Thread: The First Europeans - 1 Million Years

*Another one of those I don't quite know where to place*

The First Europeans - 1 Million Years



Our knowledge of human evolution has always been limited by the meagre quantities of hominid fossils that have been discovered. But a system of limestone caves at Atapuerca in northern Spain has yielded an embarrassment of riches by comparison with an otherwise patchy hominid record.

The pit of bones
Since the 1980s, archaeologists have recovered the remains of 32 individuals from a chamber at the bottom of a 14m (45ft) shaft known as La Sima de los Huesos ('The Pit of Bones'). The bones, which date to around 300,000 years ago, comprise 75% of hominid fossils known between 100,000 and 1.5 million years ago.

"Atapuerca was a good place to live. There was a river nearby and it was high up, so it was a good vantage point for hunters. The cave shelters there provided them with refuge," says Professor José Bermúdez de Castro of the National Museum of Natural Sciences in Madrid and co-director of the Atapuerca research team.

Oldest European
The remains at La Sima belong to a species of hominid called Homo heidelbergensis. But another site at Atapuerca has produced the remains of the oldest human ever found in Europe; a partial skull belonging to a young male who lived 780,000 years ago. This skull was discovered in 1994, when the Atapuerca team were excavating the site of an old railway cutting at the Atapuercan locality of Trinchera Dolina.

The specimen shares many similarities with Homo ergaster. But Professor Juan Luis Arsuaga of the Complutense University of Madrid and co-director of the Atapuerca research considers it different enough to give it a new species name: Homo antecessor. Not all palaeoanthropologists accept this classification because it is based on a juvenile specimen and key characteristics of a species often develop only in adulthood. Professor Eudald Carbonell of the Rovira i Virgili University in Tarragona, Spain says recent examination of the Trinchera Dolina remains suggests Homo antecessor could not have been ancestral to heidelbergensis. Instead, says Carbonell, antecessor was probably extinct by around 600,000 years ago.

Source and rest of article

Here is a light write up of some of the results found at La Sima de los Huesos ('The Pit of Bones'). From such digs to we attempt to look back on the daily lives and rituals of early man in an attempt to understand our beginnings. The picture that has been painted of such life was one of hardship, early death, and the continual battle just to remain alive.

Originally Posted by cleft

*Another one of those I don't quite know where to place*

The First Europeans - 1 Million Years



Our knowledge of human evolution has always been limited by the meagre quantities of hominid fossils that have been discovered. But a system of limestone caves at Atapuerca in northern Spain has yielded an embarrassment of riches by comparison with an otherwise patchy hominid record.

The pit of bones
Since the 1980s, archaeologists have recovered the remains of 32 individuals from a chamber at the bottom of a 14m (45ft) shaft known as La Sima de los Huesos ('The Pit of Bones'). The bones, which date to around 300,000 years ago, comprise 75% of hominid fossils known between 100,000 and 1.5 million years ago.

"Atapuerca was a good place to live. There was a river nearby and it was high up, so it was a good vantage point for hunters. The cave shelters there provided them with refuge," says Professor José Bermúdez de Castro of the National Museum of Natural Sciences in Madrid and co-director of the Atapuerca research team.

Oldest European
The remains at La Sima belong to a species of hominid called Homo heidelbergensis. But another site at Atapuerca has produced the remains of the oldest human ever found in Europe; a partial skull belonging to a young male who lived 780,000 years ago. This skull was discovered in 1994, when the Atapuerca team were excavating the site of an old railway cutting at the Atapuercan locality of Trinchera Dolina.

The specimen shares many similarities with Homo ergaster. But Professor Juan Luis Arsuaga of the Complutense University of Madrid and co-director of the Atapuerca research considers it different enough to give it a new species name: Homo antecessor. Not all palaeoanthropologists accept this classification because it is based on a juvenile specimen and key characteristics of a species often develop only in adulthood. Professor Eudald Carbonell of the Rovira i Virgili University in Tarragona, Spain says recent examination of the Trinchera Dolina remains suggests Homo antecessor could not have been ancestral to heidelbergensis. Instead, says Carbonell, antecessor was probably extinct by around 600,000 years ago.

Source and rest of article

Here is a light write up of some of the results found at La Sima de los Huesos ('The Pit of Bones'). From such digs to we attempt to look back on the daily lives and rituals of early man in an attempt to understand our beginnings. The picture that has been painted of such life was one of hardship, early death, and the continual battle just to remain alive.

I live in Spain and I remember when in 1994 they unearthed in Atapuerca the remains of the oldest human even found in Europe. Fascinating stuff

I believe the article has a serious error. It says the oldest known human remains are 780,000 years old. We as a separate species have so far been traced back to less than 200,000 years. I think the article made a mistake and said "human" when it meant "homo."

The errors is common and a result of a strange way of thinking characteristic of anthropology. There is the conception that there is no real or significant division between us and our ancestors because we are part of and a continuation of the biological evolution. The fact is, however, that we, we humans, have not evolved at all as far as we can tell during our whole existence as a species! All the evolution led up to us and ceased less than 200,000 years ago when we appeared. Any further evolution occured only in Erectus, Neanderthalis and Florenseinsis. The reason why all this is ignored is that sociologists have totally failed to address the whole issue of social evolution and thus, people are led to believe we continue to progress thru biological evolution rather than any other way. No one understands what social evolution is. The whole subject is barren desert. Sociologsts are so afraid of it that they have turned to the study of groups and given up entirely the whole subject of society which was supposed to be their field! They have even take up "the sociology of the body" in order to change the subject!

The scientific concensus is that we as a species began almost 200,000 years go. It had been 100.000 years but is now stretched back almost twice as far.

charles
http://humanpurpose.simplenet.com

like charles has already mentioned, modern man (homo sapiens sapiens) emgered approximatly 200.00 years ago.
The article focuses on the first finding of a homo ...... in europe. As far as I know the first ancestor of homo sapiens, which is not an ancestor of chimapanzees too, lived around 6 million years ago in africa (homo australopithecus).

Like charles said, the great fitness score of homo sapiens is mainly due to the increased ability to form a cultural life --> social evolution.
For example, the ability of the human brain (homo sapiens sapiens) to change during life time is enhanced a lot compared to the chimpanzee brain. Paäbo has shown, that in the human brain the amount of mRNA is about triple the amount thna in the chimpanzee brain. Whereas in the liver, there was no significant difference.
So the biological evolutions first evolved, to make a more profound social evolution possible.

Originally Posted by charles brough

The fact is, however, that we, we humans, have not evolved at all as far as we can tell during our whole existence as a species! All the evolution led up to us and ceased less than 200,000 years ago when we appeared.

This is a highly radical claim. Would you care to substantiate it?

What is radical about us being unchanged biologically since we emerged less than 200,000 years ago? If we had changed during that time, then we would be modern humans only since that change. It is the very reason that anthropologists know of no change since then that enables us to say we go back almost 200,000 years! There is more change between the races than there is between us and our almost 200,000 year old ancestors.

The idea that we have long since stopped evolving biologically is disturbing only because the Baptists and Penticostals have sensitized us and made us all defensive about evolution.

However, what I say is to Hell with the "Creationists," we do not need to be evolving physically in order for evolution to explain things! All we need to do is accept that societies became the units of human evolution and that they have undergone a non-biological, natural selection process ever since.

How is it then, that societies have evolved? I think it is a really top-notch question, but does anyone know of anyone who is even trying to answer it? Oh, I know about the "meme" theory, but that is about as speculative, useless and unclear an "expanation" as is "Dialectial Materialism."

Still, it can be explained---and is at http://humanpurpose.simplenet.com
Everyone is invited---or shall we say CHALLENGED?---to examine it.

Charles

Originally Posted by charles brough

What is radical about us being unchanged biologically since we emerged less than 200,000 years ago?

Charles, I am certainly not disputing that the emergence of culture and the construction of complex societies has added a new level to the framework of (broadly defined) evolution, lifting aspects of it from the biological realm to the social. However, it is equally clear that homo sapiens has not stopped evolving. I cite three simple examples below to demonstrate this:

Definition:
A commonly accepted definition of evolution is ‘the change in allele frequency within a population from generation to generation.” Are you seriously suggesting that such changes are not present in the human population?

Geographic:
The variations in the genetic character of the different ‘races’, wherein the maximum variability is found in Africa, the next in Asia, the least in Europe and the Americas, is evidence for the evolution that occurred as man migrated ‘Out of Africa’. One instance of this may be seen here, http://www.cmb.usc.edu/people/noahr/microsats.pdf
where the authors note their studies “confirm a model of human evolution in which human populations expand in size and through space following the departure of a small group from Africa.”

Specific:
In 20003 a team at University College London, investigating the prions responsible for CJD announced that “Cannibalism may have spread a deadly brain-wasting disease among human populations thousands of years ago and may have eventually helped people evolve a resistance to such diseases”.
http://www1.cs.columbia.edu/nlp/news...55-24-112.html

From examples such as these it is clear that evolution of modern humans is an ongoing process, which was why I characterised your claim that it was not occurring as ‘radical’. I stand by that assertion.

Originally Posted by charles brough

What is radical about us being unchanged biologically since we emerged less than 200,000 years ago?

What does radical mean to you? It is not a very meaningful statement, because it basically claims that if we ignore all of the changes that have occurred over the past 200,000 years then we can accpt this statement.

If we had changed during that time, then we would be modern humans only since that change.

Your statement implies a single change, which is not valuable. Anyway, you are correct. Our species has not been "modern humans" for 200,000 years.

It is the very reason that anthropologists know of no change since then that enables us to say we go back almost 200,000 years!

By what authority do you claim to speak for all anthropologists?

There is more change between the races than there is between us and our almost 200,000 year old ancestors.

Sure.

The idea that we have long since stopped evolving biologically is disturbing only because

Just because it is short on value does not make it disturbing.

How is it then, that societies have evolved? I think it is a really top-notch question, but does anyone know of anyone who is even trying to answer it?

It is a good question, and many people are trying to answer it.

Charles, in addressing your central thesis I overlooked one minor point.

Originally Posted by Charles Brough

The idea that we have long since stopped evolving biologically is disturbing only because the Baptists and Penticostals have sensitized us and made us all defensive about evolution

1. The Baptists and Penticostals have not sensitized me - they have nothing relevant to say about evolution.
2. They have not made me defensive about evolution. There is nothing of substance requiring defense within the theory of evolution.
3. The idea, that we have long since stopped evolving biologically, is not disturbing, it is simply wrong.

Another thing to remember is that humans are not evolving in any one direction - the limiting factor in reproductive success varies greatly around the world.

Daniel

DNA sequencing software

Originally Posted by daniel tillett

Another thing to remember is that humans are not evolving in any one direction

Can you be more specific about what you mean? I consider that humans are evolving in one and only one direction, forward.

Originally Posted by Hermes

Originally Posted by daniel tillett

Another thing to remember is that humans are not evolving in any one direction

Can you be more specific about what you mean? I consider that humans are evolving in one and only one direction, forward.

That is, on the face of it (and also when you bury into it quite deeply), is a nonsensical statement.
Evolution does not have a direction.
Direction (especially terms such as forwards, or backwards) is especially misleading. Direction implies that the population is moving towards a 'better' version of itself. It is not. 'Better' has no meaning in the context of evolution.
The processes of evolution tend to select for 'fitness'. Changes in phenotype that are appropriate for one environment, that make the organism 'fit', or 'fitter', may be neutral or even damaging in another environment.
Consequently, to speak about the direction of evolution is potentially misleading, since it suggests that evolution is taking 'us' or 'them' somewhere. [To infinity and beyond, as Buzz Lightyear declared.]
Secondly, as Daniel has succinctly pointed out, because humans are living in a variety of environments the selection pressures upon different populations are different: evolution will be taking different paths. There is, if you insist upon using the word, more than one direction to current human evolution. In the present global set up there is a sufficient interchange of genetic material between groups that the isolation that would be necessary for speciation to occur seems unlikely to occur.

Originally Posted by Ophiolite

That is, on the face of it (and also when you bury into it quite deeply), is a nonsensical statement.
Evolution does not have a direction.

How cute of you. Rather than say what is objectively true, that you cannot make sense of it, you insert your subjective impression in an objective manner, saying that the statement is nonsensical in all scenarios. Feel free to understand as you do, but to objectify your subjective impression does not make it any more objective.

Although I basically agree with your explanation, I do not in any way see how it supports your conclusion. In conclusion, your conclusion is nonsensical.

Originally Posted by Hermes

Originally Posted by Ophiolite

That is, on the face of it (and also when you bury into it quite deeply), is a nonsensical statement.
Evolution does not have a direction.

How cute of you. Rather than say what is objectively true, that you cannot make sense of it, you insert your subjective impression in an objective manner, .

That I cannot make sense of what? Evolution, or the 'direction' that evolution allegedly has, or your post. Please clarify your ambiguity.
I have not inserted a subjective impression. If I were doing so I would use a phrase such as "I think", "it seems to me", "it appears that". The statements I have made are objective descriptions of evolution. I will be happy to consider peer reviewed papers that challenge any or all of these statements.
It is yourself, on the contrary, with your view that human evolution has only a single direction, forwards, that is wrong and working with an impression. It might be interesting to learn how you came by it.

Your later comments illustrate that I will have to take second place for cuteness.

Originally Posted by Ophiolite

It is yourself, on the contrary, with your view that human evolution has only a single direction, forwards, that is wrong and working with an impression.

OK, I see that you have some large degree of certainness that your position is correct. Please provide objective proof that you position is correct, which would justify your stating with such a high degree of certainty that your position is correct and mine is not.

The absence of sustained direction from evolutionary changes is such a given of evolutionary biology that it is difficult to pull examples immediately from the literature. Consider however that evolution proceeds through the actions of natural selection, genetic drift and gene flow. These are directed only in the sense that they respond to environmental influences, which are not systematic. Hence the changes themselves can not be systematic and must lack overall direction.
Here, as an example, are some quotes from a detailed article on the evolution of horses. If you read the full article you will see that I am not taking these quotes out of context and that the non ‘direction’ of evolutionary change is one of the points the author is making.
http://www.talkorigins.org/faqs/horses/horse_evol.html

Different traits evolved at different rates, didn't always evolve together, and occasionally reversed "direction".

In other words, horse evolution had no inherent direction. We only have the impression of straight-line evolution because only one genus happens to still be alive, which deceives some people into thinking that that one genus was somehow the "target" of all the evolution.

The "direction" of evolution depends on the ecological challenges facing the individuals of a species and on the variation in that species, not on an inherent "evolutionary trend".
"Bully..." contains essays on "fox-terrier size" Hyracotherium and on the fallacy of perceiving a direction of evolution in the horse family.

Just for completeness Evolution’s Arrow, by John Stewart (available online here http://www4.tpg.com.au/users/jes999/) presents the other side of the case. Stewart is not main stream. His views are definitely not orthodox as is demonstrated by his publishing methodology. Is there anything bad about being unorthodox? No, but being unorthodox and wrong can be a troubling combination.

As to the continuing evolution of man and its divergent character I recommend you google "sickle cell anemia". West Africans commonly have a recessive gene that when expressed results in an anemic condition, with, if I recall correctly, several possible complications. The upside of the gene is that it imparts a resistance to malaria. The mutation that caused it has been advantageous in West Africa where malaria is common. This, like all adaptations, is a random response to a chance environmental characteristic. It is not directed.

Originally Posted by Ophiolite

The absence of sustained direction from evolutionary changes is such a given of evolutionary biology that it is difficult to pull examples immediately from the literature.

Quite rightly, you have demonstrated that it is not worth even attempting to pretend that there is any absolute and objective proof of your position as opposed to mine. What you posted here is more reasonable to me than your last post, as here you are presenting an opinion, rather than claiming to know the truth value of one opinion over another.

What you posted is a reasonable opinion, but I do not agree with it entirely.

My position is more along the following line: Time flows in one direction, forward. As you, and each of us, evolves through our life, as we age, our future is to a degree random and without direction. This is what you seem to be claiming. However, this randomness and lack of direction can be understood to be limited by a greater context, in that people cannot evolve backward to a younger state of mind or body. I agree with you that there is randomness, but that evolution can be framed within a greater context within which there are directional constraints to the randomness.

Originally Posted by Hermes

Quite rightly, you have demonstrated that it is not worth even attempting to pretend that there is any absolute and objective proof of your position as opposed to mine.

That is not what I am demonstrating at all. I have given you a single clear example of where it is repeatedly noted that evolution does not have a direction. I have explained that statements to this effect are rare because they are a given.

Originally Posted by Hermes

What you posted here is more reasonable to me than your last post, as here you are presenting an opinion, rather than claiming to know the truth value of one opinion over another.

I am sorry if I was unclear. I am not expressing an opinion, well certainly not my own. The vast majority of evolutionary biologists do not consider evolution to have a direction.

Originally Posted by Hermes

As you, and each of us, evolves through our life, as we age, our future is to a degree random and without direction.

I have absolutely no idea what the individual has to do with evolution. Evolution does not change the indiivdual. Evolution changes populations. Why are you clouding the issue with talk of individuals?

Originally Posted by Hermes

However, this randomness and lack of direction can be understood to be limited by a greater context, in that people cannot evolve backward to a younger state of mind or body. I agree with you that there is randomness, but that evolution can be framed within a greater context within which there are directional constraints to the randomness.

Again, drop references to individuals. They are irrelevant. The directional contraints are a pressure to move towards 'fitter' phenotypes. These constraints are determined by the nature of the environment and thus are continually fluctuating in direction. That is why direction is a very poor term to use in this context. I offered the alternative of paths. This has the advantage of capturing the vaqriability of direction the paths may take and the possibility of branching.
Hermes, this is all pretty basic stuff. Do you have any background at all in biology? It would help to know so I can avoid talking either up or down to you.

Originally Posted by Ophiolite

That is not what I am demonstrating at all. I have given you a single clear example of where it is repeatedly noted that evolution does not have a direction. I have explained that statements to this effect are rare because they are a given.

I am sorry if I was unclear. I am not expressing an opinion, well certainly not my own. The vast majority of evolutionary biologists do not consider evolution to have a direction.

I do not understand your purpose in holding a discussion. You seem to be presenting and defending the most popular current consensus as clear and unchallengeable fact. You consider that any challenge to current consensus is invalid, even your own. Surely you are aware that current consensus will change over time. How can it change if no one challenges it? I believe that all serious challenges should be entertained. You have the right to ignore my challenges, as you seem to ignore your own, or to give them a hearing. But to dismiss them because they are not current consensus in your mind is prettyy valueless to me. What is the point of your discussing? Is it to have us all agree on the current consensus? In your statement above, you state what you believe "the vast majority" believe. So what? In your mind, this seems to mean that it is therefore to be taken as absolute fact, and not to be discussed or challenged in any way. If this is your take, then we should stop our discussion, as I see no merit in a discussion with someone who only wants to defend the faith.

Originally Posted by Ophiolite

I have absolutely no idea what the individual has to do with evolution. Evolution does not change the indiivdual.

I accept the first sentence, and therefore do not understand how you feel comfortable stating the second.

Originally Posted by Ophiolite

Evolution changes populations.

Although true, this is irrelevant. Evolution does change population. It also changes individuals, rocks, and everything else in the universe.

Originally Posted by Ophiolite

Why are you clouding the issue with talk of individuals?

Why are being so strict in limiting your use of the word evolution so that the various uses of the term must remain completely unrelated?

Originally Posted by Ophiolite

Again, drop references to individuals. They are irrelevant.

Perhaps it is you who should widen your context.

Hermes,
there are two major points I take from what we have been discussing.
Firstly, we are talking about evolution in the context of this thread. It was here that Charles Brough declared humans had not evolved in the last 2000 years. In the context of this thread evolution, biological evolution, is defined as the change in the allele frequency within a population over time.
I can talk about how televisions have evolved from the simple black and white sets of the 50s.
I can talk about how the Labour Party in the UK has evolved from a left wing pro-worker party to a middle of the road, in some cases right wing, entity.
I can talk about how my golf swing has evolved from merely bad to truly abyssmal.
None of these uses of evolution have anything to do with evolution in the context of this thread. Stop driftng (or jumping) off topic.
Within the context of the this thread your statement that evolution "changes individuals, rocks, and everything else in the universe." is wrong. If you are going to use such a wide definition in adiscussion on human biology and evolution give us a warning in future- something like an announcement large off topic definition about to be introduced.

Secondly, in relation to 'evolution having no direction', I am not defending the faith, as you put it, I am defending the facts. Since you finally concede that conventional wisdom holds this to be true, and you are the one challenging conventional wisdom, please provide some facts that support your contention that evolution has a direction. I shall be happy to debate those points with you, though I suggest a new thread would be the appropriate place.[/b]

Originally Posted by Ophiolite

we are talking about evolution in the context of this thread. It was here that Charles Brough declared humans had not evolved in the last 2000 years. In the context of this thread evolution, biological evolution, is defined as the change in the allele frequency within a population over time.

You are wrong. It is you who decided arbitrarily to limit this topic in this manner. There is no reason why any of us should decide on our own or in conjunction with you to arbitrarily limit the meaning of his words to such a small range of their utility. If you wish to limit them thus, then I claim that you should use more precise words. The fact that you prefer limited scopes and I prefer wider contexts does not give me any impetus to search for the most limiting scope in your words that I can think of. I have no idea why you wish to be so limited in scope, but use more limiting words, define your words more carefully, or state that you wish to keep the scope extremely limited. To say that humans have not evolved in 200,000 years is frankly quite ridiculous, in my opinion. I feel the same way about your desire to use highly limited contexts with no desire to search for broader contexts and relationships.

None of these uses of evolution have anything to do with evolution in the context of this thread.

Again you are wrong. It is false to state that the although the thread uses generic words highly limited interpretations of the words MUST ABSOLUTELY be used, just because you have no desire or ability to search for greater contexts.

Within the context of the this thread your statement that evolution "changes individuals, rocks, and everything else in the universe." is wrong.

Wrong. I agree that within YOUR PERSONAL interpretation of the context of the thread this is true. I have no need to recognize your unspoken and unclarified interpretation as valid. Now that you clarify it, I still have no requirement to agree.

Secondly, in relation to 'evolution having no direction', I am not defending the faith, as you put it, I am defending the facts. Since you finally concede that conventional wisdom holds this to be true,

I consider this funny. You are NOT defending the facts, but rather certain interpretations of the facts. Do you not recognize this? I have no problem with this, but you seem to think that the current consensus should be accepted as fact. That is what you said before and what you are repeating here. I call that being a defender of the faith. How can you expect science to improve if everyone were to be like you and defend the current consensus?

Originally Posted by Hermes

You are wrong. It is you who decided arbitrarily to limit this topic in this manner.

It is clear you do not understand the difference between and on-topic post and an off-topic post. I will gladly debate till the cows come home, or indeed evolve into some advanced life form, with as wide a definition as you wish, or indeed no definition at all, placed upon evolution, or any other word. But I will not do so within a thread where the applicable definition has been explicitly and implicitly stated. This is a convention that has proved useful in maintaining productive dialogues on many forums. I am sorry you disagree with this convention.
I leave you to your disagreeable position.

Originally Posted by Ophiolite

It is clear you do not understand the difference between and on-topic post and an off-topic post. I will gladly debate till the cows come home, or indeed evolve into some advanced life form, with as wide a definition as you wish, or indeed no definition at all, placed upon evolution, or any other word. But I will not do so within a thread where the applicable definition has been explicitly and implicitly stated. This is a convention that has proved useful in maintaining productive dialogues on many forums. I am sorry you disagree with this convention.
I leave you to your disagreeable position.

I think that you are being quite humerous, but it is clear that we should not attempt to hold a discussion. You think that I should conform my usage of words to your extremely narrow definitions of words and that I should limit all context and interpretation to what you consider are the most common consensus in science, and you have no interest, although you frequently claim that you do, in discussing anything that does not conform exactly to them. You even state that you refute your own opinion for that reason. What possible value could there be in such a debate? To present mainstream thought solely in order to demand agreement is pretty boring to me. On top of that, you claim the right to demand that my usage of words conform to your extremely limited usage. There seems to be no value in attempting to hold a discussion, so let us leave it at that.

Originally Posted by Ophiolite

I am sorry

Next time you think that you have something meaningful to say, please do not send me a wimpy private message telling how wonderful you are. Say what you have to say here on the forum like everyone else.

For anyone who is sad enough to have an interest on the 'wimpy' message sent to Hermes, here it is:
I don't know if you are trying to be deliberately provocative, or if you have simply failed to acquire any manners. Please do not place words in my mouth. Convention on forums asks that one stick more or less with the thread topic and its context. Interesting thoughts that arise which are off-topic should lead to new threads. That's not my opinion, that's a system that has evolved over time. You seem unable to understand this, which in my view means you are either thick or deliberately obtuse. Since several of your posts show a certain native intelligence and a smattering of scientific knowledge I must presume the latter.
Welcome to my ignore list.

[Mod Hat]

Hermes, I must say I find your behavior in this thread to be disagreeable and ad hominem in nature. To say the least, it is counter to positive, intelligent discussion and I ask that you refrain from making posts such as your last where you present an out of context private message to the public forum. It would seem that the PM in question was intended by Ophiolite to reach an understanding and not to be used as a point of counter-attack.

With regard to the thread topic, it is very clear that the working definition of "evolution" should be along the lines of modification by descent or genetic change in a population through time; or a similar, biological definition and not intended to be used in the metaphorical or philosophical sense. We can infer this from the initial posts which refer to the evolution of Homo sapiens over the course of the last 200,000 years.

[/Mod Hat]

With regard to "direction" in evolution, there really shouldn't be a lot of debate here. It is apparent that evolution isn't "directional" in that it seeks only to "improve" or "increase" or some similar monodirectional description as it occurs. Rather, evolution is affected by multiple forces to varied degrees within various populations.

While natural selection implies an "improvement" selected to provide an advantage in a niche environment, it certainly isn't the only evolutionary force nor does an allele that is selected for a given environment ensure that it will always be an advantage.

The evidence is all around us. If it is given that the ancestor to all modern species is a common single-celled organism, then the presence of simple as well as complex species should be enough to say that evolution is pressured more by stabilizing selection than directional selection.

Sticking to humans as a species, we can see stabilizing evolutionary advantages among the varied populations in the world: longer torsos & limbs among African populations to allow for optimum ability to displace heat without being so large as to be inefficient at using available energy; sickle cell traits among African populations which resists malaria; smaller torsos among northern populations to better conserve core heat; lactose tolerance among pastorlist populations.

Each of these adaptations were the result of multidirectional evolution where alleles are selected based upon fitness for the niche the population found itself in.

Non-human examples of multidirectional evolution are abundant. In Camalids, the llama and the camel are two, distinct species with the same common ancestor. They evolved separately on different continents. Neither is "more evolved" than the other.

Evolution is relative to the environment and not "directional." Mutation and drift will occur in individuals within a species. Variation within a population is affected by gene flow between populations. Stochastic expression of an allele will either be favorable, neutral or deleterious to the individual. Individuals that survive will pass on these expressions. Those that don't survive won't.

An environment that changes can cause a favorable phenotype to become a deleterious one. A wetland can be favorable to an amphibian, but if the environment should become either terrestrial or marine because of a drying or inundation the amphibious phenotypes would be deleterious. Likewise, sickle-cell is an evolutionary advantage in malaria affected environments, but once you move individuals to non-affected environments this adaptation reduces the individual's ability to survive.

This is my position on whether or not evolution is directional based upon what I understand of evolution. I'm open to modifying this position, but only at the expense of convincing data.

But I will also say that this is not another, unnamed, science board and the stylistic banter that occurs there doesn't appear as welcome here. Be as harsh as you want with ideas and concepts, but lets please avoid taking personal pot-shots at each other.

" Evolution does not have a direction."

Actually, this is the standard model of evolution. I read in Dr. Gould's essays once that a species could as well evolve as devolve. The pygmy mammoths found in the last few years at the end of the Ice Age rather indicate this.

Evolution has NO necessary direction.

and I agree with you, Ophiolite, that the human species does not in all likelihood date back 200K years. About 100K years to the time of Cro-Magno man, was the first truly modern human. Cro-magnon is now extinct, however, & succeeded by H. sapiens sapiens, altho most would be not easily distinguishable from H. sap. sap.

Before that our genus was Homo but erectus, mostly, for at least 1-3 million years.

We are very likely still evolving. I recall reading some genetic reports that a human brain gene related to microcephalus indicated some fairly rapid recent changes, perhaps within the last 10K years, too. Allowing a larger brain, than not.

So, evolution is still going on. But it occurs very slowly and like the minute curvature of the earth, is relatively invisible, unless one takes a good vantage point. Which mention of the round earth is quite apt, as few persons 1000 years ago knew of it, and it was then about as astonishing to most people as evolution would be 900 years later. And I think will have about the same outcome as the earth being round fact has become extent and generally accepted. [/quote]

As Steve says, homo sapiens has been evolving in the last 200K years.

For example (and there are many), two new alleles which apparently regulate human brain size and development appeared ca 37,000 years ago (in the Middle East) and ca. 5800 years ago (Europe and Middle East).

This distinctive mutation is now in the brains of about 70% of humans, and half of this group carry completely identical versions of the gene. The data suggests the mutation arose recently and spread quickly through the human species due to a selection pressure, rather than accumulating random changes through neutral genetic drift.

http://www.newscientist.com/article.ns?id=dn7974


- on another subject, there is actually increasingly strong evidence of multiregional evolution of the human species in the last 200k years. This is a subject for a different thread, I think.

Originally Posted by silylene

- on another subject, there is actually increasingly strong evidence of multiregional evolution of the human species in the last 200k years. This is a subject for a different thread, I think.

I would still subscribe to the single, Out of Africa view. I hope you start that new thread with details of this 'increasingly strong evidence'.
If you have citations to hand for brain size alleles I would appreciate it.

Steve, did I say homo sapiens did not date back 200k years? I clearly mispoke. I think conventional views place the 'emergence' of h.sapiens at around 170k or 180k, which is only 20k adrift of the 200k figure.

In passing you mention the use of the word devolve in a Gould essay. It is not a word I especially like since it contains the implication that evolution does have a direction. I believe this is one of the most poorly grasped aspects of evolution by the general public, and through the misperception that is does have a direction, provides a more ready acceptance of the ideas of 'directed evolution' and 'intelligent design' by said public.

Originally Posted by Ophiolite

If you have citations to hand for brain size alleles I would appreciate it.

See the New Scientist article I cited above in the prior post. Sorry I don't have the original Journal citations.