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Invasions! Sol, D. Espècies
invasores: el problema de sobreviure en nous ambients Alien species: the problem to survive in novel environments Why can alien species, whose initial populations are generally small and genetically depleted, succeed in establishing themselves in environments in which they have had no opportunity to adapt? This paradox is usually best understood by employing a classical paradigm, that describing the pre-adaptations of non-indigenous species to novel environments. The idea is that some species are successful invaders because they have attributes that allow them to survive and reproduce in novel environments. Progress in recent decades has provided firm evidence that vertebrate species differ in their invasion potential, and that such differences are associated with certain characteristics that facilitate establishment in novel regions. Although a number of these features seem to synergistically combine to enhance the ability of some species to overcome various barriers, only two of these characteristics provide any general explanation as to why some vertebrates are such extremely successful invaders: a broad ecological niche, and a high degree of behavioral flexibility. These traits are believed to facilitate the success these vertebrates enjoy in establishing an appropriate niche in a variety of environments, even in those to which they have had no opportunity to adapt. |
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