Animal Domestication

ABSTRACT
The behavioral changes from the effects of captivity of domesticated and wild animals are something that is fairly well understood and studied. However, there is lack of information concerning the morphological changes in animals that have been brought from the wild into captivity. The relative evidence of changes needs to be evaluated in a wide variety of mammalian taxa to have appropriate conclusions, using non-mammalian examples for a fair comparison, however limitations will be set. Morphological effects of the domestication-process are something that will be considered when comparisons are presented between hard and soft tissues in domestic and captive animals to their wild counterparts. Relative changes are; differences in skull

Chandra et al. (1999), presented more evidence concerning the cranial thickening in lions, particularly of tentorium cerebelli and the parietals, and concluded that the deficiency of vitamin A could be the source of the problem. Additionally to changes of pathological origin, there are great differences concerning the body size and rate of maturity between captive and wild animals, evidence suggest that better nutrition while captive could be the cause. A good example is given by Smuts, Anderson & Austin (1978), they found that the dimensions of the cranium of a small sample from a captive lion cub was great than those of the wild from the same geographical area. In addition, observations showed that wild lion cubs were smaller than captive cubs of the same age and are thought to be because of various periods of starvation in the wild animals - a great factor displaying the impact of selective evolution. Schaller (1972) reported that a captive-raised, but wild-caught, lion cub was almost twice the size of wild cubs of similar

Areas that do appear different in captive animals are mostly related to the feeding apparatus, probably due to different mechanical properties of the previously mentioned captive diets. Groves (1982) reported that badly placed trays of feed or the feeding of unsuitable foodstuff caused smaller skulls of captive Indian rhinoceroses (while their mastoid and zygomatic breadths were increased together with a higher occipital crest than those from the wild). Additionally, a study (Meers, 1996) of American alligators showed cranial changes displaying broader maxillae and pre-maxillae, flatter profile and less rigidity and sculpting on the cranial surface than those from the wild. The changes were most likely to be caused by the biomechanics of the feeding