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Terrestrial Origins Briefing

Earth with liquid water, is more than 3.6 billion years old

cellular life has been around for at least half of Earth's history

birds or mammals didn't exist until 250 million years ago

the majority of past and current organisms either have already or will go extinct

for the last 2 million years, the earth's biota resembles the current land mix

notable exception are recent megafauna like mammoths, giant sloths and saber-tooth tigers

many current species (e.g. horses) can mate both intra- and interspecies (but produce sterile hybrids, mules)

an extreme example of rapid evolution, the hominid cerebellum doubled in size within 100,000 years, but at a miniscule 0.02% increase per generation

one of the fastest rates of evolution in the fossil record translates to 0.06% character change per generation
Credit: NASA

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