Something not mentioned is that Austen lived very close (c. 2 hour walk away) to the home of Rev Gilbert White, who many regard as the world's first naturalist.

His method of detailed observations of common animals, insects and plants living in their natural habitats (rather than dead in cases) was quite revolutionary in its day, became popular in the scientific world at that time and almost certainly influenced indirectly Darwin's own studies. He even wrote a detailed study of earthworms, something Darwin did later famously, though there's no suggestion of direct influence.

It would not be a surprise if Austen became well acquainted with the works of a famous local "celebrity" as White as well.

I read someone call Austen the Drosophila melanogaster of evolutionary psychology. They seem to study her work like theologists study bibles. The fruit fly comparison makes it sound like they are studying a specimen. But my theory is that they recognize her as a colleague who happened to write in a different genre.

I was recently reading Washington Irving's first book, from 1809, where he mentioned Darwin arguing that humans are descended from monkeys, and I thought "that seems a little early." Turns out he was talking about Charles Darwin's grandfather, Erasmus, who laid some of the groundwork for Charles, and he was famous for writing romantic poems about scientific subjects like reproduction of flowers to help encourage more people to get involved with science.

Ornamentation makes perfect sense as long as it consumes rare resources.

When you can find enough resources to build expensive ornamentation in good times, you can probably survive hard times decently well, only your ornamentation will suffer.

But when you use all the resources that you can get for breeding as much as possible in good times, the population will probably collapse in bad times.