What was first: appearance or function?
2006/06/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria
The cacti have evolved to absorb the scarce water around them and maintain what they achieved, developing special physiological and anatomical characteristics.
Researchers at Yale University wanted to know how these adaptations have emerged throughout evolution and tried to answer the question: What was first, the change of appearance or the development of a water saving strategy?
To answer the question they have focused on the cactus of the genus Pereskia. This genre is precisely the most primitive. It is divided into two branches, one of which does not resemble the rest of cactus, although it has similar functions. For example, its leaves are conditioned to store water and perform photosynthesis, in an unusual way in other cacti.
Analyzing the peculiarities of the species of the genus Pereskia, the botanists have concluded that the cacti adapted to the scarcity of water first physiologically and that later they developed the anatomical characteristics that allow them to save and store water.
