<
https://www.sciencealert.com/flowers-are-evolving-to-self-pollinate-and-it-could-be-a-big-problem>
'Insects numbers have declined so much that plants are now taking reproduction
matters into their own hands (or petals). They're evolving to self-pollinate
more often, rather than rely on ever-rarer insects to carry their pollen far
and wide.
That's the conclusion of researchers from the French National Centre for
Scientific Research (CNRS) and the University of Montpellier in France, after
they ran a genetic analysis of modern field pansies (
Viola arvensis) against
older ones grown from seeds collected in previous decades.
This disruption of 100 million years of evolution is likely to have serious
consequences, according to the study team. It may cause insect declines to
accelerate, as well as making plant populations less diverse and more
vulnerable to environmental change.
"Population genetics analysis reveals a 27 percent increase in realized selfing
rates in the field during this period," write the researchers in their
published paper, indicating a sharp increase in the pansies opting for
self-pollination.
"We documented trait evolution towards smaller and less conspicuous corollas,
reduced nectar production and reduced attractiveness to bumblebees, with these
trait shifts convergent across the four studied populations."
The flower's surface was around 10 percent smaller on average compared with
those that bloomed 20 to 30 years ago, the results showed, while nectar
production levels had dropped by 20 percent. The study showed that modern
plants were also less frequently visited by insects.
You can see the feedback loop going on here: fewer insects means fewer
pollination visits, which means the effort and energy that a plant is putting
in to produce nectar and make itself attractive is going to waste. As it
shrinks its petal size and cuts down on making nectar, the diminishing numbers
of insects have even less reason to stop by.'
Via Rixty Dixet.
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
