As a the sub-title implies, this is the story of Gluck's gradual awakening to the possibility that researchers using animal test subjects need to weigh their career advancement agendas and the hoped for — but by no means certain — benefits to human welfare, against the physical and psychic damage inflicted on the animals in their labs.
In my case, Gluck was preaching to the choir.
If we are supposed to be more intelligent and more ethically evolved than animals and can, thus, with out qualms use them and use them up in any way that we choose, then it seems to me we should be smart enough to realize that by crippling and exterminating species after species we fully responsible for our own demise. It is time to retire the title "homo sapiens" and to come up with another one that is more accurate.