Moreover, the morphological sets of landforms selected by Davis as chronological "mile posts" for his cycle of landform change (i.e., stages of development) have been found to constitute special, generally polygenetic arrays of landscape features that reflect the interplay of several environments and that have little or no sequential time significance.
Future studies are based on the hypotheses (1) that the vestibular nuclei play a key roll in the adaptation to AGF conditions, (2) that the stimulus transducing systems in the sense organ are affected by AGF conditions, and (3) that fertilized eggs will be converted to normal adults guided by physiological and morphological set points representing the genetic programs.
After we carefully smoothed the contour and filled the holes using additional morphological opening and closing operations (with morphological element set to be 'disk' shape, with 10 and 20 pixels in diameter, respectively), we achieved better thinning results in Figure 5b and c, which however were still not as good as the detected PS in Figure 5d.
Therefore, like larval and hard-part morphology, which are continuously updated [ 62, 63], morphological character sets derived from internal organs of sea urchins will serve as a useful systematic reference for future studies.
Our morphological data set, associated with the great amount of phylogenetic results, allows an assessment of the morphological variation in mandibles among both hystricognaths and sciurognaths.
The construction of morphological character sets for phylogenetic inference is dependent on robust determination of homology.
Further, the new morphological data set significantly rejected the reference phylogeny (P < 0.000067).
The morphological data set presented here is an enhanced version of the Wetterer et al. (2000) data set.
Scrutinising the morphological data set for characters potentially coupled functionally with social parasitism [ 1, 2, 13, 54, 55, 63, 64] yielded 37 characters which we hence excluded from our morphological data set.
The first three principal components (PCs) account for 96.9% of the total variance in the morphological data set.
