Similar DNA sequences in genes can be evidence of c) common ancestry. This similarity often indicates that different species share a common ancestor from which they have evolved.
When organisms have strikingly similar DNA sequences, it suggests that they have diverged from a shared lineage at some point in the past. This can be traced through evolutionary biology, where the genetic makeup of an organism provides insights into its evolutionary history.
While mutations can alter DNA sequences over time, the presence of similar sequences across different species typically points to the fact that those species have a common ancestor. In contrast, binomial nomenclature is a system of naming species and does not directly relate to genetic similarities, and different anatomy might not reflect genetic similarities at all. Thus, the most convincing interpretation of similar DNA sequences is that they are a sign of common ancestry.