Breast Implants and Eyeglasses

[Undertoad]

Mate of higher quality:

It is the job of all living things to reproduce their DNA.

Male sexual response is wired to look for appropriate procreators: young, healthy, receptive, feminine, with wide hips capable of surviving childbirth and healthy breasts to produce milk so that the young that will survive.

Female response is probably similar, looking for appropriate alpha males that can produce quality offspring, protect the cave, successfully hunt and/or gather and maybe even raise their place in society. (Not being a woman, I find it hard to understand how the response differs...)

That's "higher quality". And once it no longer applies, as it inevitably will; once the woman has mothered and produced those offspring, once the man has spent years hunting and gathering both their bodies will make new signals to the world and present them as, strangely, inappropriate mates; then comes the "second wives syndrome" for couples including men too shallow to recognize and overcome their base instinct.