B chromosomes in populations of yellow‐necked mice – stowaways or contributing genetic elements?

Figures & data

Figure 1 Geographic location of the three examined populations(1, Adal; 2, Mt. Cer; 3, Mt. Avala).

Figure 2 Linear measurements taken on each skull ofApodemus flavicollis (CBL, condylobasal length; ZW, zygomatic width; NL, nasal length; CW, cranial width; BZW, bizygomatic width; NW, nasal width; MIOW, minimum inter‐orbital width; IM3, distance from the 3rd upper molar to the upper incisor; PL, palatal length; UDL, upper diastema length; LUM, length of upper molars; MXHR, maximum height of rostrum; CH, cranial height; TML, total mandible length; IDL, inferior diastema length; MH, mandible height; LLM, length of lower molars).

Table I. Eigenvectors of the first three principal component (PC) scores based on 16 cranial and mandible variables in Apodemus flavicollis. The variables are arranged after their principal component loadings.

Traits	PCl	PC2	PC3
BZW	0.700	−0.058	0.079
MH	0.690	0.078	0.310
IM3	0.630	−0.215	0.089
TML	0.582	0.166	0.297
ZW	0.570	0.020	0.151
CW	0.541	0.170	−0.099
UDL	0.541	−0.391	0.235
MIOW	0.389	0.249	0.097
LUM	0.024	0.847	0.117
LLM	0.061	0.817	−0.016
CH	0.003	0.568	−0.094
MXHR	0.146	−0.081	0.862
IDL	0.231	−0.100	0.804
NW	0.107	0.055	0.495
NL	0.225	0.081	0.427
PL	0.250	0.263	−0.400
Eigenvalue	3.742	2.193	1.456
Total Var	23.4%	13.7%	9.1%

Figure 3 Principal component scores(mean±SE with 95% confidence limits) for the three populations studied.

Table II. Canonical discriminate function (DC) and results of Discriminant Function Analysis.

	DC1	DC2	Wilks' λ	Partial λ	F (2,230)	p‐level
MXHR	0.815	−0.132	0.397	0.772	33.96	***
LLM	0.168	0.793	0.334	0.918	10.24	***
IM3	−0.261	−0.639	0.334	0.918	10.23	***
NW	−0.374	−0.108	0.327	0.936	7.90	***
IDL	0.401	0.093	0.325	0.943	7.00	**
TML	0.338	0.268	0.325	0.943	6.96	**
BZW	−0.355	0.018	0.322	0.953	5.73	**
CH	−0.132	0.433	0.320	0.959	4.94	*
LUM	−0.161	−0.550	0.319	0.960	4.79	*
PL	0.134	0.149	0.311	0.986	1.67	n.s.
MH	0.166	−0.108	0.310	0.989	1.26	n.s.
MIOW	−0.043	−0.199	0.309	0.990	1.10	n.s.
UDL	−0.130	0.097	0.309	0.992	0.92	n.s.
NL	0.107	0.023	0.308	0.994	0.68	n.s.
ZW	−0.104	0.084	0.308	0.994	0.67	n.s.
CW	−0.027	−0.036	0.307	0.999	0.07	n.s.
Eigenvalue	1.405	0.357
Cumulative variance Explained (%)	79.7	100.0
*** p<0.001; ** p<0.005; * p<0.01 (Bonferroni correction was applied).Wilks' λ = 0.307, F (32,460) = 11.60, p<0.001.

Figure 4 Scatterplot of the scores for pairs of discriminant functions.

Table III. The classification matrix and percent of correctly classified cases in each population (proportional to the respective group size).

	% correct	Mt. Cer	Ada	Mt. Avala
Mt. Cer	66.94	81	23	17
Ada	84.62	10	55	0
Mt. Avala	82.26	11	0	51
Total	75.40	102	78	68