http://en.wikipedia.org/wiki/Devolution_(biology)

I can actually see a scenario where deevolution is possible outside of extinction.

Imagine I mankind were to be plunged into the dark ages again. Now imagine if free thinking were to be suppressed for traditional ways. Things would gradually dissolve especially when disease began to run rampant again. If you killed off enough humans I am sure that out of a need to survive would revert to more feral things. It would just take time and a few generations.

I agree, there is no biological devolution. There are no positive or negative trends in evolution, the only criteria is the increased survival chances of the individual and his or her offspring that makes a random mutation "good" or "bad".

Devolution, as a concept, exists in other spheres, such as morality. Morality is again a sticky concept, is it good, or bad, to have morality? It's served a good purpose for humans, dogs, cats and birds, but it has not served reptiles and fish. Yet fish and reptiles are co-existing in time with humans and mammals and birds.

A fish needs no morality to survive. A human does. If the human loses parts or all of his human morality, he or she will hinder the survival of his or her own, or that of his or her offspring.

Therefore, morality, as much as it is a human/warm-blooded animal trait, can devolve, that is, lose its value, by changing itself or if the situation commands no concern for morality for the individual's survival.

Therefore "moral devolution" in a survival sense is a changing of morals which retards survival chances. This presents when the situation does not change, the situation that fosters the helpfulness of morality, but the morality changes, by becoming less inclusive of actions that are approved by the moral code, and therefore the changed morals are hindering the survival chances of a morally devolved individual and/or his or her offspring.

De-evolution or devolution, as I and others use the term, is apart from natural selection. The references used above all relate, one way or another, to natural selection such as the loss of eyesight in a fish species always in a lightless cave.

Devolution is the unnatural change in a species by controlled breeding, not natural selection. This has been done for millennia with dogs and cats. In more recent times man has created conditions where the natural selection process does not apply and it is advantageous for the least fit to have many children and the most fit have few.

Stalin's murder of the intellectuals is a good example.

You know considering that evolution is always a process of change seeking out the best suited life forms to live on in a given environment deevolution really is not possible. Evolving to a reverted state IS more likely possible and plausible. What would happen to us if say we had a new Ice Age that went on for 100,000 years? Our written history loosely begins where the Ice Age ended. We may develop features more attuned to a colder environment and become more Neanderthal like. That is not to say Homo Sapien would revert to Neanderthal in as much as physically imitating one. Neanderthals were remarkably adapted to cold weather survival. Then again it is possible for Humans to revert to a more Feral state. Aborigines are arguable a more feral human. Then again Chimpanzees could very well act like our fore fathers did too. Stripped of our tools we would revert to a more animalistic way of living. But a change "backwards" can be a change for the best if it means the species surviving a catastrophic change in environment.

I dunno, my ex-husband had a brow ridge.

Absolutely.




Interesting - so you apply the term in a way that relates directly to genetics, but not to natural selection. Is see the validity of this distinction, yet I'm concerned with how easily some people may misunderstand that to imply that evolution itself has a 'direction'.

Tangentially, one could argue that all human actions that effect the the gene pool of a group (including controlled breeding) can be considered 'yet another selective force, just like the ones you recognize as 'natural' selective forces'.

As best I can tell, all historic references to Darwin's "evolution" use the concepts of "natural selection" and "survival of the fittest". Once you "select" the weakest pup, kid, baby, or kitten, for whatever purpose, natural selection and fitness criteria are absent.

Dogs were bred by selecting the "nicest" pup from wolves. Within three generations of hand selection, a wolf can be bred that does not have the genetic ability to mature, keeping the animal in a puppy state (wolf puppies are nice to humans like dog puppies). The inability to never mature is a definite weakness which diverges from "survival of the fittest" and therefore is a di-evolutionary trait; but only if compared to surviving in the wild.

Humans are the classic examples of causation of unnatural events... unless of course one considers everything a human does as natural which makes the term "natural" meaningless.

In this context, yes, you are right about that. We can't use the word 'natural' to indicate the non-human sphere of activities and also include humans in that sphere - thats just nonsense.

Its not complete nonsense, though, to (idiomatically) use the phrase 'natural selection' to refer to 'the means by which genes are encouraged to increase/decrease in frequency amongst a population', and to consider both human and non-human causes.

I'm not saying thats the 'right' viewpoint, either. Simply that we can choose to consider human and nonhuman causes together, or separately.




I think we both agree that having a good understanding of the modern theory of evolution sometimes requires that we have to look beyond Darwin's concepts at more modern concepts.


I'm curious what the word 'fittest' means to you, in the phrase 'survival of the fittest'? From an evolutionary perspective, it means only 'best suited to propagating their genes in some particular circumstance' - and has nothing inherently to do with being the strongest or fastest or smartest of best camouflaged or having the best vision or sense of smell or...




Sometimes nature selects for the weakest or the slowest pup.




Its true that humans breed non-human animals to have qualities that would be disadvantageous to them if they were to be return to the wild.

Its also true that interacting with a certain predator sometime causes animals to develop qualities that would be disadvantageous to them if that predator were to suddenly be absent. This is not devolution, its evolution.

There is no such thing as a 'better genome for survival' for a species - only 'a better genome for survival in certain circumstances'.

Frankly Evolution is governed also by the interplay of all species around that life form. For instance, if a Dinosaur existed today (A herbivorous one!) it would commit suicide just eating becasue many plants today are toxic to prevent predation. Back in their era no plants were toxic that we knew of by fossil records. Plants reacted to protect themselves from grazing animals. Likewise no let us look at Goats. Once upon a time they were meat eaters. I can argue strongly from first hand witness that they are scavengers and omnivorous with a very strong herbivorous tendency. Goats are not anything like sheep and are two distinctly different animal lines. Goats can eat stuff that would kill a sheep or any other herbivore. They have adapted to be immune to some plant toxins. Poison Oak for instance. My mom tied her Nubian goats next to Poison oak to eradicate it. Problem was that the Goats would then ooze the poison from their body oils and petting the goats resulted in Itchy red rashes. Dropping a goat herd in the Dinosaur era could have been catastrophic for young herbivorous dinosaurs if predators couldn't eat enough goats to keep their numbers in Check. If goats ate all the low lying vegetation before the baby dinosaurs had a chance to feed to grow large enough to utilize the taller trees as they got big enough they would die off unless the Dinosaurs adapted a survival strategy against the goats.

Likewise Predators always adapt to their prey. If the prey gets smarter the predator needs to get sneakier and even faster. Technically speaking an Alligator should be a fairly weak animal considering if you wrestle on they tire very quickly. They can only hold on and tear food apart unlike many mammals who can chew everything apart. But they have been around millions of years and are actually quite successful at what they do. On top of that the walking wallets are social creatures who share kills to help tear food apart to eat. One drags a deer or any hapless animal into the water, and all of them bite down, twist, and gulp. Repeat till the carcass is utterly gone. Swallow a couple of Gastrolyths for desert, and find a place to sun for a week! They are what I call a proven design. Evolution is a lot akin to Sticks, paper, scissors. It guesses (mutation) and it likewise sticks to what works but when the environment suddenly shifts there is another form of mutation called Punctuated Equilibrium. That is usually a result of an Invasive species being introduced. Then again hot and cold shifts also play hard in this game.

Now with genetic manipulation on the horizon it may be possible to gene slam something or someone and devolve them but I bet that would have very serious consequences.

IT!!! DA DA DAAAAAAAA!

I have to agree that by a basic understanding of what evolution is ... a term directly related to "natural sellection" ... then devolution would basically be the term for "non natural sellection" which is what we as humans have been practicing for a very long time.

Now the only good argument against its existance {devolution] would be that ... human tinkering is natural in itself ... so all of what we claim as non natural is actually natural in the sense that anything we choose to do is nature working through human interference.

That is the essence of my point. However, there has to be a distinction between the definition of "natural" and "unnatural" for the word to mean anything. My definition of unnatural, in the context of evolution, is "affected by man". This concept make the term "natural selection" become a key element. Evolution can therefore go any direction without man's influence.

With man's influence, directly by selective breeding or indirectly by war, malice, hunger, or fun, de-evolution turns survival of the fittest into "survival according to man's actions."

I wonder if the Dodo was tasty?

True, but this distinction isn't necessary for the phrase 'natural selection' to mean something. Our language is just filled with idioms and misnomers that we take for granted.

The unintended, unexamined consequences of human actions are providing a significant degree of selective pressure across the globe - and this is completely separate from the issue of breeding. To suggest that part of the mechanism of evolution (labelled 'natural selection') is only properly considered outside of human influence would be to deny a tremendous component of the actual (natural or unnatural) selective influences.

Biologist will often simply say 'selection', or specify the kind of selection more meaningful than simply discriminating between 'human caused' and 'not human cause'.

Humans are an inseparable part of the evolutionary picture. I agree with you that 'natural selection' may be a misnomer.




Yes, and evolution might equally go in any direction *with* humanity's actions.



Setting up 'survival of the fittest' with 'survival according to man's actions' strikes me a a misleading dichotomy. You still haven't explained to me what you think of when you say "fittest" in "survival of the fittest", and I'm very curious to know.



Are you making the point that the influence that humanity has had on evolution has been disruptive? Undesirable?

The earth and science seems to have a ying to the yang in everything.....and all is possible......maybe global warming is a de-evolution for the dinosaur age to become again and maybe different species of man will de-evolutionize back into neandrathal man hence the Mayan change in 2012....the earth degree changes towards warmth and de-evolutionary change

No, not at all. We have other terms for selective pressure thats caused by humans, such as 'breeding'. It doesn't matter whether the selective pressure originates from human or non-human sources - the proper biological term for the consequence is 'evolution', never 'devolution'.

I see it as useful for humans, sometimes, to discriminate between non-human selective pressure and human-motivated selective pressure. The process of evolution makes no such distinction, and biologists sometimes use the phrase 'natural selection' to include 'breeding' and other effects of human actions. If you think this is a misnomer, I somewhat agree.



Of course humans influence evolution; if you want to specify 'human influenced evolution' there are better ways than using a misleading and incorrect term like 'devolution'.

Evolution is blind. Evolution does not select for any person's concept of what fittest ought to mean. Evolution only selects for the qualities that favor propagation of those genes in that particular circumstance. Therefore, the whole idea of an evolution/devolution dichotomy makes no sense whatsoever, and encourages people to wrongly think that evolution has a direction. The process of evolution doesn't care whether selective pressure originates from humans or not.


Edit: To (redundantly) clarify: Its the assumption of 'moving in a direction' which underlies the typical evolution/devolution dichotomy that makes no sense. I do agree with both of you that discriminating between human-caused and not-human-caused evolution is sometimes helpful.

Thank you for illustrating the misunderstandings that can arise when people use the term 'devolution'.

It is possible (if terribly unlikely) that we could evolve to have qualities more like Neanderthals than modern day humans... If this were to happen, this would be evolution.

"Fittest" has various meaning relating to man but only one outside of man's influence. Dogs are bred which could not survive in any condition outside of ownership by man and that includes feeding and care. The dog breeder carefully "selects" for some "quality" that is foreign to nature but somehow appealing to man. The dog thereby fills a part of man's niche in nature by none of it's own.

Man goes in an kills every natural predator in an area opening a niche for rabbits, deer, and other prey to generate any number of genetic defects who multiply totally outside the natural order. These freaks of nature are due to devolution due to man's input.

Man stopped the evolution of the Dodo altogether. How could you deny devolution when the result was extinction not caused by natural selection.

Man itself has stopped evolving in a natural way. The species is fed in areas that harbor no food, disease is prevented from thinning population, and the world dynamics encourages the least able to survive to have the most children. There is nothing natural about this and would therefore fall directly into devolution.

Stalin's butchering of the intellectuals, if allowed to occur for about three generations, could have removed the possibility of genius from the genome of that group. This is devolution. This is not survival of the fittest, it is murder and genetic manipulation by man.

Currently, women children are killed in India and China in large numbers due to the "perceived" greater value of a man child. The consequences of removing vast numbers of children who never got a chance to prove their "fitness" is devolution.

"Fittest" outside of man's influence is simply which offspring are strong, smart, lucky, and healthy enough to bring in another generation. This is evolution.

The Dodo didn't die by asteroids, climate change, or competition. They were eaten by us. The "fitness" of their offspring didn't matter.

Ummmm that was de-humor.........LOL.....geesh scientists can't get a laugh outta nunya