Step 1 : Introduction to the question "what is the primary limiting factor that determines why no female animal can produce a very large number of very large eggs?"
Reptile eggs, bird eggs, and monotreme eggs are laid out of water, and are surrounded by a protective shell, either flexible or inflexible. Eggs laid on land or in nests are usually kept within a warm and favorable temperature range while the embryo grows.
Step 2 : Answer to the question "what is the primary limiting factor that determines why no female animal can produce a very large number of very large eggs?"
From the Google Book "Evolution Of Life Histories: Theory and Analysis" we have the answer as follows. Optimal Propagule Size : Constraints on Propagule Size There are clearly physical limits to how large a propagule can be: for example, a hummingbird cannot lay a goose-sized egg. In vertebrates other than fish an obvious limiting factor is the size of the pelvis through which the egg or neonate must pass. Following a suggestion by Tucker et al. (1978), Congdon et al. (1983) and Congdon and Gibbons (1987) noted that in some turtles, egg size increases with female body size and postulated that selection favors a larger egg size than can pass through the pelvic aperture, and hence a female will maximize her fitness by maximizing the size of her eggs as she gets larger. In two species, Chryseniys picra and Deirochelvs reticularia, the size of the pelvic opening increases at the same rate as egg width, while in Pseudemys scrips egg width varies little with female size. Long and Rose (1989, p. 316) tested "the hypothesis that natural selection favors larger pelvic girdles in female turtles to facilitate the passage of eggs" by comparing the relative sizes of pelvic girdles in con specific males and females of the three species....Continue reading. https://books.google.co.in/books?isbn=0412023814 Page : 352
Step 3 : Other interesting facts related to the question "what is the primary limiting factor that determines why no female animal can produce a very large number of very large eggs?"
The largest recorded egg is from a whale shark, and was 30 cm × 14 cm × 9 cm (11.8 in × 5.5 in × 3.5 in) in size. The default color of vertebrate eggs is the white of the calcium carbonate from which the shells are made, but some birds, mainly passerines, produce colored eggs. Small eggs with little yolk are called microlecithal.
No comments:
Post a Comment