Passage Summary: Because some dogs are genetically almost identical to wolves while others are very different, it proves that the 'wolf-like' dogs were tamed much later in history.

Conclusion: Some dog breeds must have been domesticated from wolves much more recently than other dog breeds were.

Reasoning: Genetic similarity to the ancestor (wolves) varies significantly between breeds, with some being much closer to the ancestor than to their fellow descendants.

Analysis: The argument makes a leap from 'genetic similarity' to 'timing of domestication.' It assumes a direct correlation: the more a descendant looks like its ancestor genetically, the more recently it must have split off. To support this, we need a principle that formalizes this link. Look for an answer that states that a high degree of genetic similarity between a domesticated breed and its wild ancestor is a reliable indicator of a recent domestication event.