Interesting opinion piece on evolution

[beskeptical]

I've often heard that humans are getting taller, though one poster in this forum once claimed it wasn't true. Perhaps you know.
But let's assume it is true--does that mean we have been evolving towards being taller?

Human evolution is really on a very slow time scale. It took thousands of years for skin color to evolve to very light and then back to dark again as people migrated up and down Earth's latitudes.

People come in various sizes from Pygmy tribes to Zulus, from very fat Eskimos to very thin Japanese. I doubt one could conclude we are getting taller as a race based on current evidence. A visit to a local museum though will show much smaller clothes were worn by the pioneers in America in the 1700 and 1800s.

The question is whether or not we are better fed or genetically larger. I don't know if there is an answer to that question if you are only looking at a small population segment. As humans, you'd have to look at an average like one does with global temperature.

[Disinfo Agent]

But, at least for some human populations, there is indication that average height has increased in the last few centuries, would you agree?

[beskeptical]

But, at least for some human populations, there is indication that average height has increased in the last few centuries, would you agree?

Sure, and genetically, some human population groups have different size characteristics.

But didn't you ask if we were getting genetically bigger?

For one, there is only one 'race' of humans so you'd have to look at the whole race to answer your question, and two, it would take a lot of data over a long period of time to determine if an increased size was related to genes or food supply.

[HenrikOlsen]

I've often heard that humans are getting taller, though one poster in this forum once claimed it wasn't true. Perhaps you know.
But let's assume it is true--does that mean we have been evolving towards being taller?

Archaological evidence from Denmark indicates that the average modern man is taller than the average medieval person.
On the other hand, it also shows that people from the viking age was as tall as we are.
Add to that that if you take a pygmy from birth and feed him like a european, he grows to about the same size, and you'll conclude that the majority of size variation is diet driven more than evolutionary.

[Disinfo Agent]

Archaological evidence from Denmark indicates that the average modern man is taller than the average medieval person.
On the other hand, it also shows that people from the viking age was as tall as we are.

That's contradictory, since the Vikings were Medieval men.

Add to that that if you take a pygmy from birth and feed him like a european, he grows to about the same size, and you'll conclude that the majority of size variation is diet driven more than evolutionary.

I have no trouble believing that that can happen to some pygmies, but it's harder to believe that it happens to pygmies on average. There's a reason why they're called pygmies.
(Note: what I doubt is not that pygmies can grow taller if they're raised with a European diet; it's that they can grow to be as tall as Europeans, on average.)

I found this source that argues what I've often heard, that, yes, humans have been getting taller in the last few hundred years, and, no, it's probably not due to evolution. Here's an interesting quote:

[...] the observed increase in height has not been continuous since the dawn of man; it began sometime around the middle of the nineteenth century. In fact, examinations of skeletons show no significant differences in height from the stone age through the early 1800s. Also, during World Wars I and II, when hunger was a frequent companion of the German civilian population, the heights of the children actually declined. They only recovered during the post-war years.

This kind of zigzag change -- in such a short period of time -- seems to show that recent variations in average human height have not been driven by genetics.

So I ask: if even our bodies can go through appreciable changes without any significant evolution of our gene pool, why not our ideas? I think most people would agree that their minds have more freedom to change than their bodies. Until proven otherwise, I tend to agree with them.

Sure, and genetically, some human population groups have different size characteristics.

But didn't you ask if we were getting genetically bigger?

For one, there is only one 'race' of humans so you'd have to look at the whole race to answer your question, and two, it would take a lot of data over a long period of time to determine if an increased size was related to genes or food supply.

That's an interesting objection, but I think it should cut both ways. If the fact that there's only one human race means that we should always look at average trends for the whole human race when we study height, then we should also look at the whole human race if we want to claim our ethics are evolving.

[HenrikOlsen]

That's contradictory, since the Vikings were Medieval men.

We count the ages slightly different in Denmark, Medieval is counted as starting at the end of the Viking age.
Not contradictory, just a matter of slightly different use of a word.

[Disinfo Agent]

Archaological evidence from Denmark indicates that the average modern man is taller than the average medieval person.
On the other hand, it also shows that people from the viking age was as tall as we are.

I'm interested in the statement that people from the Viking age were as tall as we are. Can you point me to a source?

[beskeptical]

.....
So I ask: if even our bodies can go through appreciable changes without any significant evolution of our gene pool, why not our ideas? I think most people would agree that their minds have more freedom to change than their bodies. Until proven otherwise, I tend to agree with them.

That's an interesting objection, but I think it should cut both ways. If the fact that there's only one human race means that we should always look at average trends for the whole human race when we study height, then we should also look at the whole human race if we want to claim our ethics are evolving.

First, social or cultural change is very rapid compared to genetic change. White Australians wear hats and sunscreen. It will be a very long time before they develop dark skin.

Second, both genetic and social/cultural change is continuous regardless of rate of change.

Third, one can define social/cultural groups. They have overlap but they are identifiable through various measures.

While one can find the gene that makes dark skin, for example, not everyone with dark skin will have it. There are no race genes that set apart one human ethnic group from another. The amount of genetic material that accounts for our 'ethnic' features such as skin color and facial features is a very small amount of our total genetic material.

There are no genetically different groups of humans one can call a different race. We haven't been isolated from each other long enough to have evolved into different races. There may be many genetic markers in Australian Aboriginals for example that you don't find in other groups. But there is no single marker in all of them which one can say marks them as a distinct race.

[archman]

How are you defining "race" Beskeptic? At a subspecies level?

[SolusLupus]

How are you defining "race" Beskeptic? At a subspecies level?

As my Sociology book has said, Race is an illusion that we create for ourselves. You can actually change your effective race in a single planeride.

Some Sociologists claim that there are only 10 races throughout the world; others claim there are thousands. It's a subjective meter. Do you change race when your jaw grows wider? Or when you're taller? How about shorter? How about when your skin is a particular skin tone?

Is a half-German, half-Asian girl more german or asian? Or is she either?

It seems to me that race is more a subjective and cultural "label" more than an objective scientific one.

[beskeptical]

....
Some Sociologists claim that there are only 10 races throughout the world; others claim there are thousands. It's a subjective meter. Do you change race when your jaw grows wider? Or when you're taller? How about shorter? How about when your skin is a particular skin tone?

Is a half-German, half-Asian girl more german or asian? Or is she either?

It seems to me that race is more a subjective and cultural "label" more than an objective scientific one.

It is certainly not a genetic distinction. That's what genetic research clearly revealed about 10 years ago.

From Maynard V Olsen, Stanley Fields, & Mary Clair King's work at the U of WA, the human genome has about 3 billion base pairs. Between any two people we differ by about 0.1% or 3 million base pairs. But that difference is the same amount whether the two people are from the same village or not, from the same country or not, or, from the same continent or not. And as I already mentioned, the amount of genetic material that makes up our outward features is not significant as far as any 'race' distinction. In other words, it's an arbitrary distinction between any two individuals.

One way I illustrate it is to ask, why don't we use blood type as our 'race' categories?

Genetically, humans are very distinctly, without any doubt, without any controversy in science, one single race.

[archman]

Genetically, humans are very distinctly, without any doubt, without any controversy in science, one single race.

And yet, we have populations possessing strikingly similar phenotypes.

Most (if not all) of the biologists I know would very much dispute that all of humanity is one big melting pot of genetic homogeneity. If not using "race" as the delineating marker, something else must be substituted to denote genetic distinctiveness within the human populations that possess distinctive phenotypes.

Strain? Ethnic Group? Breed? Infraspecies? Genetically-distinct sub-population? That last ranking is becoming quite fashionable with the biologists. The orcas in Puget Sound are one of the more popular examples.

[Disinfo Agent]

First, social or cultural change is very rapid compared to genetic change.

Which is a good argument against cultural evolution.

Second, both genetic and social/cultural change is continuous regardless of rate of change.

I guess I need to explain better what I meant by that remark. The reproductive process involved in evolution is discrete. It works by selecting and recombining a finite number of genes, at a specific moment in time. Once your father's sperm has fertilised your mother's egg, you are set for life. You won't get to change your genotype anymore. End of story.

By contrast, you can change your culture and your ethics at any time in your life.

Furthermore, whereas all your genes are inherited from your father and your mother, your ideas can be learned from your parents, or your uncles, or your grandparents, your neighbours, your siblings, your children, and even people you see on TV. From another perspective, whereas in the evolution of the species the genes of each generation are derived from the genes of the previous generation only, when it comes to culture and ethics there is no such limitation: you can learn from people who lived, two generations, three generations, or ten generations ago; you can even learn from people of your own generation.

[beskeptical]

And yet, we have populations possessing strikingly similar phenotypes.

Most (if not all) of the biologists I know would very much dispute that all of humanity is one big melting pot of genetic homogeneity. If not using "race" as the delineating marker, something else must be substituted to denote genetic distinctiveness within the human populations that possess distinctive phenotypes.

Strain? Ethnic Group? Breed? Infraspecies? Genetically-distinct sub-population? That last ranking is becoming quite fashionable with the biologists. The orcas in Puget Sound are one of the more popular examples.

I believe you are incorrect about "most biologists", unless the biologists in question quit expanding their knowledge base 20 years ago.

The idea there are 'phenotypes', 'breeds', or whatever might be based on a lack of understanding about genetics in general, (I know you are very intelligent but you do have some misconceptions about genetic grouping here), and how certain groups of humans come to have certain genetic characteristics but cannot be placed in distinct genetic groups. I'll use the term 'race' for the purpose of this discussion. By 'race' I mean a grouping of individuals which can be determined genetically in addition to outward physical features.

We do have clear ethnic groups, but that division is not a genetic one. The Orcas may remain in family groups but to become different 'races', individuals would have to never change groups over a very long period of time. Unless that occurs, you merely have Orca families, not Orca 'races'.

So let me explain because the problem here is in understanding the difference between inheriting a specific mutation or even a group of mutations verses diverging from one genetic 'group' or 'race' to another.

Going back before we had modern day travel with human groups mingling all over the planet simultaneously, we all started as Africans. Human groups migrated out of Africa in different waves. Each group that migrated out restarted a gene line with all the elements of the old gene line. The humans left behind continued to have genetic mutations that were passed on to their offspring but would not have been passed on to the offspring of the group that left. And, the group that left would continue to have mutations that were passed on to their offspring but which would not exist in any members of the group left behind. These mutations have been used as 'genetic markers' to identify migration routes.

However, a single mutation does not make a new 'race', obviously. And, a single mutation is passed on in various percentages to the offspring of any two people. Even a large accumulation of genetic mutations or differences does not automatically make a new 'race'.

What you need to get a new 'race', is a group of human migrants that become isolated from the group they left AND enough time has to pass for the isolated group to develop along a different genetic path than the group left behind.

In humans, the isolation occurred a number of times. Native Americans, Pacific Islanders, and Australian Aboriginals are some examples. But what did not occur was enough time for any of the human groups to emerge as distinct from the groups that they originated from.

What appears to be making them distinct are some of their outward features. But let's look at a different example. Suppose you have a family that is tall, blue-eyed and blond and a family that is short, brown-eyed and brunette. Would you call those two families different races? If the blonds were Swedish and the brunettes Italian, would you call them different races? How about Italians and French, or English and Swedes?

People can have strikingly different outward appearances but not be considered different races. What does differ between them that makes them look different? Obviously their genes. But each and every one of us except identical siblings differs from each and every other one of us. And, it turns out that, interestingly enough, we all differ by pretty close to the same amount relative to the very large amount of DNA in the human genome. Of the roughly 3 billion base pairs we all have, roughly 3 million (0.1%) will differ from any other human on the planet, including, I believe, your relatives though I'm not sure about first degree relatives and haven't had time to check on that.

If you had a genetically pure European, African, Asian, Native American, Pacific Islander, and Australian Aboriginal and you looked at their genomes, without knowing they were different appearing, you could not tell from their genomes that any of them differed from any other in a distinct way. They would all appear to be from the same 'race'.

If you took groups of the same individuals above and you looked at their genomes, you could not group them by race. Why not, it seems counter intuitive. Won't all the blacks have some genetic sequences in common that all the whites don't have and vice versa? Well it turns out they don't.

So how can that be if each group has features in common that differ from the other groups'? Even if they did, (which as I said it turns out they don't), wouldn't all blonds have some genetic sequence in common that differs from all brunettes'? How about everyone with type A vs everyone with type B blood? How about rH factor? How about Down's syndrome? How about sickle-cell disease? Are people with Down's syndrome a different race? Do families with more manic depressives constitute a different race?

In order to become a genetically distinguishable group, unless you are looking at single or even a small group of genetic markers, there has to be a certain minimum number of genetic differences, AND, all the members of the two groups must have those differences. There are no genetic differences that all members of any ethnic group have. Even if the group members all look alike, not all of them will have the same combinations of genes to give them that appearance. Dark skin might be more common in persons with sickle cell trait, but not everyone with dark skin has the trait, and so on.

And even if the members of the other group do not look the same, they will still have some of the genes that make up the other group's appearance. We all have African genes, for example, even though not all of us have dark skin. Caucasians have Asian genes and Asians have genes that Aboriginals took with them to Australia.

Were Aboriginal peoples able to remain isolated for a much longer period of time, true race diversion could have taken place. But they didn't and it didn't.

Outward appearance isn't enough to make a race category. It most certainly made ethnic categories. But so did religion, nationality, customs, and so on. That is where 'race' divisions belong, in the ethnic groups or categories. But not in genetic or biologic categories. There aren't any such things. I'm as closely related to black people as I am to white biologically.

[beskeptical]

Which is a good argument against cultural evolution.

I guess I need to explain better what I meant by that remark. The reproductive process involved in evolution is discrete. It works by selecting and recombining a finite number of genes, at a specific moment in time. Once your father's sperm has fertilised your mother's egg, you are set for life. You won't get to change your genotype anymore. End of story.

By contrast, you can change your culture and your ethics at any time in your life.

Furthermore, whereas all your genes are inherited from your father and your mother, your ideas can be learned from your parents, or your uncles, or your grandparents, your neighbours, your siblings, your children, and even people you see on TV. From another perspective, whereas in the evolution of the species the genes of each generation are derived from the genes of the previous generation only, when it comes to culture and ethics there is no such limitation: you can learn from people who lived, two generations, three generations, or ten generations ago; you can even learn from people of your own generation.

We're just arguing 2 sides of the same coin, DisInfo. I thought I said that earlier. You can define many words in many ways. if I use one definition and you use a different one we may think we disagree when all we really disagree on is how a word was defined.

You are taking a very literal definition of the term evolution as if it only applies to biological evolution. With that definition I agree with your posts. I happen to use the term evolution in a much broader way. What term would you use, for example to describe how the first planes 'evolved' into modern day jets?

[Disinfo Agent]

I wouldn't like to shift the topic towards the advance of technology, which I'm not sure we can model the same way as more subjective constructs such as culture and ethics.

You say you just have a broader concept of "evolution" than I. Can I ask how you would explain that broader concept? Is it just a synonym of "change"?

[SolusLupus]

I wouldn't like to shift the topic towards the advance of technology, which I'm not sure we can model the same way as more subjective constructs such as culture and ethics.

You say you just have a broader concept of "evolution" than I. Can I ask how you would explain that broader concept? Is it just a synonym of "change"?

Well, why not?

Culture, "ethics", and "morals" have changed an incredible amount over the past two thousand years amongst the major societies. While some cultures keep to traditional values, there is evidence of change.

There seems to be a push for certain changes, mainly centering around freedom. When given a choice over having power and not having power, the average person would desire to have power, unless keeping to traditional beliefs that it's "amoral" to be empowered (Like in India, when it's considered a sin to up your social class).

Evolution can be scientifically proven and demonstrated conclusively, yes. But then, cultural changes are obvious. When pre-industrial concepts came into the new and coming Industrial ages, there was much social strife. Then things changed over time, and laws were passed to prevent a return to that way of life.

In the end, though, I really couldn't care less. Whether or not you want to call social change "evolution" or not, I don't care. Society changes throughout time, and whether or not it can be compared to "evolution", really doesn't matter. It's a matter of semantics.

[beskeptical]

....
You say you just have a broader concept of "evolution" than I. Can I ask how you would explain that broader concept? Is it just a synonym of "change"?

Incremental change.

What term would you apply to incremental change in non-biological systems?

[Fr. Wayne]

"Evolution can be scientifically proven and demonstrated conclusively, yes. "

Conclusive proof of a theory renders a scientific law. Did I miss the class that proved evolution? Please point me in the right direction so that I may further enjoy this "race" issue.

[archman]

I believe you are incorrect about "most biologists", unless the biologists in question quit expanding their knowledge base 20 years ago.

No, I am not. But we don't work with humans, which is perhaps where the confusion lies. I work with animals.

Phenotypes are the classic and still all around most popular method for differentiating sub-populations within wild species. Where genetic study comes in, it is very common for us to verify (and occasionally refute) genetic distinctiveness within sub-populations.

Where genetic work becomes VERY useful is where we find genetic distinctiveness in phenotypically identical organisms, separated by not-so-great geographical distances. I'll throw out the brachyuran crabs Menippe adina and Menippe mercenaria as a recent example of this, as I work in an invertebrate lab. Another case of genetically distinct stocks I know off offhand includes the "offshore" and "inshore" west Atlantic bottlenose dolphins (Tursiops truncatus). I only have secondhand word regarding orcas, but they are considered to have genetically distinct sub-populations as well, as are other cetacean species.

[quote]Genetics-inferred, within-species distinctness is very much acknowledged in the animal world, and subject to very high levels of current research. It is the focus of entire theses. Which is why I find it difficult to understand that such distinctness is not claimed to occur in humans. We have clear and present differences in physical appearance that can be unequivocally traced to ethnicity. Pedantics aside as to what is/isn't the true definition of "race", there SHOULD BE genetic markers differentiating ethnic groups.

I don't get it. Either the animal and human biologists use different genetic tests, or they're using wildly different definitions of genetic distinctness. If I can take two visually identical (down to mouthparts!) stone crabs from opposite coasts of Florida and determine that they genetically represent different stocks from the same species, how is it that we cannot infer the same between Australian aborigines and Vikings?

Now please forgive me if I cut and paste a few of your earlier comments. These are the ones I have specific questions about.

There are no genetic differences that all members of any ethnic group have. Even if the group members all look alike, not all of them will have the same combinations of genes to give them that appearance.

I would assume that with modern humans at least, between-population interbreeding will bias a lot of contemporary measurements. But accounting for that, there should be genetic patterns that explain why it is that Asians look fundamentally different in appearance from west Europeans. After all, the pattern IS there. It's certainly not environmentally-derived.

Were Aboriginal peoples able to remain isolated for a much longer period of time, true race diversion could have taken place. But they didn't and it didn't.

What's the cutoff? If they become incapable of breeding, that classically rates as a separate species. If they don't, they get lumped into a subsidiary taxonomic ranking.

Heck, dogs all are genetically one species, but they certainly have different genetic variants that are maintained by careful breeding. One strain even comes with a specific defect in the urinary tract that makes them pee out the wrong stuff (dalmatians?). Different dog breeds are routinely referred to as "strains"; I am sure they are even referred to as "races" on occasion. These aren't cultural monikers, certainly.

[SolusLupus]

"Evolution can be scientifically proven and demonstrated conclusively, yes. "

Conclusive proof of a theory renders a scientific law. Did I miss the class that proved evolution? Please point me in the right direction so that I may further enjoy this "race" issue.

I'm sure someone else can point you to a link. I don't have one available.

The concept of evolution has been proven, yes. Genetics is known and studied, and evolution itself has been shown to take place (for instance, snakes "evolving" to be smaller in an area to a size that doesn't make poisonous frogs deadly has been shown). There is no question as to whether or not evolution is "true". It's the details of evolution that makes up the theory.

[Wolverine]

Two nitpicks:

1. Evolution specifically describes a change in allele frequencies over time. It's a biological term which shouldn't be used loosely to describe cultural/societal behavior nor other tangental topics which belong in the sociological arena.
2. Scientific theories are never "proven" -- proofs are for mathematics, science deals with evidence.

[Fr. Wayne]

Two nitpicks:

1. Evolution specifically describes a change in allele frequencies over time. It's a biological term which shouldn't be used loosely to describe cultural/societal behavior nor other tangental topics which belong in the sociological arena.
2. Scientific theories are never "proven" -- proofs are for mathematics, science deals with evidence.

Thank you.
Archman:
"I don't get it. Either the animal and human biologists use different genetic tests, or they're using wildly different definitions of genetic distinctness. If I can take two visually identical (down to mouthparts!) stone crabs from opposite coasts of Florida and determine that they genetically represent different stocks from the same species, how is it that we cannot infer the same between Australian aborigines and Vikings?" Excellent inquiry here.

[HenrikOlsen]

What term would you use, for example to describe how the first planes 'evolved' into modern day jets?

Intelligent design.

[HenrikOlsen]

I don't get it. Either the animal and human biologists use different genetic tests, or they're using wildly different definitions of genetic distinctness. If I can take two visually identical (down to mouthparts!) stone crabs from opposite coasts of Florida and determine that they genetically represent different stocks from the same species, how is it that we cannot infer the same between Australian aborigines and Vikings?

I saw mention of a study that did just that, using blood samples from lots of englishmen.
It was shown that the distribution of genetic markers identifiable as being from the vikings fit the geographical areas settledby vikings who then bred with the locals.
I unfortunately don't have a link, I think it was a BBC World science report.

[Disinfo Agent]

1. Evolution specifically describes a change in allele frequencies over time. It's a biological term which shouldn't be used loosely to describe cultural/societal behavior nor other tangental topics which belong in the sociological arena.

The ideas of evolution (random mutation + natural selection) can be applied to other problems. There is, for example, the interesting field of genetic algorithms.

Now, if someone had shown that:

a) social changes are entirely produced by modifications of our genes;
or that
b) while social change is not caused by biology, it can be well described by a model that uses the ideas of the theory of evolution

then I would have no problem with saying that culture and ethics 'evolve'. Since, however, no one appears to have shown that social changes happen according to the same mechanisms as Darwinian evolution, and there are good reasons to doubt that that is the case, I essentially agree with you, Wolverine.

Replying more directly to Beskeptical and Lonewulf, if change is what you are talking about, then you should call it 'change'. The word 'evolution', applied to social phenomena, can be misleading.

What term would you use, for example to describe how the first planes 'evolved' into modern day jets?

Intelligent design.

Indeed!

[Fram]

The ideas of evolution (random mutation + natural selection) can be applied to other problems. There is, for example, the interesting field of genetic algorithms.

Now, if someone had shown that:

a) social changes are entirely produced by modifications of our genes;
or that
b) while social change is not caused by biology, it can be well described by a model that uses the ideas of the theory of evolution

then I would have no problem with saying that culture and ethics 'evolve'. Since, however, no one appears to have shown that social changes happen according to the same mechanisms as Darwinian evolution, and there are good reasons to doubt that that is the case, I essentially agree with you, Wolverine.

Replying more directly to Beskeptical and Lonewulf, if change is what you are talking about, then you should call it 'change'. The word 'evolution', applied to social phenomena, can be misleading.

I do believe social, cultural, ethical changes can be called "evolution", as they happen by some of the same mechanisms as Lamarckian evolution (which is also Darwinian evolution, but E., not C. Darwin...): changes someone makes are inherited by his children, a change made by an ancestor is continued by his children and so on (very simplistic explanation, I know).
This is part of the way e.g. art evolves: you don't start from scratch, and you don't start with the same background every generation again, but you continue to build upon what the previous artists did. Although this mechanism is now less important than it used to be (in arts), it is still a main source of the development of art, and the same goes for politics, ethics, ...

[Disinfo Agent]

Lamarckian evolutionism is totally different from Darwinian evolutionism! Unfortunately, the difference is subtle, so there are still people who speak of evolution in Lamarckian terms. I even had biology teachers who did that, sometimes.

Lamarck proposed that individuals changed to fit their environment, and that those changes were inheritable. For example, the ancestors of giraffes, by reaching for higher and higher branches in trees to feed themselves, managed to grow slightly longer necks than their ancestors, and that increase was inherited by their descendants.

Darwinian evolution, however, does not proceed through individual effort, but through collective elimination. As much as giraffes may stick out their necks, it won't make the next generation have longer necks, because changes due to exercice are not inherited. Rather, it's natural selection which, by making life (and thus reproduction) harder for giraffes with shorter necks, drives the increase in neck length.

When people say 'evolution' nowadays, they usually mean the Darwinian theory, so I still think the term is misapplied in social contexts.

[Ken G]

But what this is saying is that because Darwinian evolution proceeds via a genetic code, and social constructs have no such genetic backbone, then there is simply no way the word evolution can apply to both. I think that's co-opting a word. The word evolution has been around a lot longer than Darwin, and it's most general meaning is gradual change due to selection pressures (if you drop the latter part, you even get the word used in astronomy, but that is a misapplication really.) The nature of the pressures, and how the changes are passed forward in time, are details that belong in the adjective applied to evolution (like Darwinian). i realize this approach can encourage misconceptions in biological evolution of the type DA is talking about, but a word is a word. Even Darwinian evolution most likely can be broken into subclasses that proceed in very different ways, such as when sexual reproduction is or is not involved. Still, DA's central point is well taken that if one is going to use the same word here, one should take pains to stress the important differences.

[grant hutchison]

Yes, it strikes me that people are simply talking past each other because of different usages of the word evolution. In its meaning of "unfolding or development according to inherent tendencies", evolution has been around for a long time, and it's uncontroversial (I think!) that political systems, technologies and languages, among other things, evolve in this sense of the word.
But when people debate the teaching of "evolution" in schools, they are using shorthand for Darwin's insight that biological evolution occurs by a process of natural selection. If that baggage is mentally attached to the word "evolution", then it is glaringly evident that the design of a jet engine does not evolve by natural selection from that of a piston engine.

Grant Hutchison