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Re: "Oxygen Helped Mammals Grow, Study Finds"

Mike Taylor wrote:

On the Internet, no-one knows who you are.  How can you tell that I'm
not an algae colony with unusually developed typing skills?

(I'm not really an algae colony, of course. I'm a lobster.)

I'm a slime mold!

David Marjanovic wrote:

One more quote (refs removed):
"Whereas the relatively rapid decline in oxygen at the end-Permian and early Triassic is suggested to have been a major factor contributing to the extinction of terrestrial animals (mostly reptiles) at this time, the rise of oxygen over the ensuing 150 My almost certainly contributed to evolution of large animals.

This may be a daft question, but I had heard/read that oxygen levels were relatively high during the Permian. This allowed large flying insects (_Meganeura_) to thrive during this period, owing to the higher oxygen tension in the atmosphere. The end-Permian drop in O2 may have contributed toward their extinction too.

Interesting how the authors use "secular" -- apparently for "long-term".

As in "The data presented here provide evidence of a secular increase in atmospheric oxygen over the past 205 My that broadly corresponds with three main aspects of vertebrate evolution, namely endothermy, placentation, and size."

I think we need to know more about the religious beliefs of marsupials before we can draw any firm conclusions.