In terrestrial vertebrates, what is the advantage of having surfaces for O2/CO2 exchange inside the animal(i.e. in the lungs), rather than on the surface (i.e. in gills or skin)?
The key adaptive advantage of internal gas exchange as in the lungs is the conservation of water. The terrestrial air is always under-saturated by moisture (water), and hence, water loss is inevitable. The less the moisture saturation in the air, the greater the risk of water loss. In this scenario, having an internal gas exchange surface is protective in nature against dessication. Using skin as a gas-exchange surface possess a greater risk of water loss as the humidity plummets. Lungs, on the other hand provide a greater opportunity for exploring a greatwr range of habitats.
In terrestrial vertebrates, what is the advantage of having surfaces for O2/CO2 exchange inside the animal(i.e....
Why is gas exchange more difficult for animals with gills than animals with lungs? What advantage does countercurrent exchange give for gas exchange in the fish?