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Essay sample - Evolution of colouration in bird eggs
Pages 11 (2761 words)
The theory of evolution posits the idea of natural selection, through which certain species are able to survive because of the advantages accorded to them by one or more particular traits. Charles Darwin in his germinal publication The Origin of Species (1859) describes this: "Natural selection acts solely through the preservation of variations in some way advantageous, which consequently endure" (153)…
One key fact states that the more diversified a population becomes, the more likely it is to survive as a species. This increases its ability to occupy more territory and gain access to more sustenance, or to spread itself out and become more inconspicuous among predators. Several species of birds demonstrate this type of variation at the embryonic stage. The eggs they lay are coloured or spotted in particular ways, the complete reasons for which have been somewhat elusive to researchers for some time. In fact, birds are the only species that produce pigmented egg shells (Gosler, et al. 2005, p. 1105), and this leads scientists to believe that the pigmentation serves a discoverable purpose. Such reasons as crypsis and the prevention of parasites have been hypothesised. Other hypotheses have been based on sexual selection or on the chemical structure of the eggshell and its influence on eggshell fragility and vulnerability. Hybridization has also been suggested as a factor that influences egg colour. These hypotheses, though varied, have important implications on the evolution of the bird shells and can give insight into the reasons for the various pigmentations that birds' eggs carry.
Safety is a very important issue for birds when it is noted that their eggs ...
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