If your religion does not permit you
to “believe in science” then read no further. You won’t like this. I am not of
the opinion that scientists know everything there is to know. Quite the
opposite. We will always have more questions than answers. That is the nature
of science.
Being a devotee of science I get a
little tired of seeing “aliens” in science fiction shows that look an awful lot
like humans. Those of you who follow my blog know that I am a fan of Star Trek.
But Star Trek, both the original series and its successors, is probably more guilty of this than anyone. Consider the following: We have Vulcans who look like humans
but with pointed ears; Romulans, who look like humans with pointed ears;
Klingons, who have changed in the various incarnations but even at their most
outlandish, just look like humans with plates on their forehead; Kardashians,
who look like humans but with big boobs and butts (sorry I couldn’t help
myself); I mean Cardassians, who look like humans with scaly necks and ridges
on their face; Bajorans, who look like humans with nose wrinkles (even if I did
have a crush on Major Kira); Talosians, who look like humans with big heads;
Ferengi, who look like humans with big heads and big ears. Andorians, who look
like blue humans with antennae. I could go on and on, but you get the point.
To think that natural selection that
developed on a different planet would produce anything that remotely looked
like us would be like taking a million monkeys who were banging on a million
typewriters and having two of them produce identical 200 page novels (maybe with one or two words different).
There are certainly parallel
characteristics that appear through evolution. These happen because of convergent evolution and divergent evolution. The fact that
goldfish and sharks both have fins is an example of divergent evolution. They
share a common ancestor way back in the evolutionary chain that developed fins
as a good way of producing locomotion through the water. That common ancestor
had offspring and descendants that eventually branched off into new species.
Those species had descendants which eventually branched off into more and more
species. Most of them retained the fins because fins work well, and fish with
fins survive better than fish without fins. This is call divergent evolution
because as all the species diverged from one ancestor, they kept the same trait
(fins). In this way we can see that they are all related, at least back to that
one ancestor.
Convergent evolution is a bit
trickier. Bats, birds, and some insects all have wings. But in this case, they
do not share a common ancestor that had wings. Bats, birds and insects all
evolved wings completely independently from each other. This may be why bat
wings, bird wings, and insect wings all look quite different. They all perform
the same function (flight) but in each case evolution had to reinvent something
that looked like a wing. They developed wings because being able to fly is a useful
thing, and there is only one kind of structure that will help you to achieve
flight.
Electric organs in fish is another
interesting case. Electric eels are the most well-known of fish with electric
organs, but there are actually lots of fish that produce an electric charge,
though in most cases it is used for navigation (like sonar) rather than as a
defense mechanism. As it turns out electric organs developed independently no
less than five times. I guess it is just a handy adaptation when you live in
murky water. But this is another example of convergent evolution. They all
share the same trait even though they do not share a common ancestor with that
trait.
So you could say that the same
pressures that sculpt the life evolving on other planets, might lead (through
convergent evolution) to the same characteristics that developed here; in other
words: humanoids. Not very likely. Even if you started with a planet that was
exactly like the Earth of three and a half billion years ago, and started with
the exact same building blocks for life, and it were to evolve an intelligent
species, there is no reason to think they would look anything like us. They
might share a few of our characteristics through convergent evolution, but
probably no more than the similarities shared by a dragonfly and a fruit bat.
Evolution is a huge roulette wheel.
Random mutations happen in life and most of the time those mutations are bad
and lead to the death of an organism before it can reproduce, but every once in
a great while you will get a mutation that has advantages (like fins) and that
will be passed on to the offspring. Organisms that have the advantage will
survive and reproduce better than the organisms that don’t, so those that don’t
eventually die out.
It seems like Hollywood has been less
human-centric in its aliens in recent years. I hope that trend will continue,
though, if the story is good enough . . . I will probably watch it anyway.
(My novel Star Liner, is now available as an
ebook through Copypastapublishing.com, Amazon, or the other usual online
sources. For those who like to turn physical pages, the paperback will be out
soon).
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