Re: [asa] Shermer and Inevitability

Hi Mike,

One thing that Shermer seems not to consider is whether, having once arisen, the very presence of technologically adept intelligent life does not preclude the emergence of a second, similar species. After all, at least some evolutionary scenarios suggest that Cro-Magnons drove Neandertals to extinction. If competition can result in the elimination of an already existent intelligent, technological adept species, what are the odds that similar competition can prevent emergence of such a species in the first place?

Another way of thinking of this is in terms of evolutionary niches.

One could posit - and it seems rather to coincide with what we actually observe - that there are vaguely defined "levels" within an ecosystem within which species compete for resources. At the lower levels the resources are reasonably abundant and this allows a very large number of various species to fill that "niche". But, as we ascend, the resources get harder and harder to exploit, competition gets more and more fierce, and thus only one or two species are able to adapt to fill the niche's at the higher levels.

So, to put this crudely, one finds;

Millions of bacteria
Thousands of plants
Hundreds of herbivores
Tens of predators
One "super-predator"

The very fact that the "super predator" is able to dominate all other species in the battle for survival means that once this species arises, it is not soon likely to be displaced. Further, it is not likely to allow any similar species to emerge. Such a species is also going to arise late in the evolutionary process for the simple reason that it has to be an emergent adaptation from a "lower" level.

I don't see then that the late emergence of only one "super predator" (i.e. an intelligent, technically capable species like ourselves) should be so very remarkable.

It is, incidentally, simply wrong that only the primates have technological intelligence! Off hand I can think of one group (birds) and three species - otters, beavers and dolphins - who demonstrate an ability to construct artefacts or use tools.

These are very cursory thoughts, but I hope you find them a helpful point of departure for further reflection.

Blessings,
Murray

Nucacids wrote:
> Michael Shermer makes an argument that doesn’t strike me as being as
> strong as he thinks it is:
>
> http://www.scientificamerican.com/article.cfm?id=will-e-t-look-like-us
>
> Shermer writes:
>
> “What are the odds that intelligent, technically advanced aliens would
> look anything like the ones in films, with an emaciated torso and limbs,
> spindly fingers and a bulbous, bald head with large, almond-shaped eyes?
> What are the odds that they would even be humanoid? In a YouTube video,
> produced by Josh Timonen of the Richard Dawkins Foundation for Reason
> and Science, I argue that the chances are close to zero”
>
> and explains:
>
> “if something like a smart, technological, bipedal humanoid has a
> certain level of inevitability because of how evolution unfolds, then it
> would have happened more than once here.”
>
> Not necessarily. If event X has the likelihood of happening once every
> 3 billion years, then after 3 billion years, it becomes inevitable and
> it happens once. It’s like the lottery. If the odds of winning are a
> million-to-one, if a million people play, someone will win. That the
> winning is inevitable does not mean a thousand people from that million
> should win.
>
> Shermer also adds:
>
> “But of the 60 to 80 phyla of animals, only one, the chordates, led to
> intelligence, and only the vertebrates actually developed it. Of all the
> vertebrates, only mammals evolved brains big enough for higher
> intelligence. And of the 24 orders of mammals only one—ours, the
> primates—has technological intelligence. As the late Harvard
> evolutionary biologist Ernst Mayr concluded: “Nothing demonstrates the
> improbability of the origin of high intelligence better than the
> millions of phyletic lineages that failed to achieve it.” In fact, Mayr
> calculated that even though there have evolved perhaps as many as 50
> billion species on Earth, “only one of these achieved the kind of
> intelligence needed to establish a civilization.””
>
> But this is like arguing that since there was only one winner of the
> lottery, it was not inevitable that someone, somewhere would win. Yet if
> enough people play, it becomes more likely that someone will win to the
> point that it becomes inevitable. And the more people that play, the
> more people who do not win.
>
> Inevitability does not mean an event should happen multiple times. It
> would depend on how likely that event was. And unless we have
> independent evidence about this probability, we cannot rule out
> inevitability because the event happened once.
>
> Mike
>

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Received on Fri Nov 6 22:24:28 2009