Species/Talk

The definition I learned in high school (I know, I've set myself up to be wrong already) was: two animals are the same species iff they can produce fertile offspring. Was that wrong/has it changed?--BlackGriffen

(1) That definition can only apply to sexually reproducing species (how do you determine whether or not two bacteria, each of which can reproduce alone by splitting, can "interbreed"?) (2) Even among higher species, the lines aren't that sharp. There are severals "sets" of species, such as arctic seabirds, where species A can and does interbreed with B, and B with C, and C with D...but A cannot interbreed with D. So where do you draw that line? --LDC