81–90 of 97 posts
I'm sure the ability to mate isn't exactly the definition of a "species," but it seems like a decent way to get a grip on the extremely gradual genetic changes predicted/described by evolution. This article made me ask the question: How would you be able to recognize the "first human"?
I've always wondered something about evolution (or rather, speciation): how many generations removed could an ancestor and descendant be and still be theoretically able to mate? I'm sure the ability to mate isn't exactly the definition of a "species," but it seems like a decent way to get a grip on the extremely gradual genetic changes predicted/described by evolution. This article made me ask the question: How would…
There are exceptions like those with dogs where one dog may be physically too small or too large to breed with another. I'm kind of irritated that some claim species cannot be created when a chihuahua and a Newfoundlander could not possibly inter-breed. If dogs like that were stumbled upon in the wild they would obviously be classified as entirely different species.
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Xenophanes of Colophon supposedly lived to 95. Pyrrho of Ellis lived to 90, and Democritus to 109. On the other hand, Epimenedes is supposed to have lived to the age of 154 or 290 depending on whom you believe, so take these numbers with a grain of artery-clogging sodium chloride.
Go back far enough in history and numbers get even less believable, just think of Methuselah.
Not to detract from the insight but: Until very recently life expectancy at birth hovered between 20 and 35 years, but in the past century it has risen to 67 years Most of this increase has been due to a precipitous crash in infant mortality, rather than a soaring increase in the median life expectancy. For example, even in the 1500s it seems a well-to-do Englishman (who lived a somewhat more hazardous life medically…
I still don't understand why the average is used instead of median (or average of data between the first and third quartile), when people talk about life expectancy. It leads to misconceptions.
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All true, though, as far as I know, hunters and gathers who manage to survive childhood still die quite early, no? [1] They appear very healthy but thats partly because there are pretty much no grand parents. I might be wrong about this. Also, a diet high in animal protein might make you very fit but it is thought to be a cause for cardiovascular disease [2]. Actually, afaik, this is the reason why government still g…
Nutrition isn't the only issue. Hunter-gatherers have a much higher chance of a violent death; not just because of the risks of hunting, but because tribal warfare drafts the majority of able-bodied men. Even the ritualized warfare commonly used among present-day hunter-gatherers is likely to cause deaths. http://en.wikipedia.org/wiki/War_Before_Civilization
So which of my down voted post above was bullshit? I'd like to learn.
[2] http://www.psychologytoday.com/blog/sex-dawn/201103/steven-p...
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One interesting fact regarding population growth is that worldwide, having children on aggregate is a inferior good: if parts of Africa and Southeast Asia can make some significant gains in the next few decades, we will likely see population peak sometime this century.
Children can't be compared to goods. There's biological things at worth beyond self interest. That is to say, people want children, even though its not in their self interest. I'd posit, if you were to try to assign children a status as a good in a wealthy culture, they'd be a luxury good. They cost a great deal, are effectively useless, but still desired.
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Yes, I think a limit on productivity amounts to a limit on knowledge. Does knowledge have a limit? There's no evidence for it; all our present mathematics of complexity suggests not (but it's possible one will be discovered...) However, energy needs do seem to increase with productivity, and there's limit on how much energy we can get from the sun (a dyson sphere encloses the sun, capturing all its energy). But there…
There are actually mathematical limits to the amount of information that can be stored within a given volume, the Bekenstein bound, which is a lot like a limit to knowledge.
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As long as the measure of productivity corresponds to something physical (which even bits on a harddisk are), then an exponential increase in productivity (as we have seen in the past) would eventually require humanity and its products to form a sphere whose radius grows faster than the speed of light. Do you agree that that is a pretty hard limit?
I think you may have skipped some steps... Could you fill in the middle a bit? I'm confused.
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"Common Malthusianism" is a strange name to apply to a claim Malthus didn't make. Malthus didn't attempt to extrapolate current trends, he merely pointed out (correctly) that there will eventually be a limit to productivity. From "An Essay on the Principles of Population": We may be quite sure that among plants, as well as among animals, there is a limit to improvement, though we do not exactly know where it is. It i…
> he merely pointed out (correctly) that there will eventually be a limit to productivity I don't understand this point. Why would there be a limit to productivity, especially with machines and computers to leverage our efforts thousandfold and more? And how could anyone know that such limit exists, even if it is actually reached one day? That would require predicting any possible innovation of the future.