I agree. I'm inclined to think the concepts are more subtle, not less. Some traits are shaped by sexual selection because of their deleterious effects. It's an

I agree. I'm inclined to think the concepts are more subtle, not less. Some traits are shaped by sexual selection because of their deleterious effects. It's an honest signal: if you can survive despite having that crappy trait, you must be really robust! You can't conceptualize that as a fitness hit, because of what fitness means in the context of evolutionary biology. But you had better be able to conceptualize it somehow, because it's interesting and important if true.