Obligatory disclaimer: real life sucks, but sometimes you
get to see something new and unusual in it all the same. Case in point – bears,
brown bears, to be more precise. For the last few days, Yahoo News and similar
websites were discussing about the various mutant grizzlies that had appeared
in the Banff national park. One is all white, (but not an albino, a different
mutation). The second is still a cub, mostly brown, but with a white head,
giving it a rather panda-like appearance. Cool, eh? But so what?
For one thing, it helps us to understand as to how the bears’
coloring scheme has evolved in general. With the exception of the giant panda,
the modern bears are largely monochromatic, especially the American black, the
brown, and the polar bears, but as those recent cases of mutated grizzlies
showed, there are always exceptions to this rule, and just because a bear is
supposed to be brown, (or black, or white, or etc.), doesn’t mean that it is
going to be.
Yes, most discolored animals tend to die-off more quickly
than their normal-colored counterparts for a variety of factors, but if an
animal is large enough, (say, a sperm whale, or even ‘just’ an African bush
elephant), then it may survive into adulthood and reproduce.
This is where it gets even trickier, because genetics. An
animal’s coloration, (whether it is an elephant, a zebra, a hyena or a guinea
pig), is defined by the DNA that it had inherited from its parents – usually. Sometimes
the DNA misfires and we get albinos, leucistic animals, melanistic, (all black),
and so on, but if they do reproduce, there is no indication that this genetic
flaw will be inherited by its’ offspring, because the latter have different DNA
– a mix from both parents, which changes the game entirely. Put otherwise,
while breeding in captivity is one thing, (just look at all the breeds of
domestic pigeons, geese, or even goldfish, for example), breeding in the wild
is something else, and while it is possible that a ‘miscoloured’ animal will
survive to sexual maturity, (as the first out of the two grizzlies in our case is a sexually mature animal and not just
a cub), the odds of its’ offspring inheriting its’ atypical coloration is even
less. What next?
Hard to say. For today, actually, I wanted to discuss the
cockroaches. Yes, they are far less majestic than the bears are, but they are
far, far older, having appeared back in the Mesozoic, during the Cretaceous
period. Superficially, they are similar to beetles, but they are much less
derived than the beetles are; whereas the beetles undergo a full metamorphosis,
(rather like butterflies, honeybees, and flies), the cockroaches do not – their
youngsters are not grubs like those of beetles, but are miniature versions of
the adults.
Another important difference of cockroaches from beetles are
the ooteca – whereas beetles just lay their eggs into rotting wood, ground, onto
tree bark or someplace else, the cockroaches actually carry them in a sort of
an ‘egg case’ until the eggs hatch and the young cockroaches scatter to begin
their own lives.
…In any case, the physical similarity of cockroaches and
beetles is superficial; whereas beetles are found all over the world, in all
sorts of ecosystems, cockroaches are much more tropical, and in the wild are
found usually in jungle ecosystems, or elsewhere wherever there is plenty of
heat and moisture. Since their closest relatives are the termites, this does
include underground. Pause.
…Termites deserve their own mention – sometimes they’re
still called ‘the white ants’ because of their color, but they are very
different insects from ants. Sometimes it’s obvious – the termite mounds are
much bigger, in a different league altogether, from anthills, or hives of bees
and wasps – and sometimes, not so much: whereas all worker ants, (wasps and
bees), are all females, in the termite communities, both sexes are represented
equally, plus worker and soldier termites are much more different from each
other physically than those of ants or wasps.
Out of the two groups, the termites are the more derived
ones, and may have involved from the cockroaches, (albeit different ones than
those that live in human houses), but so far, no one knows for certain. Fossils
of both cockroaches and termites are rare finds, so it is hard to make any
decisive statements about them, at least right now.
…Moreover, for now, this is it. See you all soon instead.
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