JBS Haldane thought so, writing in his Causes of Evolution: “Degeneration is a far commoner phenomenon than progress. It is less striking because a progressive type, such as the first bird, has left many different species as progeny, while degeneration often leads to extinction, and rarely to a widespread production of new forms…But if we consider any given evolutionary level we generally find one or two lines leading up to it, and dozens leading down” (pp 152-153).
I’m not a biologist, but as I understand it, the whole idea of progress/degeneration is considered false ( or at least of limited use ) in evolution. Evolution is about adaptation, not progress along some path to perfection.
Remember, science is value-free. When a new genetic characteristic emerges, it can help the organism survive better, or not; but it cannot be classified by its inherent nature as “degeneration” or “progress.”
What exactly is meant by the term ‘progress’? Does the loss of eyes in a cave fish that had sighted ancestors represent ‘progress’ or ‘degeneration’? Why?
It means what you want it to mean, as far as I can tell. IIRC the whole idea of evolution as a process of improvement ( including the phrase “survival of the fittest” ) was created by the early social Darwinists. Progress means “stuff I like”; degeneration means “stuff I don’t like”.
Exactly; in which case, except mutations that happen to briefly prevail against selective pressure by pure accident, everything could reasonably be described as ‘progress’.
If we were to define “progress” as gaining characteristics that increase the creature’s chance to survive and pass on genes and “degeneration” as losing charactertics that help “progress,” or gaining characteristics that hinder survival, then progress is the rule in evolution, because evolution is the process by which “progressive” characteristics are propagated, and “degenerate” are eliminated.
You’re right that mutation will more likely cause a degenerate characteristic than a progressive one, but part of evolution is that those with degenerate characteristics will either die out, or will be outbreed by those with more progressive characteristics, by this definition of progress and degerate.
Evolution can cause degeneration, but only by filling niches. If a member of a species has a mutation that causes them to go after a different food source, or otherwise fill a different niche, that member may prosper, even if that member is more degenerate that its base species, because it no longer competes with its base species. However, whithin a niche, evolution will always select for survival traits.
Now, if by progress you mean bigger, faster, stronger, etc, its probably a wash. It depends if the advantages of being bigger, faster, stronger outweigh the dissadvantages of greater caloric needs and longer development time.
As Steve Gould has put it, a lot of the confusion about evolution arises because the metaphor that’s most often used for it is a ladder, whereas the proper metaphor is a bush. A ladder has a direction, it goes from point A to poing B by nature. A bush expands in all directions, with some branches growing faster and farther than others, but it doesn’t grow in a particular direction per se, it expands in ALL directions, as available space, energy and nutrients permit. That’s the way species evolve, they fill whichever niches are available.
Literally true, but this does not mean that most are harmful, in fact most are neutral. Not surprising when you consider how much junk dna we have.
Taber nailed it. Selective disadvantages will eventually get weeded out. Not always immediately, but over time. The race may not always go to the swift, but that’s the way to bet.
What do you mean by this? As others have said, how do you define “progress”? Compared to many non-primate mammals, we have gained the ability to see stereoscopically, but lost the abilty to smell well. Compared to our ape relatives, we have lost the ability to swing through the trees, but gained the abilty to walk and run bipedally. Are we making “progress,” or are we “degenerating”?
The consensus among evolutionary biologists these days would be that Haldane’s formulation is essentially meaningless.
Since the OP’s quote, including the omission, exactly matches what Gould happens to quote in The Structure of Evolutionary Theory, I suspect that it’s being read at least slightly out of context. Haldane was referring to a fairly specific sense of “degeneration” and assuming some then-current background.
The passage (on p82-3 of 1990 Princeton UP reprint of The Causes of Evolution) comes from Haldane’s conclusion, in which he attempts to survey “evolution as a whole”. He begins by spending several pages giving a rather standard account of the history of life, leading up to humans. The rest of the conclusion was him undermining the conventional notion that this was obviously some sort of progress. He points out that some lineages haven’t changed over long periods of time. Then:
He then goes on to admit that “progress” and “degeneracy” are loaded words, but thinks their application is obvious enough. Rather amusingly - and in a passage that has often been echoed since - he proceeds to question whether humans are an obvious advance over monkeys (his choice of word) by cataloging the various flaws an ape modified to walk upright is subject to. Most of the remainder of the conclusion is a critique of various philosophical attempts to endow evolution with a progressive purpose.
Haldane isn’t directly talking about whether individual mutations are beneficial or harmful (in whatever sense). The effect of selection on them is the subject of the main text, with the conclusion explicitly switching to this consideration of “evolution as a whole”. He’s now interested in the history of lineages.
Throughout the book, he links the ideas of progress and degeneracy to the idea that most lineages undergo a natural progression that ends in a return to primitive types and then extinction. “Racial senility” in the terminology of the day. Such notions were popular in the previous couple of generations and he could duly cite the authorities who’d studied this empirically. The examples of “degeneracy” he quotes above are meant to be specific instances of this happening in lineages. He even suggests (p16) that bird are just cresting the top of their peak, while us mammals are on the slide and reptiles are goners.
His explanation for these patterns (p77) is that, while natural selection is the main cause of evolutionary change, variation is not unconstrained and so “evolution can only follow certain paths”.
Most modern biologists - as the likes of Colibri can no doubt explain in detail - no longer see such meaningful patterns, beyond underlying randomness, in the history of lineages. So the whole question that Haldane was wrestling with here is now a non-issue.
I can’t resist quoting one line from towards the end of his conclusion (p90):
I’m surprised that anyone should still hold with this notion, given the fact that a value-free scientist is neither possible or desirable. Consider Weber’s dictum that an ‘attitude of moral indifference has no connection with scientific “objectivity”’.
In an essay published in 1976, Popper makes explicit the link between scientific method and other values:
“Our motives and even our purely scientific ideals, including the ideal of a disinterested search for truth, are deeply anchored in extra-scientific and, in part, in religious evaluations. Thus the ‘objective’ or ‘value-free’ scientist is hardly the ideal scientist. Without passion we can achieve nothing – certainly not in pure science. The phrase ‘the passion for truth’ is no mere metaphor.”
One problem with strongly value-based accounts of history, for example, the history of biological evolutionary theory, is the impoverishment that comes with their exclusiveness, with their tendency to lead to the closing of the gates of interpretation. If they are written largely by people who share the values in question, and if those who do not share them are not attracted to work upon the subject matter in question, then the probability of bias being identified and removed as a result of criticism is reduced. When certain values are closely identified with certain subject matters, this may have the undesirable consequence that those not favourable to certain values may simply choose to work on other topics.
Thus one particular danger of a certain worldview coming to exercise a predominance in an academic field is likely impoverishment in terms of published contributions, and of the interpersonal criticism, focused on ideas and not on the person, that is so important to the scientific enterprise.
I believe, roger, that BrainGlutton oversimplified. In reference to the progress/degeneracy debate, the statement should perhaps have been “scientifically observed phenomena are value-independent”, IOW, in the case at hand, evolution happens as it happens regardless of whether we think the result is more or less desirable per our value system.
Firstly, at least in terms of your point, you appear to be quoting Popper out of context. Off course, Popper and Weber aren’t gods, they were just some guys with opinions about stuff. Were they right, wrong? I dunno: but they can’t make your arguments for you.
Secondly, the fact that individual scientists are motivated by all sorts of human biases and motives is not the same thing as talking about science being value free insofar as it considers the natural world.
Haldane seems to be applying his own values to “progress” and “degeneration”. In the example of the flightless birds, the species involved have gained by not devoting resources to creating and maintaining the full gamut of bone/muscle/etc. development required to fly in an environmental niche that no longer requires flight. The eyeless cave fish have also gained by not putting resources into growing useless eyes. For each species, this is “progress” because it results in a better fit into the current niche.