Table 5.

Average effect of chromosome O on thermal preferences (°C).

		Frequency		Average effect
Population	Coordinates	Ost	${\text{O}}_{3+4}^{*}$	Ost	Rest
Málaga (Spain)	36°43'N - 4°25'W	0.080	0.407	-0.4506	0.0392
Punta Umbría (Spain)	37°10'N - 6°57'W	0.066	0.410	-0.4494	0.0318
Calviá (Spain)	39°33'N - 2°29'E	0.057	0.590	-0.4485	0.0271
Riba-roja (Spain)	39°33'N - 0°34'W	0.148	0.324	-0.4530	0.0787
Queralbs (Spain)	42°13'N - 2°10'E	0.290	0.493	-0.4395	0.1795
Lagrasse (France)	43°05'N - 2°37'E	0.330	0.590	-0.4312	0.2124
Montpellier (France)	43°36'N - 3°53'E	0.362	0.557	-0.4232	0.2401
Villars (France)	45°26'N - 0°44'E	0.389	0.581	-0.4155	0.2645
Leuk (Switzerland)	46°19'N - 7°39'E	0.595	0.365	-0.3267	0.4800
Vienna (Austria)	48°13'N - 16°22'E	0.625	0.270	-0.3095	0.5158
Tübingen (Germany)	48°32'N - 9°04'E	0.606	0.351	-0.3205	0.4930
Louvain-la-Neuve (Belgique)	50°43'N - 4°37'E	0.397	0.540	-0.4130	0.2719
Groningen (The Netherlands)	53°13'N - 6°35'E	0.502	0.405	-0.3733	0.3763

${\text{O}}_{3+4}^{*}$ pools gene arragements O₃₊₄ and O₃₊₄₊₈ used in the present work. Together with O_st, their combined frequency is ≥ 0.90 in central European populations and drops to approximately 0.50 in south-western Europe, where arrangement O₃₊₄₊₇ is also frequent. However, from our previous data [34] no difference in T_p is detected between O₃₊₄₊₇ and ${\text{O}}_{3+4}^{*}$, which justifies their pooling and allows estimating average effects assuming two gene arrangements: O_st and the rest. Gene arrangement frequencies where taken from the "new collections" in Solé et al. [52] and Balanyà et al. [54].