Determining which forms of reproductive isolation have the biggest impact on the process of divergence is a major goal of speciation research. These barriers are often divided into those that affect the potential for hybridization (premating isolation), and those that occur after mating (postmating isolation), and much debate has surrounded the relative importance of these categories. Within the species Mimulus aurantiacus, red- and yellow-flowered ecotypes occur in the southwest corner of California, and a hybrid zone occurs where their ranges overlap. We show that premating barriers are exclusively responsible for isolation in this system, with both ecogeographic and pollinator isolation contributing significantly to total isolation. Postmating forms of reproductive isolation have little or no impact on gene flow, indicating that hybrids likely contribute to introgression at neutral loci. Analysis of molecular variation across thousands of RAD-seq markers reveals that the genomes of these taxa are largely undifferentiated. However, structure analysis shows that these taxa are distinguishable genetically, likely due to the impact of loci underlying differentiated adaptive phenotypes. These data exhibit the power of divergent natural selection to maintain highly differentiated phenotypes in the face of gene flow during the early stages of speciation.
env_layers
env_layers.zip
this file contains the environmental data used in species distribution modeling in "STRONG PREMATING REPRODUCTIVE ISOLATION DRIVES INCIPIENT SPECIATION IN MIMULUS AURANTIACUS" Sobel and Streisfeld, Evolution
Within the folder, there are 10 .asc files that contain the gridded environmental data specific to San Diego County, CA, USA. Files come from the following sources:
1) bias.asc: a bias layer incorporated into distribution modeling to account for variation in grid size of Worldclim layers across relatively large spans of latitude.
2) bio1.asc: Annual Mean Temperature
3) bio4.asc: Temperature Seasonality
4) bio5.asc: Max Temperature of Warmest Month
5) bio6.asc: Min Temperature of Coldest Month
6) bio12.asc: Annual Precipitation
7) bio15.asc: Precipitation Seasonality
8) bio16.asc: Precipitation of Wettest Quarter
9) bio17.asc: Precipitation of Driest Quarter
10) geology.asc: basic geologic bedrock material
climate data are from: 8 Bioclim layers from the publicly available Worldclim current conditions (~1950-2000) 30 arc-second resolution Global Climate Data database
address: http://www.worldclim.org/bioclim
accessed: February 1, 2012
Geology data were from: US Geologic Survey
address: www.usgs.gov
accessed: February 1, 2012
Geology data are coded as numerical categories, with the following key:
VALUE ROCKTYPE
0 andesite
1 argillite
2 greenschist
3 sandstone
4 diorite
5 peridotite
6 intermediate volcanic rock
7 gabbro
8 alluvium
9 water
10 slate
11 schist
12 mafic volcanic rock
13 serpentinite
14 landslide
15 dune sand
16 blueschist
17 glacial drift
18 conglomerate
19 phyllite
20 limestone
21 mudstone
22 shale
23 dacite
24 granodiorite
25 gneiss
26 sand
27 greenstone
28 plutonic rock
29 metasedimentary rock
30 chert
31 melange
32 quartzite
33 basalt
34 rhyolite
35 siltstone
36 hornfels
37 metavolcanic rock
38 felsic volcanic rock
39 tephrite (basanite)
40 dolostone
41 trachybasalt
42 peraluminous granite
43 mica schist
44 quartz monzonite
45 orthoquartzite
46 granite
47 marble
48 anorthosite
49 tonalite
50 quartz diorite
51 pelitic schist
variable_extraction
variable_extraction_readme
this file contains environmental data for locations of Mimulus aurantiacus populations in "STRONG PREMATING REPRODUCTIVE ISOLATION DRIVES INCIPIENT SPECIATION IN MIMULUS AURANTIACUS" Sobel and Streisfeld, Evolution
each row represents an individual population record.
the columns represents 1) an abbreviated name given to each population, 2) the ecotype of the population, 3) longitude of the population, 4) latitude of the population, 5-13) values for each environmental variable. see env_var_buffers_readme for description of variables.
pollinator_visitation
pollinator_visitation_readme
This file contains data used to calculate pollinator reproductive isolation in "STRONG PREMATING REPRODUCTIVE ISOLATION DRIVES INCIPIENT SPECIATION IN MIMULUS AURANTIACUS" Sobel and Streisfeld, Evolution
each row represents a different bout by a specific pollinator
the columns represent: 1) a name for the array site, 2) the day observations were performed, 3) the kind of pollinator [HB=hummingbird; HM=hawkmoth], 4) the number of transitions from one red-flowered plant to another, 5) the number of transitions from one red-flowered plant to a yellow-flowered plant, 6) the number of transitions from one yellow-flowered plant to a red-flowered plant, 7) the number of transitions from one yellow-flowered plant to another
pollen_comp
pollen_comp_readme
This file contains data used to calculate gametic reproductive isolation in "STRONG PREMATING REPRODUCTIVE ISOLATION DRIVES INCIPIENT SPECIATION IN MIMULUS AURANTIACUS" Sobel and Streisfeld, Evolution
each row represents a specific pollen competition cross
the columns represent: 1) an identification number for the cross, 2) the flower color of the maternal plant, 3) the name of the maternal population, 4) the name of the paternal population from the alternate ecotype, 5) the count of homozygous offsrping, 6) the count of heterzygous offspring, 7) the frequency of heterozygous offspringwered plant to another
seed_set
seed_set_readme
This file contains data used to calculate seed set isolation in "STRONG PREMATING REPRODUCTIVE ISOLATION DRIVES INCIPIENT SPECIATION IN MIMULUS AURANTIACUS" Sobel and Streisfeld, Evolution
each row represents a specific cross
the columns represent: 1) an identification number for the cross, 2) the category of cross, 3) the population of the maternal parent, 4) the ecotype of the maternal parent, 5) the family of the maternal parent, 6) the individual of the maternal parent within the family, 7) the population of the paternal parent, 8) the ecotype of the paternal parent, 9) the family of the paternal parent, 10) the individual of the paternal parent within the family, 11) the number of seeds produced
hybrid_viability
hybrid_viability_readme
This file contains data used to calculate intrinsic postzygotic isolation due to relative hybrid viability in "STRONG PREMATING REPRODUCTIVE ISOLATION DRIVES INCIPIENT SPECIATION IN MIMULUS AURANTIACUS" Sobel and Streisfeld, Evolution
each row represents a specific cross, and 32 offspring were assayed per cross
the columns represent: 1) the combination of populations involved in the cross (see key below), 2) the category of the cross, 3) the number of individuals that germinated out of 32, 4) the frequency of germination, 5) the number of dead individuals out of 32, 6) the frequency of mortality, 7) the frequency that survived
key to population_combo
1 = red ecotype; ucsd population
2 = red ecotype; elf population
3 = red ecotype; lh population
4 = yellow exotype; lo population
5 = yellow ecotype; pct population
6 = yellow ecotype; potr population
pollen_viability
pollen_viability_readme
This file contains data used to calculate intrinsic postzygotic isolation due to relative hybrid fertility in "STRONG PREMATING REPRODUCTIVE ISOLATION DRIVES INCIPIENT SPECIATION IN MIMULUS AURANTIACUS" Sobel and Streisfeld, Evolution
each row represents one replicate
the columns represent: 1) the category of the cross, 2) the combination of populations involved in the cross (see key below), 3) the cross level replicate number, 4) the specific offspring of each cross replicate, 5) the sample replicate number within a plant, 6) the count of inviable pollen grains out of 200 total counted, 7) the frequency of inviable pollen grains
key to population_combo
1 = red ecotype; ucsd population
2 = red ecotype; elf population
3 = red ecotype; lh population
4 = yellow exotype; lo population
5 = yellow ecotype; pct population
6 = yellow ecotype; potr population
SRA212479
Raw reads from a 100bp single-end Illumina 2000 sequencing run of a Pst-I generated RAD-seq library. Barcodes are sorted into individual fastq files for each member of the 6 populations sequenced. Filenames begin with the population name, followed by a unique individual number. Red-ecotype populations sequenced are: ucsd, elf, and lh; yellow-ecotype populations are: lo, pct, and potr.