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New Zealand Tree Stuck In Evolutionary Time Warp
sciencehabit writes "A eucalyptus-like tree from New Zealand is still waging a battle that should have ended over 500 years ago. The tree continues to sport evolutionary adaptations, such as barbed leaves, to protect it from a large, flightless bird known as a moa. There's just one problem: the moa went extinct around 1500 AD."
So, they're implying that evolutionary traits should disappear after a relatively short period? Why? I'd suspect they may fade away over centuries, but not necessarily.
Serious? Seriousness is well above my pay grade.
The kangaroo still hasn't come up with a better way to bring up it's kids. Having your embryo climb all the way up to your pouch is sooo last Megennium.
-- Cheers!
This does not prove anything.
Plant A, under evolutionary pressure, develops a mechanism with which it protects itself from moas.
Plant B, which is not under evolutionary pressure, does not develop such a system.
Evolutionary pressure disappears, but growing the defense mechanism does not constitute an evolutionary disadvantage, so it stays in place.
Under the influence of random mutations, some plants might revert back to the old style, but this is a big might, since evolution works more by accretion than by shedding things.
I really do not see anything relevant here.
In other news, humans still have an appendix.
Just because something is useless doesn't mean evolution will remove it - its only when it becomes actually detrimental and individuals start removing themselves from the reproduction chain that things change.
Intelligent design is simple, everything can be explained because a god decided it had to be so. So our eyes work the way they work because god said so and you can't go questioning god. However god is not perfect. Why are some men color-blind while some women can perceive an extra color? Why can't we see ultra-violet? Why is that other animals have 4 or even 5 cones while we got only 3? It doesn't sit well with the ID idea that birds and fish got far better vision then we do.
But evolution is NOT a perfect replacement. We humans are detectors of patterns. That is why we see a face on mars or jezus on toast. Simple test. Imagine me holding something between my fingers. You see a short squared long white piece of wood of perhaps 4mm x 4mm x 3cm. What am I holding? Be honest, you think it is a match isn't it? It is a fair guess. You KNOW that most pieces of wood shaped like this are matches because that is really one of the only reasons to shape wood like this. And you might be right EXCEPT I might ALSO be holding a would be match that hasn't yet had its head put on OR a "toothpick" used by dentist to wedge teeth apart.
As pattern seekers we like to think that everything has a reason and evolution does not. Evolution just is. In this case, there were a dozen sapplings some of which had leaves that the bird didn't see and which were eaten. The ones that weren't, survived to reproduce. With the bird gone, the selector is gone but not the reason for the change. Over time more and more of the leaves might change and since now there is no bird to eat them, they might survive. It could well be that the leaves we see now are FAR less good at camoflage then the leaves 500 years ago, but with no selecting taking place anymore, all the plants are surviving.
that is evolution. Random minor variations that result in different species if the enviroment forces a selection of what variation survives till reproduction.
But there is no goal to it. The plant did not choose to have a certain colored leave. Just random mutation. Some work, some don't. But unless someone causes you to be eaten for a mutation, then there is nothing wrong with it and if you can attract a female with it, then you reproduce.
the original article btw never implies that the plant should have changed back. Just the "editors" that picked the story up.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
The Slashdot summary of this story is spectacularly bad, particularly the 'should have ended over 500 years ago'.
Five hundred years is completely negligible on an evolutionary timescale. If trees - TREES - you know, big woody things that grow really slowly - had evolved significant changes in that time it would be headline news.
The research that led to this story wasn't remotely aimed at calling evolution into question, quite the contrary. Scientists are interested in the causes of the changes that these trees go during their lifetimes - and they have shown that these metamorphoses are probably due to the moa bird. Which is quite interesting, if probably not Slashdot-worthy.
#define struct union
And humans still have tailbones.
It's a good thing, too, what with all the muscles and tendons that attach to the tailbone. What would they attach to if we didn't have a tailbone? I mean, can you imagine not having a tailbone as a vital part of the weight-bearing structure? We wouldn't be able to sit down.
Life is short; think quickly.
I would have assumed the plants kept their evolutionary advantages against herbivores because there is insufficient pressure to remove the spines on the leaves. Kind of like why we still have an appendix. Its useless, but appendicitis is sufficiently uncommon that there isn't enough evolutionary pressure to do away with it completely.
The additional growth required to change the leaves like that is going to be non-zero cost. Appendixes are more or less free (they're tiny). I also suspect that these trees would grow faster if they had big bright green leaves as saplings. So I figure there's one of two reasons they haven't evolved away: 1) it helps against deer too, there was only about 300 years without deer or moa, 2) they haven't gotten a random gene mutation to drop it in the last 500 years (500 years is pretty damn short)