Geometric Morphometrics to the Study of Skull Sexual Dimorphism in aLocal Domestic Goat Breed

摘要

The existence of sexual dimorphism in the White Rasquera goat breed has long been known, with males being larger than females. However, no study so far has explored this dimorphism separately in its size and shape components. Here we analysed twenty-three skeletonized skulls from adult animals (11 males and 12 females) belonging to this breed by means of geometric morphometric (GM) methods using 7 landmarks on dorsal aspect. Differences observed between the sexes are size related, with males bigger than females. Shape is also an important component separating males from females. The difference in skull form between sexes may be interpreted in relation to extensive management styles of the animals: being under a low anthropogenic influence they tend to reinforce their natural sexual size dimorphism. This being the first known study to apply GM to a domestic goat breed, we advocate for further GM research in domestic breeds in order to have the possibility of comparing populations and easily exchanging information between research centres.