James Craig, Shine Richard
Zoology Department, A08, The University of Sydney, 2006, Sydney, NSW, Australia.
Oecologia. 1988 Mar;75(2):307-316. doi: 10.1007/BF00378615.
Previous studies have suggested that tropical and temperate-zone lizards may differ fundamentally in life histories. We tested the applicability of this idea to Australian species by comparing temperate-zone species of agamid and scincid lizards with their congeners from the seasonal tropics. Data were derived from dissection of 1,941 specimens and from published information. Clutch size and egg size were positively correlated with mean maternal body size in most lizard species from both climatic zones. Mean body size of the lizards studies did not differ between the tropics and the temperate zone, nor did egg or hatchling size. However, tropical skinks showed considerably (approximately 20%) lower clutch size and relative clutch mass than did temperate-zone skinks. This difference was partly due to the higher incidence of species with low, invariant clutch size in the tropical lizard fauna (as seen in other continents as well), but primarily due to a trend for lineages (especially genera) with relatively high fecundity to be more common in the temperate zone than in the tropics. In contrast to studies on African lizards, our data suggested that modification of clutch size between areas has not occurred within genera: congeneric species from the tropics and temperate zone did not differ in clutch size. Production of more than one clutch per annum by individual females was common in both climatic zones. Tropical lizards may differ from temperate-zone species in showing higher reproductive frequencies, more rapid growth and earlier maturation. However, most of these effects may be due to phenotypic responses to environmental conditions (especially longer annual activity season), rather than to genetically based lifehistory adaptations.
先前的研究表明，热带和温带蜥蜴的生活史可能存在根本差异。我们通过比较温带的鬣蜥科和石龙子科蜥蜴与其来自季节性热带地区的同属蜥蜴，来检验这一观点对澳大利亚物种的适用性。数据来源于对1941个标本的解剖以及已发表的信息。在来自这两个气候带的大多数蜥蜴物种中，一窝卵的数量和卵的大小与母体平均体型呈正相关。所研究的蜥蜴的平均体型在热带和温带之间没有差异，卵或幼体的大小也没有差异。然而，热带石龙子的一窝卵数量和相对窝卵质量比温带石龙子低得多（约20%）。这种差异部分是由于热带蜥蜴类群中一窝卵数量少且恒定的物种发生率较高（在其他大陆也有这种情况），但主要是由于繁殖力相对较高的谱系（尤其是属）在温带比在热带更为常见。与对非洲蜥蜴的研究不同，我们的数据表明，同一属内不同地区之间一窝卵数量并没有发生变化：来自热带和温带的同属物种在一窝卵数量上没有差异。在这两个气候带，雌性个体每年产不止一窝卵的情况都很常见。热带蜥蜴与温带蜥蜴的不同之处可能在于，它们具有更高的繁殖频率、更快的生长速度和更早的成熟。然而，这些影响大多可能是对环境条件（尤其是更长的年度活动季节）的表型反应，而不是基于基因的生活史适应。
