11. What is a species?
Although species are fundamental to evolution, it has proven difficult to develop a single definition\xa0 we can use on millions of\xa0 organisms including plants, animals,\xa0 their fossils, or even asexually reproducing organisms. I discuss three different species concepts, why they work, and their limitations. Along the way, I talk about dancing male jumping spiders, lung-less salamanders, Dark-eyed Juncos.\xa0