I am interested in reading on a fairly specific topic, and I would like suggestions. I don’t know any way to describe this other than be giving the two examples I have thought of:
Some time ago my family and I visited India. There, among other things, we saw many cows with an extra, useless leg growing out of their backs near the shoulders. This mutation is presumably not beneficial to the cow, but it strikes me as beneficial to the amateur geneticist. Isn’t it incredibly interesting that a leg can be the by-product of random mutation? Doesn’t that tell us a lot about the way genes are structured—namely that somewhere out there is a gene that encodes things at near the level of genes—some small number of genes corresponds nearly directly to major, structural components of the cow. It’s not all about molecules, or cells, or even tissues! Gene’s aren’t like a bitmap image—they’re hierarchical and structured. Wow!
Similarly, there are stories of people losing specific memory ‘segments’, say, their personal past but not how to read and write, how to drive, or how to talk. Assuming that these stories are approximately true, that suggests that some forms of memory loss are not random. We wouldn’t expect a hard drive error to corrupt only pictures of sunny days on your computer since the hard drive doesn’t know what pictures are of sunny days. We wouldn’t even expect a computer virus to do that. At least we wouldn’t unless somewhere the pictures of sunny days are grouped together, say in a folder. So the brain doesn’t store memories like a computer stores images! Or memory loss isn’t like hard drive failures! Somewhere, memories are ‘clumped’ into personal-things and general-knowledge things so that we can lose one without losing the other and without an unfathomable coincidence of chance.
Neither of these conclusions is either specific or surprising, but I know nothing about neurology and nothing about genetics so I’m not sure how to take these ideas further than my poor computer science-driven analogies. If someone who really knew this subject, or some subset of it, wrote about it, I can’t help but feeling that this would be absolutely fascinating. Please, let me know if there is such a book or article or blog post out there! Or even if you just have other observations that’ll make me think “wow” like this, tell me!
What makes you think that the extra limbs were caused by mutations? I know very little about bovine biology, but if we were dealing with a human, I would assume that an extra leg was likely caused by absorption of a sibling in utero. I have never heard of a mutation in mammals causing extra limb development. (Even weirder is the idea of a mutation causing an extra single leg, as opposed to an extra leg pair.) The vertebrate body plan simply does not seem to work that way.
Pure speculation! However, this was a wide-spread occurrence not just one or two cows hinting at some systematic setup. I also don’t remember the details as it was many years ago and I was quite young—it’s possible that there was a pair of legs.
A gene can become more common in a population without being selected for. However, invoking random genetic drift as an explanation is generally dirty pool, epistemically speaking. We should expect a gene that creates extra useless legs to be selected against. (Nutrients and energy spent maintaining the leg could be better used, the leg becomes more space for parasite invasion, etc.) Assuming that you were dealing with such cattle, you should assume that some humans were selecting for them. (No reason necessary. Humans totally do that sort of thing.)
I cannot think of any examples of a mutation causing extra limb development in vertebrates. However, certain parasites can totally cause extra limb development in amphibians. I doubt this is the case, but it is more likely than mutation.
Alternatively, consider there existing a selection effect on your observations. I wager that Indian cattle are less likely to be culled for having an extra leg that American cattle are. I’m just going off of stereotypes here, however.
‘clumped’ into personal-things and general-knowledge things so that we can lose one without losing the other
Are you sure that your example is personal vs general, rather than episodic vs procedural? The latter distinction much more obviously benefits from different encodings or being connected to different parts of the brain.
I’m not sure of anything regarding this—all I know is that it tells me a little bit, not very much, and that it would tell someone better versed in this more.
I am interested in reading on a fairly specific topic, and I would like suggestions. I don’t know any way to describe this other than be giving the two examples I have thought of:
Some time ago my family and I visited India. There, among other things, we saw many cows with an extra, useless leg growing out of their backs near the shoulders. This mutation is presumably not beneficial to the cow, but it strikes me as beneficial to the amateur geneticist. Isn’t it incredibly interesting that a leg can be the by-product of random mutation? Doesn’t that tell us a lot about the way genes are structured—namely that somewhere out there is a gene that encodes things at near the level of genes—some small number of genes corresponds nearly directly to major, structural components of the cow. It’s not all about molecules, or cells, or even tissues! Gene’s aren’t like a bitmap image—they’re hierarchical and structured. Wow!
Similarly, there are stories of people losing specific memory ‘segments’, say, their personal past but not how to read and write, how to drive, or how to talk. Assuming that these stories are approximately true, that suggests that some forms of memory loss are not random. We wouldn’t expect a hard drive error to corrupt only pictures of sunny days on your computer since the hard drive doesn’t know what pictures are of sunny days. We wouldn’t even expect a computer virus to do that. At least we wouldn’t unless somewhere the pictures of sunny days are grouped together, say in a folder. So the brain doesn’t store memories like a computer stores images! Or memory loss isn’t like hard drive failures! Somewhere, memories are ‘clumped’ into personal-things and general-knowledge things so that we can lose one without losing the other and without an unfathomable coincidence of chance.
Neither of these conclusions is either specific or surprising, but I know nothing about neurology and nothing about genetics so I’m not sure how to take these ideas further than my poor computer science-driven analogies. If someone who really knew this subject, or some subset of it, wrote about it, I can’t help but feeling that this would be absolutely fascinating. Please, let me know if there is such a book or article or blog post out there! Or even if you just have other observations that’ll make me think “wow” like this, tell me!
What makes you think that the extra limbs were caused by mutations? I know very little about bovine biology, but if we were dealing with a human, I would assume that an extra leg was likely caused by absorption of a sibling in utero. I have never heard of a mutation in mammals causing extra limb development. (Even weirder is the idea of a mutation causing an extra single leg, as opposed to an extra leg pair.) The vertebrate body plan simply does not seem to work that way.
Pure speculation! However, this was a wide-spread occurrence not just one or two cows hinting at some systematic setup. I also don’t remember the details as it was many years ago and I was quite young—it’s possible that there was a pair of legs.
Forgive me, for my biology is a bit rusty.
A gene can become more common in a population without being selected for. However, invoking random genetic drift as an explanation is generally dirty pool, epistemically speaking. We should expect a gene that creates extra useless legs to be selected against. (Nutrients and energy spent maintaining the leg could be better used, the leg becomes more space for parasite invasion, etc.) Assuming that you were dealing with such cattle, you should assume that some humans were selecting for them. (No reason necessary. Humans totally do that sort of thing.)
I cannot think of any examples of a mutation causing extra limb development in vertebrates. However, certain parasites can totally cause extra limb development in amphibians. I doubt this is the case, but it is more likely than mutation.
Alternatively, consider there existing a selection effect on your observations. I wager that Indian cattle are less likely to be culled for having an extra leg that American cattle are. I’m just going off of stereotypes here, however.
Are you sure that your example is personal vs general, rather than episodic vs procedural? The latter distinction much more obviously benefits from different encodings or being connected to different parts of the brain.
I’m not sure of anything regarding this—all I know is that it tells me a little bit, not very much, and that it would tell someone better versed in this more.