Modern ecophysiologists and related fields often rely upon the comparative method for studying patterns and processes. This method allows researchers to infer evolutionary processes from consistent correlations between specific modifications to organisms and a particular habitat. For example, several different plant lineages that live in desert habitats have lost their leaves (as described above). This morphological modification is hypothesized to minimize the absorption of solar radiation and loss of water. This change has occurred independently in several plant groups (i.e., the desert habitat was invaded multiple times by different plant groups), and the closest nondesert relatives of these plants do not show these morphological adaptations, which reveals that the plants did not have these traits prior to invading. Therefore, we infer that leaf loss is a trait that arose in direct response to living in the desert. By making these across and within-group comparisons, ecophysiologists can infer that leaf loss is an adaptive response to desert living that provides a fitness advantage to the plant species that possess it.
Was this article helpful?