7/28/2023 0 Comments Yellow autumn trees![]() The red colour could also be a warning of the presence of toxins in the leaf. If leaves look dead, or just not green (and by association, young and tender), that could turn off a hungry folivore. Or they could be doing almost the opposite: discouraging potential leaf-eaters. Maybe the red leaves are designed to attract animals which will help the tree disperse its seeds, advertising the ripe fruit on offer. Each leaf preserves an ancient memory of a different world, millions of years ago But it could also be that the red pigment is somehow adaptive: that red autumn leaves are a product of natural selection, because they perform a function which offers some advantage to the tree. ![]() Perhaps it’s simply a change in leaf physiology linked to cooling temperatures. It’s possible that the red pigments are manufactured in the leaf as a side-effect of something else that’s happening at this time. The red is new: it’s being made in the leaf as the days grow shorter.Įvolutionary biologists have long pondered the phenomenon of the changing colours of autumn leaves. In particular, where leaves do become red in autumn, it’s not that the red pigments (anthocyanins, also the colour in blackberries) are simply being unveiled as the green of summer fades. It might be part of the story – and is certainly true of many yellow pigments – but it’s not all of it by any means. Autumn’s changing colours in Wiltshire – timelapse video Guardianīut are those colours nothing more than pigments which have been there all along, and which simply become unmasked as emerald chlorophyll breaks down? That would be a very short rabbit hole – and this would have ended up a very short article indeed.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |