2 Chapter 1 Origin , Systematics , and Morphological Radiation

INTRODUCTION Deer have always been significant elements of aboriginal cultures in every part of the world where they occur, be it as source of food, hides, and/or medicines. Similarly, the representations of deer in cave paintings, their inclusion in heraldic shields of some countries, their appearance in folkloric legends and innumerable toponymies, illustrate the sociocultural significance of these mammals. At present they are of great interest, both from aesthetic and cynegetic perspectives. The greatest attraction that deer present for humans lies possibly in the possession of antlers in the males; antlers are used to manufacture diverse utensils. The reindeer (Rangifer tarandus) is the only species in which the females also have antlers. Conversely, these are absent in the Chinese water deer (Hydropotes inermis), while males of this species have long canine teeth (Putman 1988). Some controversy surrounds the question of the primitive or derived nature of the presence of antlers and consequently, whether their absence in Hydropotes is a derived character (Janis and Scott 1987, Scott and Janis 1987), given that antlers were present in the earliest recorded fossil deer (such as Dicrocerus). This hypothesis is supported by the several molecular analyses (Gilbert et al. 2006; Kuznetsova et al. 2005; Pitra et al. 2004; Randi et al. 1998), in which Hydropotes appears as sister group to some genera of Odocoileinae. Another perspective proposes that the evolution of antlers took place after the differentiation of the lineage that led to this genus, and that there is no evidence supporting a secondary loss of those structures (Hamilton 1978). In another phylogenetically close group, the musk deer (Moschus spp. Moschidae), males also lack antlers and possess markedly enlarged canines. However, the members of this genus are currently not considered as “true deer” (see citations in Grubb 2005). Compared to Eurasian species such as the red deer (Cervus elaphus), fallow deer (Dama dama), and axis deer (Axis axis), the antlers of Neotropical species are smaller and simpler, with the exception of Blastocerus dichotomus. This lack of spectacularity, along with other factors such as an historical deficiency of specific research focused on these taxa, may be the reason why Neotropical species have been less studied than their Northern Hemisphere counterparts, for which diverse aspects, including population dynamics, mating systems, reproduction, genetics, habitat requirements and use, have been extensively studied (Barrette 1987; Putman 1988; Geist 1998; Eisenberg 2000).