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Mar
25
comment Do homing pigeons fly straight home or follow certain “highways”?
Some time ago I saw a TV programme (probably on BBC in the UK) that claimed they follow literal highways, i.e. they mostly navigate by flying above roads and remembering which intersection to turn off at. (But I've no idea how clearly established this is, given that my reference is a TV programme.)
Mar
2
comment Why do living fossils like crocodiles remain so constant and not evolve?
(The reason I only covered them briefly is that you already covered them in your answer. This was only intended as a complement to yours.)
Mar
2
comment Why do living fossils like crocodiles remain so constant and not evolve?
@rg255 to answer your first point, it's typically much easier to lose complex features than to evolve them in the first place. E.g. vertebrate eyes evolved only once but have been lost but have been lost many times. (I don't know if a species exists that is known to have lost its eyes and then un-lost them, but I very much doubt it exists.) If the developmental pathways responsible for the jaw hinge mechanism have been lost they are very unlikely to reappear. On your second point I can only plead guilty to the lack of references, but I did mention the other two things, albeit briefly.
Feb
28
awarded  Teacher
Feb
28
awarded  Yearling
Feb
27
answered Why do living fossils like crocodiles remain so constant and not evolve?
Jan
7
comment What are we missing about the real workings of the evolutionary process?
@AMR "I may be entirely wrong, but I don't hear Evolutionary or Paleo Biologist saying that we need computer simulations to understand the subject" - actually there are quite a number of very senior and influential evolutionary theorists who use simulation extensively. Szathmáry and Nowak both come to mind straight away, though there are many others.
Jan
6
comment What are we missing about the real workings of the evolutionary process?
Deutsch's "doubt that any 'artificial evolution' has ever created knowledge" seems unfounded to me, since there are a moderate number of well-documented examples of exactly that, in the form of electric circuits that work in ways no human ever designed, and that sort of thing. (But I have not read Deutsch's paper and perhaps he addresses those.)
Jan
6
comment What are we missing about the real workings of the evolutionary process?
In my opinion it's mostly due to the constraints of computing power, which was very limited throughout most of the field's history, and is even now not quite enough. Because of this, we tend to use the smallest population we can get away with, and very strong selection pressure, because otherwise we would be waiting too long for anything to happen at all. But with small populations and strong selection you should not really expect anything other than strong convergence to a local optimum.
Jan
6
comment What are we missing about the real workings of the evolutionary process?
This is known in Artificial Life circles as "the problem of open-ended evolution." It is (still) an area of active research (e.g. there was a workshop on it at the last ALife conference in York, UK last year) but nobody believes with certainty that they know the answer at this stage.
Mar
26
awarded  Curious
Mar
25
comment Mathematical models of lineage selection
@Remi.b I'm pretty aware of that argument (not sure which side I fall on), but lineage selection in the sense I intend it is not the same as either of them - it's not about adaptations that benefit relatives, it's purely about adaptations that benefit your descendants, several (or many) generations later.
Mar
25
comment Mathematical models of lineage selection
Thank you, these references look extremely useful.
Mar
25
asked Mathematical models of lineage selection
Jan
5
comment Are there known examples where an evolved mechanism “echoes” one originally provided by the environment?
Great, thanks, I will certainly look into this in detail. (I might accept this answer but let's see if anything else comes up first.)
Jan
5
comment General time reversible model of evolution and Felsenstein model
You can find some information, with references to the original papers, on this Wikpedia page: en.wikipedia.org/wiki/… (I won't try to offer a summary, because it's not by field.)
Jan
5
revised Are there known examples where an evolved mechanism “echoes” one originally provided by the environment?
added 34 characters in body
Jan
5
comment Are there known examples where an evolved mechanism “echoes” one originally provided by the environment?
I've re-written the question, and I hope it's clearer now.
Jan
5
revised Are there known examples where an evolved mechanism “echoes” one originally provided by the environment?
added 2452 characters in body; edited title
Jan
5
comment Are there known examples where an evolved mechanism “echoes” one originally provided by the environment?
(Though I guess your examples are somewhat lacking in the "echoing the environment" property, because the 'complicated anatomical mechanisms' they use don't resemble the original environmental mechanism. I do need to clarify what I mean by that, and I hope to find the time today or this week.)