Hmmm... I remember I tried something at this site once. Evidently, I gave up - lack of interest from anyone other than myself. Ah well. I think my style was too baby for those "in the know" and too detailed for those, um... "not".

I did kinda work on most of these prior posts here- and I think I tightened it a tiny bit and made it one single thingy. Figured I may as will pop it here.

Especially since once of the core ideas talked about is in the news today.

1. No one knows.

An email was sent to PZ Meyers, a vocal opponent of anti-evolutionists, in which the following was asked:


I was confused by the question.

The quick answer to the above question is: No one knows. No animal, plant, microbe, or whatever, says "Hmm... it's time to evolve! OK here we go... grrrrrrrrrrrrrr," followed by a POP! as wings sprout from it's rear.

And, though the questioner assumes it to be so, even humans aren't in control of how our species will change and diverge over millions of years. We have influence, far more influence, than most species, no doubt. But control? No.

More importantly, the question assumes that you or I, or a plant or animal, can somehow feel evolution happening in us. It doesn't work that way. Each of us is just a single frame of film that makes up a very, very long movie.

Even a whole species, over time, doesn't "know" to evolve.

No more than millions of hydrogen atoms know how to condense into a star or we know how to grow from baby to adult.

All things follow some combination of rules: of Physics/Mathematics, of Chemistry, of Biology. In the case of natural selection (the basic mechanism of evolution), the rules, in their most direct form, aren't that complicated once they are spelled out.

So... again, the question above confuses me. It wouldn't confuse me in a world where the basic concepts of nature were unknown. But that is not this world. Here, there is understanding to be had. It is also a world, unfortunately, where many are not aware of what is known. There's a lot of people that share blame for this - scientist and non-scientist alike. But the fact is, it is a situation that exists - one which desperately needs to be addressed.

Before I forget - I really, really want to point this out - not knowing a thing is not a something of which anyone should feel bad. The day you think you know everything with absolute certainty is the day you have deceived yourself utterly. That is a dangerous day. Knowing what you don't know, and asking to find answers, is how everyone learns.

So, in my own little way, I want to try spelling out a simple summary of the concept of natural selection as it is currently understood.

1. We're all random mutants:

The instructions for making all living things is in our DNA. Essentially every animal, plant, or whatever, is born with a tiny number of errors in its DNA instructions. Also, these errors are basically random. One animal will have a mutation in some his part of the DNA instructions, another will have a mutation in a different spot of the instructions. Most of these changes, or mutations, really don't do much to harm or help the being which receives them. But the changes are new set in the instructions and these will be passed on to their children who will also end up with yet new mutations. And so, over the generations the mutations accumulate in a population.

2. Natural challenges are thrown at populations all the time:

Nature constantly throws challenges at populations: Way too hot or cold, lack of food, too many predators, a poison or toxin seeps into the environment, lake water levels shrink or overflow, a volcanic eruption drastically alters the environment of the planet, an asteroid strikes ... really just think of something bad, and it probably already happened more than once in the world. And these are just the really drastic ones. More subtle challenges - many at any given time - happen pretty much continuously.

3. Any given challenge of nature makes some DNA mutations more beneficial than others:

When a new natural challenge happens, especially to a big population, some individuals may have changes in their DNA instructions allow them to thrive better under the new conditions. If so, then they and their descendants will carry those changes forward. Those that have less ability to thrive under those conditions will be lost, over time, and take their genes with them.

4. The longer the challenge lasts, the more the beneficial changes set in and develop, and the more the harmful changes become lost:

Sometimes a severe natural challenge arises but only briefly (imagine there being a horribly bitter winter one year which really takes a toll on all the animals in an area. But then for many years afterward, the winters return to normal). In these cases, while the genetic changes - say an increase in hairiness - may have helped some survive over others, the removal of the severe pressure removes the need for that specific changed DNA.

The longer a specific challenge lasts (for example, say it's not just one cold winter, but a new ice age has begun) the more this selective filtering will happen.

First, the ones having the original useful mutation will remain the most able to survive. Then, as new mutations occur, there are new random DNA tweaks. Again, while the new mutations are random (as they always are), it is the tweaks that continue to improve survival within this stressful environment that will endure in favor over the others - even over the tweaks that FIRST allowed them to survive.

The longer this pattern continues. the more apparent the physical changes - ones that have become continuously better at their special function - will be.

5. No one knows this is happening to them:

All of this is due to constant pressure over generations - to be more warmer, more able to hop or fly from tree-to-tree, more able to see better, run better, etc, etc. Even we humans, with the ability to think in detail, don't really know the environmental challenges that will be thrown at us tomorrow, or in a thousand years, and which particular traits will help us get through them.

No one knows it's "time to change". Change happens every time a new person, animal, or plant is born.

And, just sometimes, a useful change is there at the right time. And so the change sets into the population. But, rest assured, no one is aware of it - feeling the change.

What they - we - are aware of is that we are living our lives the best we can.

And that's enough of a responsibility right there. without worrying about "how to evolve".

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2. Arguments in Bad Faith

I don't sit well when people use a public stage to spout off misinformation - especially regarding issues about which I happen to have some knowledge.

As in politics, people using deceptive tactics in anti-science or anti-medicine crusades are usually doing it for a reason: to sway people to their pre-defined cause by, essentially, lying.

One of the most insidious forms of lying to convince people that the “other side” is wrong goes something like this:

1. “This is what the other side believes:” (Insert description that is actually not what the other side believes and, importantly, has a hole in the general logic of the argument)
2. “Well, here’s a bit of evidence that totally goes against their view:” (Insert fact that is possibly, but by no means necessarily, true. Fact should be designed to reveal the previously created logical hole)
3. “I have shown you the (false) hole in their logic.”
4. “Therefore, the other side is full of BS and our side rules.”

The main reason I worry about this approach is it’s very easy to get people to believe distortions of truth when the people haven’t been given a basic understanding of the facts in the first place.

Not surprisingly, this has come up in the context of the biological evolution of species, something which is an absolute fact of nature, the precise mechanisms of which are still under reasonable scientific discussion. In fact, it’s astonishing to realize the shear number of different versions of the above deception with regards to evolution.

To illustrate, here’s a good example of the deception to which I refer – following the same pattern which I outlined above:

1. Evolution says that when DNA is mutated, a new species is created
2. DNA Mutations are always bad, making mutant babies which mostly die at birth
3. How can a mutation make a new species when a mutation makes a dead baby?
4. Therefore, evolution doesn’t happen.

Now, anyone reading that argument – especially when simply breezing through a magazine article – could be easily forgiven for simply accepting that argument It makes some sense. Um…except for the fact that the first two lines are completely false.

And deep down, all I want to do is explain why they are false. Which means I have to explain what is true. But I want to do so with an eye to presenting an overview as opposed to a highly detailed description (for which there are many, many sources).

So I guess, I’ll just do that in my own way.

And I’ll start at the heart of a wrong assumption: that "mutations are BAD".

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3. You are a mutant.

You're a mutant.

It’s not an insult.

You are, and were, from the very beginning of your genetic existence, someone that was built with mutated DNA.

Here’s a bit of what I mean - just a little bit.

You were given half of your DNA – the instructions of life – by your father and half by your mother.

We all might think that if your Dad compared the DNA that he gave you to the DNA with which he started life, that they would be a perfect match.

And it probably is. Nearly perfect.

Nearly.

But not quite.

At the least, what he would actually find is that his original DNA, the sequence of letters he was born with, and the DNA he gave you had a couple of hundred tiny differences, scattered randomly throughout. A similar fact is true for your mother’s contribution as well.

This is a consistently demonstrable fact, a consequence of the slight imperfection of the machinery that copies our DNA.

The DNA they each gave you contains numerous mutations – changes in DNA .
They both gave you mutated DNA.

So - without question – you are a mutant.

My stating this raises two questions: (1) How did that happen? (2) Why do I not have six toes, or something equally “mutanty”?

Your instructions were copied less-than-perfectly

To think about this, let me just describe some background with a way too simple and utterly inaccurate analogy:

Your DNA is a book of instructions, written in a simple alphabet (as it is made of only 4 letters, unlike our 26 letter alphabet).

Now, this instruction book is sometimes described as a "blueprint" of your body. However, that’s a bit inaccurate.

All your book really contains is the diagrams to make a wide variety of tools and materials that are, generically, called “proteins”.

And it’s these proteins, each one described in your DNA instruction book, that work together in a highly intricate dance of interactions and combinations to build you.

So, again:

• DNA is the instructions, written in a simple alphabet, that says how to build proteins.
• Proteins are the things that actually go about building you.

OK... given that background, what is a mutation?

The most basic description of a mutation is: any change somewhere in the DNA instructions.

There are many types of changes that can happen, some massive and some almost imperceptible, but I’ll focus on the simpler ones.

Imagine someone has your book of DNA instructions and is given the task of making a copy of the whole thing by hand. (And in fact, this copying happens all the time in most of the cells in your body.)

OK, so, the guy who’s doing the copying is pretty darn good. He rarely makes mistakes and he’s also very diligent at double checking his work so as to correct the occasional error he does make.

So the copy is really, really pretty darn faithful to the original.

But… it’s a big book. Once in a very, very long while, the copying guy misspells a word (In the analogy, say, “cat” is copied as “car” or “kat”) and also happens to not notice the error, so it doesn’t get corrected.

Once he’s moved on to later pages of the book, there is no going back. The error is now a permanent part of the copied book.

That’s a mutation.

Other times, he might accidentally delete or add one or many letters. (In the analogy, “color” becomes “collor” or “colour”)

These are also mutations.

There are even more elaborate ways that changes in DNA instructions happen, but these basic ones illustrate the point, I think.

And here’s where the difference between your parents’ DNA and your DNA comes up:

See, for the most part, both your father and mother were built up using the instruction books they were born with.

And as the years went by, eventually, your mother-to-be started making egg cells and your father-to-be made sperm cells – the two things that, together, make a child.

Each round of “making cells” is, in fact, a round of copying the DNA instruction book and putting it into a new cell. And each round of copying has that chance of a mistake being made, somewhere, nearly randomly.

That chance, again, is low. But over the years, the copying happens often enough that it happens often enough.

And for an average 30 year old man, enough rounds of copying have happened that a hundred or so random errors – mutations - have crept into the instructions contained within any given sperm cell. Similar events are true for any given egg from the mother.

And then one sperm and one egg meet and, of course, that’s the start of a baby. A baby with a couple of hundred mutations!

You. Me. Everyone.

You are a mutant.

And yet most of us are not particularly unusual compared with anyone else, to the best of our knowledge.

How can this be?

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4. Quiet Accumulations

To recap from the prior post:

• DNA is the instructions, written in a simple alphabet, that says how to build proteins.
• Proteins are the things that actually go about building you.
• You (as a human) start off life already having a bunch of mutations in your DNA

If we all start with a couple of hundred mutations in our DNA, why don’t we all have three arms and twenty eyes - or at least look like Hugh Jackman?

I suppose it's worth making a semantic distinction here with words like mutant and mutation.

The spelling changes in your DNA instructions are the “mutations”. The protein which is encoded by the altered DNA is a “mutant” protein. The organism (animal, plant, microbe) that was created with those mutant proteins is often also called a “mutant”.

Calling one with a change in their DNA a “mutant” would be correct, whether or not one could actually see any bodily evidence of the changes which the mutation has caused.

However, in the common usage – the non-scientific language - people think of a "mutant" as some person with a demonstrable change from the norms of humanity - a six-toed foot, for example. So, by that measure - a very extreme measure - very few of us would think of ourselves as mutants.

But this clouds the simple fact that each of us truly do contain mutations. We are not simply re-assortments of our parents’ genetic information. Each of us has a scattering of new changes within us – we were conceived and born with these changes.

And yet, here we are, most of us, looking more or less like our family and even our friends.

Why, if we all have genetic “abnormalities” do we not all look or work much differently than anyone else?

Most mutations neither harm nor help:

So, here’s the deal: most genetic mutations have no major effect on how you function as a human or how you look, at least compared to the normal variations seen throughout humanity.

In these cases - again the most common - the net result is that there is no discernible difference between how you function with that mutation and how you would function without it. It is a fact of statistics and the way DNA and proteins work that most mutations will not actually cause any real problem or benefit at all.

Same difference:

In many cases, this “no harm, no foul” result is because the particular mutation in the DNA instruction causes absolutely no change in how the proteins – the actual machinery and materials of you - are built. This is called a “silent” mutation.

There’s a detailed reason that this is possible - but for now, just think of how you, a reader of English, would interpret the words “color” and “colour”. Depending on where you live (the US or UK), one is probably the preferred spelling, but you know that they both mean the exact same thing – it’s just a minor spelling variation about which most English speakers are forgiving.

Essentially the same thing happens with many words in DNA instructions. There are quite a number of DNA words that can be spelled with minor variation and yet mean precisely the same thing.

So mutations in DNA that simply result in accepted spelling variations will not change the protein that it encodes in any way at all.

Close enough for government work:

Other times, the change is not a simple spelling variation but actually does alter how the protein is built. However, even with a change in the structure, many are minimal enough to actually keep the protein functioning in approximately the same way as the original. This is termed a “neutral” mutation.

Imagine you had instructions to make a chain to lock a bike to a bike rack. The instructions call for 50 metal oval links and a very intricate lock mechanism on one end.

And the instructions are not in the shorthand we might be used to, like this:


The instructions are more linear, step-by-step, no matter how repetitive it seems, like this:


Followed by the (likely) hundreds of individual steps to make a lock from scratch, attached to the chain of links, and then it's done.

Now, imagine the instructions got slightly garbled so it suddenly said to do this:


Well, a metal square link isn't quite the same as a metal oval link, but it still serves the purpose of being a solid link, and the chain is about the same length – so, in the end, we still have a usable bike lock system.

These "neutral" mutations happen quite often. And, in such cases, it’s almost as harmless a change as the previous type of silent mutation.

(Note: A very different outcome might have happened had we mucked about with the very intricate makeup of the lock mechanism, or if a metal link had been replaced with a link made of silly putty.)

Sooner or later... the day comes when you can't hide from what you've done anymore. A day of reckoning.

As mentioned previously, at conception, every human child is a recipient of a couple of hundred of these type of mutations. Now, considering your DNA instruction set is made up of a few billion letters, this is an almost imperceptible amount of change.

And because silent and neutral mutations, introduced one by one in the DNA instruction book, are often not even noticed, this allows genetic mutations creep into a population over time.

But over time, over many generations, it begins to add up. Think about this:

• You inherited a few hundred mutations from your parents.
• You give all of those plus a couple hundred more to each child you might have.
• They give their new mutations, plus yours and your parents’ mutations to their children.
• And those children (your grandkids), in turn, give the mutations from your parents, you, your child, and themselves to your great grandchildren.

And it goes on.

And this has always been happening since before we were born and will continue to happen long after we’re gone.

And those are just the simple spelling errors. There's far more dramatic mutations out there as well.

Because of all this, the changes accumulate.

And, again, many of these end up being no benefit and no harm.

But at some point, for one of many reasons, a mutation - be it a brand new one or a combination of older ones - will make a difference.

For one of your descendants, who knows how many generations away, this accumulation of mutations could ultimately lead to something very harmful.

Or, almost as likely, they could result in something that will save their life and the lives of *their* descendants.


Or it just might make their eyes bluer.


You really won’t know until the day that it kicks in.
But that day (or many days, or century, or millennium) ends up being very important.

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5. We are the things that worked.

To recap:

• DNA is the instructions, written in a simple alphabet, that says how to build proteins.
• Proteins are the things that actually go about building you.
• You (as a human) start off life already having a bunch of mutations in your DNA.
• Most of these mutations have little or no effect on your ability to live and flourish.
• But, on occasion, a mutation makes a difference, for good or for bad.

“Oh my GOD! It's a MUTANT!!!”

There are, indeed, mutations that result in very serious effects. The most obvious examples of this are birth defects that decrease the likelihood of surviving for long after birth or at least to adulthood. Of this type, most are so severe that such a one would likely never even make it through pre-birth development and would not even be born.

These are the ones - aside from the ability to shoot ice from our hands or to look like Hugh Jackman - that people commonly think of as “mutations”.

But the rest... are a little more subtle.

Sometimes, a mutation makes a difference right when it emerges - if it affects something immediately important in how something physically develops or it's ability to continue living.

Other times, even though it changes something physically (whether you can see it or not), a mutation may not impact anything enough to effect an organism's development or life *if* it doesn't really impact the needs it has in that particular environment.

Relative benefit, relative harm

So, as for the smaller fraction of mutations that do have a noticeable effect:

• Some cause harm, possibly minimal, possibly huge.
• Some cause a benefit, possibly minimal, possibly huge.

As an example, we can consider changes that affect an organism's ability to obtain or efficiently utilize food.

Some possible beneficial results of a mutation that increase the ability to obtain energy from food:

• Can outrun others to get food,
• Can forage better or root around for untapped food sources,
• Can eat items not commonly eaten or too harmful for most to eat,
• Can use strength as a tool to either kill animals easier or fight off competitors
• Can biologically extract more energy from less food (net result, you need less food to survive)

Some possible detrimental results of a mutation that decrease the ability to obtain energy from food:

• Slower, when speed is important for getting to the food
• Less ability to forage for food sources (anteater with a stumpy snout?)
• Less ability to tolerate food types, especially when those are the only foodstuffs available.
• Less physical strength when ability to take down an animal is critical or when competition for food is carried out by strength.
• Able to extract less energy from the same amount of food (net result, you need more food to survive).

(As a side-comment: notice that being "the strongest" is just one of many things that may - or may not - help an individual to survive. Some people, even today, insist on interpreting a famous term "Survival of the fittest" to mean some form of "Survival of the strongest". This is absolutely wrong.)

Now it’s important to note here - with this food acquisition example - that in times of plenty, there might be so much food available that everyone has enough to eat and there’s no particular harm or benefit to the above changes in ability, assuming they are not too severe.

In this case, where the pressure caused by food availability is very low, it's possible to have a population of animals with both the original food-using ability and the altered one to be intermingled without any noticeable advantage of one over the other. If the environment is not one in which this mutation is noticed, there is little pressure on the animals with the relatively decreased ability.

It’s when food becomes more scarce that any benefit or harm, food-wise, will become noticeable to the population.

Just able to make it through

Under this pressure of nature (ie, sudden limited food sources) the harm or benefit of any abilities will ultimately be noticed in one way:

Which ones are able to survive this pressure, and which ones are not.

Compared to those better equipped to cope with the pressure, more of those individuals that are less able to survive the pressure will succumb before they have children. And so the genetics that caused them to be less able to cope will diminish in the population over time.

Taken to the extreme, if the pressure (ie, lack of food) continues long enough, over enough generations, the genes which resulted in a lesser ability to cope could ultimately be gone from the population.

But note: all the survivors had was simply a better ability to deal with a particular circumstance over time. It could have been lack of food, it could have been too cold or too hot, or increased radiation, or a new disease, or anything else you can think of.

Usually it's many of these at once.

Nothing about an individual's survival, or more importantly, the genetics behind it, says anything about it's superiority or advanced nature.

That which allowed survival was simply the best thing available at the time.

Not more advanced, just the fortunate recipients of survival

To drive the point home, there have been uncountable numbers of species that - after all their "advancement" - suddenly ended up without even a "best". Given a particular challenge - some lasting numerous generations, others happening abruptly - most species on Earth, after millions of years getting through all sorts of things, one day found themselves with nothing that ultimately could save them.

So, in the end, the use of the term "good genetics" (a term I've heard tossed about) is something I find particularly annoying. That term is so vague that it is essentially meaningless. But the way people use it is to mean something like, "to be more advanced".

This is simply false.

On a purely biological level (as opposed to philosophical), the fact that we, each of us, is here on Earth means nothing more than that we (via all our ancestors) made it through the hoops and hurdles of time.

More likely than not, in many cases, we just made it.

We are all a mish-mash of thousands of things that were good enough for government work. Some functioned well, some even exceedingly well, and some just got us by. Some things got tweaked to work better, others still truck along almost the same as they were when they first appeared.

Nothing about us is, in any way, perfect. And biologically speaking, we are not in any way a goal of this process.

Put simply, we – each and every plant, animal and microbe on Earth - are all amazingly fascinating, walking, talking collages of things that worked.