---
_id: '1398'
abstract:
- lang: eng
text: Hybrid zones represent evolutionary laboratories, where recombination brings
together alleles in combinations which have not previously been tested by selection.
This provides an excellent opportunity to test the effect of molecular variation
on fitness, and how this variation is able to spread through populations in a
natural context. The snapdragon Antirrhinum majus is polymorphic in the wild for
two loci controlling the distribution of yellow and magenta floral pigments. Where
the yellow A. m. striatum and the magenta A. m. pseudomajus meet along a valley
in the Spanish Pyrenees they form a stable hybrid zone Alleles at these loci recombine
to give striking transgressive variation for flower colour. The sharp transition
in phenotype over ~1km implies strong selection maintaining the hybrid zone. An
indirect assay of pollinator visitation in the field found that pollinators forage
in a positive-frequency dependent manner on Antirrhinum, matching previous data
on fruit set. Experimental arrays and paternity analysis of wild-pollinated seeds
demonstrated assortative mating for pigmentation alleles, and that pollinator
behaviour alone is sufficient to explain this pattern. Selection by pollinators
should be sufficiently strong to maintain the hybrid zone, although other mechanisms
may be at work. At a broader scale I examined evolutionary transitions between
yellow and anthocyanin pigmentation in the tribe Antirrhinae, and found that selection
has acted strate that pollinators are a major determinant of reproductive success
and mating patterns in wild Antirrhinum.
acknowledgement: "I am indebted to many people for their support during my PhD, but
I particularly wish to thank Nick Barton for his guidance and intuition, and for
encouraging me to take the time to look beyond the immediate topic of my PhD to
understand the broader context. I am also especially grateful to David Field his
bottomless patience, invaluable advice on experimental design, analysis and scientific
writing, and for tireless work on the population surveys and genomic work without
most of my thesis could not have happened. \r\n\r\nIt has been a pleasure to work
with the combined strengths of the groups at The John Innes Centre, University of
Toulouse and IST Austria. Thanks to Enrico Coen and his group for hosting me in
Norwich in 2011 and especially for setting up the tag experiment. \r\n\r\nI thank
David Field, Desmond Bradley and Maria Clara Melo-Hurtado for organising field collections,
as well as Monique Burrus and Christophe Andalo and a large number of volunteers
for their e ff orts helping with the field work. Furthermore I thank Coline Jaworski
for providing seeds and for her input into the design of the experimental arrays,
and Matthew Couchman for maintaining the database of. \r\n\r\nIn addition to those
mentioned above, I am grateful to Melinda Pickup, Spencer Barrett, and four anonymous
reviewers for their insightful comments on sections of this manuscript. I also thank
Jana Porsche for her e ff orts in tracking down the more obscure references for
chapter 5, and Jon Bollback for his advice about the analysis. \r\n\r\nI am indebted
to Jon Ågren for his patience whilst I finished this thesis, and to Sylvia Cremer
and Magnus Nordborg for taking the time to read and evaluate the thesis given a
shorter deadline than was fair. \r\n\r\nA very positive aspect of my PhD has been
the supportive atmosphere of IST. In particular, I have come to appreciate the enormous
support from our group assistants Nicole Hotzy, Julia Asimakis, Christine Ostermann
and Jerneja Beslagic. I also thank Christian Chaloupka and Stefan Hipfinger for
their enthusiasm and readiness to help where possible in setting up our greenhouse
and experiments. "
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Thomas
full_name: Ellis, Thomas
id: 3153D6D4-F248-11E8-B48F-1D18A9856A87
last_name: Ellis
orcid: 0000-0002-8511-0254
citation:
ama: Ellis T. The role of pollinator-mediated selection in the maintenance of a
flower color polymorphism in an Antirrhinum majus hybrid zone. 2016. doi:10.15479/AT:ISTA:TH_526
apa: Ellis, T. (2016). The role of pollinator-mediated selection in the maintenance
of a flower color polymorphism in an Antirrhinum majus hybrid zone. Institute
of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:TH_526
chicago: Ellis, Thomas. “The Role of Pollinator-Mediated Selection in the Maintenance
of a Flower Color Polymorphism in an Antirrhinum Majus Hybrid Zone.” Institute
of Science and Technology Austria, 2016. https://doi.org/10.15479/AT:ISTA:TH_526 .
ieee: T. Ellis, “The role of pollinator-mediated selection in the maintenance of
a flower color polymorphism in an Antirrhinum majus hybrid zone,” Institute of
Science and Technology Austria, 2016.
ista: Ellis T. 2016. The role of pollinator-mediated selection in the maintenance
of a flower color polymorphism in an Antirrhinum majus hybrid zone. Institute
of Science and Technology Austria.
mla: Ellis, Thomas. The Role of Pollinator-Mediated Selection in the Maintenance
of a Flower Color Polymorphism in an Antirrhinum Majus Hybrid Zone. Institute
of Science and Technology Austria, 2016, doi:10.15479/AT:ISTA:TH_526 .
short: T. Ellis, The Role of Pollinator-Mediated Selection in the Maintenance of
a Flower Color Polymorphism in an Antirrhinum Majus Hybrid Zone, Institute of
Science and Technology Austria, 2016.
date_created: 2018-12-11T11:51:47Z
date_published: 2016-02-18T00:00:00Z
date_updated: 2024-02-21T13:51:39Z
day: '18'
ddc:
- '576'
degree_awarded: PhD
department:
- _id: NiBa
doi: '10.15479/AT:ISTA:TH_526 '
file:
- access_level: open_access
checksum: a89b17ff27cf92c9a15f6b3d46bd7e53
content_type: application/pdf
creator: system
date_created: 2018-12-12T10:14:51Z
date_updated: 2020-07-14T12:44:48Z
file_id: '5106'
file_name: IST-2016-526-v1+1_Ellis_signed_thesis.pdf
file_size: 11928241
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has_accepted_license: '1'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
page: '130'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '5809'
pubrep_id: '526'
related_material:
record:
- id: '5553'
relation: popular_science
status: public
- id: '5551'
relation: popular_science
status: public
- id: '5552'
relation: popular_science
status: public
status: public
supervisor:
- first_name: Nicholas H
full_name: Barton, Nicholas H
id: 4880FE40-F248-11E8-B48F-1D18A9856A87
last_name: Barton
orcid: 0000-0002-8548-5240
title: The role of pollinator-mediated selection in the maintenance of a flower color
polymorphism in an Antirrhinum majus hybrid zone
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2016'
...