About of all species on earth have become extinct.

99%

Explanation:

So, about 99% of all organisms that have ever existed on this planet are extinct today. While that number may sound startling, the reason is that, well, life on Earth has existed for about three and a half billion years, so things are going to change over time. A way to remember how humans have influenced biodiversity laws which can actually lead over time to extinction, the complete removal of the species on the planet, is this mnemonic device, HIPPOC. This stands for habitat alteration, invasive species, pollution, population growth meaning human population growth, overexploitation, and climate change.

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explanation:

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substitution is the answer in this case