It may not be the direct ancestor of living birds, however, and it is uncertain how much evolutionary divergence already was present among other birds at the time.
In the context of the 2R hypothesis, the time of SBP2/SBP2L divergence is uncertain.
Although the cause of the high divergence is uncertain, it is presumed that the sequences of the region have paralogous origins that had been duplicated in the past.
Meanwhile, Liu proposed the concept of entropy to describe the divergence of an uncertain set.
While a consensus is emerging on the topology of the evolutionary tree [1] [5], although with occasional disagreement [6] [8], divergence times remain uncertain.
The associations between host genotype and parasite resistance are currently unknown in the benthic-limnetic system, and so the underlying mechanism of MHC divergence is still uncertain.
Estimates of evolutionary time based on restricted data tend to be highly uncertain, but based on sequence divergence we find it is reasonable to consider C. a. lupaster as a distinct taxon within the grey wolf species complex.
The early history of the clade remains uncertain due to ancient rapid divergence events that are unresolvable even with our genomic-scale data, although this might be largely an effect of several problematic taxa subtended by long branches.
However, the placement of the three remaining Drosophila GATAs (serpent, GATAd, and GATAe) has been uncertain due to extensive sequence divergence within the generally well-conserved dual zinc finger domain.
A sufficient condition not only ensuring the stability of the initial uncertain model but also the non divergence of the computed bounds (i.e. adaptive thresholds) is also given.
