排序方式: 共有55条查询结果,搜索用时 15 毫秒
51.
52.
53.
Successive waves of extinction of large vertebrates have swept the globe since the Pliocene. In contrast to such episodes in earlier geological epochs, many of the species of large herbivores and carnivores, flightless birds, and giant tortoises which became extinct during this period were not replaced in these niches by other species. Relying on data from the fossil and archaeological records as well as on ethological and palaeo-ecological arguments, the authors explain why hominids are to be held responsible for this ecological genocide. Possible ecological and climatic consequences of the extinctions are discussed. These considerations cast doubt upon the notion of early hominids as scavengers. 相似文献
54.
55.