General Discussion Thread

[FrogEater]

Oh my... you mean the world is going to be ruled by Lars AND Nimphy ?

[Fimbulvarg]

Out of curiosity, do you know how long we've been recording weather/Climate patterns?  That's something I've always wondered but never really felt like digging through...

...That's a really good question actually. I would assume people in the past were generally more concerned with the weather (also you might be amazed at the number of natural phenomena that were just blamed on divine moods. Some scholars link the witch trials of the 17th century to the Little Ice Age). That doesn't hurt all that much given that there's a whole discipline of paleoclimatology trying to deduce past climates with amazing techniques (isotope levels in fossile shells and the like).
I would assume once again that the start of long-term weather recording might have started when people invented tools for it. Rain and wind are easily measured (in theory); Thermometers and barometers where invented around the late renaissance I believe. I don't know when hygrometers (atmospheric moisture readers) appeared.
At any rate precise and consistent live climate pattern recordings are a fairly recent thing considering that statistics only got involved recently and that the tools (radars, satelites) have become more advanced.

As for live readings of atmospheric CO2 levels they commenced after the war at some island near Hawaii with a weird name. We know about past CO2 levels thank to paleoclimatic research. The graph is steadily climbing.

EDIT: Forgot a very important thing - the first world climate map based on global climate records appeared in the interwar period.

[Fimbulvarg]

Although, as a student of Evolution, it's slightly worrying that 30 feels like long time to me...

Hey, that's cool! I've been pondering something I read once actually - we know that people in Europe are genetically more disposed towards lactose tolerance than people in Asia most likely because cattle livestocks were more common there during the neolithic revolution. Could this be called an instance of human evolutionary divergence?

[Sigrid Marie]

Yess, to all of these things.  Rain-swimming is a rare occurrence, but a nice one.
Our previous dog used to be afraid of lightning, because our house got struck when she was home alone.  We had to bring her inside or she would scratch the paint off of the door. 

I swam in the ocean during a thunderstorm once, which is probably the least smart thing I have ever done but was also totally worth it. Aww, poor doggy :C

[ThisCat]

Sure, that's what people fear, especially in Florida and such places. My objection, which I should probably just have written out from the start to avoid misunderstandings, is that the wind is quite capable of blowing into a full scale hurricane without climate change being involved.

Additional trivia: the wind blows due to differences in athmospheric pressure (the density of the air molecules). The greater the pressure drop over a distance the stronger the wind. Differences in temperature (which causes differences in air molecule density) is the main cause of the differences in pressure.
If you open a meteorological map of Norway you can see the culprit behind this weather marked as a big red L.

Yeah, heh, I knew that. I didn't mean all storms are here because of global warming, I'm just saying there's going to be more of them.

[Fimbulvarg]

I swam in the ocean during a thunderstorm once, which is probably the least smart thing I have ever done

Is it though? Salt water is a pretty excellent conductor for electricity ...

But I acknowledge your badassery and level of "I don't even care" in the face of (assumed) danger.

[Sigrid Marie]

Is it though? Salt water is a pretty excellent conductor for electricity ...

But I acknowledge your badassery and level of "I don't even care" in the face of (assumed) danger.

It isn't?? :O Because I was trying to tell people that I didn't think it was dangerous at all, but all the grown-ups told me I shouldn't swim during a thunderstorm. Well, this just proves once again that being older doesn't necessarily mean knowing better

[Fimbulvarg]

It isn't?? :O Because I was trying to tell people that I didn't think it was dangerous at all, but all the grown-ups told me I shouldn't swim during a thunderstorm. Well, this just proves once again that being older doesn't necessarily mean knowing better

Well don't take my word for it. I'm on the "I guess it might be safe so it's totally safe" level.

[asadderandawiserman]

Hey, that's cool! I've been pondering something I read once actually - we know that people in Europe are genetically more disposed towards lactose tolerance than people in Asia most likely because cattle livestocks were more common during the neolithic revolution. Could this be called an instance of human evolutionary divergence?

Well it's certainly a result of the mechanism behind evolution, but whether or not you'd actually call it evolutionary divergence is a matter of semantics.

Most people define 'macroevolution' (which is what most people call normal evolution) as when a species splits into two species, and two species are considered distinct when they can no longer interbreed to produce fertile offspring (although in many cases they can still breed, for example to produce ligers (lion/tiger) or mules (donkey/horse)). This isn't a perfect definition, but it's the best we've got at the moment, and divergence in this manner is complicated, something I don't entirely understand as quite a young student, and technically unproven. Nonetheless, it's fairly well agreed that for it to happen, a certain degree of isolation is needed, although this need not necessarily be physical isolation (genetic isolation of populations can be caused by subtle shifts in behaviour.)

It's entirely possible that, given loads and loads of time, the example you gave could have led to true divergence, since the two populations were extremely isolated, but due to modern transport technology, the human race is turning more and more into one super population, which will almost certainly mess up the system in ways we don't really understand. As a result, I doubt this factor will be particularly important in any future divergence, but who knows? Nonetheless, the example you gave is, in everything but name, evolution in action, and pretty cool no matter what you call it.

Sorry, that ended up quite long, I hope I explained it OK. I should also say again that I'm not a particularly experienced student at this point, and this is all based on my understanding, which could be wrong.

EDIT: Hmm... the forums seem a little patchy in taking my posts at the moment. This post didn't show up the first time, but luckily I'm a smidge paranoid and had copied it just in case.

[Sigrid Marie]

Well don't take my word for it. I'm on the "I guess it might be safe so it's totally safe" level.

So am I, so I'll take your word for it anyway.

[Eich]

It isn't?? :O Because I was trying to tell people that I didn't think it was dangerous at all, but all the grown-ups told me I shouldn't swim during a thunderstorm. Well, this just proves once again that being older doesn't necessarily mean knowing better

Well, looking at the way that lightning travels to the ground, you aren't really at an increased risk because of the terrain, the water just has some waves, no trees or telephone poles, or anything.  But, if lightning does happen to strike near you, you are going to die, because the salt water's relatively high conductivity (compared to lakes, creeks, etc. [which still have enough minerals to electrically ground you]) ensures that you are grounded.  How far away is safe?  I have no idea.  I would hope something like a kilometer would be safe, but it's not exactly something I'd be willing to test on a forumite. 

[Sigrid Marie]

Well, looking at the way that lightning travels to the ground, you aren't really at an increased risk because of the terrain, the water just has some waves, no trees or telephone poles, or anything.  But, if lightning does happen to strike near you, you are going to die, because the salt water's relatively high conductivity (compared to lakes, creeks, etc. [which still have enough minerals to electrically ground you]) ensures that you are grounded.  How far away is safe?  I have no idea.  I would hope something like a kilometer would be safe, but it's not exactly something I'd be willing to test on a forumite.

So what you're saying is that it's actually not that safe? Oh well, I survived.

[Eich]

So what you're saying is that it's actually not that safe? Oh well, I survived.

Not at all.  o_o  But we're glad you did! 

[Fimbulvarg]

Well it's certainly a result of the mechanism behind evolution, but whether or not you'd actually call it evolutionary divergence is a matter of semantics.

Most people define 'macroevolution' (which is what most people call normal evolution) as when a species splits into two species, and two species are considered distinct when they can no longer interbreed to produce fertile offspring (although in many cases they can still breed, for example to produce ligers (lion/tiger) or mules (donkey/horse)). This isn't a perfect definition, but it's the best we've got at the moment, and divergence in this manner is complicated, something I don't entirely understand as quite a young student, and technically unproven. Nonetheless, it's fairly well agreed that for it to happen, a certain degree of isolation is needed, although this need not necessarily be physical isolation (genetic isolation of populations can be caused by subtle shifts in behaviour.)

It's entirely possible that, given loads and loads of time, the example you gave could have led to true divergence, since the two populations were extremely isolated, but due to modern transport technology, the human race is turning more and more into one super population, which will almost certainly mess up the system in ways we don't really understand. As a result, I doubt this factor will be particularly important in any future divergence, but who knows? Nonetheless, the example you gave is, in everything but name, evolution in action, and pretty cool no matter what you call it.

Sorry, that ended up quite long, I hope I explained it OK. I should also say again that I'm not a particularly experienced student at this point, and this is all based on my understanding, which could be wrong.

EDIT: Hmm... the forums seem a little patchy in taking my posts at the moment. This post didn't show up the first time, but luckily I'm a smidge paranoid and had copied it just in case.

Yeah, that seems reasonable. In a way the answer is actually kind of obvious - little differences, like Asians having epiphanthic folds and so forth, are all around us without it having much significance. The main question then as you say is "when does it qualify as significant evolution". It's an interesting thought experiment though, imagine if the human race had actually diverged into separate human species. In a way it's good that we didn't given our propensity for xenophobia.

The forum has refused to add some of my posts as well actually. Luckily I've been able to salvage and repost most of them.
Edit: such as this post.

[asadderandawiserman]

Yeah, that seems reasonable. In a way the answer is actually kind of obvious - little differences, like Asians having epiphanthic folds and so forth, are all around us without it having much significance. The main question then as you say is "when does it qualify as significant evolution". It's an interesting thought experiment though, imagine if the human race had actually diverged into separate human species. In a way it's good that we didn't given our propensity for xenophobia.

The forum has refused to add some of my posts as well actually. Luckily I've been able to salvage and repost most of them.
Edit: such as this post.

That is a really interesting thought, and I'm surprised that it's never occurred to me. I really don't know whether divergence would be possible in modern human society, so I'd assume that the societies would have to exist separately for crazy amounts of time. I have no idea whether a sentient species could ever last more than 100,000 years without destroying itself, or if two separate sentient species would experienced the universe in completely different ways. Even two populations could be separated long enough to speciate, I doubt the societies would even vaguely resemble ours, so who knows if xenophobia would be an issue. Grr, so much we don't know.