Cell-biological and molecular evidence is consistent with the absence of key features of meiosis I, including synapsis and recombination.
Yet, some molecular evidence is consistent with past recombination events between MaSp1 and MaSp2 [12], [40], [40], and thus repeat units may have transferred from one gene to the other.
It will be important to determine if these inactivating mutations are shared with Palaeognathae (tinamous and ratites), in which case molecular evidence would be consistent with the loss of enamel in the common ancestor of Neornithes rather than independently in Neognathae and Palaeognathae.
However, the molecular evidence presented here is consistent with B arising from B, but supports evolution of B directly from an ancestral species of P. autumnale.
Reports of apparently independent genetic determination of maxillary and mandibular dentitions, based on tooth size data derived from twins, are consistent with the molecular evidence.
Some authors have argued that such a bottleneck may have occurred in the ancestor of birds at the end of the Cretaceous period [ 6], although this conclusion is not consistent with recent molecular evidence placing the radiation of the avian orders well prior to that time [ 7].
Therefore, they are also fully consistent with genetic and molecular evidence on gap gene regulation (see [ 7], and references therein).
Here, we continue to recognize the full species status of many of these taxa [sensu 8] that is most consistent with the overwhelming morphological and molecular evidence [27], [28], but adopting the genus-level revision to Chelonoidis [26].
Although we have not provided conclusive molecular evidence for movement of the repeat, our analysis is consistent with the recent finding that endogenous repetitive sequences are involved in a subset of chromosomal rearrangements mediated by Ds excision [29].
