Name: Darwin asks why do cottonwood leaves flap in the wind @StanEvolve
Uploaded: 2023-08-04T01:29:31-0400
Duration: 8 min 17 s
Description: Why do cottonwood, poplar, and aspen leaves flap in the wind? Many scientists say it is because this increases the diffusion of carbon dioxide into the leaves. But this would also be the case for all other plants, not just cottonwoods. The explanation is probably that cottonwoods, which already had flat petioles, could then and only then benefit from fluttering leaves.

Uploaded August 2023 | Updated September 2026, 1 week ago

Why does one species of sumac (Rhus copallina) have photosynthetic wings on its compound leaves and another (Rhus glabra) does not? Does it really make that much difference to plant growth or fitness? We do not know and maybe cannot know. All around you are unanswered and perhaps unanswerable evolutionary questions.

Darwin in a forest that is not a wilderness

Darwin asks why do cottonwood leaves flap in the wind