Final answer:
The discovery of DNA changed scientists' thoughts about humans by providing insights into heredity, genetic diseases, and evolution.
Step-by-step explanation:
The discovery that changed scientists' original thoughts about humans is: Option 1: The discovery of DNA. DNA (deoxyribonucleic acid) and, in some cases, RNA (ribonucleic acid) are the primary sources of heritable information. The discovery of DNA has had a profound impact on our understanding of heredity, genetic diseases, and biological evolution.
The discovery and subsequent study of DNA have transformed the field of biology by allowing for the description and manipulation of genetic material. This has significantly expanded our knowledge of how the human body works, our human origins, and how we can survive and adapt as a species. Moreover, the study of DNA has aided in understanding the role of microbes in human health, which has changed our understanding of disease.
In summary, the discovery of DNA has enabled scientists to make claims and predictions about natural phenomena, evaluate alternative scientific explanations, and justify the selection of data needed to answer scientific questions. This underpins not only our knowledge of biology but also has implications for medicine, genetic engineering, and a multitude of other scientific disciplines.