[Luminal]

iNow said:

I don't doubt the existence of supervolcanoes. I don't doubt their commonality in the existence of this planet, nor their effect on the life the planet supported during their eruption.

I do doubt the use of this idea as an explanation for the reasons australopithecines went extinct... especially since you cannot even describe a single event that occurred at the right time and the right place... also, the lack of other plant/animal deaths during the same time... also, the fact that homo survived.

Also, maybe it was aliens that did it.

Come on. If you're going to speculate, at least root it in something valid. Just because you saw a special on discovery channel last week doesn't mean that the topic of said special is the answer to each question you encounter.





Sorry for my tone... Long day. Lots of pissed off executives who have been drilling me for real explanations and not fluffy speculations without support. Mea culpa.

...

You are equating large volcanic eruptions with aliens, as a factor in evolution, to make my suggestion sound absurd. And stating that I'm getting my information from the Discovery Channel.

Can you back those claims up? One would do well to avoid including exaggerated or created statements in other areas than just science.

All I was suggesting was that supervolcanoes exacerbated existing selection pressures, and that there is a possibility that these eruptions in conjunction with other advantages homo had, was a factor in the extinction of said species.

The reason this possibility came to mind was that the Lake Toba eruption reduced the human population by 60%. If something happened once, if could have happened before. I don't know why people get so cranky over a simple suggestion.

[iNow]

Fair enough. So, exactly which supervolcano do you presume wiped out australopithicines? What year?

[Luminal]

I don't think any supervolcano wiped them out, but it is possible that it reduced them to such a level at a particularly bad time that homo established firm dominance or even finished off their cousin species. I'm not going to get more specific than that, because I do not know.

I cannot answer which specific supervolcano was involved if any. The exact date for the extinction of australopithecines is in a fairly large time frame; supervolcanoes occur multiple times every 100,000 years; the circumstances of the extinction of the australopithecines could have been triggered by a supervolcano but the species itself struggled on for many years after before succumbing; scientists certainly do not know every supervolcanic eruption throughout history, especially when you start getting past 1 MYA.

The point... it was only a suggestion, and the possibilities are too varied to state any certainty.

[CDarwin]

Luminal said:

I don't think any supervolcano wiped them out, but it is possible that it reduced them to such a level at a particularly bad time that homo established firm dominance or even finished off their cousin species. I'm not going to get more specific than that, because I do not know.

I cannot answer which specific supervolcano was involved if any. The exact date for the extinction of australopithecines is in a fairly large time frame; supervolcanoes occur multiple times every 100,000 years; the circumstances of the extinction of the australopithecines could have been triggered by a supervolcano but the species itself struggled on for many years after before succumbing; scientists certainly do not know every supervolcanic eruption throughout history, especially when you start getting past 1 MYA.

The point... it was only a suggestion, and the possibilities are too varied to state any certainty.

You've encapsulated all the problems with your hypothesis in that statement. A) You're still thinking of the Australopithecines, an extensive lineage inhabiting the entire continent of Africa, as a "species." B) You're suggestion simply isn't testable.

[Luminal]

A) I'm not thinking of them as a species, and I was aware of what I said when I said it. Sometimes speaking in extremely precise terminology wears on the brain when speaking informally on an internet site. If I was writing a paper, I might use my terms more strictly.

B) Suggestions need not be testable... because they are suggestions. If someone reads my supervolcano suggestion, thinks on it a bit, and realizes a way to test it, wonderful. If not, no loss.

I think you encapsulated what irritates me about many scientifically-inclined individuals: an over-emphasis on terminology and semantics instead of ideas. Overall, I think this may harm science because it shifts focus to precision in communication rather than understanding in communication.

You see, humans have this amazing ability to convey meaning perfectly without fully spelling out every word in exact detail. If I said "cars" when referring to vehicles in general, you would understand. If I use "species" when referring to genera, you understand as well.

[CDarwin]

Luminal said:

I think you encapsulated what irritates me about many scientifically-inclined individuals: an over-emphasis on terminology and semantics instead of ideas. Overall, I think this may harm science because it shifts focus to precision in communication rather than understanding in communication.

You see, humans have this amazing ability to convey meaning perfectly without fully spelling out every word in exact detail. If I said "cars" when referring to vehicles in general, you would understand. If I use "species" when referring to genera, you understand as well.

But it's not a simply a matter of semantics. It doesn't matter what word you use, you're still treating the australopithecines as a single species whose destiny can be controlled by single events like the eruption of super-volcanoes. You're ignoring the fact that at most times during their long history, there were multiples species of australopithecines existing all over Africa, and their very long decline doesn't seem to be due to any single event.

Your suggestion also fails to explain why the australopithecines suffered but not other species in Africa, and there's the testability thing.