See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/335310914 What do wind-dispersed species tell us about loss of dispersal potential on islands? - Presentation Presentation · July 2019 CITATIONS READS 0 69 1 author: Mario Mairal Stellenbosch University 38 PUBLICATIONS 217 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Consequences of polyploidization: from single traits to population dynamics View project 'WORLDCLIMB': Patterns of the climbing impacts on cliff vegetation of the Mediterranean Biome: implementation of an innovative and comprehensive methodology in a worldwide geographical range View project All content following this page was uploaded by Mario Mairal on 21 August 2019. The user has requested enhancement of the downloaded file.
What do wind-dispersed species tell us about loss of dispersal potential on islands?
Flightless birds in islands
Flightless insects in islands Darwin’s wind hypothesis
Reduced of dispersal ability in island plants Pappus Cynareae, Centaurodendron Cichorieae, Dendroseris Madiinae, Argyroxiphium Island Island Mainland Mainland Island Mainland (Juan Fernández) (Juan Fernández) (Hawai)
Reduced of dispersal ability in island plants Bidens pilosa (American mainland) Bidens (Asteraceae) (Carlquist 1966) Society Islands Marquesas Islands Pitcairn Islands
Dispersal ability in plants Fleshy fruits Plumes and wings Barbs and hooks Endozoochory (internal animal) Floating diaspores Epizoochory (external animal) Anemochory (wind) Thalassochory (water)
Evolution of dispersability: Anemochory Allows for testing the evolution of dispersability from a mechanistic point of view Dispersal potential is related to the morphological structures of the diaspore Small seeds with high surface/volume ratio Develop plumes or wings facilitating aerial transport
Efficiency of dispersal: Anemochory Achene attached to a feathery plume (pappus) as Predictor of dispersability If selection favours dispersability: Pappus >Ratio pappus to achene size , > Wind dispersal (Sheldon & Burrows 1973) Achene
The loss of dispersal on islands hypothesis Mainland New populations New populations population On islands On islands Selection Low Medium Low Medium High Low dispersability High dispersability High Medium dispersability Old populations Intermediate age on islands populations on islands Older island populations show reduced Selection dispersal potential relative to mainland Selection populations or to young island populations (Cody & Overton 1996) Low Low Medium High Medium High dispersability dispersability
Loss of dispersal on islands hypothesis (LDIH) Fragmented vs. Unfragmented landscape Mainland vs. island locations Anemochorous species of Asteraceae Crepis sancta Cheptou et al . 2008 Cody & Overton 1996 Dispersal ability in island populations decreased within a few generations Rapid evolution towards lower dispersal
Difficulties to support the LDIH T wo Epilobium species 27 endemic plants in Rumex bucephalophorus the Canary Islands Vazačová and Münzbergová 2014 Talavera et al. 2012 Fresnilo & Ehlers 2007 These species showed higher dispersal ability on islands compared to mainland
To estimate the loss of dispersability … Restricted island endemics Relative amount of time Previous studies Detailed spatio-temporal Phylogenetical tools population histories Nowadays
García-Verdugo et al . 2017 Canary Islands Cape Verde Periploca laevigata
García-Verdugo et al . 2017 Free falling trials Inverse of seed terminal velocity (Vt) Phylogeographic framework Estimates of dispersal ability
García-Verdugo et al . 2017 Western Canaries Dating analyses Canary Islands Cape Verde Cape Verde Mediterranean islands Classification of lineages as old or young Eastern Canaries Oldest lineages showed the highest estimates of dispersal ability Dispersal ability may be favoured, rather than negatively selected for, on islands
García-Verdugo et al . 2017 Correlation Haplotypes Islands with higher availability of habitats, Successful dispersal very rare among islands had populations with more dispersive seeds and extensive within islands Islands with higher within-island habitat availability generally have populations with more dispersive seeds
García-Verdugo et al . 2018
García-Verdugo et al . 2018 Spatio-temporal Phylogeography Periploca Kleinia
García-Verdugo et al . 2018 Population age and dispersability Ancestral areas Recent populations Kleinia and Periploca displayed parallel increases in diaspore dispersability when compared with their respective mainland sister-species
García-Verdugo et al . 2018 Seed size General pattern of increased seed size documented on islands (Kavanagh and Burns, 2014) This is linked to loss of dispersability in anemochorous diaspores (Burns, 2018) Kleinia Periploca Increased seed size Decreased seed size Loss of dispersal potential is not the consequence of selection for larger seeds
The evolutionary potential of dispersal and persistence traits in island adaptative radiations: the subtribe Sonchinae in macaronesian archipelagos. Mairal et al . In prep Adaptative radiation to study the evolution of dispersal traits Sonchus has shown: • Morphological variability related to dispersal ability (dimorfism of pappus) • Variability in traits related to persistence (longevity, woodiness, growth habit) We tested dispersal syndromes and persistence traits • Phylogenetic signal (Pagel´s λ , D statistics) • Niche conservatism (variance of Ackerly, reversals in Mesquite) • Dispersal traits were less phylogenetically conserved than persistence traits. • Persistence traits (longevity and woodiness) favour/promote niche conservatism
Main insights 1) LDIH is not common phenomenon to all island taxa 2) Dispersal ability can be favoured on islands : possibly because traits enhancing wind dispersal availability are positively selected when habitat availability is high 3) It is necessary to integrate phylogeography for hypothesis testing: linking phylogeography, plant traits and lineage differentiation. 4) Test both phylogenetic signal and the level of niche conservatism to infer the evolution of dispersability 5) An study on anemochorous plants on islands around the world might elucidate the contribution of dispersal structures vs. seed size
Acknowledgements DRD Travel Grant Carlos García Verdugo Zuzana Münzbergová Juli Caujapé Castells THANK YOU FOR YOUR ATTENTION www.mariomairal.com
Pho hoto / / Image Credits • Mycelis muralis. Wall lettuce- www.terrain.net.nz • Inaccessible Island Rail ( Atlantisia rogersi ) - Brian Gratwicke • Solanum nigrum berries – Wikipedia, Vishal Sharma • Anatalanta aptera – Sub-Antarctic wingless fly- AFBA Project • Antrops truncipennis - Burton & Croxall, A Field Guide to the Wildlife of South Georgia • Bidens pilosa – Wikipedia, Wibowo Djatmiko (Wie146) • Bidens pilosa - Sherwin Carlquist • Calycopteryx moseleyi - B. Chaubet • Crepis sancta - KU Leuven • Dendroseris litoralis - Andrew Masson • Imagen filogenia - Filogeografía y vertebrados, Capítulo 14, Ella Vázquez Rodríguez • Epilobium angustifolium - Paul Slichter • Epilobium hirsutum - Ferran Turmo Gort • Euphorbia atro - garden.org • Fleshy fruits - Elmar Robbrecht, Tropical Woody Rubiaceae. Characteristic Features and Progressions. Contributions to a New Subfamilial Classification • Flightless cormorant ( Phalacrocorax harrisi ) – Wikipedoa, Charles J Sharp. • Flightless moth – Pringleophaga marioni . AFBA project webpage • Habitat fragmentation photo- Ecography Journal. • Hypochaeris radicata - www.commanster.eu • Javan cucumber seed ( Alsomitra macrocarpa ) - Scott Zona • Kakapo 2 – JIDANCHAOMIAN. Flickr • Logo phylogeny-fr- www.phylogeny.fr • Molecular Clock - theconversation blog • Picea abies seeds with wings – Gmihail, at Serbian Wikipedia • Rumex bucephalophorus - Jose Quiles • Schoenophilus pedestris - Kohn 1962 • Stephen island wren - illustration by John Keulemans • Taraxacum sect. Ruderalia. MHNT-Didier Descouens • White-throated Rail ( Dryolimnas cuvieri ). Source: Alamy View publication stats View publication stats
Recommend
More recommend
