More than 99 percent of all organisms that have ever lived on Earth are extinct. As new species evolve to fit ever changing ecological niches, older species fade away. But the rate of extinction is far from constant. At least a handful of times in the last 500 million years, 75 to more than 90 percent of all species on Earth have disappeared in a geological blink of an eye in catastrophes we call mass extinctions.

Though mass extinctions are deadly events, they open up the planet for new forms of life to emerge. The most studied mass extinction, which marked the boundary between the Cretaceous and Paleogene periods about 66 million years ago, killed off the nonavian dinosaurs and made room for mammals and birds to rapidly diversify and evolve.

5 0

3 years ago

Given his purpose and the audience of workshipers to whom he spoke do you think edwards sermon was effective why or why not

TEA [102]

Yes, his sermon was highly effective because contemporary readers can feel the fear and sting of Edwards’ threats

8 0

3 years ago

suppose you're writing a letter and you recall a word you'd like to use, but you don't know how it's spelled. If you wanted to l

allsm [11]

Looking up the word the way you think it is spelt.

4 0

3 years ago