Fig. 2From: Allelic diversity and patterns of selection at the major histocompatibility complex class I and II loci in a threatened shorebird, the Snowy Plover (Charadrius nivosus)Phylogenetic network showing relationships among Snowy Plover MHC class I alleles (a), and MHC class II alleles (b) characterized from eight populations. Long alleles at MHC class I are represented with a white square, whereas non-classical alleles are represented by black squaresBack to article page