Mechanical Engineering vs Human Biology at Stanford

I will be a senior this fall in high school, and I am planning on applying to Stanford REA.
I saw on Stanford’s website that there is still a pretty significant gender gap in mechanical engineering, so I was wondering if I would have a better chance of getting accepted if I applied for ME vs hum bio, and then switch to hum bio if I get accepted.
I took AP Calculus BC in 10th grade, ended AP Physics Mechanics with a 98 and a 5 on the AP exam, and will be taking AP Physics E&M and multivariable calculus next year. On the other hand, I only ended AP Biology with a 93.
But, one of my main ECs is a biology lab internship, and I did get a 800 on the biology SAT.
Which major do you think will give me the biggest chance of getting accepted?

Your essays and other parts of the application will be more authentic if you specify the major you actually intend to do, even at colleges that do not formally admit by major.

I agree with uc, writing an application on something you are passionate about will be more beneficial. The major you apply to does not have a significant bearing on your chance of being accepted when compared to other factors like gpa, test scores, APs, extracurriculars, and especially essays.

In another thread you wrote:

I could be wrong but I don’t believe you can apply to Stanford REA if you are applying ED to UPenn.