|
Animals need plants for food, since only plants can capture the Sun's energy. Once the ferns had moved onto the land, it wasn't long before animals followed them. The first were the arthropods.
Cockroaches, dragonflies and scorpions began to live on land around 420 million years ago. They had to solve the same sort of problems as the plants did when they left the water. They already had stiff skins and by evolving a waxy coat they could stop themselves drying out. A bigger problem was how to get rid of their waste products without having lots of water around them to wash the waste away. They managed to solve this too. But most difficult of all was how to reproduce without water. This was so difficult that the first arthropods on land, like the ferns before them, were still tied to the water for reproduction. Dragonflies need water to reproduce even today. |
|
|
Useful Links |
