Is evolution still ongoing?

[Desiree]

My knowledge of biology is very limited and I know just the basics, so please enlighten me.

This evolution phenomenon has started way way back in the past and as a result, today we see varieties of species including humans. My question is: are WE (present species) still being evolved and developed into new forms and species? Has this process reached its peak yet and levelled off or no it never stops? I tend to think, say 1 million years from now, WE are not going to be as much different and diverse as we were 1 million years ago. Is evolution a trend which could be plotted for future times, predicting what WE will look like or turn into.

There are computer softwares which illustrate how a teenage will look like when he/she is 40 or 50. Is there such predictions in evolutionary biology to predict what WE will look like/turn into in for example 50,000 years.

[DaleSpam]

One of the big weaknesses of modern biology is the inability to use it to predict things like that. Evolution is a theory with great explanatory power but rather limited predictive power. However, for simple organisms, in simple environments it is possible to accurately predict evolutionary trends, so there is some hope that the predictive power of evolutionary theory will improve significantly in the near future.

[Borek]

Evolution still works, although - in the case of humans - it lacks at the moment its driving force.

You don't have to be fit to survive and procreate, you have to be very, very unfit to loose your chance. And even if you are very unfit, medicine will do everything it can to let you survive and make some kids, that will be even more unfit than you are. So in the case of human race there is most likely no evolution at the moment.

[kingdomof]

If I recall correctly, there is one prion which about 10% of the population is immune to because they lack a certain protein which doesn't have a function. Don't take my word for it, but use it more as a thought device.

[wildman]

One of the big weaknesses of modern biology is the inability to use it to predict things like that. Evolution is a theory with great explanatory power but rather limited predictive power. However, for simple organisms, in simple environments it is possible to accurately predict evolutionary trends, so there is some hope that the predictive power of evolutionary theory will improve significantly in the near future.

Bacteria have been evolving VERY rapidly to counter our antibiotics. This is a serious health concern. It is also classic natural selection in a VERY complex environment -- our bodies(although with simple organisms). This should have been very predictable.

[DaleSpam]

Bacteria have been evolving VERY rapidly to counter our antibiotics. This is a serious health concern. It is also classic natural selection in a VERY complex environment -- our bodies(although with simple organisms). This should have been very predictable.You are right, it is a complicated environment. I am not an expert in the literature, but I am not aware of any study where the development and propagation of anti-biotic resistance in a pathogen population was quantitatively and accurately predicted outside of laboratory conditions.

[BoomBoom]

Has this process reached its peak yet and levelled off or no it never stops? I tend to think, say 1 million years from now, WE are not going to be as much different and diverse as we were 1 million years ago.

There is no "peak" in evolution, it is an ongoing process though it does go through "plateaus" when the species' environmental conditions and habits do not change for long peroids of time.

I believe you are correct that we will become less diverse in the future since our merging of cultures and travel will most likely continue to increase. Segregation brings out diversity.
Although 1 million years is a long time and we may not be very similar at all to the way we look today.

Today we are still working on predicting individual chemical pathways on a cellular and tissue level, but in the future our knowledge may be complete enough to have reliable models to make such predictions.

Unless, of course, in the future we start custom building our babies. :)

[russ_watters]

It is also important to understand that evolution is a process that takes generations to manifest. If you walked past an actual Neanderthal on the street one day, dressed in modern clothes and wearing a baseball cap, you may not even notice him. And they lived on the order of 50,000-100,000 years ago.

[Ivan Seeking]

Evolution still works, although - in the case of humans - it lacks at the moment its driving force.

You don't have to be fit to survive and procreate, you have to be very, very unfit to loose your chance. And even if you are very unfit, medicine will do everything it can to let you survive and make some kids, that will be even more unfit than you are. So in the case of human race there is most likely no evolution at the moment.

Not entirely true. For about the last century, the impoverished are most likely produce the most offspring.

[Borek]

Not entirely true. For about the last century, the impoverished are most likely produce the most offspring.

Good point, missed that. In the past cenrturies it was more or less the opposite - those rich had more children. Not necesarilly legal ones ;)

[Ivan Seeking]

It has often made me wonder what, if any, genetic selection is occurring. Of course we can to an extent correlate race to poverty.

[Borek]

To some extent no elimination, no selection. But this anticonception thing skewes statistic of reproduction.

[lisab]

If the poor/uneducated are having more children than the rich (which appears to be the case in many places), there IS selection - the poor/uneducated are favored over the rich/educated.

[DaleSpam]

Is there a poverty gene or an education gene?

Just because one demographic reproduces more than another does not imply evolution is occuring. There must be a genetic trait defining that demographic for evolution to occur.

[Ivan Seeking]

Is there a poverty gene or an education gene?

I don't think it is that simple. Consider for example alcoholism, which is generally claimed to be genetic. In the US, how much of the poverty rate can be attributed to acoholism or addiction? This is not to say that all poor people are alcoholics and addicts, but are people with a strong genetic predisposition to alcoholism and addiction more likely to be impoverished and produce more offspring than they might otherwise?

Are there genetic traits that tend to give people an advantage in the pursuit of wealth; such as good looks, and health?

Are you more likely to receive a college education or to be successful beyond poverty, based on intelligence? Is intelligence partly a function of genetics?

[DaleSpam]

I actually don't have an opinion on the answer to the question "is there a 'poverty' or 'education' gene". I tend to think, like you, that it is not a simple question, and I have never been convinced that such "nature v nurture" questions are ever clearly answered.

My point is that unless there is a genetic component to poverty then the fact that poor people reproduce more is not a driving force in human biological evolution. The weaker the genetic component, the less relevant it is for evolution.

[Moonbear]

It has often made me wonder what, if any, genetic selection is occurring. Of course we can to an extent correlate race to poverty.

While this may get more into social sciences than biology, it seems to me there is a trend more toward blending of the races more so than the past isolation of people that led to formation of distinct races. It's a fairly modern concept that a man from the US who is of mixed African and European ancestry could meet an Asian woman and have a child who grows up and marries someone of Middle Eastern ancestry. It takes only a few generations to blend all the continents again.

As to the original question, yes, evolution is always ongoing. And as others have pointed out, there isn't really a predictive aspect to the theory, it's mostly evaluating changes that have already occurred in hindsight to understand how species have changed.

[TheStatutoryApe]

I can't remember where it was but Evo recently posted a link to an article describing newly found incidents of speciation due to changes in environment from GW.

http://evolution.berkeley.edu/evolibrary/news/060701_warming
Not the same article but the same topic.

[wasteofo2]

As long as some individuals - for whatever reason - have more offspring (who grow to breed) than others, and some children die before breeding, evolution is occuring.

People are still dying for various reasons, and if they die before they breed, or before they breed as much as they might've, they're being selected against. Just because we have various methods of extending life beyond the limits other animals face, does not mean we are subverting evolution. Human society itself is an evolutionary benefit of our species, we have protection from other animals, medicine, surgery, family members who'll care for us. These are all evolutionary adaptations that help us survive.

So yes, evolution is still ongoing. Especially now, as people of different populations who in the past were isolated by geography are mixing at increasing rates, we'll see all sorts of new combinations of gene traits that were very unlikely hundreds of years ago, with more chances for mixes of various traits to produce even more fit humans.

[Borek]

First of all - how do we define evolution?

Because what is happening to the human population is not necesarilly evolution in terms of "producing better fit individuals". They are somewhere in the population. Are there more of them? Does their number grow, together with the population? Or does their number goes down, as their genes are mixed with genes of those less fit? What wins - sheer population growth, or lack of selection?

What is happening is rather that the population becomes more and more diverse, gaussian tails become longer and longer in all directions, mean value (whatever it means) shifts because of the processes that have been signalled earlier. But is it still evolution in Darwin's terms?

So, if we define evolution as shifting of the mean (and that's not a completely absurd thing, as evolution doesn't touch single individuals, but whole populations), it is still ongoing. If we define it as a production of better fit, it doesn't. At least IMHO.

[DaleSpam]

As long as some individuals - for whatever reason - have more offspring (who grow to breed) than others, and some children die before breeding, evolution is occuring.Biological evolution only occurs if there is some genetic trait that differentiates the two groups. If the genes are the same and it is only some environmental factor then no biological evolution occurs.

[BoomBoom]

While this may get more into social sciences than biology, it seems to me there is a trend more toward blending of the races more so than the past isolation of people that led to formation of distinct races.

In the context of genetic diversity, this statement is certainly more biological than social. :D

We can easily see how isolation within a certain environment can effect how a population adapts genetically in a relatively short period of time (evolutionarily speaking) by looking at the phenotypical differences within the worlds' human races.

I am surprised by all those that seem to think this process ever stops.

Living things will always adapt to a changing environment and ours is changing quite drastically. By environment I am NOT speaking of global warming...I mean our diets (junk food and microwaves), technology (couch potato-living and comfy drives to desk jobs), etc.. But we will adapt to all these changes of lifestyle.....eventually.

[DaveC426913]

First of all - how do we define evolution?

Because what is happening to the human population is not necesarilly evolution in terms of "producing better fit individuals".
I do not believe that better fit individuals is a requirement of evolution, no. I believe evolution simply requires changes that are inherited that increase in the gene pool.

[Count Iblis]

Evolution still works, although - in the case of humans - it lacks at the moment its driving force.

You don't have to be fit to survive and procreate, you have to be very, very unfit to loose your chance. And even if you are very unfit, medicine will do everything it can to let you survive and make some kids, that will be even more unfit than you are. So in the case of human race there is most likely no evolution at the moment.

Wouldn't this lead to degeneration? Mutations will accumulate, we'll become less fit, have all sort of (genetic) diseases, yet we'll survive because of medical technology.

[Evo]

Wouldn't this lead to degeneration? Mutations will accumulate, we'll become less fit, have all sort of (genetic) diseases, yet we'll survive because of medical technology.That would be an unfortunate result of people reproducing thanks to medical intervention. Normally these people would not have reproduced. We're predominantly going to see this kind of thing more in Western Cultures that have access to this kind of medical intereference with nature.

I was discussing this with someone yesterday. In the future will people want a medical background check on their future spouse? Do you want to knowingly pass down a terminal illness or crippling disabilty to your children if you know in advance and can avoid it? There is always the risk for some people to pass on a genetic disease, but if this person would have never been born, or if he/she has a hamily history of people that would not be born and they have little hope of living a long and healthy life, would it be something that you would take into consideration? Perhaps decide not to have children? If I was on the fence about a guy, knowing something like this might be what it takes to move on.

[Borek]

Wouldn't this lead to degeneration? Mutations will accumulate, we'll become less fit, have all sort of (genetic) diseases, yet we'll survive because of medical technology.

As far as I read that's already happening, unfortunately I can't provide reference as article I have on mind was published in Polish insert to Polish edition of SciAm about ten years ago. It was by some PhD anthropologist.

Look around you - how many of our friends and relatives will be long dead if not for the medical assistance they are getting? Why so many women have problems getting pregnant? In many cases they are already daughters of women that had the same problem 20-30 years ago so they have - stupid as it sounds - inherited the problem. Things like lactose intolerance, coeliac disease - higher and higher fraction of the population is affected. That's the degeration.

[LowlyPion]

Things like lactose intolerance, coeliac disease - higher and higher fraction of the population is affected. That's the degeration.

On the other side of things I believe that something like sickle cell anemia offers some benefits against malaria. This suggests then that it's not wholly clear that artificially selecting toward eliminating what today may be seen as "degeneration" wouldn't weaken the human genome as well by selecting against enzymes and protein productions in intermediate stages that may offer positive selection in future generations for unforeseen perturbating factors that may arise in nature.

Certainly whatever robustness that evolution may have must come from the range of variations that are presented in each generation to be selected for the next. Some things presumably that offer little chance of survival in any generation can seemingly be selected against safely, if such selections would never live to reproduction anyway.

Personally I think that the heroic attempts to fulfill everyone's reproductive agendas is misguided in the same way as remembering that through the middle of last century, there were such efforts made stopping forest fires - to the point that the resulting fires became all the bigger and more devastating. Hence the current practice of controlled burning.

Nature seems to have a pretty consistent pay me now or pay me later way of maintaining things it seems.

[TheStatutoryApe]

Biological evolution only occurs if there is some genetic trait that differentiates the two groups. If the genes are the same and it is only some environmental factor then no biological evolution occurs.

Unless I am mistaken I believe that environmental factors (or even simple random mutation) can change DNA. Perhaps these changes are not drastic enough though to promote evolution.

[LowlyPion]

Unless I am mistaken I believe that environmental factors (or even simple random mutation) can change DNA. Perhaps these changes are not drastic enough though to promote evolution.

I think he was trying to draw a distinction between the process of selection, whether it's environmentally imposed or imposed through behavior and the actual changes that would become a part of the future genome for the species.

And yes chance ultimately needs to play a hand, whether by radiation happenstance like cosmic rays, or by other means, to introduce the first instance of the trait in the species so that it may be selected for in succeeding generations.

[Gear300]

In the future we will no longer be the homo sapiens we are now. We will turn into gigantic blobs of goo and thought...we will also be partially artificial...and will no longer have the need to use the bathroom more than once a day...yes it will be amazing.

[Gear300]

I think he was trying to draw a distinction between the process of selection, whether it's environmentally imposed or imposed through behavior and the actual changes that would become a part of the future genome for the species.

And yes chance ultimately needs to play a hand, whether by radiation happenstance like cosmic rays, or by other means, to introduce the first instance of the trait in the species so that it may be selected for in succeeding generations.

...and yup...evolution can occur macroscopically and microscopically. It can occur smoothly and randomly. It is an ongoing process...all systems are essentially dynamic and its rare that you'd ever find a steady one...processes in nature are usually always dynamic.

[LowlyPion]

In the future we will no longer be the homo sapiens we are now. We will turn into gigantic blobs of goo and thought...we will also be partially artificial...and will no longer have the need to use the bathroom more than once a day...yes it will be amazing.

Perhaps when we teach robots to think for themselves and replicate themselves we will have served our evolutionary purpose?

[Gear300]

Perhaps when we teach robots to think for themselves and replicate themselves we will have served our evolutionary purpose?

Perhaps so...

[DaleSpam]

I think he was trying to draw a distinction between the process of selection, whether it's environmentally imposed or imposed through behavior and the actual changes that would become a part of the future genome for the species.Exactly. Biological evolution is a change in gene frequency within a population. The driving force for evolution is natural selection. If there is a trait which is naturally selected, but which is not genetic, then that selection does not cause biological evolution.

Say that some species' coloration is dependent on environmental factors (e.g. available diet) instead of genes. Say further that one color is naturally selected over another (e.g. through preferential predation). Then those of the right color will more often survive to reproduce, but their children will not inherit the color trait because it is not genetic. The frequency of genes in the population will not change.

[LowlyPion]

Exactly. Biological evolution is a change in gene frequency within a population. The driving force for evolution is natural selection. If there is a trait which is naturally selected, but which is not genetic, then that selection does not cause biological evolution.

Say that some species' coloration is dependent on environmental factors (e.g. available diet) instead of genes. Say further that one color is naturally selected over another (e.g. through preferential predation). Then those of the right color will more often survive to reproduce, but their children will not inherit the color trait because it is not genetic. The frequency of genes in the population will not change.

Yes, but I rather think the environmental circumstance in your example will ultimately tipple some change into the genome by other means at a minimum, because if it is diet that causes the coloration then a preference for that diet and avoidance of the predated will surely be selected for. And that preference will cause the domination of that color in the species even though the color gene itself was not altered. There will be an apparent preference gene, even if only such preference is born out of some third unrelated factor like the predated color causing berries give gas and indigestion.

It's a beautifully complex process.

[BoomBoom]

The driving force for evolution is natural selection. If there is a trait which is naturally selected, but which is not genetic, then that selection does not cause biological evolution.

Natural selection is not a "driving force" at all. It is nothing more that a selection process, similar to a medium we may use for bacteria in a petri dish. It does nothing to describe the process of genetic adaptation itself.

The driving force of genetic adaptation is within the genome itself, most likely controlled by a variety of regulatory proteins. Gene duplications are probably a huge factor in adaptation and may be triggered by environmental stress factors (I read a good paper in Nature on this and will try to find the link). As well as many other genetic mechanisms.

I'm sure the driving force is still a selection process, but this selection process is on the level of proteins and interactive feedback loops within the genome, not the over simplistic Darwinian viewpoint of "survival of the fittest" of the organism itself. Even void of any "natural selection" at all, genetic variation and adaptation will continue at its own rate.

Darwin was a bright guy for his time, but we really need to get out of the 19th century when thinking about evolutionary processes.

[DaleSpam]

Yes, but I rather think the environmental circumstance in your example will ultimately tipple some change into the genome by other means at a minimum, because if it is diet that causes the coloration then a preference for that diet and avoidance of the predated will surely be selected for. And that preference will cause the domination of that color in the species even though the color gene itself was not altered. There will be an apparent preference gene, even if only such preference is born out of some third unrelated factor like the predated color causing berries give gas and indigestion.

It's a beautifully complex process.Yes, what you describe here is certainly reasonable. Basically, any given trait could be described as lying somewhere on a continuum between completely genetic traits and purely environmental traits. In higher animals most traits probably arise from some combination of genes and environment.

Given an equal selection pressure on a given trait, biological evolution will occur more rapidly the further towards the "purely genetic" end the trait lies, with "purely environmental" traits yielding no biological evolution regardless of selection pressure. Today, the genetic component of human traits such as "poverty" is probably negligible, so the fact that poor people reproduce more than rich ones is not likely to be a strong driver for human evolution.

[Moonbear]

Natural selection is not a "driving force" at all. It is nothing more that a selection process, similar to a medium we may use for bacteria in a petri dish. It does nothing to describe the process of genetic adaptation itself.

Thank you for clarifying this. It's a common misconception that even biology students get wrong too often and thus confuses everyone.

[Moonbear]

Wouldn't this lead to degeneration? Mutations will accumulate, we'll become less fit, have all sort of (genetic) diseases, yet we'll survive because of medical technology.

There is no such thing as degeneration or devolution, as some call it, with regard to evolution. Evolution doesn't have a specific direction. All evolution refers to is change in the genetics of a species or population over time. Whether it leads to an increase in fitness or extinction, it's still evolution.

[DaveC426913]

There is no such thing as degeneration or devolution...I was going to make the same point, but I'm not so sure in this specific case.

All evolution refers to is change in the genetics of a species or population over time.I thought there was an element of selection too. And heredity.

But in the case of humans with technology, the ones who are breeding and propogating their genes are not the ones who are under selective pressure. And they're not passing on traits that they're accumulating.

Hm. I'm using hte wrong words. I just mean that an increase in a given gene in the population has become decoupled from the selection process.

[BoomBoom]

I just mean that an increase in a given gene in the population has become decoupled from the selection process.


That still doesn't mean that evolution isn't happening. Sure, a good bottleneck and isolated population with rigid and harsh living conditions would probably accelerate that process...OR it would lead to the populations' extinction.

Pretty much any and all genetic adaptations are being passed on since most everyone of the human race breeds...meaning all positive adaptations are in the population and being spread around. Some negative traits are being passed out as well, however, I think that mate selection preferences kind of counter this as most people would rather partner with smarter, stronger, healthier, and more attractive inividuals.

I believe the fact that our population has come up with technology to counteract isolationism and we see a mixing of previously isolated races has only made our species more robust and strong. While a disease could come along and wipe out an entire isolated culture, it is probably impossible for any pathogen in a mixed robust population to kill everyone.

[Count Iblis]

Perhaps sexual selection keeps evolution on the "right course" if for some prolonged time the natural selection pressures (like e.g. predators) become absent?

On the long term, the sexual preferences will also evolve....

Anyway, in case of humans, there may be a selection pressure for women to become infertile, because IVF treatment often leads to twins.

[BoomBoom]

Anyway, in case of humans, there may be a selection pressure for women to become infertile, because IVF treatment often leads to twins.

That would be working on the assumption that the cause of the infertility was genetic and dominant, which probably is the case in only a small percentage of IVF cases. Also, probably half the cases for IVF are due to male infertility, so the effect would not be exclusive to females.

[DaveC426913]

That would be working on the assumption that the cause of the infertility was genetic and dominant, which probably is the case in only a small percentage of IVF cases. Also, probably half the cases for IVF are due to male infertility, so the effect would not be exclusive to females.Yah, guys and ladies, take your laptops off yer laps and your cellphones off yer belts...

[DaleSpam]

take your laptops off yer lapsOuch! (http://news.bbc.co.uk/2/hi/health/2503291.stm)

[LowlyPion]

That would be working on the assumption that the cause of the infertility was genetic and dominant, which probably is the case in only a small percentage of IVF cases. Also, probably half the cases for IVF are due to male infertility, so the effect would not be exclusive to females.

And of course whatever effect there may be, it seems difficult to believe that it can really be that great. I understand that since 1981 there have been 200,000 births through IVF. In the same period there have been - last 27 years - there have been over 100M births in the US, which suggests only a .2% bias - assuming that the causes were for infertility are 100% genetic in nature, which we know can't be the case because at a minimum some vasectomies are reversed by surgical sperm retrievals that result in IVF.

[DaveC426913]

And of course whatever effect there may be, it seems difficult to believe that it can really be that great. I understand that since 1981 there have been 200,000 births through IVF. In the same period there have been - last 27 years - there have been over 100M births in the US, which suggests only a .2% bias - assuming that the causes were for infertility are 100% genetic in nature, which we know can't be the case because at a minimum some vasectomies are reversed by surgical sperm retrievals that result in IVF.Oh Jeez. This is my wife's specialty. She worked for one of Canada's foremost doctors specializing in IVF multips. I hope she doesn't smell this discussion on me when I get home or she'll come rampaging through this thread... :eek:

[shamrock5585]

the concept of natural selection is pretty complex in a broad view but i ask... where does natural selection come into play for humans anymore? I've heard that it is predicted that humans may not need their pinky toe and in the future we will no longer have them... but why would that be... if some genetic mutation came about that brought a human with only 8 toes... why would that person me anymore fit than a regular human... that person would would breed and so would people with 10 toes... there is nothing that makes that person more or less fit for the environment so no selection would occur... humans make no selection at all... we select that all humans have the right to be alive and so nature seems to not intervene... ugly and stupid people still reproduce (in fact more than smart people haha) and they probably always will... it may be seen that a person with blonde hair and blue eyes and an IQ of 150+ to be more fit than others but humans have overcome nature to where we can manipulate it to an extent and make our own selection... so no evolution occurs to make a blonde hair blue eyed genius survive and reproduce more than a 400 pound unable to walk person with multicolored skin and smells like garbage... some freak will have a fetish for it and they will reproduce haha... no natural selection

it seems so clear to me but i am very open for others to poke holes in my argument, maybe give me some insight.

[shamrock5585]

the only way i see humans evolving is their immune systems... basically like the movie i am legend. but that would require an enormous amount of environmental pressure.

[BoomBoom]

it seems so clear to me but i am very open for others to poke holes in my argument, maybe give me some insight.

Read the other posts in the thread and you will find the holes have already been poked. :wink:

[bobze]

I thought there was an element of selection too. And heredity.

But in the case of humans with technology, the ones who are breeding and propogating their genes are not the ones who are under selective pressure. And they're not passing on traits that they're accumulating.

Hm. I'm using hte wrong words. I just mean that an increase in a given gene in the population has become decoupled from the selection process.


Hey Dave,

The fact of biological evolution is simply the change in allele frequencies in a given population from generation to generation.

The theory of evolution, explains why and how these changes occur. For example, one such aspect is Natural selection. Which occurs when Darwin's 4 postulates are met. Those being;
1. Individuals within a population vary
2. Some of that variance is passed on
3. More offpsring are produced than can be supported by the environment
4. Survival is not random, the best combinations of variation are more likely to survive and reproduce.

Its important to note however, that we have come a long way since Darwin's day and we know that NS is not the only selection process nor determinant frequencies of a evolutionary lineage. Things like sexual selection, genetic drift, epigentic inheritance (though this is a much newer idea, there is some interesting evidence nonetheless) all play important rolls in how allele frequencies are maintained.

People quickly get confused when confronted with this definition of "evolution", because people tend to think of evolution in snap shots (really a fault of our nervous system imo). I find it best, when explaining how these small changes in allele frequency manifest to make the biodiversity present on earth today to use an analogy.

I like color bars for illustrating an evolutionary lineage the most, so bare with me for a moment while I explain. It also, imo, better explains transitional fossils as well.

First I think it maybe important to define what we are talking about here. What is a transitional form or fossil? Or even a missing link for that matter?

To understand this we need to understand a bit about species, more importantly lineages.

All life today and throughout the history of earth can be thought of as a continuation or a branching of a lineage. Species is a concept we use to making talking about organisms easier. Species are not real, it is just a man made concept given name. The point where one species begins in history and another ends is arbitrary, because a species is not a set thing --We think this is so, because our perception of time and our short stay here on earth.

Its best to describe life as a descendant of a lineage. A lineage therefore, is a ancestor and all of his descendants --An unbroken line. In this case though, we are referring to populations as ancestors and populations as the descendants.
http://mediagods.com/tools/images/spectrum.jpg
I think the easiest way to picture it is to think about the color spectrum.

(For the sake of me not having to create a new color bar with a time scale, please imagine time 0 starts on the left hand side and increase going right to the end, which represents present day)

He we can think of the ancestor as one single point (a hue, saturation and value) on the left hand side. The population descendants then are the colors that follow toward the right. Each point is slightly different from the first, Just as in biology each generation's allele frequencies slightly differ from their parent generation.

We apply the term species to a whole grouping of colors, the species red for instance. But in reality each generation is slightly modified from the next, such that we have this slow transition from color to color (what we might collectively lump together as species).

This then means, that each slight change in gradient is a transitional form. Because looking at the past, we can see in every "color generation" slight modification from the previous generation.
This also means that every generation is a transitional form.

The consequence of this is that "transitional forms" as you and other creationists demand is a human construct which only is representative of a snap-shot of evolutionary history --In hindsight as well.

The other consequence of this is that all fossils are transitional, as they are representative of only that generation of organisms.

For example, were I to find a fossil of the RGB value FF3030 which corresponds to the color:
http://www.mech.tohoku-gakuin.ac.jp/rde/contents/library/ps2img/colors/gifs/firebrick1_w.gif

then I know (with the completeness of this color spectrum) that it is transitional. A transition between the populations FF3029 and FF3031. Granted the 3 populations may look nearly identical to the naked eye, but at the populations genomic level they differ.

So you ask to see a transitional fossil? Head to your nearest limestone quarry and spend some time looking at the stones --All of those fossils encapsulated for time immemorial are your evidence.


Let's talk for a moment of missing links and why this is such a poor concept.

Often growing up we were taught science is "searching for the missing link". One day well find it and piece all of our evolutionary history together. This is a lie, one created by media and high school science teachers who seemed to lack and interest in teaching real science.

Missing link implies evolution is a large step process. Going back to the color bar, we might say the missing link between the "red and green species". But, if we find a representative of that "yellow species" what have we done? We have opened the door for the need to find two more missing links, one on either side of the representative yellow species.

Whats worse, is the concept implies that our color evolutionary history went from red to yellow to green. What we have done is gloss over the thousands of slightly different hues that occur in between them.

Edit: apologies not sure how to display a picture, is that allowed here?

[bobze]

the concept of natural selection is pretty complex in a broad view but i ask... where does natural selection come into play for humans anymore? I've heard that it is predicted that humans may not need their pinky toe and in the future we will no longer have them... but why would that be... if some genetic mutation came about that brought a human with only 8 toes... why would that person me anymore fit than a regular human... that person would would breed and so would people with 10 toes... there is nothing that makes that person more or less fit for the environment so no selection would occur... humans make no selection at all... we select that all humans have the right to be alive and so nature seems to not intervene... ugly and stupid people still reproduce (in fact more than smart people haha) and they probably always will... it may be seen that a person with blonde hair and blue eyes and an IQ of 150+ to be more fit than others but humans have overcome nature to where we can manipulate it to an extent and make our own selection... so no evolution occurs to make a blonde hair blue eyed genius survive and reproduce more than a 400 pound unable to walk person with multicolored skin and smells like garbage... some freak will have a fetish for it and they will reproduce haha... no natural selection

it seems so clear to me but i am very open for others to poke holes in my argument, maybe give me some insight.

You're right NS is very complex, much more so than your description here. Humans very much indeed still have selection pressures being exerted on us, they may just not be as simple and obvious as some of those found in the animal kingdom.

For instance, the malaria parasite kills millions of people a year, mostly children and mostly people who have yet to reach a reproductive age. This then supports selection for sickle cell heterozygous genotype, which bequeaths individuals who are carriers of the disease an increased resistance to the parasite.

We would expect, or predict even, that in this region of the world we would also see an increase in the frequency of those with Sickle cell. And we do, its rather interesting to look at the overlay maps of SCA and malaria and see the evidence of ongoing human evolution.

In fact, any time some dies before reproductive age due to "natural" causes (disease, genetic abnormality etc) we can say that natural selection is acting upon our populations. Because in those cases survival and reproduction is not random, those combinations of variation are removed from the population and such combinations are no longer passed on.

[LowlyPion]

... because people tend to think of evolution in snap shots (really a fault of our nervous system imo).

It's more than that I'd say. If for no other reason than the fact that the fossil evidence is so terribly incomplete despite our trips to the quarries. What we are presented with today are incomplete and highly fragmented specimens. Snapshots at best - more like hints at snapshots seen through a glass darkly. We are in most cases left to infer tremendous leaps over the periods of thousands to millions of generations that may be represented in inferred successors. Its a picture that is so sparse, that inferring any linkage still leaves the tree extraordinarily sparse.

If the fossil record recorded all of the species and generations, not to mention the continuum of ecosystems, big and small, that have sustained or pressured them all, then we would require another way to deal with all that massive detail than the sparse data set we currently have to work with.

[BoomBoom]

Hey Dave, .....
...
The consequence of this is that "transitional forms" as you and other creationists demand is a human construct which only is representative of a snap-shot of evolutionary history --In hindsight as well.
...

Wow! Are you accusing Dave of being a creationist??!! :surprised :rofl:


I see no creationists or ID'ers in this room...<looks over shoulder>

[bobze]

Wow! Are you accusing Dave of being a creationist??!! :surprised :rofl:


I see no creationists or ID'ers in this room...<looks over shoulder>

No I am not, that is another post I have made and I copy and pasted much of it over.

[shamrock5585]

You're right NS is very complex, much more so than your description here. Humans very much indeed still have selection pressures being exerted on us, they may just not be as simple and obvious as some of those found in the animal kingdom.

For instance, the malaria parasite kills millions of people a year, mostly children and mostly people who have yet to reach a reproductive age. This then supports selection for sickle cell heterozygous genotype, which bequeaths individuals who are carriers of the disease an increased resistance to the parasite.

We would expect, or predict even, that in this region of the world we would also see an increase in the frequency of those with Sickle cell. And we do, its rather interesting to look at the overlay maps of SCA and malaria and see the evidence of ongoing human evolution.

In fact, any time some dies before reproductive age due to "natural" causes (disease, genetic abnormality etc) we can say that natural selection is acting upon our populations. Because in those cases survival and reproduction is not random, those combinations of variation are removed from the population and such combinations are no longer passed on.

i guess you read my first post but skipped my second one about immune system evolution... this is evolution but still there is human intervention involved. There may be other things that come into play that make sickle cell appear more frequently as well...
I guess i ask the question, will humans evolve physically in a sense where skin, or physical features will change? I lean towards the implication that we wont due to our unnatrual intervening. but who knows after a millions years... a hundred seems long to me and that is but a fraction of the time it actually takes.

[Count Iblis]

As some others have pointed out in this thread, humans won't be around for much longer. Hugo de Garis has the right perspective, if you ask me (http://www.bbc.co.uk/sn/tvradio/programmes/horizon/broadband/tx/singularity/clash/)

[LowlyPion]

As some others have pointed out in this thread, humans won't be around for much longer. Hugo de Garis has the right perspective, if you ask me (http://www.bbc.co.uk/sn/tvradio/programmes/horizon/broadband/tx/singularity/clash/)

I'd say that de Garis is merely echoing Azimov and the I Robot view of things. Not exactly original. It makes a good movie, but such artilects in practice will undoubtedly require people, unlike our lack of need for gnats. If the artilects would ever come to such conclusions, then they wouldn't be so smart after all. If they were really smart as ge Garis fantasizes about they would recognize the marvelous construction of our chemistry and ability to heal and self reproduce; the extraordinary dexterity to work with things big and small to shape the world around us; to evolve to meet the pressures of changing conditions. And the most daunting of all they would recognize if they were created by us they could be destroyed by us.

I'd say that they would need us so much in fact that I doubt they would try to do away with us so much as try to help us from doing away with ourselves. After all entropy is a relentless business, and they would need all the help that they can get to carry on.

[Count Iblis]

I'd say that de Garis is merely echoing Azimov and the I Robot view of things. Not exactly original. It makes a good movie, but such artilects in practice will undoubtedly require people, unlike our lack of need for gnats. If the artilects would ever come to such conclusions, then they wouldn't be so smart after all. If they were really smart as ge Garis fantasizes about they would recognize the marvelous construction of our chemistry and ability to heal and self reproduce; the extraordinary dexterity to work with things big and small to shape the world around us; to evolve to meet the pressures of changing conditions. And the most daunting of all they would recognize if they were created by us they could be destroyed by us.

I'd say that they would need us so much in fact that I doubt they would try to do away with us so much as try to help us from doing away with ourselves. After all entropy is a relentless business, and they would need all the help that they can get to carry on.

It's the economy, stupid :rofl:

There will be a rapid increase in the intellectual capacity of the artilects. Economic competition will be the main driving force. When artificial intelligence outperformes humans intelligence a CEO will want to replace his biological employees by artilects who work for free. If he doesn't want to do that for ethical reasons, his competitor will and he will go out of business.

So, there will be people who will become enormously powerful persons thanks to the artilects. They'll control a major fraction of the world's economy. Now when these CEOs have meetings in their board rooms, only the CEO is a human being, the rest are artilects. After all, humans are much dumber and would never be qualified enough to take part in the discussions.

But then, the CEO him/herself is a human being, so he/she has no real input in what decisions are taken, because if the CEO is intelligent enough to have a real input, then that implies that his/her articlects are not very intelligent, so the company wouldn't last long.

We thus end up in a situation where the artilects are taking all the decisions, the humans are kept alive by an infrastructure they do not control. They could not control it because it is based in technology that was never designed by humans. Also going back to the old system is no option because the old generation of humans who were still in control of the old infrastructure have died out.

So, we'll have become totally dependent of the artilects, like animals in a Zoo. We can only hope that our descendants will be treated better than the people in the film Logan's run.

[shamrock5585]

u have an interesting view on things... stop doing drugs!

[jal]

I have read "pop" books from the experts.
-------
Sean B. Carroll has addressed the role of DNA in his book, “The Making of the Fittest”. He even has an excerpt on the web.
The Making of the Fittest
http://seanbcarroll.com/books/The_Making_of_the_Fittest/excerpt/
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Martin Kenneth Jones has written about:
“The molecule hunt: Archaeology and the search for ancient DNA.”, London: Allen Lane
Those educated in the new field of Bioarchaeology are probably aware of the work being done at …
http://www.arch.cam.ac.uk/pittrivers/
The George Pitt-Rivers Laboratory for Bioarchaeology accommodates a diverse range of projects from various parts of the world.

You might be interested in this recent broadcast, (22 February 2007), This week, “In Conversation” Martin Jones traces the origin of ancient crops.
http://www.abc.net.au/rn/inconversation/stories/2007/1847869.htm
========
I'm sure that evolution is still going on and that the researchers will be presenting us many surprises in the near future.
jal