Biological Joumal of Ùlt Linnean Socitty ( 1994), 52: 177- 196. With 4 figures

Genetic variation and differentiation in the
lizard, Podarcis wagleriana {Reptilia:
Lacertidae)

MASSIMO CAPULA

Via F. Arena, 54, 00171 Roma, llaly

Reuiutd 13 }tl11uary 1993, acuptdfor publicatiO'fl 26 May 1993

      T he elcctrophoretic variacion at 26 presum\)(ive gene loci '"as inve>tigalro in populations of Podarcif
       IJJ(JR/trilllUJ from Sicily, che Aegad ian lslands, and the Aeolian b lands. For interspecifìc comparison,
      samples of the closely related lizard P. sicula from che same gcogra phic area were also used.
       Population heterogeneit)' analyses carried out by the euimacjoo of F-staUstics and Nci's sta nda rd
      ge.netic disca nce, showed a high genetic homogeneit y within P. sicukl, but a noticcable genetic

    ndifferemiation wit hio P. w~ltriaWl. In the lauer species, Nei's ra nged from O to 0.212, and ahis is

       because the Aeolian popula tions were quii.C distinct from those ìnhabitiog Sicily and the Aegad ian
       hla nds. Fixed ditferencf$ klcolifiM aa thrce loci (Ck, A a11, Gp-4) comributcd to a relatively high
       value of Nci's standard generic d isaance betwecn the two popuhtc:ion groups (D= 0.147). This value
       is vcry sirrular lo those found comparing pairs of wcll-recognized biological species includcd in the
       genera Podarcis a od Lacerta. E.nimation ofthe time ofevolutionary diverge nt e shows th at the Aeolian
       a nd Sicilian popuJations of P. wagJeriana have becn isola ted geogmphically far a long timc {0.7 Myr
       accord ing lO Nei's formula; 2 M yr according tu Sa rich's cali!Jra tion), indicating evolutiooary
       divcrgence a\ the sp~ies leve\. B a~ on gmtuc. and biogeogr<\phic da ta , it is suggc:.tt:d the
       recogniòon of full specifìc staws for the Aeolian popuJations, for which thc name P. ra.ffonei comb.
       nova (Aeolian wallliza.rd) is proposcd. Electrophorctic data a nd comparative specaes d istributions

      suggcst ahat (l) Podmru sicilia rcccntly oolonizcd the Aeolia n Islands, and (2) it has competed
       successfully with P. ra.ffonei in this a rea, gread )' reducing ahe range of the latter and causing ahe
      extinction of most of its populations. In faca. P. sicula is widespread in the Aeoliao Archipelago,
       whilc P. rajfrmri is confined at prl'Sent to one large island (Vulca no) a nd three ti ny islands

       (S trombolicchio, Scoglio Faraglione, La Canna). This can be consider ed a dassic example of
       compe titive exclusion of a native form (P. roffQntÌ} by a species accidemally inaroduced by nUln
       (P. sicula).

       ADDITIONAL KEY WORDS:- Podarru rtJjfonti - P9tk:rfii sit111a - Podartis lllagleriiJII(J - allozyme
       d ectrophoresis - popuJa tion heccrogeneity - gene Aow - ge.netic d ivergence - biog-eography.

                                  CON"f ENTS

lotroduclion .                                                                  178
M a\c:rial and me\hods .
                                                                                l 78
     Sampling .
      Elcctropborais                                                            118
      Analy$iS .
Rerults                                                                         180

      Genetic varia bility                                                      180
      PopuJation heterogen eity
     Geoe How                                                                   182
      Quster analysis a nd multidimen»onal scaling ordìna tion                  185
                                                                                186

                                                                                188

                                                                                188

0024-4066/94/060117 +20 S08.00f0  177

                                                © 1994 T~ Linnea n Society of Londo n