Reasonable as far as it goes, it does raise some other questions about whether there is a single evolutionary origin of such a plant.
We found that P. falcipes is a single evolutionary lineage with poor geographic structuring.
Such a transformation was implicit in the assumption that they were related genera, but it would have been a single evolutionary transformation, and it now appears to be a developmental transformation that occurs repeatedly.
In the PI clade there appears to have been a single evolutionary transition to parthenogenesis; among the PII Panagrolaimus strains the phylogeny suggests a single transition to hermaphroditism.
In other words, the move from direct life cycles with one host to complex life cycles with multiple hosts was a single evolutionary event.
The Bayesian clustering and admixture analyses in the present study revealed a genetic similarity of the nicotianae genotypes which strengthens the hypothesis that the adaptation to tobacco was a single evolutionary event.
As pointed out by Park et al. (2007), a sister group relationship between Cestoda and Trematoda also suggests that the transition from direct life cycles on a single host (as in Monogenea) to complex life cycles with multiple hosts (as in Cestoda and Trematoda) was a single evolutionary event.
The simplest model (MB1) was a single evolutionary model (GTR + ΓI) fit to the entire dataset followed by additional models (MB2-MB9) that were created by the addition of dataset partitions among and within non-coding and coding gene fragments (Table 1).
We provide convincing evidence supporting LGT as the mechanism responsible for this adaptation, and rather than being a single evolutionary event, it appears to have occurred multiple times, with all Streptococcus species known to be major causes of mastitis identified as possible donors.
The most parsimonious explanation for the origin of the C-(I) form appears to be that a single evolutionary event, characterized by the deletion of the three residue turn and loss of the zinc-binding motif, occurred in the Betaproteobacteria lineage and was inherited monophyletically by the descendant Betaproteobacteria and the Gammaproteobacteria.
