Table 2.
Estimations of T50 and slope factor obtained from fitting population survival curves to a sigmoidal dose–response model
T50 values and slope factors are considered as estimations of the average tolerance of populations and of the within-population polymorphism, respectively.
| Pop | Type | T50 (μM CdSO4) | Slope factor | R 2 | n | ||
|---|---|---|---|---|---|---|---|
| Estimated ±SE | 95% CI | Estimated ±SE | 95% CI | ||||
| I28 | NM | 188.7±1.03 | 175.5 to 202.9 | –2.462±0.20 | –2.937 to –1.986 | 0.99 | 8 |
| I30 | NM | 230.1±1.02 | 215.4 to 245.7 | –2.215±0.38 | –3.131 to –1.300 | 0.99 | 16 |
| SK2 | NM | 133.2±1.06 | 115.8 to 153.2 | –2.004±0.61 | –3.448 to –0.559 | 0.98 | 10 |
| AU | M | 235.3±1.03 | 217.3 to 254.8 | –2,669±0.62 | –4.145 to –1.193 | 0.98 | 8 |
| PL22 | M | 352.5±1.03 | 324.6 to 382.7 | –2.158±0.34 | –2.981 to –1.335 | 0.97 | 12 |
| PL15 | M | 379.2±1.01 | 368.5 to 390.1 | –5.282±0.42 | –6.289 to –4.276 | 0.99 | 5 |
| LAN | M | 370.9±1.02 | 347.6 to 395.8 | –2.947±0.58 | –4.319 to –1.574 | 0.97 | 5 |
| I16 | M | 337.1±1.01 | 324.1 to 350.7 | –3.830±0.29 | –4.534 to –3.127 | 0.99 | 14 |
NM, non-metallicolous; M, metallicolous; SE, standar error; CI, confidence interval; n, sample size.