What characteristics would you look for to determine if a specimen was once alive and is now dead?

To determine if a specimen was once alive and is now dead, key characteristics to look for include the presence of organic material, such as cells with complex structures, which indicates biological origin. Additionally, signs of decay or fossilization, such as preserved tissues or mineralized remains, can suggest a former living state. Other indicators include the presence of specific biochemical markers, such as DNA or proteins, and any evidence of past metabolic activity, like growth rings or patterns of wear.