A few days ago we were studying the formation of "reaction wood"
Reaction wood is what trees develop after being tilted by a landslide, shifting ground, etc to make themselves grow upright once more. After the traumatic event happens to the tree to tilt it over, the subsequent year's wood is denser and thicker as a result of parts of the cells of the trees growing as if on steroids. This more robust wood strengthens the tree and causes it to be able to grow upright once more.
Well, on conifers ("evergreen" trees like pines, spruces, firs) the reaction wood is formed on the UNDERSIDE of the stem or limb that has fallen, to PUSH it up.
On angiosperms (like oaks, aspens and beeches) the reaction wood is formed on the TOP of the limb or stem that has tilted or fallen to PULL it up.
When asked why these two types of trees developed basically opposite ways of doing the same thing the professor answered that these mechanisms evolved SEPARATELY. (***So this is parallel or convergent evolution- you evolution buffs?)
I thought it is so amazing that nature, operating blindly, has developed these similar solutions for similar problems but, because there is not a "designer" there are differences in both cases... The same "template" for the same problem has not been used, if you will... (Once again, the evolution buffs will tell me if I am making mistakes in that analogy here)
I was thinking that there probably are differences in the conditions that each of these traits developed- like perhaps the angiosperms with their broad spreading branches that continually droop need a different mechanism to stabilize themselves than the more upright conifers that perhaps under go different types of stresses to their stems when say moving ground or hillslope slumping knocks them akimbo...
Such interesting questions to ponder...
Isn't nature awesome!?!?!
-K
Really Cool Evolution Tidbit... ("Isn't Nature Awesome?" ;)...)
by Kudra 7 Replies latest jw friends
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Kudra
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Sparkplug
Most awsome Kudra. Kind of made me think of a program I was listening to on the redwood forest. How when one is struck by lightening it is known to implode like a structure does when folding in on itself for demolition. (I bet someone hears it fall in the forest. Anyhow, it was interesting because the commentator was speaking of how there is a ridge that forms along the valley that a dead redwood makes. (or can form) It sounded just fantastic to stand as this person was and see a treeline that had formed so many years ago. It was rediculous the amount of time that these trees had been building upon this ridge. Something like Roman times.
Well this is nothing doing with evolution, but your tidbit made me think of that tidbit and well I found it pretty amazing!
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Kudra
I really love trees.
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Kudra
So sparky, was he saying that the trees grew out of the fallen redwood along the line where the tree was laying? Very neat. I have indeed seen that in the woods- it is so wonderful to walk around in the forest and to be told a story about the forest's past by the unusual and unique forms of growth you see before you...
It is so amazing.
You might like the spruce story- it creates what are known as "octopus trees"!
When a spruce is cut down so there is a stump or it falls down so it is a timber along the forest floor, little spruce seedlings can sprout on top of the stump or on top of the fallen-down timber (from seeds that fall or are placed there by animals etc).
These seedlings grow to mature trees and eventually their roots grow down and over the stump or fallen tree. In time the original stump or fallen trees decomposes and completely vanishes. However, the trees that have gorwn over the top of it will still be there in the original position: roots growing down around a now "invisible" stump or log!
In effect, the tree now looks like it is standing up on its roots, like an octopus up on its legs!
How totally cool! -
Madame Quixote
Well, you and I do a few things blindly, too, Kudra.
I suspect it is that way for simple-celled creatures as well.
I'm about to finish reading A Rivier Out Of Eden, and all I can do is think, how amazing nature is, and how extraordinarily a long, long, long time it took for evolution to accomplish certain things, and that it really is far simpler and less mind-boggling to imagine a very brainy creator, but I think it's also an absurd idea, as well (the creation thing, I mean, although understandable that so many choose to believe such nonsense; after all, it is easier, it seems).
Research suggests that the simple "camera eye" of some organisms only took 500,000 (yes! thousand!) years to evovle, according to some computer evolutionary models. Amazing!
On the trees, it does seem logical that different species might evolve different evolutionary response patterns to similar disruptions; it's really not all that surprising that they developed similar patterns of response, just different sides of the coin - er, tree limb. very interesting!
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Sparkplug
was he saying that the trees grew out of the fallen redwood along the line where the tree was laying? Very neat. I have indeed seen that in the woods- it is so wonderful to walk around in the forest and to be told a story about the forest's past by the unusual and unique forms of growth you see before you...
Exactly! The dent left by such a giant tree decomposed or imploded is a valley of sorts ...Huge. So same as your octopus spruce, animals and such leave seedlings, or they collect causing a row to grow up. Very neat indeed. Now I would like to see an octopus tree.
I think I spent most of my childhood up a tree with a book or two. I once played rollerskating Israelite pricesses from Zanadu in a tree. Skates and all. Spent a summer in the most beautiful Aspen tree in Santa fe. Then I was such a chicken sheet geek I could not even spell out my full name but I wrote initials in the top of mine and a boy I thought I would die if I did not marry. So many of us had memories of this tree...I even got a letter from a friend 20 some years later when it was cut down. so sad.
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Madame Quixote
Know what else is amazing - (something also I learned while reading) - those blue-headed wrasse fish can change sex?!! The most dominant (largest) female of the group becomes a male when the male of the harem croaks!!!! Astonishing.
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Madame Quixote
These seedlings grow to mature trees and eventually their roots grow down and over the stump or fallen tree. In time the original stump or fallen trees decomposes and completely vanishes. However, the trees that have gorwn over the top of it will still be there in the original position: roots growing down around a now "invisible" stump or log!
In effect, the tree now looks like it is standing up on its roots, like an octopus up on its legs!Do you have any pictures of this? I'd love to see it! I will be in Portland in the summer; are there any redwood forests in Portland, Oregon, I wonder. I've always wanted to see one in person!