What alternatives to Creation VS Evolution are there?

[Sleeper]

There's evolution, and there's Creationism. What other conceivable possibilities for the origins of life are there?

A possible alternative to Darwin's "natural selection weeding out ineffective genes and favoring others" is Lamarck's "acquired traits getting passed on somehow". A possible alternative to Christian creationism is the totally awesome Scientologists' Creationism. Other religions have different varieties of "Aliens Did It" and "A Sky Wizard Did It."

Another possibility, I guess, is what creationists frequently misrepresent evolution as: Totally random chance.

Surely there are other possibilities, though?

[idobox]

Not exactly alternatives, but there is the idea life arrived on Earth on meteorites. In the past, people also believed life would spring out of inert stuff, and then they discovered germs.

A particularly obnoxious variety of creationism is intelligent design, the idea that evolution happened, but instead of random mutations being selected because they are more efficient, a magical sky wizard directed all that.

[ahammel]

For sci-fi, alternate-universe purposes, I suppose there's the steady state (i.e., life has always existed).

[Quizatzhaderac]

I hope you like Wikipedia links.

I think one important thing to remember is that the question "Where does life come from" generally requires two theories. A theory of abiogenesis (how any life came to exist in the first place) and a theory of evolution (how one species can change or become two).

Creationism deals with abiogenesis and generally doesn't deal with evolution (enough species were created initial for stable ecosystems), with a specific rejections of social Darwinism and humanity not being present in the initial creation.

Decent with modification and natural selection (aka scientific evolution) completely leaves abiogenesis to other theories. There are scientific theories of abiogenesis, but we're nowhere near concensus

Ibitobox mentioned spontaneous generation. Life is produced from conditions, not other life. A stagnant pool produces algae, old bread produces mold, garbage produces flies. This is often how it works in video games: pokemon are randomly generated wherever there's tall grass, even if the characters talk about them breeding; trees grow where there's an open field, sunlight and rain, seeds are assumed.

Lamarckism isn't so much "acquired traits getting passed on somehow", since the genetic mechanism is the same as with natural selection. It was more "used traits are reenforced at the genetic level, somehow". Before they knew how DNA worked this made a lot more sense. So instead of a gene that caused muscle, and another gene that causes to build muscle up when it's used, a person would just have some genes for muscle that get increased when muscle is used.

Panspermia -Life exists throughout the universe. Doesn't mention where it originally came from or how new species emerge. Cool though. More-so for not being refuted.

I also think there are some creation myths where the whole universe was originally one organism that fractured.

Or just to be original: The are/were perfect timeless gods, and we (and animals) are their inbred, mutant morlock descendants.

[bigglesworth]

Lamarckism isn't so much "acquired traits getting passed on somehow", since the genetic mechanism is the same as with natural selection. It was more "used traits are reenforced at the genetic level, somehow". Before they knew how DNA worked this made a lot more sense. So instead of a gene that caused muscle, and another gene that causes to build muscle up when it's used, a person would just have some genes for muscle that get increased when muscle is used.

Indeed for a while there was a prevailing thought that Darwinian selection occurred in multicellular organisms and Larmarkian in single-celled organisms - because that's what it looks like under a microscope.

[idobox]

And Lamarkism is not totally dead. Some people are studying whether epigenetics could explain a from of it, with parents silencing detrimental genes for their children, or transmitting various information through RNA in the gametes. I have no idea how much these theories are considered, though.

[tomandlu]

Not exactly alternatives to evolution, but my own two pet hypothesis are:

1. Evolution is subject to evolution - in other words the frequency and amplitude of variation will evolve towards the optimal level

2. Evolution will, if possible, evolve to react to the external environment (a form of Lamarkism) - e.g. when populations fall (due to an environmental change - isolation, catastrophic event, predation, etc.), then the variation of genetic material will also fall (less potential breeding partners = less variation). If this reduction could be recognised by the DNA, then mechanisms might kick in to increase the frequency and amplitude of variation. Sort of like a gambler who is already in serious trouble risking one last big throw on the basis that it can't really get any worse, but it can get a lot better...

IANAEB, so I've no idea if either of these are mainstream hypothesis/theories.

[Mindworm]

What about Boltzmann's theory?
If we postulate a universe with maximal entropy and random spikes downward, it becomes more likely that the universe as we see it, stars, species and all, was "created" like 5 minutes ago (including memories of a more distant past) and merely looks like it should be older.
Of course, it is more likely still, that you are just a brain in a universe of otherwise maximal entropy (uniform radiation or something) and all your perceptions are imaginary.

That's pretty alternate, as far as semi-plausible theories go.

[qetzal]

What about Boltzmann's theory?
If we postulate a universe with maximal entropy and random spikes downward, it becomes more likely that the universe as we see it, stars, species and all, was "created" like 5 minutes ago (including memories of a more distant past) and merely looks like it should be older.

If that were true, why would objects in the universe seem to have a consistent age? Why would our memories seem to be consistent with each other?

If the universe were created 'whole' out of some random entropic fluctuation, there wouldn't be any reason for it to have the appearance of a consistent history. I'd expect to see all kinds of anomolies, like the Sun and all the planets appearing to have wildly different ages, or stars all moving in random directions and velocities. Or more to the point, species that showed no apparent evolutionary relationship to one another.

Instead, both life on earth and the universe itself give every appearce of having evolved in a gradual and consistent manner over billions of years. Creationists can reasonably posit that God made it look that way on purpose for his own inscrutable purpose.¹ But I don't think there's any reason that a random entropy spike would do that.


¹At least, it's potentially reasonable if you're already accepted the premise of a sufficiently powerful and intentional God.

[idobox]

It would indeed be far more probable to have a universe with different apparent ages than the one we observe, but it would still be far more probable for the universe we observe to have appeared just like that, than for it to have evolved from the extremely low entropy of the big bang.


The whole point of the Boltzmann brain, as I understand it, is to show random fluctuations of entropy and the anthropic principle cannot explain the initial low entropy of the universe, not to suggest we are actually Boltzmann brains

[qetzal]

Well, this is waaay out of my area, so I realize my opinion doesn't mean much here. Still, if the options are 1) the universe was randomly created in it's current state, and just by chance, essentially *everything* looks like it evolved from a much earlier state, versus 2) the universe was randomly created at some much earlier state and then really did evolve to its current state, it's hard not to think the latter would be more likely. But I have no idea how one would attempt to calculate such probabilities.

[PM 2Ring]

Well, this is waaay out of my area, so I realize my opinion doesn't mean much here. Still, if the options are 1) the universe was randomly created in it's current state, and just by chance, essentially *everything* looks like it evolved from a much earlier state, versus 2) the universe was randomly created at some much earlier state and then really did evolve to its current state, it's hard not to think the latter would be more likely. But I have no idea how one would attempt to calculate such probabilities.

Well, there are actually 3 options being considered here, the 3rd option being is that there is no actual universe out there, all that exists is some kind of brain hallucinating a universe. Note that this Boltzmann brain does not need to persist for any appreciable length of time.

Option 2 requires that the universe was originally in a state of extremely low entropy, and so without some mechanism to create this low entropy state option 1 is more likely to arise than option 2. Similarly, option 3 is actually the most likely, since it's quite cheap in terms of entropy requirements. Few people consider this to be a satisfactory state of affairs.

[tomandlu]

Option 2 requires that the universe was originally in a state of extremely low entropy, and so without some mechanism to create this low entropy state option 1 is more likely to arise than option 2.

http://forums.xkcd.com/viewtopic.php?f=18&t=88951&p=3111109#p3111109

[edit] wrong link

[kellerbustinout]

There is an alternative that mixes both intelligent design and also evolution together. I read like a 12 page argument by a random scientist on a website. For the life of me though i have not been able to re-find the website. If anyone does know this theory and info on what its called let me know. But the concept is that evolution occurs but it is not random and it isn't controlled by a wizard in the sky. Supposedly for some reason which i am not sure the website shows evolution is intelligent. I can give speculation on what that means but i will finish up the concept. All evolution is designed to create the best possible sentient, conscious life form. So evolution is experimentation that its intelligence is undergoing. Evolution then is not just random it is through design or experimentation for intent on designing a life form capable of consciousness. There is a theory, it is called pantheism, but it is gaining some prestige among a certain group of scientists and physicists on the nature of the universe and consciousness. It is the idea that the universe itself is alive. it is a conscious being. The brain is also believed to not be the source and creator of consciousness but only a receiver of consciousness.Something about at the subatomic level, in the micro tubes of neurons, the brain is receiving consciousness. The neurons then and the rest of the brain is only a memory storage device and also a transport control device. So the main idea is the universe as a being has engineered life to become conscious.Interesting concept i think. I'm willing to accept it is plausible till absolutely proven wrong. Which if you look into history when it comes to science, the majority is usually wrong. It is the minority thinkers who end up having the answers no one else could of had. So if i was a wise business man i would invest in the minority which would be this view. As of why the universe would do this i could not even begin to speculate. Its completely speculating the mind of a God. There is no way to know currently.

[tomandlu]

There is an alternative that mixes both intelligent design and also evolution together.

I can see several problems with this, not least of which is that it falls victim to Occam's razor (don't create more entities than are required). Beyond that, what medium does this universal conciousness occupy? If this intelligence exists anyway, why does it need to express itself through life? What evidence exists that might indicate that intelligence has some special significance to the forces of evolution?

I've got nothing against the notion that evolution may itself be subject to evolution, and therefore may be more efficient than blind chance alone would dictate, but 'extraordinary claims require extraordinary proof,' which in this case would mean that you'd first need to establish that something is happening that requires additional explanation. Otherwise you're into homoeopathy territory - trying to explain a phenomena that doesn't even exist in the first place.

[KrO2]

I was going to disagree with that post like tomlandu did, but this is the fictional science forum. That framework is a perfectly valid fictional setting. I even feel like I might have read something with something similar once, but I can't remember what it was or even any details. Arguing that keller's thing is true goes well into crackpottery, but this thread isn't looking for true theories. And this particular one could be pretty self-consistent and interesting.


I am going to give in and go off topic to comment on one paragraph, though:

Which if you look into history when it comes to science, the majority is usually wrong. It is the minority thinkers who end up having the answers no one else could of had. So if i was a wise business man i would invest in the minority which would be this view.

So many problems. "Ideas come from the minority thinkers:" Wrong. Answers come from a small minority of minority thinkers, the ones who happen to be right. But you have to agree that the odds of an idea being true are much higher if it's accepted than if it's not.
"The majority is usually wrong:" Wronger than wrong. They're not completely correct, of course, since the scientists aren't omniscient, but this absolutely does not mean you should disregard everything anyone thinks because it's partly wrong.
"You should invest in the minority:" Not if you want to maximize your chances of being right. Unless you're in a position where you have better information than the current experts, in which case this doesn't apply.
"...which would be this." Wrong. Also probably the worst part of the whole thing. There are loads of hypotheses that are not accepted. Even aside from the fact that the outlandish ones are less likely than the mainstream ones to be true, what makes you think this particular minority view is the correct one?

Basically, I'm not even considering the possibility that this might actually describe our universe, but I have nothing against it as a setup for a fictional one. Actually I kind of like it, once you manage to define what the "best possible" organism would be. There should be more than one form, of course. Mainly I just like the idea of the universe actively trying to get its goal everywhere possible. And intelligence is a much more interesting goal than entropy. Who wants to maximize that?

[Copper Bezel]

Yeah, it's not bad as fictional science goes. The latter part where it goes completely to woo is just the Force.

On the slightly more plausible bit under real science rules, I think that protection against mutation and the use of horizontal gene transfer and sexual reproduction* are probably about as complex as plausible real-world elements of evolution modifying itself as you can get, since the benefits have to be to the individual, which evolution can't act on itself in, since individuals don't evolve.

I mean, it really requires group selection to have evolution evolve. You need something like massive numbers of successive generations acting as genetically isolated, eusocial colonies, in the sense that cells form colonies, but over time instead. The colony is the new individual, and it copies true enough to stack up a huge number of generations (and evolve) without splitting to compete with itself or breeding with anything else (so that it's still an individual thing on which selection acts.) And it'd basically be a logarithmic step up in time from the usual process, because the super-individuals that have survived would be the ones that evolved the most successfully, and so on. But then you need selection pressures inside the colonies, too, to get the ordinary evolution in the first place that's the basis of the other level's fitness....

But if there's any way for such a mechanism to form, it seems like it would be self-reinforcing from there by the same mechanism. It'd just take a really extraordinary number of generations to get started.

* Then again - doesn't sexual selection already count? Individuals act as genetically-programmed gatekeepers for genes other than their own, which certainly sounds like evolution keeping an eye on itself.

[Drowsy Turtle]

In a way you could describe eugenics as evolution evolving couldn't you?

[KrO2]

I'd think that universe would approve of eugenics. Those civilizations that it can get to practice eugenics and continue practicing it could out-evolve others pretty effectively, assuming they're advanced enough to do it competently.

Or it might evolve a species with a scientific bent, that it could try to get to create a (preferably sentient) large lump of computronium. That ought to be way more "evolved" than anything that would evolve directly, and could speed up the processes as well.

I think the common theme here is that it should get the inhabitants working on its goals intentionally. And if some of them don't like the idea of creating more and more intelligent species, it would be interesting to see how the universe deals with them.

I never thought of this before, but you know those diagrams of species selection with the local maxima?
Natural selection pushes the population average toward the top of whatever lump it happens to be on, but can't go between them.

It occurs to me that in a situation like this, part of that graph might be asymptotic.

[tomandlu]

In a way you could describe eugenics as evolution evolving couldn't you?

The trouble with eugenics - even ignoring the ethical and moral problems - is that humans make very bad (aka subjective) decisions when trying to decide what direction human evolution should take.

That aside, KrO2 - didn't Greg Bear write a couple of books that proposed something similar? Darwin's Radio? Could you be thinking of that?

[tomandlu]

I'd think that universe would approve of eugenics. Those civilizations that it can get to practice eugenics and continue practicing it could out-evolve others pretty effectively, assuming they're advanced enough to do it competently.

That 'competently' is the killer. You have to define what definition of 'intelligence' you're selecting for, and then hope that the selection is appropriate (i.e. that you're not selecting for a race of idiot-savants). My son, for example, is arguably more 'intelligent' than my daughter (using maths as the litmus test), but, on a practical level, she's a much better problem-solver (my son in the kitchen is a terrifying thing to behold).

[AvatarIII]

in the book First and Last Men by Olaf Stapledon, I there is a bit where future humans (The Third Men) use eugenics with the aim of intelligence to create giant brains (The Fourth Men), who in turn use eugenics to create a more practical species (The Fifth Men)
http://en.wikipedia.org/wiki/Last_and_F ... an_species

another book, Cities in Flight by James Blish, has time be cyclic and the last survivors of the universe become the gods of the next, and therefore life is created in the image of humans surviving this universe, therefore creating human life in the next, implying this cycle has been going on for an infinite number of cycles, and will continue for just as long.
http://en.wikipedia.org/wiki/Cities_in_ ... ph_of_Time

[tomandlu]

On the slightly more plausible bit under real science rules, I think that protection against mutation and the use of horizontal gene transfer and sexual reproduction* are probably about as complex as plausible real-world elements of evolution modifying itself as you can get, since the benefits have to be to the individual, which evolution can't act on itself in, since individuals don't evolve.

I think there are some assumptions there that may or may not stand up to scrutiny. I get your point, but, if evolution can be optimised, then generalised long-term benefit should ensure a drift towards that trend.

* Then again - doesn't sexual selection already count? Individuals act as genetically-programmed gatekeepers for genes other than their own, which certainly sounds like evolution keeping an eye on itself.

Indeed - and I can't think of any plausible handwavium that allows directed evolution at the genetic level, but you can come up with plausible handwavium that allows optimisation of frequency and amplitude of variation as a reaction to external pressures.

[kellerbustinout]

Some of real science is going into the pantheism idea i proposed. I guess notable theoretical physicists are involved in trying to study this different kind of pantheism. It they are studying it and trying to provide a science to it then it is not fiction.There is some proof that this concept may be legitimate. In a documentary i watched on this subject of consciousnesses the scientist believed consciousness existed outside of space and time. the physics aspect of space and time and his theory was that if it did exist outside space and time then certain things would be possible. I guess a study of meditation and telepathy was done in mexico that showed amazing results. They had two individuals meditate for a few hours then they separated them in different rooms i guess that were magnetically sealed or something. they also had there brains being monitored. Well they showed one of them a a flashing light that would cause a part of their brain to light up. surprisingly even the one who hadnt seen the light, the persons brain also lit up in the same place. that is pretty amazing. so it verified a little of his theory. And there is continued work on the subject and it has a very significant underground following.if you would like to see the video go to netflix and look up the word consciousness in the search bar and you should find it. There is at least 3 major theoretical physicists who are involved in this concept.i wish i had alot of the source material on hand but alas it would take awhile to go threw my book marks. There is one book i believe that speculates on this idea. the conscious mind by david chalmers. I hope to see much of it in the near future.i do though have a problem with people not willing to be open minded on the subject of god and pantheism. I think pantheism is one of the most realistic concepts of god.Its rational to consider the possibility of god. Its irrational to deny the possibility all together.I wish science would full on take up the study of god as fact based pursuit. to study and contemplate what a god would be. i like to envision it as a biological organism.i guess like one. and that our existence happens just to be a result of its existence. i like to think of our universe and others as just condensation on a glass. the glass being the god. And i also have a problem with one of the biggest critiques atheists give to the concept of god. why does god let bad things happen. well its a big universe there an infinite number of universes. 11 dimensions of reality. its a big place. The main thing is why does it have to care about us or life all throughout the universes. Dont you think its a little selfish to believe if god did exist it would care specifically for us. Wouldnt it just be enough that it allows us to exist or doesnt interfere with our existence.I think it is unrealistic to believe that it has to care at all. what if it just bleeped into existence one day, didnt know why and where it came from. If a god did just happen to bleep into existence imagine that. You at one minute didnt exist then bam you did. Wouldnt it be disorientating even maddening. What if god is of sound mind. What if god has gone crazy from being in existence for so long. these are all interesting ideas.

[tomandlu]

Some of real science is going into the pantheism idea i proposed.

The trouble with studying god as a physical phenomenon is that there is no discernible effect to study except people's faith. Do we find that churches are immune to earthquakes, or that virtuous people are less likely to suffer ill-luck than sinners? Homoeopaths, for example, will often try to present science as "only interested in things it can explain", rather than the more prosaic truth of "only interested in things that are measurable". If god exists, then he/she/it is doing a remarkable impersonation of not existing. None of which proves that god does or doesn't exist, but it does make for boring science.

With regard to the rest - sorry, I'd love to see some proof that telepathy exists, and certainly some experiments have shown statistically unlikely results (if the results were pure chance), but we're still a long way from "yes, this phenomenon exists".

[kellerbustinout]

Well at least forming ideas of what a god would be from a scientific perspective would be nice. Although now that i think about it, it probably fall to philosophy in developing any real objective view on god. Also i was referring to a real concept on god. You have to separate fiction and mythology from the concept of god. Basically you couldnt take religions religious beliefs on god into account. youd pretty much have to start from zero and work your way up. Also though the tricky part would be trying to combine whatever concept you created with scientific fact on how it relates to the universe and physics.But reading a bit of philosophy i came across a pretty startling idea. What is mathematics. Its just symbols that help us navigate threw the universe or our home planet. But that got me thinking. Is mathematics sufficient enough to navigate the universes secrets. And also lets say that mathematics is, one question do we have the correct mathematics.Is there higher levels of math we have not achieved that without alter our theory on how the universe exist. I though am not convinced now that mathematics is sufficient to understand the universe unless of course we were capable of having perfect math. I see physicist who speculate on the mass of an atom or the mass of the sun. being that we cannot actually go and measure and weigh these things we have incorrect math. Would that mess up our theory of everything. also i came upon an idea that could potential devastate theoretical physics.There are an infinite number of parallel universe, some even containing or many containing different laws of physics. That is a bit of a problem. Our scientists base our concept of higher dimensions on our mathematics that comes from our view of physics.That is a big problem.if in another dimension the laws are different wouldnt a race of advanced life forms studying there universe and contemplating higher dimensions possibly come up with a different concept of higher dimension because the laws of physics could be so radically different, not resembling anything we could imagine. I think it is a paradox if i am using the term correctly.

[Charlie!]

You could do evolution + time loops, which would give you things like rabbits in the time of the dinosaurs.

Or you could have physical laws that actually promote a certain kind of evolution by acting directly on living things or on genetic material - like "guided evolution," but minus the gods.

You could make evolution very difficult (either no mutations or no reproduction) but make spontaneous generation easy, perhaps in the aftermath of some kind of bio-weapon? Then you might get things that are capable of controlling this spontaneous generation and get a huge boom that looks more like engineering than evolution.

Or you could go beyond creationism to Last Thursdayism, where everything was created last thursday, but that's been done.

Magic, of course, could be an option - for example, living things could have some fundamental magical force that shapes them - not necessarily divinely created, maybe reflecting some deeper Platonic reality.

[qetzal]

@kellerbustinout

You're probably talking about stuff being done by folks like Roger Penrose & Stuart Hameroff. (A quick Google will likely confirm it for you.) Penrose in particular has this idea that microtubules in neurons act as quantum computers and are the source of consciousness. I'm a biologist, not a physicist, so I can't critique the quantum physical aspects. But I do know biochemistry & molecular biology, and I don't think their claims make much sense from that perspective.

@tomandlu

I could imagine some kind of molecular system that might permit 'focused' evolution at a genetic level. As a simple example, maybe a bacterium is being starved of a particular nutrient, and that prompts amplification and hypermutagenesis of specific genes involved in that nutrient's synthesis or metabolism, with the idea that at least one of the randomly mutated copies would somehow overcome the limitation. Some existing mechanisms do things like that already, although without the specific focus on relevant target genes. But I can't think of a hand-wavium that would let such a bacterium jump directly to some mutation that would solve the issue. The bug would still need to generate a bunch of mutations at random in hopes that one or more would be beneficial.

[tomandlu]

@tomandlu

I could imagine some kind of molecular system that might permit 'focused' evolution at a genetic level. As a simple example, maybe a bacterium is being starved of a particular nutrient, and that prompts amplification and hypermutagenesis of specific genes involved in that nutrient's synthesis or metabolism, with the idea that at least one of the randomly mutated copies would somehow overcome the limitation. Some existing mechanisms do things like that already, although without the specific focus on relevant target genes. But I can't think of a hand-wavium that would let such a bacterium jump directly to some mutation that would solve the issue. The bug would still need to generate a bunch of mutations at random in hopes that one or more would be beneficial.

Hard to imagine a plausible mechanism for specificity on that level - not only does the organism have to recognise in some way what the deficiency is, but it would also need to be able to target the specific gene appropriately. I envisage a cruder mechanism - a population-is-decreasing feedback that would alert a process that could govern the rate and amplitude of mutation without any bias favouring one particular mutation over another, leaving that to natural selection.

[Copper Bezel]

Yeah, I don't see how the effects of a novel mutation could be predicted. Controlling expression's simpler and more effective. Of course, if certain genes could be linked to their effects, and environmental factors could be identified that link to that gene's behavior, then you could at least have a heritable control to moderate the gene's activity. You wouldn't want it in the code itself, because stitching DNA would likely cause more trouble than it's worth - more like a switch on top. Like an epigenetics or something. The only drawback, of course, is that this is also already a real thing. = )

Edit: Should be noted that a higher mutation rate is always "bad" for the short term of several generations. It's not a reliably useful hail Mary that a species could opt into, because more bad mutations than good, and more neutral than either, will always result. Also, evolution acts only on populations, but that's because it's the sum effect of things like selection and mutation that act only on individuals. If the population of a group or species is getting lower, that's good for any one individual, which will have less competition. There's no benefit to an individual in creating mutant children in the hope that some of them will be better off than everyone else is now.

Also, every individual that has ever died before reproducing was the first in its line to do so. The genomes that exist are blissfully unaware that anything has ever gone extinct, because they haven't experienced that and certainly haven't been adapted to the experience.

You could imagine it in selfish terms - the individual mutates its children when it sees the opportunity presented by a falling population, so that its progeny will have a better shot at taking over - but that requires that mutation is net-beneficial on average, and adapting to that circumstance would require experiencing that circumstance many, many times - in other words, a small population always on the brink of extinction.

This is, again, the same problem from earlier - you need a feedback between the two vastly different scales of time and number on which evolutionary forces work, and there's just no way to bridge that gap.

[tomandlu]

This is, again, the same problem from earlier - you need a feedback between the two vastly different scales of time and number on which evolutionary forces work, and there's just no way to bridge that gap.

Nice critique - can't really argue with that, except to note some minor counter-arguments:

1. We could be talking about a mechanism that's been around for a long time, since the first microbes, so if time is all we need... (to some extent - I take your point about the scales not just being enormous, but possibly incompatible)

2.What's sauce for the goose... if a mechanism bestows a net benefit on the species, then it must bestow a benefit on individuals - further more, those individuals who benefit would be the ones passing on their genes (which is in the end the point).

3. The main stumbling block is whether increasing mutation rates is ever a good strategy. SJ Gould's punctuated equilibrium comes to mind, but he's essentially proposing it from the other side - mutations arise because new environments favour them (or are hostile to the old forms - take your pick).

BTW I'm not really proposing a serious idea, but I am curious as to whether we might not have fully explored whether species have evolved mechanisms to get the best out of evolution. Presumably, the first people to make fires just gathered wood in the wild and didn't really store it, but then evolved better ways to handle this resource. It seems self-evident to me that life will have evolved to optimise its strategies to the maximum benefit where possible.

[Xanthir]

@tomandlu

I could imagine some kind of molecular system that might permit 'focused' evolution at a genetic level. As a simple example, maybe a bacterium is being starved of a particular nutrient, and that prompts amplification and hypermutagenesis of specific genes involved in that nutrient's synthesis or metabolism, with the idea that at least one of the randomly mutated copies would somehow overcome the limitation. Some existing mechanisms do things like that already, although without the specific focus on relevant target genes. But I can't think of a hand-wavium that would let such a bacterium jump directly to some mutation that would solve the issue. The bug would still need to generate a bunch of mutations at random in hopes that one or more would be beneficial.

Hard to imagine a plausible mechanism for specificity on that level - not only does the organism have to recognise in some way what the deficiency is, but it would also need to be able to target the specific gene appropriately. I envisage a cruder mechanism - a population-is-decreasing feedback that would alert a process that could govern the rate and amplitude of mutation without any bias favouring one particular mutation over another, leaving that to natural selection.

Yes, this kind of feedback loop already exists - a number of bacteria increase their copying error rate when they're stressed, driving up the chance of mutations that can survive whatever is stressing them.

[qetzal]

Yeah, I was starting from known general mechanisms that increase mutation rates, like the SOS response, and imagining something more specific (partly inspired by the claims by Cairns, if you know that work). Suppose enzymes remained permanently associated with their mRNAs. As long as the enzyme has substrate to act on, things are fine. But if a critical nutrient were missing, the enzymes that need that nutrient to be active would become idle. Maybe that could somehow trigger increased mutation specifically in those genes. The idle enzyme triggers some recognition of the associated mRNA, which targets mutations back to the original gene.

All very hand-wavy, of course. And it still wouldn't specifically increase favorable mutations. It would just target higher rates to genes in the relevant pathways.

And just to remind everyone, there are real examples of induced, directed mutations in specific genes: somatic hypermutation in antibody genes.

[Magnanimous]

My favorite theory is life creating itself, meaning either:

1) Life travels back in time and becomes its own ancestor. (e.g., A time traveler visits prehistoric Earth and unwittingly leaves bacteria, which start evolving.)

2) Battlestar Galactica-style colonization of new planets, where the collapse of an old humanity leads to the growth of the next one, over and over again.

[Copper Bezel]

2.What's sauce for the goose... if a mechanism bestows a net benefit on the species, then it must bestow a benefit on individuals - further more, those individuals who benefit would be the ones passing on their genes (which is in the end the point).

Maybe, but maybe not. I mean, in a few generations, a random non-neutral mutation probably is a net positive. Lose a few individuals to deleterious mutations, gain a beneficial trait, spread the surviving new trait through gene flow - that's why it works.

Yes, this kind of feedback loop already exists - a number of bacteria increase their copying error rate when they're stressed, driving up the chance of mutations that can survive whatever is stressing them.

Yeah, that's precisely the arrangement that would prove me wrong, and Wikipedia has an article on it, so I'm reading it now. = ) It's much more convincing than the immune system thing - the immune system is effectively breeding many generations of mutants within a "host organism" (and they don't even leak into to the germ line, for that matter, so it's completely isolated from the "host.") I mean, that's still an evolved system using evolution as a part, but not in a way that affects its own evolution, and the new information dies with the "host."

Edit: Wikipedia seems to believe that Cairns was wrong, but that unicellular organisms might kick into a hail Mary cancer mode when stressed that includes faulty replication, so that's something.

[Xanthir]

2.What's sauce for the goose... if a mechanism bestows a net benefit on the species, then it must bestow a benefit on individuals - further more, those individuals who benefit would be the ones passing on their genes (which is in the end the point).

That's not true at all. For example, someone being suicidally altruistic may very well be best for the species as a whole, but it's clearly horrible for the altruist themself, and they won't pass on their genes. This is why the concept of "group selection" is nonsense, as far as anyone can tell, both theoretically and experimentally.

The related concept of "kin selection" totally works, though - if you sacrifice yourself, but can make your brother at least twice as likely to pass on his genes, you come out ahead, since he shares half of your genes.

[tomandlu]

2.What's sauce for the goose... if a mechanism bestows a net benefit on the species, then it must bestow a benefit on individuals - further more, those individuals who benefit would be the ones passing on their genes (which is in the end the point).

That's not true at all. For example, someone being suicidally altruistic may very well be best for the species as a whole, but it's clearly horrible for the altruist themself, and they won't pass on their genes. This is why the concept of "group selection" is nonsense, as far as anyone can tell, both theoretically and experimentally.

The related concept of "kin selection" totally works, though - if you sacrifice yourself, but can make your brother at least twice as likely to pass on his genes, you come out ahead, since he shares half of your genes.

But 'suicidally altruistic' either exists (in which case it needs explanation - kin selection, I'm looking at you), or it doesn't (in which case it's a strawman). In any event, it's not directly comparable with the basic question - "is an increase in frequency and/or amplitude of variation a useful response to near-extinction?" Remember, the individual who has produced the 'right' variation is not only passing on the variation, but also passing on the predisposition to increased rates of variation during times of stress. Xanthir's bacteria description is pretty much the exact thing I'm rambling about.

For the notion to completely break down, you'd need some kind of variation on your 'suicidally altruistic' scenario - i.e. the carriers of the 'panic response' mechanism would increase the viability of the non-carriers to their own detriment (by, say, developing your 'suicidally altruistic' gene). Not saying that can't happen, or doesn't already happen with the standard model of evolution, but such a 'choice' doesn't invalidate the whole process of evolution - it's one of the inevitable results of an unguided process, and would just signal a dead-end for that particular mutation.

[Copper Bezel]

If it's a sexually reproducing species, though, it doesn't work. The suicidally altruistic gene in question is the one that increases mutation rate. The trait being selected is another gene, created by that mutation rate, that could be anywhere on the genome. The's nothing to ensure that the mutation-rate gene gets passed on in the same individuals that carry its beneficial product, so there isn't selection pressure acting on the original trait itself.

The suicidal altruism gene is, in this case, itself suicidally altruistic. = /

Edit: For some reason I'm picturing the effect as more diffuse, because I'm still thinking of this as something that has to spread and run through a couple of generations before the effect is appreciable.

[kellerbustinout]

How do we know evolution is random. What if we start discovering alot of advanced life and a common species is the human race or a variation. The odds of finding a species exactly like us is unlikely. Not saying that ape like creatures could be impossible. but what if we found beings on a number of different planets that are human. Using the same biological processes and built close if not exactly the same. Would that give a little proof to the idea that evolution is being led not just random. Im not a biologist or anything but that would be interesting. Also i was wondering the other day about different forms of alien life and their communication system. We use sound and vision. Well what other possible forms of communication could there be and how would their culture form.Like lets say they did have ears. well then music would not be apart of there culture. Thats a bigger question does a life form need specific types of cultures and societies to evolve into an advanced life form. How also would they pass time for entertainment.

[Copper Bezel]

Star Trek eventually worked in a directed evolution spawned by an earlier species to explain how the people of the various societies involved could be biologically human. They also had some dumb things about multiple hearts and green blood.

There's no, "what if that really happened," question here. If you travel to another inhabited planet and it has people on it, even really tall blue ones or something, then it's either God (or Platonism) or a recent cross-contamination. That realization doesn't make any of those forces more likely - if you're moving from evidence to conclusions, instead of the reverse, you'll see that it just makes sexy blue alien chicks impossible.

And while mutation is random, evolution is not. The path isn't predictable, but neither is human history.