Introduction to Comparison of Similar Objects Whose Group Identity is Known

Abstract

Comparisons between well-known, unambiguously classified organisms is the sub- ject of all but one article in this section of the volume. The topics discussed are human sexual dimorphism, in one article by Ahlstrom and another by Wood and Lynch; ontogeny of fish by Loy et al.; species differences between closely related mice by Demeter et al. and between closely related weasels by Reig; and some fossil comparisons by Reyment. These all represent known cases of morphological differences whose cause or correlates are well identified. The shape differences here are frequently less subtle then those discussed in the section on geographic and intraspecific systematics of the previous section. Also included in this section is an analysis of hand axes by Brande and Saragusti. Although hand axes are inorganic, they are the product of ancient human hands and show a considerable evolution.