I almost immediately picked the fertility upgrade. The stamina bonuses were nice, but morphotyping was more important, especially in the short-term. And the more direct progeny I and Ambrosia had, the more morphotyping candidates there were.
I put the last point into endurance, too.
However, my luck with cool genes has run out.
〔For improving endurance, you have a choice of next genes: 'Fat Padding', 'Increased Pain Threshold', and 'Grass Digestion'.〕
〔Fat Padding: allows to accumulate fat padding by overeating, which slightly increases defense and maximum health.〕
〔Increased Pain Threshold: greatly improves pain tolerance.〕
〔Grass Digestion: allows digesting grass and tree leaves for nutrients.〕
Although I'd love to have more health, I didn't want to be fat for its sake! Pain tolerance didn't sound game-changing, either.
This left only the last gene.