No less than the prolific, award-winning E.O. Wilson writes in the Wall Street Journal that math is NOT a necessity for becoming an outstanding scientist:
He starts this way: "For many young people who aspire to be scientists, the great bugbear is mathematics. Without advanced math, how can you do serious work in the sciences? Well, I have a professional secret to share: Many of the most successful scientists in the world today are mathematically no more than semiliterate."
He goes on to explain that he took up math relatively late in his academic career and "was never more than a C student," but then continues to describe how he was always able to collaborate with mathematicians or statisticians as needed.
...Should offer some encouragement to those who struggle with math, yet are still interested in the sciences. Wilson admits that math aptitude may be more crucial to some sciences, like physics and chemistry, than for many areas of biology, and ends with, "For every scientist, there exists a discipline for which his or her level of mathematical competence is enough to achieve excellence."
I'm glad Wilson offers this reassurance to those scientifically-minded who may be self-conscious about their weakness in math. Still, one also can't help but note that Wilson is almost 84 years old… he grew up at a time and worked throughout decades when a scientist could probably more easily succeed without a good math background. I suspect this may prove more difficult (though not impossible) for scientists of the future just now being currently trained.
So, interesting advice... but might yet require a grain of salt.
ADDENDUM: Looks like another blogger has taken Wilson's piece with a big grain of salt... and offers a longish response here (with interesting debate in comments):