Leaving aside the question of animals and souls (which has already been discussed), are humans in nature, but more than animals being made in the image of God?
I think this is what is the heart of the problem: Science and Faith are so polarized with each other right now, that no one wants to appear to concede anything.
[Note: I was called away whist writing this post and came back to find the exchange between Jason and happyjoy. I think that their exchange proves exactly what I'm getting at.]
Take for instance the idea that life begins at conception. That is a no brainer, but we have scientists lining up all across university campuses to deny this obvious fact, because to concede that life begins at conception would be to concede just a little bit of ground to the religious right on the issue of abortion.
By the same token, we can see with our eyes, touch with our hands, smell, hear and yes, taste, and see that human beings have flesh, blood, produce milk, reproduce sexually, have a lot of salt in their system (that's what I meant by taste, not cannibalism, just wanted to be clear), have the same basic skeletal system, have the same basic digestive system, even have the same basic DNA, as other mammals here on this earth. But, I think what drives most Christians to say that human beings are not animal at all (because we've already acknowledged that humans are more than animals) is because to do so would concede some ground to evolutionary science.
God made man from the same earth as He did the other animals. Yes, He took special care in His creation of man, He just didn't call Adam forth from the earth as the other animals (because we are more than animals) but nonetheless, He didn't create us the same way He did the angels, either. We humans are just as much of this earth as dogs and the duck-billed platypus are.
God also acknowledges our kinship with the animals in that the first dietary law on record was that humans were not to consume the blood of the animal they ate, because the blood was its life. (Gen 9:4) The fact that God places our life's blood of higher significance than the animals, doesn't mean that the animals do not have life's blood, just as we do.
To deny that we are creatures of the flesh is to deny the Bible, I don't think anyone would argue with that. But, the very fact that we are of flesh and blood means that we are animals, we are not pure spirit, nor are we created beings, not of this earth. God created us as animals, as opposed to vegetables, minerals or spirits. But, we are animals that are far more than cattle, beasts or crawling things because we were made in God's image. Just because we acknowledge the truth of this doesn't mean that we are conceding to the unwarranted conclusions of evolutionary science. It's just acknowledging truth.