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I don't see why it's a paradox. Lots of things would offer fitness - why can't all animals talk? Why can't plants move? Surely these things would offer greater

I don't see why it's a paradox. Lots of things would offer fitness - why can't all animals talk? Why can't plants move? Surely these things would offer greater Darwinian fitness.

samatman 13y ago
It's not a paradox, it's an almost paradox, which is kind of like being almost pregnant from a logic perspective. Lamarckian and Darwinian evolution were debated and Darwin won. Lamarck's Lemma, which is a term I made up, points out that, were a random walk to create a mechanism for Lamarckian evolution, Darwinian evolution might well keep it around, as it could offer fitness. That's why I phrase it as a lemma on Darwin's theory: even if it proves true, as epigenetics suggests, it doesn't make Lamarckian thinking correct. If anything, the opposite: it shows that Lamarckian effects can be explained through natural selection. Plants can of course move, the classic example being the sensitive plant. Whether or not non-human animals can "talk" depends, basically, on whether one means "signalling" or "language proper". The bee dance can give arbitrarily complex instructions in one particular domain: there is no 'one' bee dance, each performance is roughly as unique as a sentence or so of text.
- VladRussian2 13y ago
  > Whether or not non-human animals can "talk" depends, there is at least one animal that we know is able to talk, at least in our definition of "talk" - this animal is humans, so the Evolution did produce a talking animal.
samatman 13y ago
I did want to address one other total misconception here: Darwinian fitness is a result, not an effect. There is no adaptation, at all, which predictably increases fitness. Evolution is not a direction. "Surely these things would offer greater Darwinian fitness" is as basic a mistake as "Surely we can figure out whether this program will halt without running it". EDIT: In fact, as I think about it, there is a deep connection between the thought "Knowing the genes of this organism, we may predict its fitness" and "Knowing the instructions of this program, we may predict its halting". I'd love to see a paper on that.
- tel 13y ago
  It's an effect on the side of survival, correct? It's not that some particular change was "selected" in order to increase fitness but instead that all minute changes were selected simultaneously and some were pruned. There needs to be a smooth path from the "current location in design space" to any improvement under which there is never anything damaging enough to prune off that path. And then, this "smooth path" idea relates neatly with topological notions of computability.
- rflrob 13y ago
  That doesn't seem rit to me. There's lots of adaptations that could probably increase fitness of offspring as a function of the parent's environment. In the same way, you can look at some programs and predict whether they halt, just not all programs, and potentially not even all "interesting" programs, for some definition of interesting.
  - XorNot 13y ago
    You contradict your own point though: yes, we can predict - but we can't know that a program - an arbitrary program - will halt. Evolution is much the same, but most people are worse at it because they make the mistake of prioritizing human-values as evolutionary advantages for all species. For example, cows get slaughtered by the billion by humans. But they're an evolutionary success story from a Darwinian perspective: by being easy to domesticate by early tribes and delicious, they've proliferated far beyond anything which would've happened un-aided by humans.
    - dllthomas 13y ago
      For any arbitrary program, we may be able to know that it will halt.
      - HCIdivision17 13y ago
        For any very simple arbitrary program, perhaps. But certainly not in general. That's sort of the point of the Halting Problem: you can't know because it is undecidable. Of course, there are simple and trivial programs that can be specifically analyzed, but we're definitely not to that level on any of the stuff under discussion here. The analogy really is pretty apt.
sadkingbilly 13y ago
> Why can't plants move? Surely these things would offer greater Darwinian fitness. Not necessarily for plants. They do in fact move. They just do it differently. They have no problem spreading their DNA throughout the world via seeds and pollen. They use a lot less energy too, compared with sprouting legs and getting up to walk around. If they did this, they would likely require much greater quantities of food, including protein, which would put plants at a disadvantage. In any case, plants have also evolved on a completely different fitness track than that of animals. Plants have evolved incredible manipulation of chemistry, far beyond what humans can produce today, let alone even understand. I recently finished reading Botany of Desire (Michael Pollan) where he describes how plants have co-evolved with humans, appealing to our selection of flowers, fruits, and vegetables to further distribute their DNA. Who's actually farming who? Interesting stuff.
- nollidge 13y ago
  I was being a bit tongue-in-cheek. You're absolutely right that supposed "benefits" might have unforeseen tradeoffs. In this case, having some sort of pseudo-Lamarckian inheritance could possibly be a detriment due to energy requirements or something like that. Or indeed it could have a neutral effect on fitness, in which case it's unlikely to take hold in the population, barring genetic drift or other non-selection evolutionary mechanisms.
VladRussian2 13y ago
>I don't see why it's a paradox. Lots of things would offer fitness - why can't all animals talk? Why can't plants move? Surely these things would offer greater Darwinian fitness. this is why we have live organisms that able to move - it is called animals, and we have animals that can talk, and we'll possibly have [some milleniums later] animals that are able to efficiently transfer memory through DNA (possibly after these animals become able to calculate and select what memories they'd like to encode into their own DNAs and what of these memories they want to transfer to the offsprings)... Evolution isn't finished as of today, it is possibly only starting :)
j2d3 13y ago
Animals can talk --- to each other.
jonnathanson 13y ago
Darwinian natural selection doesn't select for absolute/universal fitness, because there is no such thing. It selects for fitness into a specific, local niche. Humans may be more fit than chimpanzees in some areas, for example, but less fit in others. It is a fallacy to assume that evolution is linear, and that it progresses toward some sort of universal optimum. There is no universal optimum. There are only specific, local optima. A good example is the megalodon. From all we know, the megalodon was basically a massive, faster, more badass, more ferocious version of the great white shark. Why did the megalodon die out, and the lines that led to the great white survive? Surely big-badassedness is a desirable quality in an apex predator like a shark, right? Well, not really, because circumstances changed. Ocean temperatures changed, prey got scarcer and smaller, and eventually, size became a detriment. Megalodon was too big not to fail. What fit one day no longer fit the next. The same thing may happen to humans someday, and some other animal may step up to take our places. It seems unlikely, but nature is the one doing the "selecting" in natural selection -- not us. Environments and circumstances change, and as they change, so do the criteria that "fit" the new context. In the Darwinian sense, "fit" refers to suitability to a habitat; it does not refer to "fitness" in the modern sense of the word. Think "product/market fit," not "physically fit."

I don't see why it's a paradox. Lots of things would offer fitness - why can't all animals talk? Why can't plants move? Surely these things would offer greater Darwinian fitness.

samatman 13y ago

It's not a paradox, it's an almost paradox, which is kind of like being almost pregnant from a logic perspective. Lamarckian and Darwinian evolution were debated and Darwin won. Lamarck's Lemma, which is a term I made up, points out that, were a random walk to create a mechanism for Lamarckian evolution, Darwinian evolution might well keep it around, as it could offer fitness. That's why I phrase it as a lemma on Darwin's theory: even if it proves true, as epigenetics suggests, it doesn't make Lamarckian thinking correct. If anything, the opposite: it shows that Lamarckian effects can be explained through natural selection. Plants can of course move, the classic example being the sensitive plant. Whether or not non-human animals can "talk" depends, basically, on whether one means "signalling" or "language proper". The bee dance can give arbitrarily complex instructions in one particular domain: there is no 'one' bee dance, each performance is roughly as unique as a sentence or so of text.

VladRussian2 13y ago
> Whether or not non-human animals can "talk" depends, there is at least one animal that we know is able to talk, at least in our definition of "talk" - this animal is humans, so the Evolution did produce a talking animal.

samatman 13y ago

I did want to address one other total misconception here: Darwinian fitness is a result, not an effect. There is no adaptation, at all, which predictably increases fitness. Evolution is not a direction. "Surely these things would offer greater Darwinian fitness" is as basic a mistake as "Surely we can figure out whether this program will halt without running it". EDIT: In fact, as I think about it, there is a deep connection between the thought "Knowing the genes of this organism, we may predict its fitness" and "Knowing the instructions of this program, we may predict its halting". I'd love to see a paper on that.

tel 13y ago
It's an effect on the side of survival, correct? It's not that some particular change was "selected" in order to increase fitness but instead that all minute changes were selected simultaneously and some were pruned. There needs to be a smooth path from the "current location in design space" to any improvement under which there is never anything damaging enough to prune off that path. And then, this "smooth path" idea relates neatly with topological notions of computability.
rflrob 13y ago
That doesn't seem rit to me. There's lots of adaptations that could probably increase fitness of offspring as a function of the parent's environment. In the same way, you can look at some programs and predict whether they halt, just not all programs, and potentially not even all "interesting" programs, for some definition of interesting.
- XorNot 13y ago
  You contradict your own point though: yes, we can predict - but we can't know that a program - an arbitrary program - will halt. Evolution is much the same, but most people are worse at it because they make the mistake of prioritizing human-values as evolutionary advantages for all species. For example, cows get slaughtered by the billion by humans. But they're an evolutionary success story from a Darwinian perspective: by being easy to domesticate by early tribes and delicious, they've proliferated far beyond anything which would've happened un-aided by humans.
  - dllthomas 13y ago
    For any arbitrary program, we may be able to know that it will halt.
    - HCIdivision17 13y ago
      For any very simple arbitrary program, perhaps. But certainly not in general. That's sort of the point of the Halting Problem: you can't know because it is undecidable. Of course, there are simple and trivial programs that can be specifically analyzed, but we're definitely not to that level on any of the stuff under discussion here. The analogy really is pretty apt.

sadkingbilly 13y ago

> Why can't plants move? Surely these things would offer greater Darwinian fitness. Not necessarily for plants. They do in fact move. They just do it differently. They have no problem spreading their DNA throughout the world via seeds and pollen. They use a lot less energy too, compared with sprouting legs and getting up to walk around. If they did this, they would likely require much greater quantities of food, including protein, which would put plants at a disadvantage. In any case, plants have also evolved on a completely different fitness track than that of animals. Plants have evolved incredible manipulation of chemistry, far beyond what humans can produce today, let alone even understand. I recently finished reading Botany of Desire (Michael Pollan) where he describes how plants have co-evolved with humans, appealing to our selection of flowers, fruits, and vegetables to further distribute their DNA. Who's actually farming who? Interesting stuff.

nollidge 13y ago
I was being a bit tongue-in-cheek. You're absolutely right that supposed "benefits" might have unforeseen tradeoffs. In this case, having some sort of pseudo-Lamarckian inheritance could possibly be a detriment due to energy requirements or something like that. Or indeed it could have a neutral effect on fitness, in which case it's unlikely to take hold in the population, barring genetic drift or other non-selection evolutionary mechanisms.

VladRussian2 13y ago

>I don't see why it's a paradox. Lots of things would offer fitness - why can't all animals talk? Why can't plants move? Surely these things would offer greater Darwinian fitness. this is why we have live organisms that able to move - it is called animals, and we have animals that can talk, and we'll possibly have [some milleniums later] animals that are able to efficiently transfer memory through DNA (possibly after these animals become able to calculate and select what memories they'd like to encode into their own DNAs and what of these memories they want to transfer to the offsprings)... Evolution isn't finished as of today, it is possibly only starting :)

j2d3 13y ago

Animals can talk --- to each other.

jonnathanson 13y ago

Darwinian natural selection doesn't select for absolute/universal fitness, because there is no such thing. It selects for fitness into a specific, local niche. Humans may be more fit than chimpanzees in some areas, for example, but less fit in others. It is a fallacy to assume that evolution is linear, and that it progresses toward some sort of universal optimum. There is no universal optimum. There are only specific, local optima. A good example is the megalodon. From all we know, the megalodon was basically a massive, faster, more badass, more ferocious version of the great white shark. Why did the megalodon die out, and the lines that led to the great white survive? Surely big-badassedness is a desirable quality in an apex predator like a shark, right? Well, not really, because circumstances changed. Ocean temperatures changed, prey got scarcer and smaller, and eventually, size became a detriment. Megalodon was too big not to fail. What fit one day no longer fit the next. The same thing may happen to humans someday, and some other animal may step up to take our places. It seems unlikely, but nature is the one doing the "selecting" in natural selection -- not us. Environments and circumstances change, and as they change, so do the criteria that "fit" the new context. In the Darwinian sense, "fit" refers to suitability to a habitat; it does not refer to "fitness" in the modern sense of the word. Think "product/market fit," not "physically fit."