A test of the Grant-Stebbins pollinator shift model of floral evolution
Data files
Jan 06, 2025 version files 9.56 MB
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1._Floral_Traits.csv
10.93 KB
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10._Background_Spectra.csv
6.51 KB
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11._Eristalis_Spectral_Sensitivities.csv
15.66 KB
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12._Long-Styled_BS_Seed_Set.csv
4.82 KB
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13._Short-Styled_BS_Seed_Set.csv
5.48 KB
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14._Intermediate_BS_Seed_Set.csv
8.74 KB
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15._GE_Selection_Data.csv
5.21 KB
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16._RH_Selection_Data.csv
3.38 KB
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17._AM_Selection_Data.csv
3.52 KB
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18._Bees_and_Bee_Flies_Contact.csv
2.16 KB
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19._Floral_Trait_Means.csv
280 B
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2._Pollinator_Functional_Length.csv
932 B
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3._Visitation_Rate.csv
387 B
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4._Contact_Frequency.csv
366 B
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5._Individual_PI_and_PFL.csv
1.20 KB
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6._Tepal_Spectra_All_Ecotypes.csv
3.08 MB
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7._Tepals_and_Guides_Long-Styled.csv
2.67 MB
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8._Tepals_and_Guides_Intermediate.csv
2.09 MB
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9._Tepals_and_Guides_Short-Styled.csv
1.65 MB
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README.md
8.34 KB
Abstract
Pollinators are thought to play a key role in driving incipient speciation within the angiosperms. However, the mechanisms underlying floral divergence in plants with generalist pollination systems, remains understudied.
Brunsvigia gregaria displays significant geographical variation in floral traits and is visited by diverse pollinator communities. Because pollinators are often shared between populations, we investigated whether specific pollinators are responsible for driving floral divergence between them.
Three distinct ecotypes were identified, each dominated by three different pollinators: bees, swallowtail butterflies, and long-proboscid flies. Across seven populations, we found a pattern of association between style length and the morphology of pollinators that visit the flowers most frequently and contact the reproductive parts most often. Furthermore, we found significant linear, quadratic and correlational selection on flower number, tepal length and style length within the butterfly and bee-dominated populations. We also found partial evidence for divergent selection on these traits between experimental sites.
Our findings suggest that a handful of key pollinators that vary in their importance have the potential to drive population level divergence in floral traits, which may lead to pollination ecotype formation.
README: A test of the Grant-Stebbins pollinator shift model of floral evolution
https://doi.org/10.5061/dryad.2280gb637
Description of the data and file structure
This data was collected using floral measurements at nine localities in the Eastern Cape of South Africa. At seven of these localities, we documented visitation rates and contact with floral reproductive parts to determine pollinator importance. We additionally caught and measured pollinators for their functional body traits. At three of these localities, we also conducted phenotypic selection experiments, in which we measured floral traits from several hundred individuals and female fitness.
Files and variables
File: 18._Bees_and_Bee_Flies_Contact.csv
Description: Data used to analyse the contact of widespread pollinators with floral reproductive parts at localities where they were most important and also less so
Variables
- Ecotype: floral variety
- Population: Locality
- Pollinator: functional pollinator
- Contact: presence-absence data (1: contact; 0: no contact)
File: 17._AM_Selection_Data.csv
Description:
Variables
- population: Amakhala
- ind.: self explanatory
- TW: tepal width (mm)
- TL: tepal length (mm)
- SL: style length (mm)
- PL: petal length (mm)
- HT: inflorescence height (mm)
- FL: flower number (mm)
- seeds: seed set per individual
File: 16._RH_Selection_Data.csv
Description:
Variables
- population: Rhini
- ind.: self explanatory
- TW: tepal width (mm)
- TL: tepal length (mm)
- SL: style length (mm)
- PL: petal length (mm)
- HT: inflorescence height (mm)
- FL: flower number (mm)
- seeds: seed set per individual
File: 15._GE_Selection_Data.csv
Description:
Variables
- population: Good Earth
- ind.: self explanatory
- TW: tepal width (mm)
- TL: tepal length (mm)
- SL: style length (mm)
- PL: petal length (mm)
- HT: inflorescence height (mm)
- FL: flower number
- seeds: seed set per individual
File: 13._Short-Styled_BS_Seed_Set.csv
Description: Data obtained from breeding system experiments associated with the short style site
Variables
- Species: B.gregaria
- Individual: Individual worked with
- Ecotype: floral variety
- Treatment: experimental treatment -
- control treatment: Control
- outcross treatment: OutCross
- geitonogamy treatment:geit
- facilitated selfing:FacSelf
- Locality: site where experimental plants originated from
- Fruit_set: binary (1: present; 0: absent)
- fertilized_ovules: fertilized ovules per fruit capsule
- Aborted_ovules: aborted ovules per fruit capsule
- Total_ovules: all ovules, aborted and fertilized
File: 14._Intermediate_BS_Seed_Set.csv
Description: Data obtained from breeding system experiments associated with the intermediate style site
Variables
- Species: B.gregaria
- Individual: Individual worked with
- Ecotype: floral variety
- Treatment: experimental treatment -
- control treatment: Control,
- outcross treatment: OutCross,
- geitonogamy treatment:geit,
- facilitated selfing treatment: FacSelf
- Locality: site where experimental plants originated from
- Fruit_set: binary (1: present; 0: absent)
- fertilized_ovules: fertilized ovules per fruit capsule
- Aborted_ovules: aborted ovules per fruit capsule
- Total_ovules: all ovules, aborted and fertilized
File: 12._Long-Styled_BS_Seed_Set.csv
Description: Data obtained from breeding system experiments associated with the long style site
Variables
- Species: B.gregaria
- Individual: Individual worked with
- Ecotype: floral variety
- Treatment: experimental treatment -
- control treatment:Control
- outcross treatment: OutCross
- geitonogamy treatment: geit
- facilitated selfing treatment: FacSelf
- Locality: site where experimental plants originated from
- Fruit_set: binary (1: present; 0: absent)
- fertilized_ovules: fertilized ovules per fruit capsule
- Aborted_ovules: aborted ovules per fruit capsule
- Total_ovules: all ovules, aborted and fertilized
File: 5._Individual_PI_and_PFL.csv
Description: Data set from which we have calculated pollinator importance
Variables
- locality: any of the three short, intermediate and long style sites
- Pollinator: pollinator functional group
- PI: Pollinator importance
- PI adj: Pollinator importance adjusted
- prop.PI: Proportion pollinator importance
- length: functional length of pollinators (mm)
File: 3._Visitation_Rate.csv
Description: Used in visitation rate analysis as the number of visits per flower per hour (i.e. network)
Variables
- Pollinator: pollinator taxa
- MK: Makhanda
- AM: Amakhala
- GE: Good Earth
- KA: Kariega
- NN: Nanaga
- PA: Paterson
- RH: Rhini
File: 4._Contact_Frequency.csv
Description: Dataset used in contact analysis (i.e. contact frequency network - not shown)
Variables
- Pollinator: pollinator taxa
- MK: Makhanda
- AM: Amakhala
- GE: Good Earth
- KA: Kariega
- NN: Nanaga
- PA: Paterson
- RH: Rhini
File: 2._Pollinator_Functional_Length.csv
Description: Dataset associated with the functional lengths of pollinators in mm
Variables
- Pollinator:
- MK: Makhanda
- AM: Amakhala
- GE: Good Earth
- KA: Kariega
- NN: Nanaga
- PA: Paterson
- RH: Rhini
- PW: Petworth
- RE: Riebeeck East
File: 1._Floral_Traits.csv
Description: dataset associated with floral measurements in mm
Variables
- locality: site
- Ecotype: floral variety
- SL: Style length (mm)
- TL: Tepal length (mm)
- PL: Pedicel length (mm)
File: 19._Floral_Trait_Means.csv
Description: Used in data analysis in which the means of floral traits are required, measurements are in mm
Variables
- locality: site
- Ecotype: floral variety
- SL: Style length (mm)
- TL: Tepal length (mm)
- PL: Pedicel length (mm)
File: 8._Tepals_and_Guides_Intermediate.csv
Description: Dataset associated with colour spectra from an intermediate site, in which measurements were taken from the centre of the tepal: mid and end of tepal associated with the dominant colour of the tepal: side.
Variables
- wavelength: wavelength in nanometer
- Side: see in description
- Mid: see in description
File: 9._Tepals_and_Guides_Short-Styled.csv
Description: Dataset associated with colour spectra from a short style site, in which measurements were taken from the centre of the tepal: mid and end of tepal associated with the dominant colour of the tepal: side.
Variables
- wavelength: wavelength in nanometer
- Side: see in description
- Mid: see in description
File: 6._Tepal_Spectra_All_Ecotypes.csv
Description: tepal spectra compiled for the short-styled site, intermediate and long style sites
Variables
- wavelength: wavelength in nanometers
- Short-styled: refers to individuals from the short style site from which the spectra was measured
- Intermediate: refers to individuals from the intermediate style site from which the spectra was measured
- Long-styled: refers to individuals from the long style site from which the spectra was measured
File: 7._Tepals_and_Guides_Long-Styled.csv
Description: Dataset associated with colour spectra from an long style site, in which measurements were taken from the centre of the tepal: mid and end of tepal associated with the dominant colour of the tepal: side.
Variables
- wavelength: wavelength in nanometer
- Side: see in description
- Mid: see in description
File: 11._Eristalis_Spectral_Sensitivities.csv
Description: Hoverfly sensitivities that were imported into the fly colour vision model
Variables
- Wavelength: wavelength in nanometers, self explanatory
- R7p: photoreceptor sensitivity
- R7y: photoreceptor sensitivity
- R8p: photoreceptor sensitivity
- R8y: photoreceptor sensitivity
File: 10._Background_Spectra.csv
Description: Background spectra averaged from several items occurring in the general area in which the plants grow
Variables
- 1 nm: wavelength in 1nm intervals
- Average: average spectra taken from several items in the background, from the area in which the plants grow.
Methods
This data was collected using floral measurements at nine localities in the Eastern Cape of South Africa. At seven of these localities, we documented visitation rates and contact with floral reproductive parts to determine pollinator importance. We additionally caught and measured pollinators for their functional body traits. At three of these localities, we also conducted phenotypic selection experiments, in which we measured floral traits from several hundred individuals and female fitness.