omfglearntoplay shares a report from ScienceDaily: What determines global patterns of biodiversity has been a puzzle for scientists since the days of von Humboldt, Darwin, and Wallace. Yet, despite two centuries of research, this question remains unanswered. The global pattern of mountain biodiversity, and the extraordinarily high richness in tropical mountains in particular, is documented in two companion Science review papers this week [1, 2]. The papers focus on the fact that the high level of biodiversity found on mountains is far beyond what would be expected from prevailing hypotheses.
To confront the question of why mountains are so biologically diverse, scientists at the Center for Macroecology, Evolution and Climate (CMEC) at the GLOBE Institute of the University of Copenhagen work to synthesize understanding and data from the disparate fields of macroecology, evolutionary biology, earth sciences, and geology. Part of the answer, these studies find, lies in understanding that the climate of rugged tropical mountain regions is fundamentally different in complexity and diversity compared to adjacent lowland regions. Uniquely heterogeneous mountain climates likely play a key role in generating and maintaining high diversity. Another part of the explanation of the high biodiversity of certain mountains is linked to the geological dynamics of mountain building. These geological processes, interacting with complex climate changes through time, provide ample opportunities for evolutionary processes to act.
Another explanation of mountain richness, says the study, may lie in the interaction between geology and biology. The scientists report a novel and surprising finding: the high diversity is in most tropical mountains tightly linked to bedrock geology — especially mountain regions with obducted, ancient oceanic crust. To explain this relationship between geology and biodiversity, the scientists propose, as a working hypothesis, that mountains in the tropics with soil originating from oceanic bedrock provide exceptional environmental conditions that drive localized adaptive change in plants. Special adaptations that allow plants to tolerate these unusual soils, in turn, may drive speciation cascades (the speciation of one group leading to speciation in other groups), all the way to animals, and ultimately contribute to the shape of global patterns of biodiversity.
Read more of this story at Slashdot.
Source: Slashdot – Why Is Earth So Biologically Diverse? Mountains Hold the Answer