h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

All

A thought, it states the fly trap evolved to catch stuff by closing fast. I do not buy this. Evolution believers have us believe that small changes happen over many 1000s years, each small change having an advantage so that life form survives, passes gene down etc.

I cannot see any advantage in leafs that close slowly as they would not catch anything at all, no advantage, no genes passing down, no evolution.

The fly traps therefore must have been created...any H2G2 fan can fill in the blanks from here.

C.Hawke

The evolutionary adaptation comes as a result of the species adventures in a new and inhospitable environment.

Hello and welcome!

Why not develop this as a Guide Entry? You open a new page using the link at the bottom of your homepage. You might want to add something to your homepage too, so that we know who we're talking to.

Have a look around. There are some quite elaborately decorated homepages. Cheers!

JTG

Wow, scarry stuff indeed, one minute, brand new computer, next suggestions to design home pages.

Will take it slow, but will see what I can do.

I'm still not convince on the evolution front though.

Hi,

Wouldn't life be dull, if we all held the same opinions?

Have fun... look around. If you want to get into redecorating your homepage, there are a lot of friendly folks about who are glad to offer tips.

JTG

I still haven't really got a answer to the question have I.

Oh the dangers of making me a scout, I am delving where I haven't been (or many people have been) for a long time. Dark isn't it?

CH

The gradual changes probably came about in response to other factors that may originally have had nothing to do with catching bugs. Personally, I find the idea of intelligence at work in the universe far less credible. So would you, if you worked with the people I do.

JTG

It is always difficult to be sure of how evolution has got an organism to its current state as you can only really look at the end functioning product. The development of the human eye is always used as a good argument for creationism as it's such a complex thing and a partly functional (i.e. partly evolved) eye would give no selective advantage. There are loads of sites on the web dealing with these arguments. On the issue of the Venus Fly Trap, as with all organisms the driving force of evolution is the successful distribution of your genes to the next generation. So to speculate about the Venus Fly trap’s evolution you must also look at how its environment has changed or how it has moved to a new environment. So to be anthropomorphic about it here goes some wild speculation-
 The generic plant that it evolved from found that by having particular characteristics that adapted it to a lakeside habitat allowed it to flourish (always think in terms of producing offspring)
 Over time the lakes dried our/silted up and got choked with moss etc. Those offspring that were adapted best to that gradual change in the environment flourished at the expense of the others around them.
 The depletion of the lake also depleted the nutrients from the soil (helped by acidification). Those plants that could survive with low nutrients did well.
 Eventually the impoverished soil led to plants surviving who could supplement their diet by absorbing decaying material on their leaves.
 Overtime the most successful ones were those that could attract insects and kill them (maybe like sundews).
 Of course then there would be an advantage to passively trapping insects that were attracted (like pitcher plants)
 Finally active traps may lead to a selective advantage in a subset of these types of organisms (bladderworts and Venus Fly Traps).

All of this takes a very long time, but bear in mind that the progenitors of modern plants, mosses, ferns and algae were the first complex terrestrial organisms and have been around for at least a billion years. This is considerably longer before some worm (or whatever!) wiggled out of the pond slime and started the succession of animal life on dry land.
The generation of an oxygenic atmosphere (presumably caused by the biological action of photosynthesis) occurred about 3.5 billion years ago, only about 1 billion years after the earth is thought to have formed.

Just a few ideas,

Stuart

I'm with C. Hawke in not buying into some of this evolutionary stuff. The previous reply, while mostly very possible despite it's wildly speculatory nature, has one kink in it that I see.

Maybe it's just me, but I don't buy the species of plant which can absorb decaying matter on its leaves. Now, I'm no biologist, so if someone here is, disprove me. It seems to me that this is actually two steps. The plant needs to simultaneously develop the ability to get the decaying matter into itself and to actually be able to get the bits it needs out of the matter and put it to use within the contraints of it's prexisting anatomy. (Or whatever you call the anatomy-like structures within plants.) Without one, the other is pointless. The second point, one that I often point out, is that you have to understand that for any evolved species to survive it needs to singlehandedly be able to compete well enough with it's neighbors that it doesn't get wiped out. I've been in the wetlands of North and South Carolina, or at least very very wet bits of both, and I just don't see a plant that just happens to be able to metabolize dead matter being able to cut it in what seems to be a highly competetive enviornment like that for untold years before the skill actually becomes usefull. Especially since there's limited space in the genetic code and in all likelyhood if it starts gaining such sweeping abilities which are rather complex, it's got to loose something else. Of course, as I said, I'm no biologist. Could we get one in here, perhaps, to turn on some lights for us?

Here's a possible explanation for you, Corbin.

All plants ca absorb nutrients through their roots. In an environment where these nutrients are lacking, wouldn't it make sense for the plant to develop the ability to do the same thing using other parts of itself, such as its leaves? It could then develop more sophisticated systems, such as the digestive fluids it now uses to break down its meals and the trap mechanism.

Also, remember that climate and geographical change usually happens just as slowly as evolution. Thus, a plant that can get food this way as an occasional supplement will eventually use this ability more and more as its environment becomes more hostile. Species don't always need these specializations as they are now; just what works for the moment. For example, the eye (another feature hotly debated by creationists), could have evolved from a simple light-sensitive patch of cells, used to get closer to (or avoid) light sources.

I know this is all speculative. It's impossible to do anything other than speculate on subjects like these (until someone invents a time machine, that is).

BTW, I'm not a biologist, either. But I do play one on TV.