Saturday, April 18, 2015
Tuesday, April 14, 2015
Doggone Good Cooperation
Who'd
a thunk that our ancient alliance with wolves (who we quickly bred
into tame puppy dogs) would be related to how our ancient European
ancestors (Cro-Magnon man) out-competed the Neanderthals? It's been
known for a long time that we humans domesticated wolves tens of
thousands of years ago, and also that we outlived our Neanderthals
cousins, who disappeared some 40 thousand years ago. But the link
between these two events was only recently identified by a researcher
at Penn State University. How was this connection realized?
Neanderthals
had inhabited Europe some 200,000 years before Cro-Magnon man even
entered the scene. Neanderthals were accomplished hunters of large
herbivores such as mammoths and elk, but they also had fierce
competition from European lions, leopards, hyenas, as well as wolves.
It was very challenging and dangerous to bring down a mammoth or
bison by spears. Once you managed to kill one, lions and hyenas would
harass you and try to steal your prized meat. So Neanderthals may
have lasted a long time, but they were not all that dominant—their
population stayed modest.
Then
about 45 thousand years ago, modern humans entered Europe. Now the
Neanderthals had yet one more competitor for the hunt. Humans,
however, had an ace up their hairy sleeve: they domesticated the
wolf. It was a great example of a complementary relationship—two
potential competitors (humans and wolves, both of whom loved to dine
on mammoth meat) joined forces to make their partnership far more
effective than either one could do alone.
Those
early wolf-dogs had the job of tracking and harassing big game until
their prey tired, but then they didn't have to close in for the
kill—which could become very dangerous when they faced a cornered
and aroused adversary. Instead, humans appeared on the scene and
dispatched the prey with spears from a safe distance. Having
cooperated for the kill, dogs and humans then shared the treasure.
Together, they could also successfully fend off other carnivores who
might show up. Thus was born the human and hunting-dog team... which
proved to be a deadly combination.
In
the meantime, the Neanderthals—having been around far longer, but
who left no evidence that they ever partnered with wolves—were at a
serious disadvantage. Before long, they disappeared—followed a few
millennia later by European mammoths, bison, and giant elk. The
human-dog team was lethally efficient.
This
is just one more example of how species that managed to evolve
cooperation have fared better than those who couldn't. Yes, Darwin's
insight into the power of survival of the fittest shoes how evolution
competitively plays out, but it's not all about the fiercest
competitor always becoming triumphant. Strategic alliance have also
favored the prospering of species.
Labels:
Cro-Magnon,
dogs,
neanderthals,
species cooperation,
wolves
Friday, April 10, 2015
Friday, April 3, 2015
Palm Perfume
Everyone
knows what dogs do, immediately after they encounter another canine
in a non-aggressive manner: they sniff each other's butt. (If it's an
aggressive meeting, they growl first and then sniff butts.)
Many other animals also smell each other out, although most of them
do not directly head for the nether region. Odor is an ancient and
effective way of checking out a critter that one meets. Is this an
old acquaintance? Will I make friends with this dude? He looks pretty
tough, but maybe it's really a sexually receptive “she.”
These
are very animal-like behaviors. We humans like to believe that we are
different. We don't need to stick our schnoz into each other's
private parts to case out the newcomer. We look them in the eye to
judge their character. We shake their hand and see how firmly they
grip ours, or how long they hold on. Besides, our sense of smell is
not all that good anyway.
Well,
you can toss that belief into the trash, along with many other myths
that humans are special and different—as I've posted numerous times
on this blog. As it turns out, recent research in Israel and Germany
has shown that people unconsciously sniff their right hand,
just after shaking hands with another person. It's an unintentional
maneuver, and thus an instinctual one. What researchers
discovered—when participants were covertly filmed—was that people
frequently brought their right hand near their nose, just prior to
shaking hands, and then later held their hand near their nose for
even a longer time span, after a hand shake.
But
were they really sniffing the palm scent left by the other
person, or in an absent-minded way just bringing their hand up
towards their face? Like good scientists, the researchers installed
nasal catheters up the schnoz of participants and, indeed, verified
that they actually sniffed their hands, rather than simply itched
their nose or inspected their manicure.
What's
more, the chemicals transferred by the handshake were then lab
tested. What did they find? Two chemicals: squalene and hexadeconoic
acid; the latter is interestingly also known as palmatic acid.
Even more fascinating: these chemicals are known to be some of the
same ones that dogs look for, in their social butt-smelling rituals.
The circle comes round: we are just like dogs.
So
the next time you greet someone with a handshake, pay attention to
what your right hand does, immediately afterward. Are you responding
more to the firmness of their grip or the subtle palm perfume you
subsequently whiff? Are you picking up more on the steadiness of
their eye contact, or the subtle scent of their hexadeconoic acid
deposited on your paw?
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