Why are vertebrates so big?

Abstract

In nature, the benefits of being big are manifold (Kingsolver & Pfennig, 2004;Sauer & Slade, 1987;Stanley, 1973). Among the more noteworthy are higher survival rates, greater reproductive success, increased diet breadth and improved thermoregulatory ability compared with smaller conspecifics (Brown & Maurer, 1986;Kozłowski, 1992). For example, in the north Atlantic, a fully grown female cod (Gadus morhua) can spawn 50 times more eggs than the smallest breeders (May, 1967); on Jamaica, the largest male anoles (Anolis garmani) have the largest territories and as a result secure 90% of the mating opportunities (Trivers, 1976). It is benefits such as these that are put forward to explain the general pattern