Rates of water loss by two turtles and a tortoise indicate an inverse relationship between the dryne

Why do the water loss rates of organisms differ? One reason is that species have evolved in environments that differ greatly in water availability. As a consequence, selection for water conservation has been more intense in some environments than others. Species that evolved in warm deserts are generally much more resistant to desiccation than relatives that evolved in moist tropical or temperate habitats. In general, populations that evolved in drier environments lose water at a slower rate. For instance, turtles from wet and moist habitats lose water at a much higher rate than do desert tortoises.