Why this continual struggle, even among scientists, to differentiate human from animal traits when the evidence for similarity is overwhelming?

It points out that this is not exceptional, that many individuals live comfortably with some animal traits in their make-up.

For the most part, these inbreed-ing experiments worked as expected, reinforcing desired animal traits without adverse consequences.

Not like those patchwork demons, animal traits grafted on a human frame.

When we were out on the road just now, I felt that it was exhibiting an animal trait.

It also grants control over certain fertility rites and allows the sin-eater to take on animal traits.

But each of you has an animal trait.

When the author doesn't know the answer to some more intangible animal trait he frankly admits his deficiency; but this happens infrequently.

Every animal trait had its echo in some human quality.

Merging distinct animal traits together is sometimes a means to represent unusual, exceptional virtue or high status.