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The American robin (Turdus migratorius) is a migratory bird of the true thrush genus and Turdidae, the wider thrush family. It is named after the European robin ...
Sexual dimorphism is the condition where sexes of the same species exhibit different morphological characteristics, including characteristics not directly involved in reproduction. [1] The condition occurs in most dioecious species, which consist of most animals and some plants.
Turdus is a genus of medium-sized mostly insectivorous or omnivorous birds in the wider thrush family, Turdidae.The genus name Turdus is Latin for 'thrush'.. Most of the species are called thrushes; the term thrush is also used for many other birds in the family Turdidae, as well as for a few species belonging to other families.
In 1973, M. J. D. White, then at the end of a long career investigating karyotypes, gave an interesting summary of the distribution of chromosome polymorphism. "It is extremely difficult to get an adequate idea as to what fraction of the species of eukaryote organisms actually are polymorphic for structural rearrangements of the chromosomes.
Gynandromorphism is most frequently recognized in organisms that have strong sexual dimorphism such as certain butterflies, spiders, and birds, but has been recognized in numerous other types of organisms.
Sexual bimaturism can result in sexual dimorphism, but sexual dimorphism could also develop through differential rates of development. In many insects, the larval period of females is longer than that of males, and as a result of this extended growth period, these female insects are larger than their male conspecifics. [ 1 ]
Some monogamous species show a large amount of sexual dimorphism. Studies of sexual dimorphism raise the possibility that early human ancestors were polygamous rather than monogamous. But this line of research remains highly controversial. It may be that early human ancestors showed little sexual dimorphism, and it may be that sexual dimorphism ...
From an evolutionary standpoint, the most predominant characteristic that is often found in polygynous mating systems is extreme sexual dimorphism. Sexual dimorphism, or the difference in size or appearance between males and females, gives males an advantage in fights against each other to demonstrate dominance and win over harems. Sexual ...