Nuestro cambiante mundo y la pérdida de diversidad biológica

Abstract

En este artículo se pretende abordar algunos temas útiles para entender los problemas de extinción a los que se enfrentan los diversos grupos biológicos. En primer lugar se presenta un panorama de la gran diversidad biológica de nuestro planeta, así como del escaso conocimiento que tenemos de la misma. El mundo es dinámico, por lo que el número de especies presentes en un área determinada es resultado tanto de los procesos de formación de nuevas especies (especiación) como de las extinciones de las especies que fueron incapaces de adaptarse a cambios ambientales. Los cambios constantes de la superficie terrestre y la presencia de eventos catastróficos, son causas naturales de las extinciones. Las especies especializadas o especialistas, así como las especies endémicas (con un restringido rango de distribución), tienen mayores probabilidades de extinguirse, debido a que tienen menores probabilidades de adecuación a los cambios ambientales. La extinción de las especies por causas antropogénicas, está íntimamente ligada a la evolución misma del hombre y su civilización

In this section I address some topics that are useful for understanding the problem of extinction facing various biological groups. First, I present a panorama of the stounding biological diversity of our planet, and of our limited knowledge of this diversity. The world is dynamic and the number of species present in a given area is the result of both the processes that lead to the formation of new species (speciation) and the extinction of those species whose populations were not capable of adjusting to changes in their environment. The constant changes to the surface of the earth and the occurrence of catastrophic events are natural causes of extinction. Specialized species or specialists, along with endemic species (with a restricted distribution range) are more likely to go extinct considering that they have a lower probability of adjusting to environmental change. The extinction of species resulting from anthropogenic causes is intimately linked to the evolution of humankind and civilization. The main anthropogenic causes of species extinction are: a) Excessive hunting and collection or organisms, b) The introduction of exotic species and c) Habitat alteration. The massive loss of biological diversity is increasingly probably and concurrently, there would be a decrease in the many services these organisms provide to us. We are deluding ourselves to think that we can survive without biological diversity or that it is somehow secondary to our contemporary world. Among the reasons for conserving biodiversity there are arguments of an economic nature, about maintaining environmental quality (services provided by ecosystems), ethical reasons and finally esthetic reasons. The quality of life of future generations will depend in large measure on the decisions and actions that each and every one of us take right now about our biological surroundings. Key words: biodiversity, speciation, species extinction, endemism, bioconservation