Malmesbury
I would guess that when organelles are inherited from both parents, the traitor organelle is disadvantaged by its burden on the host, but advantaged by it’s ability to be the predominant organelle in the offspring. If the cost-benefit is favourable, then the traitor organelle will take over. OTOH, if only one parent transmits the organelle, the advantage disappears but the burden remains. So I’d expect that it makes it more difficult for traitor mitochondria to invade. Hopefully that makes sense!
Not quite, if it’s less efficient at doing the normal mitochondria work, it puts a big burden on the cell, who is then less likely to reproduce.
Thank you for spotting this, I fixed it.
It’s not so much the different types in themselves that prevent competition, but having multiple types make it possible to have a mechanism that forces all organelles to come from only one pre-selected parent. If all organelles come from the female, then a rogue mitochondria cannot take over by making more copies of itself or by poisoning other mitochondria, because the only way to make it to the next generation is to be in the female gamete, period. In other words, there’s not much an organelle can do to increase in frequency, aside from improving the overall fitness of the organism. Does that make more sense?
The n°1 reason why I said not mention fungi is that I’m absolutely not a mycologist and I wouldn’t be able to talk about them. So I greatly appreciate that you do it! Typically, I had never heard of glomeromycota, despite them apparently being involved in symbiosis with 80% of plants. I like to think that I have a decent understanding of the living world, and then I’m constantly reminded that I don’t, and probably nobody does...
According to this paper, the “root” factor is how much effort each parent invests in caring about offsprings, as in some species the male is the primary caregiver. But that’s really hard to measure and check empirically, so they instead measure “the maximum number of independent offspring that parents can produce per unit of time”, and they find very good agreement with which sex faces the most intense competition.
On notable exception is the hippocampus, where the males both face intense competition and invest more resources in the offspring. Because of course it had to be hippocampi.
The “random sampling” that causes genetic drift is applied once every generation, asexual or not, so the optimal number of types depends on the ratio of generations that are asexual vs sexual. The Constable & Kokko paper has a mathematical model to quantify how many asexual generations you need for 2 being the optimum, and it turns out that most isogamous species are well into that regime.
That being said, you’re entirely right when you ask “why is the equilibrium 2 instead of 3 or 5 or different for different species?” – Constable’s model and empirical data is only for isogamous species like baker’s yeast. It seems plausible that our isogamous ancestors were in the same regime, and then anisogamy evolved and kind of locked us into a 2-types configuration. But that’s mostly speculation, I don’t think we have any clear empirical data that confirms this hypothesis. That’s still open to investigation.
Another thing I didn’t mention is that the organelle-competition hypothesis naturally leads to 2 types, so it could simply be that.
The Talk: a brief explanation of sexual dimorphism
In their book on social dominance, Sidanius and Pratto make a relevant point: first, they cite a bunch of audit studies where researchers send fake resumes to employers, and find a marked bias against employing African American. Then, they point to Gallup polls asking people whether African American face any discrimination, and almost half of African-Americans themselves say they don’t. Same for discrimination in justice or housing. So, when the book was published back in the 90s, many black people didn’t believe in racial discrimination, even though it affected them personally in their life.
This means that people’s perception of discrimination is not so much influenced by lived experience, but by what the dominant ideology is at a particular time. Back in the 90s, racial discrimination wasn’t emphasized in the dominant discourse, so people thought it wasn’t very important. In that case, standpoint epistemology just entrenches the dominant beliefs.
Another example: today, there’s a vast body of research showing large discrimination against men when applying for housing. If you’ve ever applied for a place to rent, this has affected you personally favourably or not. But were you aware of it? If you did an online survey asking men what discrimination they face, how many of them would bring up housing discrimination? They don’t know about it, because the dominant ideology doesn’t talk about it.
I see this as a critical failure of standpoint epistemology (and the “lived experience” approach in general). Here is a 2011 survey where white Americans claimed that white people face more discrimination than black people. I don’t think this gives us any valuable information about how much discrimination white people actually face.
(I do see the value of lived experience for hypothesis generation, of course.)
Reverse-correlation: how to summon the ghost of your mental imagery
That single broader idea belongs in a single paragraph. Do not split ideas unnecessarily; and certainly do not combine them.
That’s interesting, I usually don’t think about this when writing. I will in the future.
On using words precisely: I find it more useful to think about how the reader will use the text to make an inference about what’s going on in my head. Of course words have official labels that say what they are supposed to mean, but in pratice what matters is how you think I think, and how I think you think I think (you’ll recognize a Schelling point). This may be correlated with the dictionary definitions, but it doesn’t have to. For example, the word pratice doesn’t exist, yet you can understand the meaning of this paragraph just as precisely as if I had written practice. Maybe it’s just my experience, but thinking in this way makes writing feel less constrained.
Could there be a signalling component? Nobody you see online would ever be in favour of conversion therapy, so there’s no risk for you to be mistaken for one of them. The ideology where one excludes anyone who doesn’t support gay rights become the baseline, the least sophisticated ideology, so it’s tempting to be a meta-contrarian and argue against it, which signals intelligence and freedom of mind. But IRL, you see that there are pretty homophobic people around (could be some family members at the Christmas dinner), so being a meta-contrarian is no longer an option, as it would just signal intolerance.
I agree on the point that open source software doesn’t have to be more secure. My understanding is that they are less likely to send user data to third parties as they’re not trying to make ad money (or you could just remove that part from the source). For the exploits-finding AI, I can only hope that the white hats will outnumber the black hats.
I’m also a postdoc, and my institution more or less requires having a smartphone because you can’t do anything without their proprietary 2-factors authentication. The other proprietary thing that seem mandatory is Zoom, have you found a way to escape from it?
This is just my humble opinion, but I found this post hilarious.
I see your point, and you’re right. Data leaks from big companies or governments are not impossible though, they happen regularly!
Android is (partially) open source but it’s not “free as in freedom”, which is a technically narrower thing: https://itsfoss.com/what-is-foss/
It’s time to worry about online privacy again
I agree, though it depends on whether rational design of genomes is even possible, and can do at least as well as natural selection. Can we ever come up with something like an ATP synthase? (Tbh, just maximizing the traits we know about may be enough to stay in the game for a while)
What do you mean by curating? So far I’ve tried to answer the questions and objections when I saw them, are there some I’ve missed? (Obviously I don’t pretend to be able to answer everything). Also, do you think there are some clarifications that I should add to the main text?