Table 8 Summary of main results, hypotheses, and conclusions

Ecological divergence of molecular forms

Biogeographic differences in distribution; indices of co-occurrence and niche overlap; differences in distribution of habitat suitability; segregation of karyotypes in separate clusters coincident with molecular form status on major eco-geographical gradient (first DCA axis)

Competition among taxa

Patterns of co-occurrence associated to relative abundance; reversal in relative abundance not matching environmental steepness of environmental clines; similar fundamental ecological niche (competition for the same resources)

Shared keystone predator(s) apparent competition

Niche expansion of M form

Mismatch between fundamental and realized ecological niches; relative prevalence in lower quality habitat

Phylogenetic relationship among taxa

Ecological divergence of karyotypes

Segregation along environmental gradients

Competition among karyotypes

Segregation along habitat quality gradient of 'typical' and 'atypical' karyotypes

Shared keystone predator(s) apparent competition

Adaptive role of chromosomal inversions

Non-random distribution of karyotypes along major eco-geographical gradient; concordant distribution of karyotypes between molecular forms

Phylogeographic relationship among taxa; presence of ecological adaptation genes inside inversions

Role of chromosomal inversions in reproductive isolation (lack of)

Chromosomal inversions do not fully segregate according to molecular form

Presence of reproductive isolation genes inside speciation island(s)

Epistasis

Ecological value of chromosomal inversions depends upon M/S background

Presence of ecological adaptation genes inside speciation island(s)

Reinforcement

Rarity of hybrids (despite significant hybridization and fertility and viability of hybrids*)

Fitness of hybrids; cryptic mate choice

Secondary contact after divergence in allopatry

Admixture of karyotypes in contact zone

Mismatch between fundamental and realized ecological niches