BIOL 1202 : Bio 1202 Test 1 Notes
Document Summary
Around 11 million or so species of living things on the planet. Billions of helpful bacteria are in my body. About 500 trillion live on and in the body (a lot of them are beneficial). Humans are eukaryotic and have trillions of cells. 200,000 years ago- first evidence of homo sapiens in fossil record. 500,000 years ago- look like homo sapiens but are not (in fossil record). Long before that, about 385 million years ago, our ancestors were fish. Around 4 billion years ago- life on earth began. About 13. 6 billion years ago- big bang happened and galaxy formed: all materials on earth come from this. Why did it take so long for life to begin on earth: the planet had to cool, then life began. A few centuries ago: people thought that new living things appeared all the time, they believed in the spontaneous generation of life- nonliving things spontaneously become living things.
