I expect that most animals [if magically granted as many neurons as humans have] wouldn’t reach sufficient levels of general intelligence to do advanced mathematics or figure out scientific laws. That might be because most are too solitary for communication skills to be strongly selected for, or because language is not very valuable even for social species (as suggested by the fact that none of them have even rudimentary languages). Or because most aren’t physically able to use complex tools, or because they’d quickly learn to exploit other animals enough that further intelligence isn’t very helpful, or...
The time it took to reach human-level intelligence (HLI) was quite short, though, which is decent evidence that HLI is easy. Our common ancestor with dolphins was just 100mya, whereas there’s probably more than 1 billion years left for life on Earth to evolve.
Here’s one way to think about the strength of this evidence. Consider two different hypotheses:
HLI is easy. After our common ancestor with dolphins, it reliably takes N million years of steady evolutionary progress to develop HLI, where N is uniformly distributed.
HLI is hard. After our common ancestor with dolphins, it reliably takes at least N million years (uniformly distributed) of steady evolutionary progress, and for each year after that, there’s a constant, small probability p that HLI is developed. In particular, assume that p is so small that, if we condition on HLI happening at some point (for anthropics reasons), the time at which HLI happens is uniform between the end of the N million years and the end of all life on Earth.
Lets say HLI emerged on Earth exactly 100mya after our common ancestor with dolphins. After our common ancestor with dolphins, lets say there were 1100 million years remaining for life to evolve on Earth (I think it’s close to that). We can treat N as being distributed uniformly between 1 and 100, because we know it’s not more than 100 (our existence contradicts that). If so:
P(HLI at 100my | HLI is easy) = 1100
P(HLI at 100my | HLI is hard) = Σ100n=1110011100−n>Σ100n=1110011000=11000
Thus, us evolving at 100my is roughly a 10:1 update in favor of HLI being easy.
(Note that, since the question under dispute is the ease of getting to HLI from dolphin intelligence, counting from 100mya is really conservative; it might be more appropriate to count from whenever primates acquired dolphin intelligence. This could lead to much stronger updates; if we count time from e.g. 20mya instead of 100mya, the update would be 50:1 instead of 10:1, since P(HLI at 20my | HLI is easy) would be 1⁄20.)
This is somewhat but not totally robust to small probabilities of variations. E.g. if we assign 20% chance to life actually needing to evolve within 200 million years after our common ancestor with dolphins, we get:
P(HLI at 100my | HLI is easy) = 1100
P(HLI at 100my | HLI is hard) = 0.8∗Σ100n=1110011100−n+0.2∗Σ100n=111001200−n≈1100(0.8∗0.1+0.2∗0.7)=2.21000
So the update would be more like 1:0.22 ~ 4.5:1 in favor of HLI is easy.
If you think dolphin intelligence is probably easy, I think you shouldn’t be that confident that HLI is hard, so after updating on earliness, I think HLI being easy should be the default hypothesis.
My argument is consistent with the time from dolphin- to human-level intelligence being short in our species, because for anthropic reasons we find ourselves with all the necessary features (dexterous fingers, sociality, vocal chords, etc).
The claim I’m making is more like: for every 1 species that reaches human-level intelligence, there will be N species that get pretty smart, then get stuck, where N is fairly large. (And this would still be true if neurons were, say, 10x smaller and 10x more energy efficient.)
Now there are anthropic issues with evaluating this argument by pegging “pretty smart” to whatever level the second-most-intelligent species happens to be at. But if we keep running evolution forward, I can imagine elephants, whales, corvids, octopuses, big cats, and maybe a few others reaching dolphin-level intelligence. But I have a hard time picturing any of them developing cultural evolution.
The claim I’m making is more like: for every 1 species that reaches human-level intelligence, there will be N species that get pretty smart, then get stuck, where N is fairly large
My point is that – if N is fairly large – then it’s surprising that human-level intelligence evolved from one of the first ~3 species that became “pretty smart” (primates, dolphins, and probably something else).
If the Earth’s history would contain M>>N pretty smart species, then in expectation human-level intelligence should appear in the N:th species. If Earth’s history would contain M<<N pretty smart species, then we should expect human-level intelliigence to have equal probability to appear in any of the pretty smart species, so in expectation it should appear in the M/2:th pretty smart species.
Becoming “pretty smart” is apparently easy (because we’ve had >1 pretty smart species evolve so far) so in the rest of the Earth’s history, we would expect plenty more species to become pretty smart. If we expect M to be non-trivial (like maybe 30) then the fact that the 3rd pretty smart species reached human-level intelligence is evidence in favor of N~=2 over N>>M.
(Just trying to illustrate the argument at this point; not confident in the numbers given.)
Yeah, this seems like a reasonable argument. It feels like it really relies on this notion of “pretty smart” though, which is hard to pin down. There’s a case for including all of the following in that category:
And yet I’d guess that none of these were/are on track to reach human-level intelligence. Agree/disagree?
Uhm, haven’t thought that much about it. Not imminently, maybe, but I wouldn’t exclude the possibility that they could be on some long-winded path there.
It feels like it really relies on this notion of “pretty smart” though
I don’t think it depends that much on the exact definition of a “pretty smart”. If we have a broader notion of what “pretty smart” is, we’ll have more examples of pretty smart animals in our history (most of which haven’t reached human level intelligence). But this means both that the evidence indicates that each pretty smart animal has a smaller chance of reaching human-level intelligence, and that we should expect much more pretty smart animals in the future. E.g. if we’ve seen 30 pretty smart species (instead of 3) so far, we should expect maybe M=300 pretty smart species (instead of 30) to appear over Earth’s history. Humans still evolved from some species in the first 10th percentile, which still is an update towards N~=M/10 over N>>M.
The required assumptions for the argument are just:
humans couldn’t have evolved from a species with a level of intelligence less than X
species with X intelligence started appearing t years ago in evolutionary history
there are t’ years left where we expect such species to be able to appear
we assume the appearence rate of such species to be either constant or increasing over time
Then, “it’s easy to get humans from X” predicts t<<t’ while “it’s devilishly difficult to get humans from X” predicts t~=t’ (or t>>t’ if the appearance rate is strongly increasing over time). Since we observe t<<t’, we should update towards the former.
This is the argument that I was trying to make in the grand-grand-grand-parent. I then reformulated it from an argument about time into an argument about pretty smart species in the grand-parent to mesh better with your response.
I think it might be quite hard to go from dolphin- to human-level intelligence.
I discuss some possible reasons in this post:
The time it took to reach human-level intelligence (HLI) was quite short, though, which is decent evidence that HLI is easy. Our common ancestor with dolphins was just 100mya, whereas there’s probably more than 1 billion years left for life on Earth to evolve.
Here’s one way to think about the strength of this evidence. Consider two different hypotheses:
HLI is easy. After our common ancestor with dolphins, it reliably takes N million years of steady evolutionary progress to develop HLI, where N is uniformly distributed.
HLI is hard. After our common ancestor with dolphins, it reliably takes at least N million years (uniformly distributed) of steady evolutionary progress, and for each year after that, there’s a constant, small probability p that HLI is developed. In particular, assume that p is so small that, if we condition on HLI happening at some point (for anthropics reasons), the time at which HLI happens is uniform between the end of the N million years and the end of all life on Earth.
Lets say HLI emerged on Earth exactly 100mya after our common ancestor with dolphins. After our common ancestor with dolphins, lets say there were 1100 million years remaining for life to evolve on Earth (I think it’s close to that). We can treat N as being distributed uniformly between 1 and 100, because we know it’s not more than 100 (our existence contradicts that). If so:
P(HLI at 100my | HLI is easy) = 1100
P(HLI at 100my | HLI is hard) = Σ100n=1110011100−n>Σ100n=1110011000=11000
Thus, us evolving at 100my is roughly a 10:1 update in favor of HLI being easy.
(Note that, since the question under dispute is the ease of getting to HLI from dolphin intelligence, counting from 100mya is really conservative; it might be more appropriate to count from whenever primates acquired dolphin intelligence. This could lead to much stronger updates; if we count time from e.g. 20mya instead of 100mya, the update would be 50:1 instead of 10:1, since P(HLI at 20my | HLI is easy) would be 1⁄20.)
This is somewhat but not totally robust to small probabilities of variations. E.g. if we assign 20% chance to life actually needing to evolve within 200 million years after our common ancestor with dolphins, we get:
P(HLI at 100my | HLI is easy) = 1100
P(HLI at 100my | HLI is hard) = 0.8∗Σ100n=1110011100−n+0.2∗Σ100n=111001200−n≈1100(0.8∗0.1+0.2∗0.7)=2.21000
So the update would be more like 1:0.22 ~ 4.5:1 in favor of HLI is easy.
If you think dolphin intelligence is probably easy, I think you shouldn’t be that confident that HLI is hard, so after updating on earliness, I think HLI being easy should be the default hypothesis.
My argument is consistent with the time from dolphin- to human-level intelligence being short in our species, because for anthropic reasons we find ourselves with all the necessary features (dexterous fingers, sociality, vocal chords, etc).
The claim I’m making is more like: for every 1 species that reaches human-level intelligence, there will be N species that get pretty smart, then get stuck, where N is fairly large. (And this would still be true if neurons were, say, 10x smaller and 10x more energy efficient.)
Now there are anthropic issues with evaluating this argument by pegging “pretty smart” to whatever level the second-most-intelligent species happens to be at. But if we keep running evolution forward, I can imagine elephants, whales, corvids, octopuses, big cats, and maybe a few others reaching dolphin-level intelligence. But I have a hard time picturing any of them developing cultural evolution.
My point is that – if N is fairly large – then it’s surprising that human-level intelligence evolved from one of the first ~3 species that became “pretty smart” (primates, dolphins, and probably something else).
If the Earth’s history would contain M>>N pretty smart species, then in expectation human-level intelligence should appear in the N:th species. If Earth’s history would contain M<<N pretty smart species, then we should expect human-level intelliigence to have equal probability to appear in any of the pretty smart species, so in expectation it should appear in the M/2:th pretty smart species.
Becoming “pretty smart” is apparently easy (because we’ve had >1 pretty smart species evolve so far) so in the rest of the Earth’s history, we would expect plenty more species to become pretty smart. If we expect M to be non-trivial (like maybe 30) then the fact that the 3rd pretty smart species reached human-level intelligence is evidence in favor of N~=2 over N>>M.
(Just trying to illustrate the argument at this point; not confident in the numbers given.)
Yeah, this seems like a reasonable argument. It feels like it really relies on this notion of “pretty smart” though, which is hard to pin down. There’s a case for including all of the following in that category:
Dolphins
Crows
Parrots
Elephants
Whales
Seals
Tigers
Some dogs
Octopuses
Some of the Pleistocene megafauna
And yet I’d guess that none of these were/are on track to reach human-level intelligence. Agree/disagree?
Uhm, haven’t thought that much about it. Not imminently, maybe, but I wouldn’t exclude the possibility that they could be on some long-winded path there.
I don’t think it depends that much on the exact definition of a “pretty smart”. If we have a broader notion of what “pretty smart” is, we’ll have more examples of pretty smart animals in our history (most of which haven’t reached human level intelligence). But this means both that the evidence indicates that each pretty smart animal has a smaller chance of reaching human-level intelligence, and that we should expect much more pretty smart animals in the future. E.g. if we’ve seen 30 pretty smart species (instead of 3) so far, we should expect maybe M=300 pretty smart species (instead of 30) to appear over Earth’s history. Humans still evolved from some species in the first 10th percentile, which still is an update towards N~=M/10 over N>>M.
The required assumptions for the argument are just:
humans couldn’t have evolved from a species with a level of intelligence less than X
species with X intelligence started appearing t years ago in evolutionary history
there are t’ years left where we expect such species to be able to appear
we assume the appearence rate of such species to be either constant or increasing over time
Then, “it’s easy to get humans from X” predicts t<<t’ while “it’s devilishly difficult to get humans from X” predicts t~=t’ (or t>>t’ if the appearance rate is strongly increasing over time). Since we observe t<<t’, we should update towards the former.
This is the argument that I was trying to make in the grand-grand-grand-parent. I then reformulated it from an argument about time into an argument about pretty smart species in the grand-parent to mesh better with your response.