Final answer:
Drs. Holmes and Wyman would have identified the remains as human through morphological analysis of bones and the presence of cultural artifacts, which are indicative of human origin. Today, DNA analysis can provide further confirmation, but it was not available in their time.
Step-by-step explanation:
When Drs. Holmes and Wyman set out to determine whether the remains found were human, they would have employed several approaches used in forensic anthropology and archeology. These disciplines utilize various methods to analyze bones and remains to ascertain not only the species but also potentially the age, sex, and even cause of death of the individual. By closely examining the morphology of the bones, the size, shape, and characteristics that are unique to human skeletons, experts can differentiate between human and animal remains. Additionally, if any cultural artifacts, such as buttons or coins, are found with the remains as indicated in the archeological findings referenced, this would further confirm the human origin of the remains.
In some cases, modern scientific tools like DNA analysis can be used to corroborate historical evidence or to establish a genetic relationship, as was done with the ancient remains known as Kennewick Man. This kind of analysis wasn't available to Drs. Holmes and Wyman in the 19th century, but today it serves as a definitive tool to establish human ancestry. Given the context of the question, Drs. Holmes and Wyman likely relied on the morphological analysis of the remains, and any associated findings that would indicate human use or burial practices, to confirm that the remains were human.