ISSN:
0362-2525
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
A series of nine features of the shoulder girdle, chosen as having functional significance in relation to the movements of the shoulder in arboreal locomotion, have been studied in 1188 specimens of 194 genera of mammals. The features were defined metrically and examined by means of a multivariate statistical technique: viz. canonical analysis. The study has shown that those mammals which are nonarboreal differ considerably among themselves and form the arboreal forms. But the myriad shapes of the shoulder girdle in a wide range of mammals (e.g. some marsupials, edentates, rodents, carnivores and primates) which climb or forage in trees, can be summarized mathematically by a very small number of similar canonical variates. This information correlates well with that of a previous series of studies carried out on the primates alone.The biological information that was postulated as being reflected by the individual canonical variates for the primates is also apparent for the arboreal mammals. The different variates separate the forms in ways which are consonant with what is known about the function of the shoulder in locomotion. Aspects of the shape of the shoulder defined by the analysis appear to be discernible from an examination of the contribution of the original variables to each individual canonical variate. This seems to confirm that the shape of the shoulder girdle within a very wide range of mammals is limited by a very small number of underlying factors of biological significance.One interpretation of the results suggests that the genetic model of the mammalian shoulder may have been sufficiently fixed at an early stage in the evolution of the class as to place considerable constraints upon the subsequent evolution of the shoulder in the different Orders.
Additional Material:
13 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jmor.1051260302
