{A} - INCORRECT; we need "that have" to maintain the flow of the sentence; "vanishing" is incorrect
{B} - INCORRECT; gives a false meaning that 99% appeared on Earth
{C} - INCORRECT; Passive & awkward; gives a false meaning that 99% appeared on Earth
{D} - INCORRECT; "them" is not needed
{E} - CORRECT

AnjaliOberoi wrote:Five hundred million different species of living creatures have appeared on Earth,
nearly 99 percent of them vanishing.
A. Five hundred million different species of living creatures have appeared on Earth,
nearly 99 percent of them vanishing.
B. Nearly 99 percent of five hundred million different species of living creatures that
appeared on Earth have vanished.
C. Vanished are nearly 99 percent of the five hundred million different species of living
creatures that appeared on Earth.
D. Of five hundred million different species of living creatures that have appeared on
Earth, nearly 99 percent of them have vanished.
E. Of the five hundred million different species of living creatures that have appeared on
Earth, nearly 99 percent have vanished.

Why E, why not B

I disagree with Rahul here. I don't think B commits an error in meaning because the subordinate clause "that appeared on Earth" can legally describe what comes immediately before it (500m species of living creatures).

I have 2 problems with B.

1) verb tense of "to appear" should be the present perfect (species that have appeared) rather than the past (species that appeared). the past implies an action that began and ended in the past, whereas the present perfect implies an action that began in the past but continues to the present. Since we're discussing all species from the beginning of the earth up to the present, the present perfect is appropriate.

2) We need to have "the" in front of "5 million species" because we're talking about all species. Example: "Nearly all of 4 sections on the GMAT" is worse than "Nearly all of the 4 sections on the GMAT"