| Cougar Press PO Box 894 Meadview AZ 86444 |
| Mutation |
It seems like an ugly word sometimes. Our minds can be spoiled by Hollywood versions of
mutants, hideous malformations that creep across the screen intent only on evil. How easy it is
then to forget that every lovely flower began as a mutation.
The dictionary defines the word as follows:
mutants, hideous malformations that creep across the screen intent only on evil. How easy it is
then to forget that every lovely flower began as a mutation.
The dictionary defines the word as follows:
On the evolution page, I pointed out that two of the most important trends in the billions of years
of biological change on planet Earth have been divergence and extinction. Species and orders are
said to go extinct when all of them have died. Someday genetic technology may reach the point
where vanished dinosaurs, mastodons and dodo birds can be brought back into present reality.
For now, once a particular evolutionary branch is gone, it's gone for good.
Imagine a maze of roads and streets that run through a large suburban housing development. If
all you know is that there is indeed a way through the neighborhood, you need to try this or that
route. If your particular choice ends in a cul-de-sac, a "no exit" or a dead end, your only option
is to turn around and go back to the intersection. Sooner or later, after trying however many
turns it takes, you find your way through, if there is a way...
...if there is a way, and that is the big mystery. Is there a way through? What does that mean?
Dinosaurs and dodos were both dead ends. Neanderthal man was a dead end, yet that road went
much further, in terms of time, than Homo sapiens.
So life heads down the path called humanity. Where is it that we hope to end up? Perhaps it is
true, as Marshall McLuhan proposed, that "The medium is the message." In this case I am
interpreting that in the sense of walking down a country road, heading for who knows where, but
reveling in everything about the road itself, the view, the sounds of the birds singing, the
fragrance of lilacs, the feel of the soft earth or the taste of wild strawberries.
At the intersections of this maze are where we find mutations. Mutations are events. They are
actual changes in the genetic makeup of a creature. These can be caused by ultraviolet light,
nuclear radiation or chemicals, or when mistakes occur during the copying of DNA within a cell.
In addition, for a mutation to develop, the change must occur in the cells involved in
reproduction. For one-celled creatures like bacteria, reproduction occurs when the cell splits in
two. Both cells would then carry the mutation. For creatures like ourselves that reproduce
sexually, the mutation has to be within the sperm, the egg, or the zygote that has yet to divide.
A further requirement is that the organism survives the change. It may be that most genetic
changes are fatal right from the start. Others are repaired by the cellular mechanism. If neither
of these things happen, then we have a mutation.
If this mutation turns out to enhance the survival of the organism, over time it will become well
established in the species. If, on the contrary, it makes it harder for the plant or animal to
compete, then it will eventually die out. This is a very simple description of the process called
"natural selection." This is how we diverge. First there is a mutation. Then, if the change is
good enough that the organism doesn't die, life goes on.
Of course, one mutation doesn't produce a new species. Within a species, all of the past
mutations have produced the diversity among the members. Hair color, eye color, skin tone,
body type, and thousands, maybe millions, of changes add up to why we are not all the same.
Who knows how many of these changes it takes before we are looking at a new species?
Paleogenetics is a new field, but already scientists in this area have put to rest the ideas that our
species may have bred with the Neanderthals. Neanderthal man and Cro-Magnon man did exist
during the same time, but they did not interbreed. The genetic differences between the two were
already profound enough to qualify them as separate species.
This is not so for Cro-Magnon man and modern human beings. The generally accepted theory
among the paleogeneticists today is that Cro-Magnon was modern man. The differences between
them and us are matters of culture, language, religion and any other trappings of civilization, not
genetics. He is still here. We are still here, but will we be here forever?
Neanderthal man explored his road for 800,000 years or more, but it was a dead end. Dinosaurs
were around for 150 million years before their path petered out. Was it a waste of time and
energy for these species to travel so far in time, only to die out in the end?
Is every mutation an effort to find a solution to the universal challenge of survival? Or are the
rewards of life something that every species finds along the way?
of biological change on planet Earth have been divergence and extinction. Species and orders are
said to go extinct when all of them have died. Someday genetic technology may reach the point
where vanished dinosaurs, mastodons and dodo birds can be brought back into present reality.
For now, once a particular evolutionary branch is gone, it's gone for good.
Imagine a maze of roads and streets that run through a large suburban housing development. If
all you know is that there is indeed a way through the neighborhood, you need to try this or that
route. If your particular choice ends in a cul-de-sac, a "no exit" or a dead end, your only option
is to turn around and go back to the intersection. Sooner or later, after trying however many
turns it takes, you find your way through, if there is a way...
...if there is a way, and that is the big mystery. Is there a way through? What does that mean?
Dinosaurs and dodos were both dead ends. Neanderthal man was a dead end, yet that road went
much further, in terms of time, than Homo sapiens.
So life heads down the path called humanity. Where is it that we hope to end up? Perhaps it is
true, as Marshall McLuhan proposed, that "The medium is the message." In this case I am
interpreting that in the sense of walking down a country road, heading for who knows where, but
reveling in everything about the road itself, the view, the sounds of the birds singing, the
fragrance of lilacs, the feel of the soft earth or the taste of wild strawberries.
At the intersections of this maze are where we find mutations. Mutations are events. They are
actual changes in the genetic makeup of a creature. These can be caused by ultraviolet light,
nuclear radiation or chemicals, or when mistakes occur during the copying of DNA within a cell.
In addition, for a mutation to develop, the change must occur in the cells involved in
reproduction. For one-celled creatures like bacteria, reproduction occurs when the cell splits in
two. Both cells would then carry the mutation. For creatures like ourselves that reproduce
sexually, the mutation has to be within the sperm, the egg, or the zygote that has yet to divide.
A further requirement is that the organism survives the change. It may be that most genetic
changes are fatal right from the start. Others are repaired by the cellular mechanism. If neither
of these things happen, then we have a mutation.
If this mutation turns out to enhance the survival of the organism, over time it will become well
established in the species. If, on the contrary, it makes it harder for the plant or animal to
compete, then it will eventually die out. This is a very simple description of the process called
"natural selection." This is how we diverge. First there is a mutation. Then, if the change is
good enough that the organism doesn't die, life goes on.
Of course, one mutation doesn't produce a new species. Within a species, all of the past
mutations have produced the diversity among the members. Hair color, eye color, skin tone,
body type, and thousands, maybe millions, of changes add up to why we are not all the same.
Who knows how many of these changes it takes before we are looking at a new species?
Paleogenetics is a new field, but already scientists in this area have put to rest the ideas that our
species may have bred with the Neanderthals. Neanderthal man and Cro-Magnon man did exist
during the same time, but they did not interbreed. The genetic differences between the two were
already profound enough to qualify them as separate species.
This is not so for Cro-Magnon man and modern human beings. The generally accepted theory
among the paleogeneticists today is that Cro-Magnon was modern man. The differences between
them and us are matters of culture, language, religion and any other trappings of civilization, not
genetics. He is still here. We are still here, but will we be here forever?
Neanderthal man explored his road for 800,000 years or more, but it was a dead end. Dinosaurs
were around for 150 million years before their path petered out. Was it a waste of time and
energy for these species to travel so far in time, only to die out in the end?
Is every mutation an effort to find a solution to the universal challenge of survival? Or are the
rewards of life something that every species finds along the way?
A random change in a gene or chromosome resulting in a new trait or characteristic
that can be inherited. Mutation can be a source of
beneficial genetic variation, or it can be neutral or harmful in effect.
that can be inherited. Mutation can be a source of
beneficial genetic variation, or it can be neutral or harmful in effect.
| Yoga for Carnivores by Jay Dyck |