Oct 31, 2010
And why not? The platypus is a venomous mammal that lays eggs, has a duck bill, beaver tail, webbed feet and echo-locates. Who would believe such a bizarre creature exists? The platypus truly has an interesting evolutionary history.
And the mighty platypus has an apparent superpower: stopping the construction of power plants.
A single platypus was discovered near the site of a proposed power plant in Australia, and activity on said power plant comes to a halt. Over one platypus.
I suppose the greenies would argue that where there’s one, there’s many and therefore the land should be left undisturbed. I agree with the sentiment when many animals are found, or in the case of say the Spotted Owl which caused so much consternation a couple of decades ago in North America. I agree with setting aside large amounts of land to preserve biodiversity. After all, mother nature has had billions of years to develop chemical compounds we may find useful, let’s preserve those.
In this case however, only one animal was found. Does this justify holding up a much needed power plant for Australians? I think not.
I don’t think so because I believe in springs. Not artesian wells or other sources of fresh water, but mechanical springs. I believe in them. More specifically, I believe in the damping coefficient. I make no apologies to the reader for introducing math into an article about a platypus, but I do caution the reader that the concept was introduced to the author during a differential equations (Calculus 4) course and should likely just be loosely scanned. The wikipedia article linked has a great graphic on the right showing the concept with a bouncing weight on the end of a spring.
So, back to where we were.
A single platypus obviously cannot create a local population of the bizarre animals. Given that several platypi (sp?) were not spotted, but a single animal, it seems that there is only one or generously two.
Population growth can be modeled using differential equations which include the damping coefficient illustrated by the bouncing spring on the Wikipedia article linked above. Doubt it?
Let’s perform a thought experiment assuming there are two platypi, a male and a female while introducing the concept of a damping coefficient.
Cute little guys aren’t they?
Let’s suppose in our thought experiment that the male and female are of child bearing age and produce a clutch of eggs.
Some of these eggs may not hatch due to the damping effect. Some just might not contain viable offspring.
Some of the eggs that hatch might produce young that are weak or sickly, again the damping coefficient makes its mark.
Some of the viable, healthy young will succumb to the environment (disease, virii, malnutrition, etc). Damping again.
Some of the viable, healthy young will be eaten by carnivores. More damping.
Some of the above effects may not apply to any particular clutch of eggs, but some damping will occur. In our thought experiment, let’s assume half the eggs eventually produce healthy young adults and furthermore let’s assume that there were originally ten eggs, so we have five healthy offspring that grow to breeding age.
Now the platypi have only their siblings or parents to breed with. There are maybe three or four of each sex, likely a different distribution. Some of the adults will get eaten, some will wander away and never mate. Some will choose not to mate.
The remaining will mate with their close genetic relatives. Any genetic issues will manifest themselves in the next generation, and this is the strongest damping effect. A population that shares a significant percentage of genetic code is susceptible to wholesale demise from a single genetic factor.
Consider a population wholly derived from itself with a susceptibility to a killer disease. If one member of that population comes into contact with the disease, the disease is quickly spread within the whole population and every animal dies. In other cases, detrimental birth defects will occur.
It is understanding this damping effect which caused my differential equations professor to state that no population can be derived from only one male and one female. I have no reason to argue. In our thought experiment, we have to consider that platypi aren’t over-populated in Australia, if they were there would of course be no need to protect them. So the natural (plus man made) damping effect acting on the platypi population seems to exceed the birthrate.
So how do populations thrive? That is, what really is the theory of evolution?
First off, much to the chagrin of Republican candidates everywhere, the theory of evolution simply does not state or even suggest in any way that humans derived from monkeys. Or apes. Republicans: you do know chimps are apes, right? No tails?
Nope, the theory of evolution states that we derived from monkey-daddies, which I suppose is worse from your point of view.
And to my brother’s old friend Chuck: the theory of evolution does not suggest that there should be “fish people” as you described. Nor should humans have wings, as I read in an election thread today.
The modern basis of the theory of evolution is really simple and based on an equally simple observation: genetic mutations occur. Now, I am of course not suggesting Darwin knew about genetic mutations, but he did know about Mendel‘s pea plants, although Darwin didn’t quite put it all together. Neverless, we’ve known about the effects of genes since we began farming and practicing animal husbandry, but we didn’t exactly know about genes specifically nor mutations, only inheritance.
There are three possible consequences of a genetic mutation with respect to an organism’s long term survival: (1) the genetic mutation helps the organism reproduce, (2) the genetic mutation hurts the organism’s likelihood of reproducing, or (3) the mutation has no bearing on an organism’s ability to reproduce.
Examples of a genetic mutation that might make an organism more likely to mate would be a larger display in the male peacock, or a more muscular build in a bull.
Examples of a genetic mutation that might make an organism less likely to mate would be a modification to a fish’s scales that increases drag, or a mutation in a robin that causes the female to produce thin eggs.
Examples of a genetic mutation that would have no bearing on an organism’s likelihood of mating would include skin color or hair color in humans. Yes, we’re still evolving.
Let’s perform a second thought experiment. Let’s imagine we are witnessing the common ancestor to the monkeys, apes, and hominids, a mammal population of some sort alive many millions of years ago. How many generations might that be? Let’s say we’re going back 10 million years and our ancestor had an adult breeding age of 10 years, not unrealistic in a higher mammal, human breeding can occur every 13-15 years or so and rats can breed on the order of months. So, 10 years on average per generation and 10 million years of time, that is one million generations. One million generations of compounding mutations.
Just to spite Christine O’Donnell, let’s assume our thought experiment animal is already more or less monkey like.
I could have gone back much further, well beyond the dinosaurs even, back to the time of dimetrodon around 270 million years ago. Dimetrodon is related to mammals by virtue of the fact that mammals today have differentiated teeth (cuspids, incisors and molars), and dimetrodon had differentiated teeth. Not much else does. Dimetrodon was a proto-mammal that existed millions of years before dinosaurs. Christine, your lineage is many hundreds of millions of years old, and here is dimetrodon:
Not so cute.
So back to the population of early mammals who are far more advanced than the proto-mammals and are about to stand on two feet. How might this have happened?
A series of genetic mutations that were either beneficial or not detrimental would have had to occur. Let’s take our first genetic mutation to be an opposable thumb superior to that of the monkey-daddies, or that of what would become monkeys or apes. Humans are after all the only species with a truly opposable thumb.
What would this genetic mutation entail? Well, basically it would have reduced the length of the palm, placing the thumb within reach of the tips of the fingers. This doesn’t seem like it would reduce the likelihood the organism that first had the mutation would breed. As a matter of fact, it might have increased the likelihood of the organism breeding as food would have been easier to obtain with the increased dexterity and grooming a potential mate would have been easier.
And just like how your grandparents, parents, brothers, sisters, aunts, uncles, and cousins don’t disappear when you have children, the original population is still around when this mutation occurs.
So, we have a single individual within a population with a favorable genetic trait. That trait would either be dominant or recessive. If dominate, a single occurrence of the gene causing the trait would produce the trait in offspring. If recessive, then both the mother and father would have to pass the gene to the offspring for the trait to manifest itself.
Let’s assume the trait is dominant, then all the offspring of the individual with the mutated gene for an opposable thumb would have opposable thumbs.
Let’s assume the trait is recessive, then the trait would take much longer to become established in the population. An individual receives a gene from both the mother and father for each trait (greatly simplifying here and not considering traits that are expressed as a combination of genes), if the individual receives one copy of a dominant trait, then the individual expresses that trait. In order to express a recessive trait (such as blue eyes in humans) an individual must inherit the recessive trait from both parents.
So, obviously, recessive traits take much longer to express themselves in a population, even ones that are beneficial to the population.
The four possible combinations of inherited genes and the expressed trait are following:
- both the mother and father provide the gene for the dominate trait and the dominate trait is expressed
- only the father provides the gene for the dominate trait and the dominate trait is expressed
- only the mother provides the gene for the dominate trait and the dominate trait is expressed
- both the mother and father provide the gene for the recessive trait and the recessive trait is expressed
So dominate traits spread rapidly through a population, while recessive traits spread slowly. In each case of a trait that is perpetuated throughout a population for generations, the trait must have originated from a genetic mutation that increased the organism’s likelihood of reproducing, or had no detrimental effect on the organism’s likelihood of reproducing.
So, the reader may assume the above mentioned opposable thumb mutation was dominate or recessive, it doesn’t matter. The trait will be expressed among the descendants as it is a trait that leads to the likelihood of a successful mating. Dominant traits aren’t necessarily beneficial either, dominant or recessive simply refers to the conditions under which the gene is expressed, without regard for the effect on the organism. Keeping the above paragraph in mind, a dominant mutation with a detrimental genetic expression does not pass into the population through successive generations, as the organisms with this detrimental trait are not likely to successfully mate. Damping.
Our first genetic mutation, opposable thumbs in our thought experiment, is just one genetic change in the organism, so a young with the inherited trait would be able to mate with other members of the population that do not have the trait.
Imagine the next genetic mutation produces a trait that is an improvement to the pelvis that allows those individuals with the trait to stand up higher and see above the grasses on the Savannah and thus see predators approaching sooner than their contemporaries. Clearly, this is an advantage.
And again, grandparents, parents, brothers, sisters, aunts, uncles, and cousins are still free to breed organisms without this trait. This mutation occurs for only one branch of this family tree.
Imagine another genetic mutation that slightly alters the ankle, allowing for an increase in the run speed of the organism. We now have three advantageous traits in one branch of an organism’s family tree.
Each of the above genetic mutations would be slowly working their way through the population derived from the single branch of the family tree in our thought experiment until eventually there are some individuals with each of the three advantageous traits breeding true, that is whether the traits are dominate or recessive, all young have each of the three traits because they are advantageous.
In the case of recessive traits, then both the mother and father handed down the trait which means the young have two genes for the trait and can therefore only pass down the trait.
In the case of dominate traits, then the trait is so prevalent in the population that both the mother and father have two copies of the gene for the trait, so the young would inherit two copies also.
Now, this is where it gets difficult for individuals such as Christine O’Donnell. At this point, there is not enough genetic separation within the population separating those with all three beneficial traits from those with two, one, or none to prevent breeding. The population is still freely mixing.
Until something happens.
Maybe a selfish gene becomes dominant, such as a genetic preference to only mate with taller individuals who provide more food and attention to the mate, that is those who can stand up, run fast, and groom in a certain way.
Maybe a cataclysm segregates a subsection of the population with the genetic mutations from the rest.
Maybe a dominant trait mutates detrimentally, but no individual expressing the recessive trait will breed with the individuals expressing the dominant trait. Consider that the human brown eye trait becomes associated with a birth defect, but blue eyed individuals within the population had already stopped mating with brown eyed individuals. In this case, only the blue eyed individuals would survive.
In any event, something occurs which causes a subset of the population to only breed within itself. This subset of the original population will continue to produce genetic mutations, and this whole process continues and repeats with new genetic mutations such as a lack of body hair which quite likely led to a mating preference for the same reason it does today: beauty.
The original population of individuals who are breeding without producing the three genetic mutations listed above are still free to mate, and will continue to do so.
Over time, the two groups will drift to the point where they can no longer interbreed. This is how new species are born, and it takes a very very long time. The original population would over a very long time produce monkeys, apes, lemurs, hominids, and other species we haven’t found a fossil record for.
People such as Christine O’Donnell don’t believe the world has been around for a very very long time, which is why they just simply cannot wrap their little minds around the concept of genetic drift.
Eventually, the original population of successfully breeding individuals would have produced so many offshoots with traits that are superior that they will be out competed for resources by their genetic descendants and will cease to exist. That is, the successful production of genetically superior offspring will doom the original population as they are out competed by their descendants for food and shelter. Brutal.
So, Christine, that is why the common ancestor is no longer around, and that is why platypi are real, and platypi are clearly the product of genetic drift within the mammal kingdom, and so are you. And no, you’re not descended from a monkey, quit saying that’s what the theory of evolution states, you’re making those of us who understand basic science and vote a certain way look bad by association.
I wish He could reach out with His noodly appendage and pasta-pass the wisdom into your closed little mind, but that’s not possible of course.