Appendix C. Results of the multivariate analysis showing the effects of life history traits and extrinsic threats on extinction risk.

Results of the multivariate analysis showing the effects of life history traits and extrinsic threats on extinction risk

Appendix B. Stepwise modeling procedure.

Stepwise modeling procedure

Appendix A. Investigated species and their life history traits.

Investigated species and their life history traits

Excel tables of data used in analyses and plots

A zip file of 5 excel workbooks

Frequency of Yellow <i>C. nemoralis</i> recorded as population averages in quarter degree cells of latitude and longitude.

<p>(a) the modern and historic datasets combined (b) the modern dataset and (c) the historical dataset. The Key shows the division of the frequency of the Yellow morph by intervals of 0.2.</p

Frequency of morphs in four habitat types, as predicted from the models in <b>Table 2</b>.

<p>Standard errors are shown. (a) Yellow, all differences between habitats are significant P<0.001; (b) Mid-banded, differences between dune habitat and all others are significant P<0.001. Other differences are not significant; (c) Unbanded. All differences are significant except for that between grassland and woodland. (P<0.001 for all comparisons involving dune, P = 0.023 for woodland v hedge, P = 0.027 for hedge v grassland). All P values in these comparisons were corrected for multiple testing using Bonferroni.</p

Definitions of independent variables used in the statistical analysis.

<p>Definitions of independent variables used in the statistical analysis.</p

A collection of snails from a polymorphic population of <i>Cepaea nemoralis</i> in Poland.

<p>This illustrates the variety of shell colours (Yellow, Pink, Brown) and banding (0, 1, 5) typically found. Photograph by Robert Cameron.</p

Summary of the results of General Additive Modeling of shell polymorphism in <i>Cepaea nemoralis</i> in the combined dataset of historical and 2009 samples collected throughout Europe.

<p>Statistics shown are coefficients (α) and t-values for unsmoothed terms and F-values for smoothed terms. P-values are approximate. n = sample size (number of populations), Dev% is the percent deviance accounted for by the model. Mid-banded frequency is calculated as a percentage of banded. Coefficient values are not given for the terms entered as smooth functions, because such function cannot be described by a single coefficient.</p>†<p>In this case the model omitting Habitat as an independent variable fits slightly better in terms of deviance than the model including Habitat, so no test statistic or p value can be calculated.</p

Paired sample analysis for sites sampled within 20 km of each other in the historical and modern datasets.

<p>n = number of pairs.</p