. 2014. J. Phycol. 50: 26-31.
Simulation: extrapolate what we know about trait evolution
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Complexity and diagnosability
20 characters theoretical maximum = 1,048,576
10 characters theoretical maximum = 1,024
Verbruggen, H. 2014. J. Phycol. 50: 26-31.
• higher complexity ⇒ more unique morphologies • # unique morphologies << # species in clade
total # species
# un
ique
mor
phol
ogie
s
Habitat selection
Verbruggen, H. 2014. J. Phycol. 50: 26-31.
A
B
C
D
E
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Habitat selection
Verbruggen, H. 2014. J. Phycol. 50: 26-31.
Plasticity
Verbruggen, H. 2014. J. Phycol. 50: 26-31.
A
B
C
D
E
➙ 1
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➙ 5
➙ 7
➙ 9
Plasticity
Verbruggen, H. 2014. J. Phycol. 50: 26-31.
Morphological evolution
• # unique morphologies << number of species
• null hypothesis: cryptic diversity abounds
• fundamental inability to distinguish some species (possibly many) morphologically
• problem more pronounced in simple organisms
• plasticity blurs species boundaries
Talk contents
Systematics
Thermal Niche
Trace Elements
Conclusions• test evolutionary hypotheses
• insights from parameters
• measure uncertainty
• simulation to study behavior of methods
• simulation to improve expectations
• perspectives: genome dynamics, life histories, etc.
Verbruggen, Marcelino, Costa (2014) Evolutionary dynamics of algal traits and diversity. Perspectives in Phycology 1: in press [available from www.phycoweb.net]
Acknowledgements
• Collectors
• Collaborators
• Previous workers