Viewing a single comment thread. View all comments

kittenTakeover t1_iqu7xal wrote

Body size is affected by a lot of factors. One of the biggest is if they have active aspiration and circulation or passive aspiration and circulation. The more passive the more they benefit from thin bodies with high surface area ratios to absorb oxygen.

2

knotacylon t1_iqvi1ke wrote

That's true, I forgot about that. That's why insects and other arthropods were bigger when the earth had a higher amount of O2 in the atmosphere and shrank when the O2 levels dropped.

1