atomfullerene

atomfullerene t1_j7le57o wrote

The species we use for research are called "model species". We use these species for a combination of reasons. Part of it is because they have some relevant connection to human biology (or other kinds of biology, depending on what we are studying). But just as important, if not more so, are other factors. Things like "how difficult/expensive is this animal to keep in captivity", "how much do we know about this animal in general", "what are the ethics of working with this animal", "how easy is this animal to work with in a lab setting", "how many other scientists work with this animal", and "how easy is it to get these animals".

It's not that rhesus monkeys and baboons are particularly more human-like than other old-world monkeys. But they are widely available, reasonably easy to keep (for a primate), and have had plenty of existing research done on them, which means their care and biology is understood already. All this makes them easier to use than some other species.

You can see similar patterns with lab rats and mice, zebrafish, fruit flies, C. elegans, and other model organisms. It's not that they are especially different from their relatives, but they are widely used, cheap, easy and fast to raise.

Contrasting, say, rhesus monkeys with chimpanzees....chimps are bigger, more intelligent and harder to keep suitably in captivity (so more ethical issues), they reproduce more slowly, and they are endangered. Even though they are more humanlike in their biology, working with them is kind of a nightmare. It's more expensive, you need bigger facilities, you aren't going to get ethics board sign offs as easily, and it's not easy to source chimps. And especially if you are studying the immune system, other animals are pretty close. The marginal benefit of working with chimps just doesn't outweigh the extra difficulty. Really the only time you see research done on chimps is when there's some particular reason you can't use other primates (or non-primates).

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atomfullerene t1_j73rqap wrote

It's not entirely clear to me what benefit there would be to a research team in covertly cloning a human. You obviously can't publish on it, which is the lifeblood of academic researchers. There's no obvious practical benefit to a for profit corporation, unless you want to, like, sell cloning services to rich people...in which case you have to advertise that you can do it. And it's not super clear why most governments would be interested in it.

It's certainly not impossible (especially for groups in the early stages who want to stay quiet until they have success), and after all it's a big world full of all sorts of people who try all sorts of things. I wouldn't be shocked. But I don't in general see a big motivation for people trying to covertly clone people. And generally speaking, people need motivation to spend a lot of money.

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atomfullerene t1_j70wkid wrote

Aside from the other answers, cloning has gone on to see commercial use and use in conservation (although that's just starting). There are a handful of companies (like ViaGen in the USA) who clone pets and livestock (useful for animal breeders). Cloning has also been done on a few endangered animals, for example a few years back a black footed ferret was cloned.

So the technology has moved out of the lab and into some practical applications.

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atomfullerene t1_j6uf58h wrote

First of all "seriously considering" just means " people are talking and writing about it" not anything concrete.

But even floating on Venus has advantages over gas giants. You have much higher gravity on gas giants. It is much harder to launch out of the atmosphere. The hydrogen helium mix is worse for bouyancy. The planets are much further away. And there is no altitude with decent pressure and temperature.

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atomfullerene t1_j6uehlv wrote

1: I think its better to say that the population explosion and climate change are both a result of the industrial revolution.

2: No. Populations dont have some innate ideal size that nature regulates for. But of course no population can grow forever, it will always be limited by some resource eventually. But there is nothing that ensures a population will collapse after reaching a limit, although it does happen sometimes.

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atomfullerene t1_j52sgbh wrote

> Before the dark times.

In a quite literal sense....it seems nearsightedness happens because children spend more time indoors, in conditions of indoor lighting. Indoor lighting is a whole lot dimmer than outdoor light, and that means the signaling process the eyes use to control their growth doesn't work properly.

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atomfullerene t1_j4k7a8g wrote

So first of all, it's not genes which are dominant or recessive, it's alleles. Alleles are variants of genes. For example, there's a blood type gene with alleles A, B, and O. You generally have two alleles of each gene, since you have two copies of (most) genes.

Alleles are dominant or recessive as a side effect of how they work. For example, consider a gene that's involved in melanin production. It's got an allele that makes melanin normally. And it's got an allele with a mutation that makes it not work. A cell will activate this gene if it senses the cell doesn't have enough melanin.

If you have two copies of the working allele, you get melanin. If you have one copy of the working allele and one of the busted allele, you get melanin. If you have two copies of the busted allele, you get no melanin. So the working allele is dominant.

Now, to get back to your question, can this change? Well...no. Because if an allele changes, it becomes a different allele. An allele is a specific version of a gene. If you mutate it in some way, you make a new version of that gene, a different allele.

Dominance and recessiveness aren't even absolute things, they depend on which other allele you are comparing to. For example, go back to A B O blood types. A is dominant over O, but it's not dominant over B. If you have A and O alleles, you just have type A blood. If you have A and B alleles, you have AB type blood. So is A dominant, or not?

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atomfullerene t1_j38m61b wrote

California has a management strategy to recharge aquifers during flood events like this one. It's called ag-MAR or flood-MAR.

Basically, the idea is to intentionally flood areas like orchards or fields during the winter, allowing floodwaters to soak into the ground and down to the aquifer. There are things you have to be careful about when doing this (nitrate contamination of groundwater, for instance) but it's a promising approach.

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atomfullerene t1_j2bcqhz wrote

Things that aren't yet fossilized are usually referred to as "subfossils" , which is probably how you want to search for this information

Anyway, I did some research and here's some things I found

This paper describes camel bones from about 3 million years ago on Ellesmere Island. They are embedded in layers of leaf and moss that are described as "subfossil" and the bones themselves were fresh enough to allow the removal of significant collagen for analysis. There have been reports of even older collagen/soft tissue, but that's in bones that have clearly been fossilized. I'm guessing these bones are closer to what you are talking about, given the context of their preservation.

Here's a similar study from the same area looking at beaver teeth and local vegetation, comparing isotope ratios to see what beavers were eating. So we are talking about plant and animal remains that still have organic material that isn't too heavily modified.

Finally, here's a paper that managed to snag DNA from mammoth teeth slightly more than a million years old. That's less than the previous studies, but DNA is more fragile than collagen, so we are talking better preserved specimens here.

Anyway, the answer is probably "A few million years, and you find them in frozen sediments"

Although who knows what might be frozen under the ice at the bottom of Antarctica

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atomfullerene t1_j29sdce wrote

>A brain's processing power isn't connected to brain size.

I mean there's some connection. A roundworm with 302 neurons can't process as much as a fly, which can't process as much as a mouse, which can't process as much as a human.

But it's not at all a 1:1 variation. Especially since neuron density can vary enormously in brains of different species.

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atomfullerene t1_j29qpvf wrote

This is one of several reasons the heliocentric theory took so long to catch on, despite being proposed as far back as the ancient Greeks. The existing conception of physics described above fits quite nicely with a geocentric universe, but doesn't mesh at all with a heliocentric theory. You need a whole new sort of physics (like gravity) to make sense of that.

Incidentally, this also means that Earth's position at the "center of the universe" in the geocentric theory wasn't quite as special as we sometimes think today. The earth was at the center, but the center wasn't necessarily seen as the "best" spot, it was more at the bottom of the cosmic pile, the place where all the dirt falls down to. The outer regions, aka the heavens, were often considered the "best seats" (due to their association with, well, heaven). There was often thought to be a "Fifth Element" (yes, the movie got its name from this idea) that inhabited the highest reaches away from earth and was what the stars and planets were made of.

This also means that the movement of the planets was seen as a fundamentally different sort of thing than the movement of apples. Apples were following the nature of earth, going toward the center. Planets were following the nature of their element, moving in perfect, ordered circles in the heavens.

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atomfullerene t1_j26h0bu wrote

Physics (the particle physics part) is the behavior of elementary particles.

Chemistry is the behavior atoms made of elementary particles interacting with each other via electric charge.

Cell Biology is the behavior of a big stew of hideously complex chemicals in bags of water.

Organismal biology is the behavior of millions of those bags of chemical water all stuck together.

Ecology is the behavior of millions of those organisms interacting across the surface of the earth.

Economics is like ecology, but you are looking at all the intelligent organisms, who are much more behaviorally complex and who occasionally do things like read your economics papers and alter their own behavior in response.

It's no wonder it's complicated!

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atomfullerene t1_j26br1c wrote

There is no normal procedure for the outbreak of a pandemic like Covid-19. Everything was kind of going crazy.

If you want to take the more charitable view, you could say the Chinese government was desperate to stop the virus from spreading and put a much higher priority on wiping out potential sources of infection (eg, the animals) and preventing spread (by locking down) than in getting researchers moving around to sample those animals before they were killed.

If you were going to be less charitable, you might say the Chinese government maybe didn't want conclusive proof to be found that it's mess of wet markets had, predictably, caused another zoonotic disease outbreak and was quite happy to see all the potential evidence killed off before it could be sampled....especially by any independent outside researchers.

One thing that's worth noting is that while it's academically interesting to know the exact path and intermediate hosts that covid took to get into people, it's actually not that important from a public health perspective. We know the broad strokes pretty well even without having all the intermediate steps perfectly filled in.

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