Which scientific development has given rise to the most debate about the ethics of tampering with nature?

We could say that it would be the "Gentle Cloning" since it is the manipulation of the essence of Humanity.

Gene cloning or "molecular cloning" are a set of experimental methods used in molecular biology that are used to assemble DNA molecules and achieve their copying within recipient organisms. The use of the word cloning refers to the fact that the method comprises the copied from a single molecule of DNA starting with a single living cell to produce a large population of cells that contain identical DNA molecules. Molecular cloning usually uses DNA sequences from two different organisms: the species that is the source of the DNA that you want to clone, and the species that will serve as the live receptor for copying the recombined DNA.

they died because of a disease during the first spanish colonies.

“a committee reviews the bill and marks it up to make it more viable and to reflect interests