TABLE 1. Results of model comparison for Cryptolithus tesselatus. Numbers in parentheses = set breakpoints for each threshold model; bolded values indicate best supported model. Better support is indicated by lower AICc values. AICc weights indicate the relative likelihood of each model; these are normalized to sum to 1 and may be interpreted as probabilities. See text for additional explanation of different models, and Figure 6 and Figure 9 for plots showing different model fits and slopes for the best supported model.
3D landmarks | 2D landmarks | |||
AICc | AICc weights | AICc | AICc weights | |
linear model | -114.9327 | 0.0010 | -120.283 | 0.0239 |
threshold model 1 (early shift) | -128.2149 | 0.7439 | -126.9374 | 0.6663 |
threshold model 2 (late shift) | -118.9646 | 0.0073 | -122.6766 | 0.0792 |
threshold model 3 (two shifts) | -126.0163 | 0.2478 | -124.815 | 0.2306 |
TABLE 2. Results of model comparison for Marrolithus bureaui (data from Delabroye and Crônier, 2008). See Table 1 for explanation of AICc values, text for explanation of different models, and Figure 10.1 for plot showing linear model and best supported threshold model. Values in parentheses are the natural log of centroid size for breakpoints in each model.
AICc | AICc weights | |
linear model | -356.065 | 0.0008 |
threshold model 1 (1.85) | -356.665 | 0.0010 |
threshold model 2 (2.5) | -362.037 | 0.0153 |
threshold model 3 (2.8) | -369.57 | 0.6618 |
threshold model 4 (two shifts) | -368.123 | 0.3211 |
TABLE 3. Results of model comparison for seven additional species. See Table 1 for explanation of AICc values, text for explanation of different models, and Figure 10.2-8 for plots showing linear model and best supported threshold model, set breakpoints, and data sources.
AICc | AICc weights | |||
linear model | threshold model | linear model | threshold model | |
Aulacopleura koninckii | -1678.252 | -1678.6962 | 0.4447 | 0.5553 |
Triarthrus becki | -501.786 | -598.3558 | 0.0000 | 1.0000 |
Zacanthopsis palmeri | -686.7376 | -760.1803 | 0.0000 | 1.0000 |
Haniwa quadrata | -400.8708 | -440.5485 | 0.0000 | 1.0000 |
Liostracina tangwangzhaiensis | -234.3299 | -239.6435 | 0.0656 | 0.9344 |
Apatokephalus latilimbatus | -398.1783 | -396.8969 | 0.6549 | 0.3451 |
Olenellus gilberti | -532.0049 | -553.5915 | 0.0000 | 1.0000 |