Goodness, this comment chain is going to get long... Also, I've taken care of and owned numerous dogs, but not a single one has ever even tried to dig for anything. I'm not sure if they've just grown lazy as a result of domestication or the dogs I've seen are weird.
Back to the point at hand, I believe a definition going beyond physical traits is going to be more important than ever in the future. As we get closer and closer to developing A.I. and possibly extraterrestrial contact, your strictly physical definition will be requiring drastic revising.
Also, I never said that humans need to have souls. I only said they need to be capable of loving something or someone. Yes, it is sad that small cultures* are being wiped out by the militant spread of Christianity, but such is the way of globalization and assimilation. In return for the low, low price of giving up your personal beliefs, you and your family can purchase genetically modified rice from Germany that will allow your children to grow up big and strong. I'm not sure why you have such reservations against religion, and it's not my place to ask, but you have to realize that nothing is inherently bad or good.
Another thing, where in the bible (I assume that's the religion you have the most reservations against) does it teach dark skinned people have no souls? I really want a quote. Considering that Christianity is supposed to be based on loving everyone as if they were yourself, I find it hard to believe that there is such a quote.
*Those Asian countries you are talking about are either Secular, Muslim, or Buddhist, by the way. The amount of Christians in these countries are minuscule compared to those. http://en.wikipedia.org/wiki/List_of_religious_populations