A bit later in the same chapter he says "[...] but it serves to aknowledge plainly our ignorance of the cause of each particular variation", and "The evidence that accidental mutilations can be inherited is at present not decisive". Oh, and the first two chapters are dedicated to breeding and human selection, and he legit says "if you went to a breeder and explain our theory about extinct variants being the ancestors of their cattle, they'll laugh at your face".

It seems to me that he understood the basics, but the scientific community was still divided and colecting evidence was quite hard at the time.

In the cyberpunk world, most people have to eat Kibble (a heavily processed form of food) that is said to taste kinda of like dog food, and gangs and corporations dominate all the gardens, that pay tribute to them in exchange for protection. This on it's own opens several prompts. My favorite being

1 - Someone important to you is a shell shocked veteran. You wanna make an open field with grass, some fruit trees, and away from all the noise so that they can relax there, and you're damn willing to start your own gang for that!

2 - You're a rising Solo that recently made your name as a bodyguard, and today, Arasaka decided to hire you officially... As a delivery boy.

3 - You make money secretly growing oranges in your basement and with UV lights. Talk about the fruits as if you were talking about weed.