To have existed futuristic

It is believed that tropical rainforests are home to over half of the world’s species of plants and animals; they appear to be the most diverse expressions of life ever to have existed.

I am not sure if the sentence is correct.

Should I change the last paragraph as follows?: "they appear to be the most diversr expressions of life that has ever existed OR having ever existed"

To have existed won't make any sense there since here life means wildlife that has already been in the forests and the to infinitve has a futuristic connotation although there is ever the word.

Thanks.