Colonization of Land
Adaptation to life on land is a major challenge: all land organisms need to avoid drying-out and all those above microscopic size have to resist gravity; respiration and gas exchange systems have to change; reproductive systems cannot depend on water to carry eggs and sperm towards each other. Although the earliest good evidence of land plants and animals dates back to the Ordovician Period (488 to 444 Ma), and a number of microorganism lineages made it onto land much earlier, modern land ecosystems only appeared in the late Devonian, about 385 to 359 Ma.
Read more about this topic: Evolutionary History Of Life
Famous quotes containing the word land:
“The Indian attitude toward the land was expressed by a Crow named Curly: “The soil you see is not ordinary soil—it is the dust of the blood, the flesh, and the bones of our ancestors. You will have to dig down to find Nature’s earth, for the upper portion is Crow, my blood and my dead. I do not want to give it up.””
—For the State of Montana, U.S. public relief program. Montana: A State Guide Book (The WPA Guide to Montana)