I prefer using boiling 91% isopropanol to clean things, then run scalding water through the glass for a minute or 2- It reduces the amount of stuff used which is my reasoning. I microwave my isopropanol for 45 seconds and it's totally volatile and ready to strip oils on contact.

Decals wouldn't do anything. Painting it red on the other hand... Waaaagh!!

If you ask me, it's parrots and corvids. I haven't seen an intelligent behaviour that apes or cetaceans can do that these birds cannot.

This statement. although 25+ years old, is still pretty good.

If you take a whole bunch of things that people have to learn to do (e.g. maths, spelling, logic, speed of thought, and memory), they all correlate pretty well together. So psychologists call this statistical manifold "g" for "general intelligence".

Theories like Gardner's multiple intelligences are frankly nonsensical because it ignores statistical reality, and replaces the word "talent" or "ability" with "intelligence". Thus he refers to intelligent (meaning good) dancers with a straight face.

The biological basis of intelligence is largely unknown, although brain size, number of neurons, and amount of folding is correlated.

Cognitive abilities like how much you can hold in your working memory, and how quickly you can make decisions, although correlate and plausibly cause intelligence differences.

Is it officially a 3 star system? I read something (probably from this sub) that said it was unknown if proxima was gravity bound to the other 2.

Thats a size difference in my eyes, due to a complex mating behavior humans developed over time and male physical aspects is one parameter that played/plays quite a significant role, which also indicates health.. likely the major aspects in mate selection on both sides. And could you please define what you refer to when using the term size dimorphism.

When you mix salt and vinegar you make sodium acetate and hydrochloric acid. Basic chemistry, mate.

edit: lol

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Edward’s and Patau syndrome, both of which have more than a 90% mortality rate before 1 year of age. There are extremely rare cases of survival beyond childhood which is why I said almost always, but by and large these syndromes do not allow for survival to adulthood.

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Humans do show size dimorphism (about 15%), albeit not as much as some other primates, and certainly not as much as elephant seals. There is also substantial dimorphism in upper body musculature relative to lower body, suggesting adaptations for fighting.

The rest of what you described is Darwin's male-male competition and female choice.

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Hydrochloric acid in vinegar and salt?

Have a word with your chipshop mate, lol.

People with 45 chromosomes (or to generalize to other species: individuals with mismatched chromosome counts as a result of evolutionarily recent chromosome fusion or splitting) do not generally have a high chance of being sterile. They may have a high chance of some kind of reduced fertility, though even that is not clear. There's a major detection bias here since almost no one ever gets karyotyped unless they believe they have fertility problems in the first place. This inflates estimates of how often these chromosome mismatches cause fertility problems.

The answer to the question of why any mutation that has any negative effect on fertility would spread is, as others have said, random success. In evolutionary terms, this is called genetic drift. Genetic drift is sometimes thought of as affecting neutral variation that doesn't have either positive or negative effects. However, it's been well understood from the beginning of genetic drift research that what really matters is the "strength" of genetic drift versus the "strength" of natural selection. Many things can make genetic drift stronger, like a small population or an expanding population or pops where some individuals reproduce more than others, etc. If enough of these drift exagerating factors are found in a population (as they often have to humans), then even variation with pretty strong negative effects can still spread. Beneficial mutations can also be lost in the same way.

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Thank you for the links and answer!

I wonder if the LNP’s may be behind some of the cases. There was a possible vaccine-induced myocarditis in the Novavax trial, which are LNPs with recombinant protein S. Although the the fact that it contains protein S may be confounding.

> -they just consider the parts of the chain as having well-defined positions in 3d-space, and add up energy from pairwise interactions between the parts that end up close to each others.

Yes, but also if you want an accurate calculation of that energy, you need to use quantum mechanics. The nuclei of the atoms have definite positions, but electrons do not

Ah. The OP was talking about installing a stove so I was thinking like a wood stove.

Size is not a sexual dimorphism in the human species, male and female are relatively similar in size, there are actually many women taller than man. Size, which is linked to strength, makes/made a man go up in the competence hierarchy, which makes him more attractive as a mating partner, which in turn means that the genes responsible are passed on to the next generation.

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I mean, they are not the same thing but still fall under the category of intermolecular forces. And the commenter is correct that Van Der Waals forces are caused by the fluctuating polarizations of particles at a particular distance, which is understood via quantum dynamics.

I think your misunderstanding OP's full question. They're asking, if the reproduction is difficult and the offspring are most likely sterile, how did species come to have different chromosomes at all? If we all have a common ancestor when you go back far enough, that must mean a mutation happened that caused one of them to have a different number of chromosomes. Most of the comments are saying how the actual producing offspring isnt difficult, but the fertility of that offspring is rare. But then how could those mutations in the number of chromosomes have become persistent enough that the offspring of them were fertile and able to even pass that down themselves?

Summary: If a member of a species was born with an extra chromosome, or two chromosomes fused, their offspring have a high change of being sterile. How could the increase of decrease of a chromosome become wide spread in a species if that happens?

I think some of the comments are misunderstanding OP's full question. They're asking, if the reproduction is difficult and the offspring are most likely sterile, how did species come to have different chromosomes at all? If we all have a common ancestor when you go back far enough, that must mean a mutation happened that caused one of them to have a different number of chromosomes. Most of the comments are saying how the actual producing offspring isnt difficult, but the fertility of that offspring is rare. But then how could those mutations in the number of chromosomes have become persistent enough that the offspring of them were fertile and able to even pass that down themselves?

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