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Tropical Forests

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dr.bob
194817.  Wed Jul 25, 2007 8:07 am Reply with quote

On this website, you tend to find that any query tends to spawn many more questions :)

 
Curious Danny
194820.  Wed Jul 25, 2007 8:11 am Reply with quote

You can't get a simple answer to anything can you?

 
ali
194821.  Wed Jul 25, 2007 8:32 am Reply with quote

Not to anything interesting, no.

 
ali
194824.  Wed Jul 25, 2007 8:53 am Reply with quote

There is evidence (Horodski, R.J. & Knauth, L.P. (1994) Life on land in the Precambrian. Science 263: 494-498.) that phototrophic microorganisms first colonized the land in the pre-cambrian period (more than 542 million years ago (MYa)). This is long before there is any evidence for plant life on land.

Recent evidence (Taylor, T.N., Remy, W., Hass, H. & Kerp, H. (1995) Fossil arbuscular mycorrhizae from the Early Devonian. Mycologia 87: 560-573.) suggests that the first plants colonised the land in the Ordovician (490-443 MYa) period (and not the Silurian (433-417 MYa) as previously thought).



This article suggests that they did it with the help of fungi.

 
smiley_face
194875.  Wed Jul 25, 2007 12:15 pm Reply with quote

Curious Danny wrote:
Curious Danny wrote:
A ridiculously long time ago, all life lived in the sea and the land was a barren scorched desert with howling winds hostile to life.
The evolution of plants started near the sea, where the oceans eroded the dry cracked land and allowed plants to take root on eroded cliffs and beaches.
The gradual spread of plants across the land allowed animal life to leave the sea for good.
Any estimates for how long it took for the whole of the barren landscape of the Earth to be covered in plants and made fertile for life?


I originally paraphrased the question like this as i wanted an answer, not more questions.

As dr.bob said, questions tend to lead to more questions on these forums. Also, with respect, your question doesn't exactly have a definite answer - as I initially stated, the Earth is still not "covered in plants and made fertile for life".

I suppose it's because I've been here for a while, but I don't take people questioning what I say as being a personal attack - in fact, it's what I expect, especially if I make fairly big statements without backing them up with sources.

 
dr.bob
194989.  Thu Jul 26, 2007 3:31 am Reply with quote

Indeed, that's what I like most about this site. Person A says something, person B says "no, that's not true", both parties then produce sources to back up their claims, and gradually we inch towards some kind of truth*

I've always enjoyed debating things and never see it as a personal attack on my views. If I'm wrong about something, I want to find out what I'm wrong about so I can stop being wrong about it in future**. When discussing some issue, I invariably end up knowing more about it than I did to begin with. F'r instance, I didn't know the Triassic was a very dry period before. This debate made me also realise that, before life colonised the land, there would have been no soil since soil is primarily composed of decomposed organic matter.


*Leaving aside philosophical discussions of what constitutes "truth"

**The flip-side, of course, is that, if someone else is wrong about something, I feel I'm doing them a favour by pointing out their error and correcting them. Not everyone seems to take well to this, however.

 
Curious Danny
195080.  Thu Jul 26, 2007 6:23 am Reply with quote

I think a quote is in order here:

Quote:
"Nothing exists except atoms and empty space; everything else is opinion."

Democritos of Abdera


He was really on to something there.

 
smiley_face
195083.  Thu Jul 26, 2007 6:29 am Reply with quote

Except that even that quote is up for debate. How do we know atoms exist? We can only be sure of our own existence according to Descartes.

Quote:
Cognito ergo sum - "I think, therefore I am"

 
Curious Danny
195091.  Thu Jul 26, 2007 6:38 am Reply with quote

another quote needed:

Quote:
Perhaps I'm old and tired, but I think that the chances of finding out what's actually going on are so absurdly remote that the only thing to do is to say, "Hang the sense of it," and keep yourself busy. I'd much rather be happy than right any day.

Slartibartfast


Works for me.

 
swot
195327.  Fri Jul 27, 2007 5:32 am Reply with quote

What if being right makes someone happy?

[/devil's advocate]

 
Frances
195395.  Fri Jul 27, 2007 7:45 am Reply with quote

Or unhappy? Righteousness can be deadly.

 
swot
195670.  Sat Jul 28, 2007 5:39 am Reply with quote

Quite.

 
96aelw
195729.  Sat Jul 28, 2007 12:48 pm Reply with quote

Curious Danny wrote:
another quote needed:

Quote:
Perhaps I'm old and tired, but I think that the chances of finding out what's actually going on are so absurdly remote that the only thing to do is to say, "Hang the sense of it," and keep yourself busy. I'd much rather be happy than right any day.

Slartibartfast


Works for me.


Didn't for him, though;

Quote:
"And are you happy?"
"No. That's where it all falls down."


smiley_face wrote:
Cognito ergo sum - "I think, therefore I am"


I'm assuming that was a deliberate misquote of "Cogito ergo sum", 'cos I've heard others mangle it in that identical fashion, but it's been some weeks since I was last able to correct anybody's Latin on the internet, so fully needless though it may be to do so here, I'm seizing the oppurtunity with both hands, and damn the consequences.

 
smiley_face
195749.  Sat Jul 28, 2007 3:11 pm Reply with quote

I didn't do Latin - my school failed me; though my basic knowledge of linguistics tells me that the root "cognit-" means to think (e.g. Cognition, Cognitive Behavioural Therapy, Cognitive Science...), so perhaps that's why I copied the quote out wrong.

 
ali
195750.  Sat Jul 28, 2007 3:32 pm Reply with quote

They are actually from two different sources. The cognit- words come from the Latin cognoscere; 'to learn', and the cogit- words (like the English 'cogitate') derive from the Latin cogitare; 'to consider'.

 

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