Estimation of ancestral ranges
BioGeoBEARS analyses identified DEC as the best model with restriction
to dispersal and an influence of the closure of the Panama Isthmus and
Andean Uplift (Ho7) as the hypothesis with strongest support (Figure 3,
Table 5). The tribe most likely originated in South America (node I in
Figure 3, Figure S6). The genus Archaeoprepona retained its
ancestor’s range of origin (node II in Figure 3); other ranges with high
probability also suggest a continental America origin (Figure S6).
Similarly, Mesoprepona+Prepona likely originated in South America
(node III; Figure 3); the other probable regions of origin comprise
broad ranges as for its sister genus (Figure S6). The origin ofPrepona was most likely in mainland South America, excluding high
elevation habitats of the western Andes (node IV; Figure 3). Finally,
the clade that corresponds to the transition of color patterns from
mostly blue to red Prepona species was found to have most likely
originated in the Amazon and Eastern Andes (node V; Figure 3, Figure
S6); the other ranges with high probability are narrow, where Andes,
Amazon or Chocó are also likely regions of origin (Figure S6).
Discussion
In our study we hypothesized that shifts in color patterns and/or
biogeographical events have contributed to Preponini diversification. We
also hypothesized that the tribe originated in the Amazon basin, given
its high species richness in this region. Despite finding high rates of
wing color evolution, mostly in the red Prepona clade (Figure 2;
Node V in Figure 3), we found that diversification rates in Preponini
were not dependent on color evolution. However, major landscape
reconfiguration, happening through most of the tribe’s evolutionary
history, did seem to influence speciation rates and distribution
patterns (Table 1 for models of biogeography dependent diversification
analysis results). The Panama Isthmus and the uplift of the Andes
mountain range together contributed most to the distribution patterns of
extant Preponini. Cladogenesis happened mostly through dispersal to new
ranges or splitting of broadly distributed taxa, as suggested by the
Dispersal Extinction Cladogenesis model (DEC; Table 5), and Preponini
likely originated within South America.