Those Brilliant Fall Outfits May Be Saving Trees.
As trees across the northern United States turn gold and crimson,
scientists are debating exactly what those colors are for. By By CARL
ZIMMER. [The New York Times > Science]
The scientists do agree on one thing: the colors are for something.
That represents a major shift in thinking. For decades, textbooks
claimed that autumn colors were just a byproduct of dying leaves. ‘I
had always assumed that autumn leaves were waste baskets,’ said Dr.
David Wilkinson
It turns out that the carotenoids and anthocyanins that produce those
beuatiful yellows and reds aren’t just ‘unmasked’ by the breakdown of
chlorophyll; production of anthocyanin actually increases in autumn.
‘Why’ is less clear. One theory: the vivid colors warn insect pests to
stay clear. Another: the anthocyanins protect the leaves from damage
from too much sunlight. The article summarizes research in support of
both positions.
‘People sometimes say that science makes the world less interesting and
awesome by just explaining things away,’ Dr. Wilkinson said. ‘But with
autumn leaves, the more you know about them, the more amazed you are.’
Another reminder that ‘waste’ is very rare in nature — perhaps non-existent. Another reminder that it needs to become obsolete in human affairs as well.