Publications
Partners
I am not an expert on the theory of evolution at all, and coming from a very religious background, I used to ridicule the theory of evolution just like many other believers. However, over time I read up more and more about the theory and what it was actually about. I have reached a point where I have to honestly admit to myself that there is simply no other model or hypothesis that comes even remotely close to this theory in explaining the natural world and how the species on Earth have come to be. This article is an attempt to explain the theory in its simplest terms to those that might still have difficulty in understanding it.
We shall start with a factual case study.
Fact: Elephant tusks are getting smaller
Fact check: Search for “elephant tasks getting smaller”
Summary
Over the past 150 years it has been recorded that the average size of the African elephant’s tusks has reduced by half.
What could be causing this ?
Simply put, this is classical evolutionary processes at work.
But what are these processes ?
In this case you have 2 participants in an environment: Elephants and poachers. Now, on average, you could say that the length of an elephant’s tusk follows a bell-curve distribution. This is very similar to the average length of a human being. No big leap of faith required here. So, what type of elephant would a poacher (who is knowingly committing an illegal act and would there be looking for the biggest pay-off) be hunting?
Well, the elephant with the longest tusk in a herd, of course.
What this means is that elephants with longer tusks are being systematically removed from the population, and thereby increasing the chance of the elephants with shorter tusks to procreate. It therefor becomes more likely for baby elephants to inherit the “short gene” DNA from the short-tusked parents and will therefor be likely to grow shorter tusks.
Rinse and repeat this process over several decades and voila! You end up with elephants with severely shortened tusks.
So, when someone says that nature is “selecting” elephants for their shorter tusks, this is not to imply that nature is somehow consciously making a choice. Far from it. It’s just a poetic way of describing the process taking place above. Simply put, elephants with shorter tusks have a higher survival rate than those that have longer tusks under the current environmental conditions.
As this process continues, it is quite likely that we will end up with elephants that have virtually no tusks at all.
Sure, but they are still elephants
Ah, the old micro-evolution chestnut. When someone makes a statement like that, what they actually mean is that the resulting animal still LOOKS like an elephant, albeit with several shortened tusks. This is the common argument for micro-evolution, i.e. the specific species might show small changes over time, but it would still remain the same species.
If that is your view, then consider the following:
Below are some of the common differences a leopard has from a jaguar.
1. The leopard is slightly smaller than a jaguar
2. The rosettes (dots on the fur) are smaller
3. Sexual maturity in leopard are slightly later (by about a year)
4. Leopards are physically weaker
5. The leopard’s head is not as broad, and the jaw is not as wide
6. Leopards have a slight build, jaguars are more stocky
Do yourself a favour and look at pictures of these two species (yes, species. They are actually two different species) It is very easy to confuse the two.
Now, let’s look at the differences between the wild silver fox and domesticated silver fox
1. The domesticated silver fox has a shorter face and smaller teeth
2. It has soft and droopy ears
3. It has a curved tail
4. Its fur colour has changed and became more mottled or spotty
5. It’s sexual reproduction cycle is bi-annually instead of annually.
Comparing these physiological difference, we can see that some of them are strikingly similar. But if that is the case, why would we call a leopard and jaguar by different names, but in the case of the silver fox - which was a deliberate experiment to breed a tame animal out of a wild one - we retain the same ?
Simply put, because we choose to. The distinction between jaguar and leopard was made more than a century ago, and was done simply on skeletal shapes. In the case of the silver fox, we KNOW that the domesticated version evolved out of the wild version. We also have their DNA which we can compare.
To put this into the context of the elephant with shorter tusks, nothing stops us to call this new version the short-tusked elephant (or stelephant if you want to)
The point is that basing a species’ name on visible differences is very much a subjective point of view. You could simply argue that a leopard is nothing more than a skinny jaguar, just like a grizzly bear is nothing but a big, fat overgrown Saint Bernard!
But how would selecting for domestication have an effect on appearance? That makes no sense!
Enter pleiotropy. This is where one gene has an effect on more than one trait of a specific life form. In the case of the silver fox, the deliberate selection of reduced aggression in the species has caused a lowering of testosterone production in the offspring. This in turn had the observed effect on both appearance and reproduction cycles.
In this particular experiment these results were obtained in ONLY 20 generations in about 25 years! Just imagine the effects you would have if done over hundreds or even thousands of years!
Is there a better a way to classify animals then ?
Perhaps. The problem with the current classification system is that it’s static. Unfortunately, we don’t really have a better method of classification, mainly because a static system is more intuitive to humans. That being said, a more acceptable method of distinguishing between different species is their ability to cross-breed. Unfortunately this is not so clear-cut either. But it does seem to go a longer way than the current Linneaus system.
Sure, but there are no examples of speciation in nature
Actually, there are plenty. Just search for ring species or fork species. To be clear, these are actual, observed instances of speciation in nature. Speciation is one subgroup of life form not capable of cross-breeding with another subgroup.
That may be so, but I we haven’t seen a hippo changing into an elephant
True, but then let me ask you this. At what point did we decide that a leopard is sufficiently different from a jaguar, as per the example above? Again, you can be extremely liberal in your view and state that an elephant is nothing but a long-nosed, land-dwelling hippo. You might sound stupid for saying this, but you won’t be wrong.
Well, maybe this applies to animals, but humans are different
This is the same answer. The genetic difference between a human a bonobo is astoundingly small, less than 2%! Again, at what point do you decide a monkey is a monkey, and human is a human, when our own classification made a distinction on less than a 2% difference ?
Well, monkey genes can never change into human genes
There are no regions in the DNA sequence of ANY species, including humans that have an “Off Limits” barrier around it. Every part of the DNA sequence can change or mutate. The DNA itself doesn’t know it is “human” DNA. In short, DNA is not static. The processes under which DNA can change and mutate is well understood and thoroughly studied. There is no mystery here.
Okay, but maybe this is just micro-evolution. Macro-evolution is a whole different ballgame.
No, it’s not. To walk one mile you have to take a bunch steps, most of them shorter than one meter, to do it. Macro-evolution is simply the compounding effect of a long sequence of micro-evolution.
Summary
The names of animals were not written down on the animals’ under-bellies. We came up with their names over many many years. That’s right, we did. And if you are a Christian, recall the verse in Genesis where God explicitly instructed Adam to name the animals. Since we came up with the naming system, we can call these animals whatever we want.
Where it gets tricky is when we look at the animals over time. And what this shows us that virtually every species on the face of the Earth changes over time.
And that’s what evolution is in a layman’s terms.
Credit goes to Richard Dawkins’ The greatest show on earth, which did a fascinating job expelling the theory evolution to me and providing some concrete examples that were easy to fact-check.
