Fig. 4From: Evidence for late Pleistocene origin of Astyanax mexicanus cavefishAnalysis of polymorphism in Astyanax mexicanus Texas surface vs Pachón cave population, using Hyphessobrycon anisitsi as outgroup. a Evolutionary model. b The eight SNP classes correspond to the polymorphism patterns that can be found within and between two populations. Class 1: Different fixed alleles in each population, derived allele in cavefish; Class 2: Different fixed alleles in each population, derived allele in surface fish; Class 3: Polymorphism in cavefish, ancestral fixed allele in surface fish; Class 4: Polymorphism in cavefish, derived fixed allele in surface fish; Class 5: Polymorphism in surface fish, ancestral fixed allele in cavefish; Class 6: Polymorphism in surface fish, derived fixed allele in cavefish; Class 7: Shared polymorphism; Class 8: Divergent polymorphism. x, y and z can be one of the four nucleotides A, T, G, CBack to article page