Читать книгу Neurobiology For Dummies - Frank Amthor - Страница 15

About 1 to 2 billion years after single-cell life arose, some single-cell life forms developed nuclei and became what are called eukaryotes (cells that have a nucleus). Soon after eukaryotes appeared, multicellular organisms came on the scene.

Plant-like multicellular organisms probably arose from aggregations of single cells in shallow ocean areas. These multicellular organisms diversified over more than a billion years. About half a billion years ago, 4 billion years after the earth formed, land plants and animals that we would recognize as such appeared from these multicellular ancestors.