Life of Earth Quotes

“To live on land, organisms needed vastly greater amounts of complexity.”

“The meager food web of the Earth became a vibrant one, based on the sugar produced by cyanobacteria.”

“Ancient bacteria had almost all the kinds of metabolism that we find on Earth today.”

“Almost as soon as the Earth had oceans, there were simple cells, similar to the ones we call bacteria and archaea.”

“It takes only a few years for populations of bacteria to evolve resistance to any particular kind of antibiotic...”

“Natural selection capitalizes on whatever works, whether it is of greater complexity or greater simplicity...”

“External skeletons are not strong enough to support the weight of large animals, and to this day terrestrial arthropods are small.”

“This is why evolution appears to have a direction: there are many more ways to become complex than to become simpler.”

“Evolution has no guiding mind or innate direction. It has simply made use of new opportunities: complexity, symbiosis, sex, and altruism.”

“There has always been enough carbon dioxide to keep the Earth warm enough for life, but not too much to bake it to death.”

“Insects were the first animals to fly, evolving the ability to do so at least 150 million years before reptiles and birds.”

“Scientists today understand that there is no single, upward staircase of evolutionary progress. All species are equally evolved.”

“The way evolution modified mitochondria and chloroplasts was by simplifying them. ...They degenerated and can no longer survive on their own.”

“There is about as much genetic difference between a bacterium in the soil and an archaean in a hot spring than there is between a bacterium and you.”

“The colonial growth form allowed a new step of evolutionary innovation. The different cells in the colony could start specializing on different jobs.”

“Symbiosis transformed the Earth from a broth of simple cells into everything it is today.”

“A rich oxygen atmosphere would be much denser than today's... dense enough that delicate wings could... support the weight of a huge [wingspan a little over two feet] dragonfly.”

“One of the most beautiful things about an adaptation is that once it has come into existence, it can be used for something very different than its original function.”

“Most of the vegetation on the surface of the Earth had died during the Permian extinction.”

“Scientists... have used selection to get populations of bacteria to evolve the ability to use different kinds of sugar... or to tolerate different temperatures, in just a few weeks or months.”