Probability 1: Why There Must Be Intelligent Life in the
by Amir D. Aczel
Hardcover - 240 pages (September 1998)
Harcourt Brace; ISBN: 0151003769 ;
Dimensions (in inches): 0.92 x 8.54 x 5.74
At 04:17 PM 03/09/1999 -0500, Athena Andreadis wrote:
> That the evolution of humans was an unlikely accident is absolutely true.
>To extrapolate from this that, therefore, all high intelligence is an
>unlikely accident is a common logical fallacy, taught in Logic 101.
> I suspect that transition to self-awareness and accumulation of
>technology happens when sufficient synaptic complexity has been achieved.
>Let's assume that, in each planetary lineage, it happens only once. This
>still puts it at high odds for a planet within the habitable zone of a
>mid-sequence stable star, if life has started and has been going on for
>several billion years.
> In the case of Earth, even if the geological/biological dice had fallen
>differently (for example, the dinosaurs hadn't been wiped out by the
>aftermath of the Yucatan meteorite impact), the path to complexity was set
>for its eventual outcome. The slightest change in details wouldn't have
>led to humans, but we might have astronauts descended from velociraptors
> On Earth there was at least one other lineage that achieved sentience and
>technology -- the Neanderthal humans. Although it is not certain, it is
>likely that they were independently evolved cousins, distant enough not to
>allow interbreeding. It is also likely that our Cro-Magnon ancestors cut
>them off, competing for the same niche. So once you reach that complexity
>point, you may have an explosion of sentients, though they may be variants
>of a single group. What happens after that is sociological, rather than
> Lastly, statistics are useless when we're dealing with a single sample.
>The "soft" factors in the Drake equation can be given values as high or as
>low as anyone likes, depending on the outcome desired. In the end, nothing
>will substitute for direct observation, which is a tall order when you're
>at the bottom of a gravity well and an absorbing/distorting atmosphere.
>A. Andreadis, PhD (biologist)