Consider the chicken, with its ingenious production line of eggs. Constant fertilization from a different orifice seems ideal, as (the source I just Googled suggests that) chickens have very short fertilization cycles. (They don’t have separate orifices. Poor cloacas.)
Since fertilization occurs at one end of a long tube, and birth occurs at the other, I wouldn’t be surprised if the optimal arrangement involved separate organs.
Consider the chicken, with its ingenious production line of eggs. Constant fertilization from a different orifice seems ideal, as (the source I just Googled suggests that) chickens have very short fertilization cycles. (They don’t have separate orifices. Poor cloacas.)
Since fertilization occurs at one end of a long tube, and birth occurs at the other, I wouldn’t be surprised if the optimal arrangement involved separate organs.