We compiled data on morph frequencies inTimema cristinae using samples collected in the spring using sweep nets between 1990 and 2023. All individual were scored as 'striped', 'unstriped', or 'melanistic', or occasionally when it was difficult to distinguish between the first two categories as 'intermediate-striped'. Samples from 1990 to 1999 were collected and scored by Cristina Sandoval, who then trained PN in 2000. PN collected and scored most samples from 2000 to 2023. The host-plant collected on was recorded for all individuals.

Datasets from two field experiments are included as well.

Experiment 1. A total of 513 individuals were collected from populations LA (latitude 34.41, longitude -119.80), PRC (latitude 34.53, longitude -119.86), PRNC (latitude 34.53, longitude -119.85), VPC (latitude 34.53, longitude -119.85), and WTA (latitude 34.52, longitude -119.78) between April 30th and May 4th, 2021. Numbers were as follows: green-unstriped morphs, LA 17, PRC 64, PRNC 58, VPC 71, WTA 48; striped morphs, LA 136, PRC 0, PRNC 3, VPC 26, WTA 90. Individuals were randomly assigned to one of 21 treatments (n = 20 stick insects per treatment), which varied the initial stripe frequency from 0% (0 striped, 20 unstriped) to 100% (20 striped, 0 unstriped) in 5% increments. Each of these treatments of 20 individuals was then randomly assigned to one of 21 experimental bushes (near site N2, in the general area of latitude 34.51 and longitude -119.80). Each bush was cleared of existing T. cristinae by sampling it before release. Individuals were released on the morning of May 5th by dumping them from containers; the insects cling to the branches when released in this way because of a strong clinging reflex. Individuals were recaptured using visual surveys and sweep nets on the evening of May 7th and scored as striped or unstriped.

Experiment 2. We conducted a second field transplant experiment to ask whether striped T. cristinae morphs exhibit higher fitness on Adenostoma than melanic morphs. For this experiment, stick insects were collected from a single location, PRNC (latitude 34.53, longitude -119.85). Stick insects for each pair of eight experimental blocks were captured on a single day in 2023: May 9th for blocks 1 and 2, May 11th for blocks 3 and 4, May 13 for blocks 5 and 6, and May 15 for blocks 7 and 8. For each block, 10 striped and 10 melanic stick insects (n = 20 total stick insects per block) were released onto a single Adenostoma bush at the experimental transplant site (latitude 34.51, longitude = -119.80, as in the first experiment) the day after they were collected. Two (blocks 1-6) or three (blocks 7 and 8) days after release, surviving stick insects were recaptured using visual surveys and sweep nets and scored as striped or melanic.

We used genome-wide association (GWA) mapping to identify regions of the genome associated with color-pattern (striped vs unstriped) variation in T. cristinae. For this we used a previously published DNA sequence data set comprising partial genome sequences (genotyping-by-sequencing or GBS data) for 602 T. cristinae from a single population (FHA, latitude 34.52, longitude -119.80).

Description of the data and file structure

The dataset consists of the following plain text files:

Tcris_master_32.txt = Timema cristinae stripe frequency time-series dataset. Column headers describe each field. The core data are the number of each color morph counted as given in the columns unstriped (green), striped, melanistic and intermediate. Other columns give basic collection information: location IDs, collection year, and latitude and longitude coordinates in decimal degrees, elevation in meters (elevation_Clarissa_3), host plant ID (host), and whether the site is from Refugio mountain (1) or not (0) (refugio_yn); climatic data (seasonal mean temperatures and precipitation, in degrees Fahrenheit and inches, respectively); and summaries calculated from the raw count data (total, proportion_melanistic, and proportion_striped). Empty cells correspond with data entries that are not applicable (NA).

TcristinaeGradient.csv = data for experiment 1. This text file gives the number of striped (Str) and green (Uns) stick insects released (0) and recaptured (1), along with block numbers and the total number of stick insects recaptured for each block.

SelectionMelanicStripe.txt = data for experiment 2. This text file gives the number of stripe and melanic stick insects recaptured for each numbered replicate.

fha2013_gs_bin.pheno = stripe phenotypic data for association mapping. There is one row per stick insect with each row containing a 0 or 1 to denote unstriped vs striped morphs respectively. This was used for analyses with the striped genome.

fha2013_gus_bin.pheno = stripe phenotypic data for association mapping. There is one row per stick insect with each row containing a 0 or 1 to denote unstriped vs striped morphs respectively. This was used for analyses with the green genome.

fha2013_gen_gs.geno and fha2013_gen_gus.geno = genotype files for genome wide association mapping with gemma. The files differ in terms of the reference genome use, with gs referring to the striped genome and gus the green unstriped genome. These files have one row per SNP, with the SNP ID, two arbitrary characters, and the Bayesian genotype estimates for each individual. The order of individuals matches the pheno file.

Sharing/Access information

Information on data processing and associated scripts will be available from GitHub: https://github.com/zgompert/RepeatableEvolution