Not surprising, Darwin’s writing is quite dense and syntactically complex. Why he felt the need to lump so many clauses in between commas instead of using a few more periods is beyond me. His editor should have slapped him, if he had an editor.
Darwin seems to firmly believe that domestication is a man-driven as opposed to an animal-driven or mutualistic process. He repeatedly refers to the whims and decisions of breeders in deciding which existing variations to exploit and which direction, either consciously or unconsciously, to take an animal during the domestication process. He doesn’t seem to acknowledge the potential for the animal to benefit from the process, and even if it does, Darwin implies this would be merely a side effect and not a direct effect. Ultimately, I agree with this logic, because man is ultimately deciding which variations to exploit and which animals to let reproduce. Any benefit to the domesticated animal may simply be a consequence of the necessity to have health animals in order to use them. Basically, the animals thrive because we need them to thrive for us to thrive. This doesn’t take away from our dependence on animals, such as the cow, for resources. The bond between man and domesticated animal may only be mutualistic in the sense that we need many of the resources they provide.
At the same time, Darwin may be a bit naive in this interpretation of domestication. We do depend on domesticated animals, and as time progresses and they become more intertwined with human populations, they often become integral to a civilization’s successful function. Darwin appears to have ignored this.