function of husk on black walnut Re: evolutionary purpose of husks onwalnut
Yes, thanks for the suggestion of avocado and of osage orange in
your other post. Before I agree with you on that train of thought, I
need to be assured that the husk is not the "growing part" of the
seed of the black-walnut. I need assurance that the husk is
incidental and not integral to the actual seed growth.
If it is incidental, then the sloth or giraffe would benefit from its
food and the seed benefit in spreading. But if it is integral to
the actual growth of the seed inside, then the evolutionary
pattern requires much more insight.
Compare the husk of hazelnut to that of black-walnut or the
husk of coconut or brazil nut. So I am beginning to think that
a husk, no matter what the size of the husk is somehow
related to the growth of the seed inside and thus has a function
far beyond a animal attractant to spread the seed.
Maybe the husk is the pipeline or channel for which the plant
nurtures the growing nut-seed inside. If I can rule that out, then
I would agree the husk is just incidental and whose function
maybe 100% animal spreading.
Archimedes Plutonium [Only registered users see links. ]
whole entire Universe is just one big atom
where dots of the electron-dot-cloud are galaxies
function of husk on black walnut Re: evolutionary purpose ofhusks on walnut
I don't believe the husks were necessary as actual nourishment, and I
would say you are turning one component into a big deal. The actual
seed is well protected by multiple layers. Those layers over millions
of years of evolution could have served many purposes, like the hooks
on cockleburs that both served as a propagation vector and prevented
eating. This is similar to the omnivore principle, where
overspecialization eventually led to extinction. The thick-skinned
gymnosperms had many survival strategies, and hanging on to archaic
traits is a valuable asset in adverse conditions. For example, the
previously mentioned page states that osage orange somehow survived
the extinction of woolly mammoths until the horse was imported from
Europe, some 6,000 years without any transport mechanism. Obviously
the plant was able to grow, but probably not with the genetic
distribution needed for homogenity. This may explain why subspecies
arise. Plants typically devote a good part of their metabolic product
to scattering their seeds effectively, and there is apparently a good
reason for it.