"...if you can name one useful invention that needed any Darwin imput, do say."

A great deal of genetic and genomic research is done using model organisms. This research has given rise to the invention of treatments for cancer and infertility amongst others and current day research is closing in on degenerative diseases such as Alzheimers.

A model organism is a non-human species (yeast, fly, mouse, primate) that is used to understand particular biological phenomena, with the expectation that discoveries made in the organism model will provide insight into the workings of other organisms.

Model organisms are widely used to research human disease when human experimentation would be unfeasible or unethical.

This successful strategy is made possible by the common descent of all living organisms, and the conservation of metabolic and developmental pathways and genetic material over the course of evolution.