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Evolutionary Progress (Or Not)

#96: May - July 2011 (Non-Fiction)
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DWill

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Evolutionary Progress (Or Not)

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To make Chris proud, I'm starting the new thread because the discussion we were having in "Is religion ingrained" was far off that topic. Below is my reply to Robert's last post.
The science is about facts, not values. Progress is a highly value laden term. And yet, progress can be defined in quantitative terms, as increased complexity. By this measure, earth has seen steady punctuated increase in complexity. There was nothing bigger than a microbe for over three billion years, then, when the microbes had put enough oxygen into the air, the macrobial explosion occurred at the Cambrian 600 million years ago. Similarly, we have since seen the emergence of flowers, birds, mammals, and us.
Hello again, Robert. Isn't controversy grand? Yes, what you say is true, but something in me wants to say. "So what?" If there was nowhere to go but up, what does that net us? Progress does remain a highly value laden term for a process that worked by accreting the separate systems of organisms into single organisms. This can be seen as an increase in the complexity of the top level of organism. As to the overall complexity of ecosystems, well, that's another area of judgment that doesn't depend on the complexity of the individual species. So I wonder what the basis is for an ever-increasing complexity, even a punctuated increase. With species extinction, caused mainly by habitat loss, world ecosystems have become less complex. Adding to this are introduced invasives crowding out native species.

While the word 'complex' doesn't seem to indicate value, it does present a problem of subjective judgment and a complicated problem of reducing to objective measurement.
We have our experts' opinions to deal with, too. Gould would seem to deny that such a thing as complexity increases with evolution, while Dawkins gives a weak yes.
Chopping progress out of evolution does distort the usual understanding of it. It is commonly said that horseshoe crabs have not evolved because they have stayed the same. Evolution means getting better, in common parlance at least, and this use of the term matches well to the scientific observation.
No, I just have to remain a big admirer of horseshoe crabs for their dogged stability through the eons. Change be damned. The usual understanding of evolution isn't the same as the scientific understanding of it, which is what I'm trying to get at.
I looked again at the ESS wiki - http://en.wikipedia.org/wiki/Evolutiona ... e_strategy
It makes perfect sense to me to say that once an organism had a genome that was resistant to invasion, it ceased to evolve. Now we can argue about the red queen strategy of running faster and faster to stay in one place, but that is more about arms races than something that essentially does not change. I agree with you that horseshoe crabs are evolutionary stars, but that is because they worked out their niche so early and no longer needed to evolve further. They stopped evolving, ie they stopped making progress, because they lived in a stable environment.
Here's the primary question for me: can we really close out the evolution of limulus polyphemus (marvelous name)? What makes us think we can? It's possible that the crab's environment will change enough that over thousands of years, another creature will emerge from its genome. If this means the extinction of limulus p., notice that this will be due in a sense to the adaptability of the animal.
Evolution is all about how species change in response to their environment. That is the meaning of natural selection. Your two sentences here contradict each other. Proportionate change in the gene pool is driven by environmental conditions, but that is just another way of saying that organisms change in response to their environment.
"In response" is an important semantic difference. If individuals "sense" something changing in the environment, presumably they would somehow put out suitable mutations. But the simpler and more elegant explanation is that mutations are random and some turn out to be adaptive, i.e., they increase the numbers of organisms surviving to reproduce in the existing environment.
Resilience is just one criteria for evolutionary progress among many. The evolution from algae to tree involves numerous steps with increased complexity emerging at each. I suspect that resilience has actually declined, in the sense that algae survived the Permian and Jurassic catastrophes quite easily while the more complex and sensitive higher animals died out. My resilience example should not be generalized as an indicator of progress, as often specialization reduces resilience.
I can believe that.
This question of direction in nature is where scientific prediction comes into the picture. We can predict the future by extrapolating trends from the past and present.
There might be some limited, laboratory examples of using natural selection to make hypotheses that can be tested. Or take selective breeding of animals as an example. Regarding natural selection at large, experiments would be difficult to set up and continue over the time scale needed. Perhaps the best we could do would be to be on the lookout for populations that could be changing physically due to environmental changes we observe.
Mention of the long march reminds me of the Chinese theory of dynastic cycle, whereby a dynasty starts off as tough and gradually becomes weak, at which point it is overthrown by a new tough dynasty. This is an example of directionality in evolution. We see it in the cycle of increased complexity followed by collapse in the fossil record.
For the Chinese, it probably is an example of cycles, period. It wouldn't be complexity that accounted for the takeover by the new dynasty. To switch locales, the 'barbarian hordes' attacking the Roman Empire weren't successful because of their complexity. They may have been plenty complex, but this wasn't the 'evolutionary' advantage, most likely. Virulent simplicity might instead be the ticket.
More broadly, we can see the direction of progress from simple to complex over the history of life on earth. Each successive new phase, whether amphibians, reptiles or mammals, or from ferns to flowers, presents a more complex system than its predecessor.
Granting for the moment that this is an "is," do you think there's an "ought" to be derived from it? I don't see the guide that it might provide for human culture.
The present need for human evolution requires a synthesis between the antithetical movements of science and religion, such that we tune in to the cosmos in a way that learns from empirical observation.
Unlike you, Robert, I don't see a human extinction scenario in global warming. With our technology, we can survive this. But I need to add a "for what it's worth" to that. I really don't care about human survival at all costs. If, because we lack the natural limiting mechanisms that other species have, we are wiped out, the world will go on without us. We will have had our moment and then it will be time for another specie's moment. Our demise could happen by several causes. The only vision for the world worth having emphasizes the quality of all life, including but not restricted to our own. This is for me the joining of reason and religion.
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Re: Evolutionary Progress (Or Not)

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DWill wrote:Hello again, Robert. Isn't controversy grand?
Yes, indeed. The great thing about Richard Dawkins is his willingness to explore broader implications of science, to base a broad wholistic ethical philosophy on the empirical basis of zoology. All his critique of religion boils down to his passion about ethics, his sense that valid perspectives have to be grounded in reality. He presents a severe challenge to metaphysical concepts that lack an empirical basis. We might not be surprised if Dawkins lumped ‘progress’ in with all the other metaphysical ideas that he rejects. But he endorses the idea of progress in evolution, in typically cautious fashion when discussing something that is hard to quantify, suggesting progress is an idea with legs, perhaps even with wings and brains.
Yes, what you say is true, but something in me wants to say. "So what?" If there was nowhere to go but up, what does that net us? Progress does remain a highly value laden term for a process that worked by accreting the separate systems of organisms into single organisms.
This gets to the nub about the operation of evolution. In a stable system, without external shocks, the natural tendency is for mutation to gradually fill all available niches, following the grand old inverse of Murphy, that whatever can go right will go right. An ecosystem starts off with a lack of variegation, and gradually species discover, under the pitiless force of selection, that change from the original template works better for them, delivering more offspring. We see the three iron laws of evolution, fecundity, fidelity and longevity, operating to gradually increase the complexity of a stable system. And as Dawkins observes, these laws operate for all replicators, not just for genes. “Nowhere to go but up” means the law of evolution is intrinsically progressive, always tending to increase the complexity of a stable system. Evolution is counter-entropic, ie progressive.
This can be seen as an increase in the complexity of the top level of organism. As to the overall complexity of ecosystems, well, that's another area of judgment that doesn't depend on the complexity of the individual species. So I wonder what the basis is for an ever-increasing complexity, even a punctuated increase. With species extinction, caused mainly by habitat loss, world ecosystems have become less complex. Adding to this are introduced invasives crowding out native species.
The current species loss is anomalous in evolutionary terms. We had 65 million years of relative stability (apart from the Eocene blip at 55 mya) since the Jurassic catastrophe, and about 200 million years before that since the even bigger Permian catastrophe, which our current events may compare to. The agro-industrial revolution, considered broadly, only got going about ten thousand years ago, about 0.02% of the time since the extinction of the dinosaurs. Geologically, the period of human ‘progress’ that is causing the current mass extinction is a tiny blip in time.
Generally, evolution produces very long periods of slow steady progress in complexity, followed by sudden drastic reversals of the type that we are causing now. And it is not just the top predators that become more complex; they produce a cascading increase in complexity down the food chain, as do all selective pressures.
While the word 'complex' doesn't seem to indicate value, it does present a problem of subjective judgment and a complicated problem of reducing to objective measurement.
I don’t think any objective terms contain a necessary value content. Complexity can be objectified by measures such as number of species. Value is entirely subjective, based on whether humans regard it as good. I regard complexity as good, because it holds a suite of intrinsic links to the ancient past in biodiversity.
We have our experts' opinions to deal with, too. Gould would seem to deny that such a thing as complexity increases with evolution, while Dawkins gives a weak yes.
Gould’s view, if that is a correct attribution, is ridiculous. Modern eyes are far more complex than the pinhole of a nautilus. They contain in the genome the record of the whole history of their evolution, as well as being far better at seeing. I think Gould’s beef was with progress, not complexity. The issue here for scientific fundamentalists is that any whiff of teleology has to be cast out like the devil. Progress means things get better. If you are a true Humean nihilist, denying that values can be derived logically from facts, then logically you have to reject all value terms such as progress as unscientific. Dawkins is not a fundamentalist of that stripe, so he accepts the common sense idea that evolution involves progress.
I just have to remain a big admirer of horseshoe crabs for their dogged stability through the eons. Change be damned. The usual understanding of evolution isn't the same as the scientific understanding of it, which is what I'm trying to get at.
Remember, Charles Darwin’s Origin of Species was about “Descent by Modification”. It was about how the abundant diversity of life arose from natural processes. Evolution is about explaining change. Admirable as the horseshoe crab is in its primitive stasis as a living fossil, it has not modified, so it has not evolved, and has not progressed.
can we really close out the evolution of limulus polyphemus (marvelous name)? What makes us think we can? It's possible that the crab's environment will change enough that over thousands of years, another creature will emerge from its genome. If this means the extinction of limulus p., notice that this will be due in a sense to the adaptability of the animal.
Polyphemus was the name of the Cyclops who Ulysses poked in the eye with a burning stick. He is a byword for a throwback, a primitive monster. The horseshoe crab has survived for hundreds of millions of years, so will not change much in mere thousands, except by wholesale environmental destruction causing local extinction.

If individuals "sense" something changing in the environment, presumably they would somehow put out suitable mutations. But the simpler and more elegant explanation is that mutations are random and some turn out to be adaptive, i.e., they increase the numbers of organisms surviving to reproduce in the existing environment.
Mutation is a remorseless random mechanical process proceeding at constant rate. Evolution is directional, towards adaptivity to the niche. Where a species is basically adapted as well as it can be, given its existing genetic resources, all mutations are worse and it stops evolving.
There might be some limited, laboratory examples of using natural selection to make hypotheses that can be tested. Or take selective breeding of animals as an example. Regarding natural selection at large, experiments would be difficult to set up and continue over the time scale needed. Perhaps the best we could do would be to be on the lookout for populations that could be changing physically due to environmental changes we observe.
We don’t need to worry about experiments, as nature gives us an amazing laboratory in the fossil record. Evolutionary change is always due to change in the environment, considered broadly as including climate, food and predators, or movement into an unexploited niche.
For the Chinese, it probably is an example of cycles, period. It wouldn't be complexity that accounted for the takeover by the new dynasty. To switch locales, the 'barbarian hordes' attacking the Roman Empire weren't successful because of their complexity. They may have been plenty complex, but this wasn't the 'evolutionary' advantage, most likely. Virulent simplicity might instead be the ticket.
Evolution, as descent by modification, does not occur in periods of destruction, but rather in the much longer periods of construction. Each Chinese dynasty left a higher base than its predecessor, when the devolving hordes struck.
More broadly, we can see the direction of progress from simple to complex over the history of life on earth. Each successive new phase, whether amphibians, reptiles or mammals, or from ferns to flowers, presents a more complex system than its predecessor.
Granting for the moment that this is an "is," do you think there's an "ought" to be derived from it? I don't see the guide that it might provide for human culture.
It is an obvious guide to the need for evolution in human culture. We should aim to make our planet more complex and diverse. Peace, justice and love need to be cultivated in order to combat the rampant forces of manic destruction. Progress towards human adaptation to nature requires a shift of mindset from rampant exploitation to stewardship and conservation.
Unlike you, Robert, I don't see a human extinction scenario in global warming. With our technology, we can survive this. But I need to add a "for what it's worth" to that. I really don't care about human survival at all costs. If, because we lack the natural limiting mechanisms that other species have, we are wiped out, the world will go on without us. We will have had our moment and then it will be time for another specie's moment. Our demise could happen by several causes. The only vision for the world worth having emphasizes the quality of all life, including but not restricted to our own. This is for me the joining of reason and religion.
One good source on the extinction scenario is Jim Hansen of NASA, for example his article http://www.nybooks.com/articles/archive ... he-planet/ where he says “If emissions of greenhouse gases continue to increase at the current rate—”business as usual”—… a large fraction of the species on Earth, as many as 50 percent or more, may become extinct.”
And http://pubs.giss.nasa.gov/cgi-bin/abstr ... d=ro06010m
“Anthropogenic pressures on the Earth System have reached a scale where abrupt global environmental change can no longer be excluded. We propose a new approach to global sustainability in which we define planetary boundaries within which we expect that humanity can operate safely. Transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental- to planetary-scale systems. We have identified nine planetary boundaries and, drawing upon current scientific understanding, we propose quantifications for seven of them.”

If you don't ultimately care about human survival, you are nihilistic, taking the Freddie Mercury view that nothing really matters. This is a basic problem in the refusal to base values on facts. If we have an ethical urgency about human survival and prosperity, we should be hungry to understand reality and act to maximise optimal responses for humans for the long term, which also means optimising for biodiversity.
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Re: Evolutionary Progress (Or Not)

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I was tempted to CLAIM THIS THREAD IN THE NAME OF SCIENCE! But i left it where it is...


This is a somewhat hurried post.

Sorry.




Quote:RT
The science is about facts, not values. Progress is a highly value laden term. And yet, progress can be defined in quantitative terms, as increased complexity. By this measure, earth has seen steady punctuated increase in complexity


Proliferation of species have also been retarded by massive extinctions. These great die-offs occur pretty regularly (we humans are perpetrating one even now) and in the process the great majority of diversity has already died off with no way to revive those lost species.


Progress towards some standard measure can be claimed, such as progress towards complexity, but we couldn’t say that that was progress of life in general. Nor does it mean progress towards mammal-hood, or person-hood. Rice actually has ten times the amount of genetic coding that a human being does, even considering our 90 % genetic junk quotient. By that measurement, a grain of rice is much further along in progress than any human, but I doubt that is what most would say.


In this instance, I think we have to be careful with a word like progress because it implies a goal. Goals imply a reasoning mind with some kind of agenda.



Quote:
Chopping progress out of evolution does distort the usual understanding of it. It is commonly said that horseshoe crabs have not evolved because they have stayed the same. Evolution means getting better, in common parlance at least, and this use of the term matches well to the scientific observation.


No, I just have to remain a big admirer of horseshoe crabs for their dogged stability through the eons. Change be damned. The usual understanding of evolution isn't the same as the scientific understanding of it, which is what I'm trying to get at.
Horse-shoe crabs as a class of animals have remained, but our horse-shoe crabs are not the same horse shoe crabs that first appeared. The same with sharks and crocodiles. Both have long histories on the planet, but todays are not yesterdays. They have evolved branches as well, but the trunk of those lineages hasn’t been scrapped through extinction.



Quote:
I looked again at the ESS wiki - http://en.wikipedia.org/wiki/Evolutiona ... e_strategy
It makes perfect sense to me to say that once an organism had a genome that was resistant to invasion, it ceased to evolve. … I agree with you that horseshoe crabs are evolutionary stars, but that is because they worked out their niche so early and no longer needed to evolve further. They stopped evolving, ie they stopped making progress, because they lived in a stable environment.


Here's the primary question for me: can we really close out the evolution of limulus polyphemus (marvelous name)? What makes us think we can? It's possible that the crab's environment will change enough that over thousands of years, another creature will emerge from its genome. If this means the extinction of limulus p., notice that this will be due in a sense to the adaptability of the animal.
Horse shoe crabs haven’t stopped evolving. There are four species of horse shoe crab all of which would have derived from a basal horse shoe crab-like creature which shared all the cheracteristics which these four horse-shoe crabs share with each other. The differences between these species is the evidence of the continued evolution of an already successful template, just as the variations between sharks are evidence of the same.

I understand the underlying slant that these creatures have attained a template that is extremely successful in their niche, but that does not result in the end of evolution for that template.
dwill
"In response" is an important semantic difference. If individuals "sense" something changing in the environment, presumably they would somehow put out suitable mutations. But the simpler and more elegant explanation is that mutations are random and some turn out to be adaptive, i.e., they increase the numbers of organisms surviving to reproduce in the existing environment.
You’ve got it right there, Dwill. New mutations are not generated in response to the environment, or any change to that environment. Mutations occur all the time. When and if a new selective pressure is applied, that is when those mutations might really take hold. Some really good mutations certainly did occur in any given lineage which were passed up because they were of no impact in the current environment, but which would be perfect for an environment the species might later find itself in.


Quote:
Resilience is just one criteria for evolutionary progress among many. The evolution from algae to tree involves numerous steps with increased complexity emerging at each. I suspect that resilience has actually declined, in the sense that algae survived the Permian and Jurassic catastrophes quite easily while the more complex and sensitive higher animals died out. My resilience example should not be generalized as an indicator of progress, as often specialization reduces resilience.
It is usually considered that more primitive species are better prepared for environmental change because they have more assets to adapt should the environment change and present new challenges. Seals are not the literal ancestors of whales but you can see a progression of mammalian aquatic species at work there. By that you can extrapolate a scenario where the planets oceans are somehow some way divided up into much smaller bodies of water.

A seal by virtue of retaining the functional load-bearing hips is better suited to succeed in a place where navigating from one isolated body of water to another, where whales would be stuck where they are.
There might be some limited, laboratory examples of using natural selection to make hypotheses that can be tested. Or take selective breeding of animals as an example. Regarding natural selection at large, experiments would be difficult to set up and continue over the time scale needed. Perhaps the best we could do would be to be on the lookout for populations that could be changing physically due to environmental changes we observe.j
There is a 50 year ongoing experiment in Russia where silver foxes have been divided into breeding groups based solely on their reaction to humans. As it stands we have docile pet foxes and foxes that hate us with all their hearts in two separate sections of the farm. Interesting stuff is being done in this area.

There are some really cool side-effects coming into play. With human tolerance being the sole selective pressure, rather interesting trends are occurring in the non-essential properties of these foxes. Among them, the colorations are starting to mirror the colorations of domestic dogs because the coat is no longer a determining factor in mate selection or camouflage.
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Are you pushing your own short comings on us and safely hating them from a distance?

Is this the virtue of faith? To never change your mind: especially when you should?

Young Earth Creationists take offense at the idea that we have a common heritage with other animals. Why is being the descendant of a mud golem any better?
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Re: Evolutionary Progress (Or Not)

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The silver fox experiment I recall from a PBS show, I think it might have been Nova about four months ago. The prequel to the foxes was a wolf pup who was raised like the family dog. At first, the wolf was playful and dog-like, but gradually it became obvious that natural selection hadn't prepared him to be subservient to humans. He was still wild.
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Re: Evolutionary Progress (Or Not)

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johnson1010 wrote:Progress towards some standard measure can be claimed, such as progress towards complexity, but we couldn’t say that that was progress of life in general. Nor does it mean progress towards mammal-hood, or person-hood. Rice actually has ten times the amount of genetic coding that a human being does, even considering our 90 % genetic junk quotient. By that measurement, a grain of rice is much further along in progress than any human, but I doubt that is what most would say.
Thanks Johnson. Your comment here illustrates that progress is not a simple concept. We cannot take a single measure such as genome size and say bigger is better. Genome size does not equate to system complexity, or to progress.

Progress in evolution is about a whole ecosystem, about how effectively all available niches are filled. A system that is very simple, eg a world of pigeons, rats and cockroaches, can be regarded as regressive, while a system that is very complex, such as a tropical rainforest that has been undisturbed for tens of millions of years, can be regarded as a peak of progress, if we consider biodiversity as a key marker of complexity. Existence of symbiotic sensitive organisms that live nowhere else means the ecosystem is finely attuned to its climatic circumstances.

Looking at the history of the earth, the microbial Pre-Cambrian situation was far more simple than what we have today. One of my favourite books, Rare Earth – Why Complex Life is Uncommon in the Universe, explains why it is so hard in principle for life to advance from the microbial to the multicellular level. This phase shift depends on a confluence of factors that are most unlikely to all occur together. The Cambrian revolution was a strong example of evolutionary progress, moving life to a higher level of complexity.

We can also look at memetic evolution, and say that the internet is an example of evolutionary progress in communication compared to the telegraph and Morse Code. In both cases, in nature and in technology, a complex system builds upon precedent by cumulative adaptation, with selection of successful traits and extinction of unsuccessful traits. Progress is a measure of responsiveness to selective pressure, organic survival in the case of Cambrian phyla and human utility in the case of communications technology.

It is difficult to compare an urban jungle with a real jungle on an objective measure of progress. The urban jungle changes a lot faster, but often towards greater conformity rather than greater diversity.
we have to be careful with a word like progress because it implies a goal. Goals imply a reasoning mind with some kind of agenda.
A goal does not necessarily imply intention. If we say that nature naturally fills niches, we have a natural teleology, a physical purpose, with no God driving it as intentional agent.

Even economic progress is not produced by a rational planned agenda, but by free markets. What Hayek called the fatal conceit is the idea that central planning is more efficient and effective than free enterprise. Adam Smith said growth results not from deliberate planning, but from the invisible hand of market forces. As I said in the previous thread, Dawkins notes that evolution also proceeds by the invisible hand of the free market. This is because markets are intrinsically evolutionary, operating according to the law of survival of the fittest. The agenda that achieves the goal of growth is not that of the planner, but that of the enabler who sets the rules of the game and lets the players succeed or fail on their own merits within defined rules.

Looking for goals in nature is actually somewhat metaphysical. Before readers recoil in disdain at this taboo idea, please understand that metaphysics is about unifying concepts that explain physical phenomena but are not amenable to mechanistic reduction. Unlike gravity, for example, which can be quantified, natural goals involve the mysterious unknown of a system potential. A forest, or a species, has a potential inherent in its makeup, but the boundaries of this potential are too complex to quantify. The goal of the species, what Aristotle called its telos, is to achieve its potential and test its limits.
Horse-shoe crabs as a class of animals have remained, but our horse-shoe crabs are not the same horse shoe crabs that first appeared. The same with sharks and crocodiles. Both have long histories on the planet, but todays are not yesterdays. They have evolved branches as well, but the trunk of those lineages hasn’t been scrapped through extinction.
Wiki says Horseshoe crabs are often referred to as living fossils, as they have changed little in the last 445 million years. Forms almost identical to this species were present during the Triassic period 230 million years ago, and similar species were present in the Devonian, 400 million years ago.
Horse shoe crabs haven’t stopped evolving. …I understand the underlying slant that these creatures have attained a template that is extremely successful in their niche, but that does not result in the end of evolution for that template.
This is just comparative. 400 million years of similar species shows incredible stability. Nothing is absolute in this context, but compared to the rapid evolution of mammals, the horseshoe crab is a king of permanence.
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Re: Evolutionary Progress (Or Not)

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Can you explain your conception of goals to me?

I'm not wrapping my head around that word when not in context with some intent.

Goals are the objectives to push towards. An objective of some plan. The finish line, the target, the hoop, the achievement in life, business, or art.

Any context i think of the word goal implies some mind wanting some thing.
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Is this the virtue of faith? To never change your mind: especially when you should?

Young Earth Creationists take offense at the idea that we have a common heritage with other animals. Why is being the descendant of a mud golem any better?
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Re: Evolutionary Progress (Or Not)

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In the evolutionary context we can think of goal as meaning potential.

An evolving system has an ultimate potential upper bound for its complexity, limited by the laws of physics, and by the avoidance of accidents that reverse its evolution.

Mutation is constantly testing the upper boundaries of complexity. Changes that are adaptive succeed and the rest fail. Evolution has a natural counter-entropic tendency to push a system towards greater complexity in the absence of external shocks. An evolving system naturally progresses towards the goal of maximising the successful evolutionary traits of fertility, fidelity and longevity.

Seeing natural design for these traits as solely embedded in the laws of physics is hard for our anthropomorphic assumption that a design requires a designer. Where the design is the inherent potential of a natural system, the system constantly moves towards the goal of fully realising that potential.

If we had a thousand years of peace on earth, we would find that people would become much more able to realise their potential, instead of being diverted onto other paths. The goal of progress would become vivid and attainable.
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I like that word a lot better.
In the absence of God, I found Man.
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Are you pushing your own short comings on us and safely hating them from a distance?

Is this the virtue of faith? To never change your mind: especially when you should?

Young Earth Creationists take offense at the idea that we have a common heritage with other animals. Why is being the descendant of a mud golem any better?
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This theme of progress in evolution is the topic of essay 5.4 in A Devil's Chaplain - Human Chauvinism and Evolutionary Progress - Review of Full House by S. J. Gould.

Here are some key extracts providing Richard Dawkin's views on the topic of progress.
evolution turns out to be clearly and importantly progressive in the
short to medium term. In another sense it is probably progressive in the
long term too.
Gould's definition of progress, calculated to deliver a negative answer
to the question whether evolution is progressive, is
a tendency for life to increase in anatomical complexity, or neurological
elaboration, or size and flexibility of behavioral repertoire, or any criterion
obviously concocted (if we would only be honest and introspective enough
about our motives) to place Homo sapiens atop a supposed heap.
My alternative, 'adaptationist' definition of progress is
a tendency for lineages to improve cumulatively their adaptive fit to their
particular way of life, by increasing the numbers of features which combine
together in adaptive complexes.
the heart of my adaptationist definition of
progress. This, to repeat, takes progress to mean an increase, not in
complexity, intelligence or some other anthropocentric value, but in
the accumulating number of features contributing towards whatever
adaptation the lineage in question exemplifies. By this definition,
adaptive evolution is not just incidentally progressive, it is deeply,
dyed-in-the-wool, indispensably progressive. It is fundamentally
necessary that it should be progressive if Darwinian natural selection is
to perform the explanatory role in our world view that we require of it,
and that it alone can perform.
the evolution of complex, many-parted adaptations must be
progressive. Later descendants will have accumulated a larger number of
components towards the adaptive combination than earlier ancestors.
The evolution of the vertebrate eye must have been progressive.
Ancient ancestors had a very simple eye, containing only a few features
good for seeing. We don't need evidence for this (although it is nice that
it is there). It has to be true because the alternative - an initially complex
eye, well-endowed with features good for seeing - pitches us right back to
Hoyle country and the sheer cliff of improbability. There must be a ramp
of step-by-step progress towards the modern, multifeatured descendant of
that optical prototype. Of course, in this case, modern analogues of every
step up the ramp can be found, working serviceably in dozens of eyes
dotted independently around the animal kingdom. But even without
these examples, we could be confident that there must have been a
gradual, progressive increase in the number of features which an engineer
would recognize as contributing towards optical quality.
The evolution of anything as
complex as an advanced orchid was progressive. So was the evolution
of echolocation in bats and river dolphins - progressive over many,
many steps. So was the evolution of electrolocation in fish, and of skull
dislocation in snakes for swallowing large prey. So was the evolution of
the complex of adaptations that equips cheetahs to kill, and the
corresponding complex that equips gazelles to escape.
Indeed, as Darwin again realized, although he did not use the phrase,
one of the main driving forces of progressive evolution is the coevolutionary
arms race, such as that between predators and their prey.
Adaptation to the weather, to the inanimate vicissitudes of ice ages and
droughts, may well not be progressive: just an aimless tracking of unprogressively
meandering climatic variables. But adaptation to the biotic
environment is likely to be progressive because enemies, unlike the
weather, themselves evolve. The resulting positive feedback loop is a
good explanation for driven progressive evolution, and the drive may be
sustained for many successive generations. The participants in the race
do not necessarily survive more successfully as time goes by - their
'partners' in the revolutionary spiral see to that (the familiar Red Queen
Effect). But the equipment for survival, on both sides, is improving as
judged by engineering criteria. In hard-fought examples we may notice a
progressive shift in resources from other parts of the animal's economy
to service the arms race.129 And in any case the improvement in equipment
will normally be progressive. Another kind of positive feedback in
evolution, if R. A. Fisher and his followers are right, results from sexual
selection. Once again, progressive evolution is the expected consequence.
To say that the evolution of the vertebrate
eye was progressive is to say something quite strong and quite
important. If you could lay out all the intermediate ancestors in
chronological order you'd find that, first, for a majority of dimensions
of measurement, the changes would be transitive over the whole sequence.
That is, if A is ancestral to B which is ancestral to C, the direction of change
from A to B is likely to be the same as the direction of change from B to C.
Second, the number of successive steps over which progress is seen is likely
to be large: the transitive series extends beyond A, B and C, far down
the alphabet. Third, an engineer would judge the performance to have
improved over the sequence. Fourth, the number of separate features
combining and conspiring to improve performance would increase.
Finally, this kind of progress really matters because it is the key to
answering the Hoyle challenge. There will be exceptional reversals, for
instance in the evolution of blind cave fish, where eyes degenerate because
they are not used and are costly to make. And there will doubtless be
periods of stasis where there is no evolution at all, progressive or otherwise.
Last edited by Robert Tulip on Thu May 19, 2011 4:35 pm, edited 1 time in total.
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Re: Evolutionary Progress (Or Not)

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Thanks for giving us that, Robert. If for comparative purposes we're inclined to look over at the cultures that humans have created, we should be disciplined about not inserting anthropocentric ideas of progress. I'd say rather that we should not mention progress at all, since we'll find it nearly impossible to use it as Dawkins has done for natural selection.
This, to repeat, takes progress to mean an increase, not in
complexity, intelligence or some other anthropocentric value, but in
the accumulating number of features contributing towards whatever
adaptation the lineage in question exemplifies.
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