What are the specific clues that most clearly distinguish a Darwinian explanation from a Lamarck explanation?

Darwinian evolution is based on the idea of natural selection, where individuals with advantageous traits are more likely to survive and reproduce, leading to the gradual accumulation of these traits in a population over generations. In contrast, Lamarckian evolution suggests that acquired traits during an individual's lifetime can be passed on to offspring. Specific clues that distinguish these explanations include the basis for inheritance of traits (genetic in Darwinian vs. acquired in Lamarckian) and the mechanism of how populations change over time (gradual accumulation of genetic changes in Darwinian vs. direct transfer of acquired traits in Lamarckian).