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.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.
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.
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.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.
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.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.
"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.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.
I can believe that.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.
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.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.
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.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.
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.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.
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.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.