# Tag Info

1 vote

### What pressures would force most life to possess external stomachs, and how would they avoid losing moisture on an Arid planet?

What pressures would force most life to possess external stomachs? Time Pressure Internal digestive systems are best to avoid moisture loss. But it takes a long time to develop such specialized ...
• 44.4k
1 vote

### What pressures would force most life to possess external stomachs, and how would they avoid losing moisture on an Arid planet?

Slurploc Bags Thanks to DWKraus for the Toxic Environment answer and to John for his comment on that answer about an single use external container being biologically too expensive. Those got me ...
• 2,566

### Can a person be immune to all diseases and poisons

Not possible, but ... You can approach this state by making your character an alien. His biochemistry is subtly different to ours in just about every respect. This isn't something that could happen by ...
• 11.2k

### What pressures would force most life to possess external stomachs, and how would they avoid losing moisture on an Arid planet?

Its not always external External stomach only work with extremely small body size, aquatic habitats, or a fibrous body structure. the bigger an animal is the more surface are it needs for digestion, ...
• 71.3k

### Can a person be immune to all diseases and poisons

Diseases: Yes I would argue that anything that your body resists via its immune system could potentially be harmless, if your immune system were fast enough. The human immune system is already ...
• 151

### What pressures would force most life to possess external stomachs, and how would they avoid losing moisture on an Arid planet?

Toxic Environment: Your re-evolved world has evolved desperately toxic plants. Perhaps they utilize alternative amino acids, or heavy metals, or horrifyingly destructive neurotoxins (which might ...
• 57.3k
1 vote

### Can a person be immune to all diseases and poisons

Lots of answers already. Yet, I must give a dissenting opinion. Diseases: YES Robots are immune to all diseases. Computer viruses don't count. It's possible (not plausible) to have an alternate ...
• 3,221
1 vote

### What pressures would force most life to possess external stomachs, and how would they avoid losing moisture on an Arid planet?

I think you are stuck with water vapor being lost if it is exposed to the arid environment. But there can be adaptions to reduce the amount of water being lost such as membranes designed for that ...
• 5,024

### Can a person be immune to all diseases and poisons

"Born" Your hero ain't from around here. He was raised as a human and his body was meant to pass as human under cursory exam but he is not human and not even a biological organism. Germs, ...
• 283k

### Can a person be immune to all diseases and poisons

Your hero needs a hazmat suit or some equivalent If you want to avoid poison or pathogens, don't take in things from the environment, including air, water, or food. Also, you'll probably want to cover ...

### Can a person be immune to all diseases and poisons

It is not possible to be immune to all poisons as there are so many of them and many toxic chemicals cause strong redox reactions that won't give a damn about biochemical niceties. For example ...
• 32.2k

### Can a person be immune to all diseases and poisons

Moving the Goalposts Since the general consensus is "not possible" maybe just move the goalposts a bit and think of how it (or something effectively similar) could be made to happen (since ...
• 1,360

### Can a person be immune to all diseases and poisons

Not only it won't work as you think, it might actually make them more vulnerable to death by (immune) overreaction. You see, the inside of our body is a really good place to live in: it is nicely warm ...
• 12.6k

### Can a person be immune to all diseases and poisons

Not possible at all An immune system simply can't protect against everything. A peime example is HIV. This attacks the immune system to great effect, using it to spread further. But rabies is also a ...
• 29.4k

### Can a person be immune to all diseases and poisons

BEHOLD: THE PRION I can't see how your OC could be possibly be immune to everything, because there's one specific type of infectious agent that cannot be fought with anything that isn't 100°C+ ...
• 10.2k

### Can a person be immune to all diseases and poisons

TL;DR: Powers as given: Not Plausible The Super-immune System A person's immune system is designed to suss out things like bacteria and viruses, and likely anything that could mimic it enough. It ...
• 4,240

### Can a person be immune to all diseases and poisons

Not plausible. The term poison ranges from complex nerve agents to something as simple as carbon monoxide binding to hemoglobin. An improvided immune system is something different. The effects of ...
• 99.4k

### What carbon-based alternative biochemistries would work in high-temperature, high-pressure water?

Protein thermostability can be increased by the formation of salt bridges within parts of the protein structure. Denaturing as a result of pressure would begin to occur at about 2000 atm. I don't see ...
• 419
1 vote

### Are there any glaring problems in my alternate biochemistry?

The lack of oxygen and nitrogen in the classes of biomolecules you've described so far is a little weird. Fluorine can replace oxygen as an oxidizer, but not in structural roles, and it can only ...
• 35.9k

### What carbon-based alternative biochemistries would work in high-temperature, high-pressure water?

Earthly extremophile bacteria, like Pyrolobus fumarii and Pyrococcus furiosus, have been found living between 110 °C and 121 °C, in Submarine hydrothermal vents and oceanic crust, where the pressure ...
• 245k
1 vote

### Are there any glaring problems in my alternate biochemistry?

It is unlikely that silicon tetrafluoride would exist freely in the atmosphere. SiF4 will react with the HF in the ocean, producing quantities of H2SiF6. Information from Silicon Tetrafluoride ...
• 419

### Are there any glaring problems in my alternate biochemistry?

I am not enough of a chemist to give meaningful avice. There are a few issues though that come to my mind and that may (or may not) be relevant. "Adam uses ... HFCs as a replacement for sugars&...
• 1,556

### Alternatives for Phospholipid bilayer

Silane chains Congratulations, you've discovered a justification for properly silicon-based life! Silanes are unstable in the presence of oxygen or water, but as long as you've got mostly-anhydrous ...
• 35.9k

### Alternatives for Phospholipid bilayer

Perfluoroalkyl Amides Phospholipid bilayers rely on molecules with a hydrophilic head and hydrophobic tail. In an aqueous environment, these molecules form a two layer structure with the hydrophobic ...
• 419
Accepted

### This organism can survive temperatures of 45°C. What's the next overheating-related threat?

It seems that there are eukaryotes that can live above 45 C. There is a nice review article life in extreme environments that has charts out the upper temperature limits for each taxa, at least as ...
• 5,024

### Fire heat organism

Presumably, by "cooled plasma" you mean something like nonthermal plasma, which is sometimes referred to as "cold plasma". It doesn't really matter though, because regardless of ...
• 62.8k

### What organelles(parts of a cell) did early cells most likely have?

It has been suggested that the evolution of the first Eukaryotic cells (responsible for all multicellular life) was a very unlikely freak accident when a bacterial cell somehow got inside an Achaea ...
• 32.2k
Accepted

### What organelles(parts of a cell) did early cells most likely have?

this simplest living cell is Mycoplasma mycoides, and organelle wise it is basically just a plasma membrane, DNA, and ribosomes. There is a slurry of proteins and RNA but nothing you would call an ...
• 71.3k

### Why is overpopulation not an issue on a floating island where people can live for a long time

The drug eventually drives people to death The drug builds up in a person's body over time. This can then become a problem in two ways: skipping a dose of the drug has bad consequences; or ...
• 8,578
1 vote

### Why is overpopulation not an issue on a floating island where people can live for a long time

I think no special reason is needed If your world is technologically in 1980's-1990's this is close to modern technology level. Currently in most first world countries the birth rates are close to or ...
• 1,192
1 vote

### What deficiency would make my raiders the most desperate?

Iodine. In the midwest USA there was a major iodine deficiency due to a lack of iodine in soil, which lead to plants and animals being iodine deficient. Some side effects of iodine deficiency in ...
• 51

### Why is overpopulation not an issue on a floating island where people can live for a long time

I think your questions answers your question. Twice By famine This is important because things like a famine or lack of resources (such as water), Or by sword Simply getting rid of it isn't an ...
• 51

### Why is overpopulation not an issue on a floating island where people can live for a long time

Decreased Libido: The drugs are affecting the desire of the people using them. People simply have less sex, and the levels keep going down over time. By around age 50, there is really no particular ...
• 57.3k

### Why is overpopulation not an issue on a floating island where people can live for a long time

Many Polynesian Islands had this already, no need for drugs. Population was limited by endemic warfare and blood feuds. Families with 10+ children were common. Sickness was almost unknown until the ...
• 20k

### Why is overpopulation not an issue on a floating island where people can live for a long time

Sausage party Dudes, dudes, dudes. It is the island of ever-young dudes. They play the sports, argue about the rules, make wars on other islands, grill, and generally engage in never-getting-senile ...
• 283k

### Why is overpopulation not an issue on a floating island where people can live for a long time

If the drug drastically lowers infant mortality then population growth will halt naturally. we see this in countries where infant mortality drops low enough, people have fewer children. Evolutionarily ...
• 71.3k

### Why is overpopulation not an issue on a floating island where people can live for a long time

The drug makes people sterile. Most people can have their first few children before they need the drug, but once they take it for the first time, they are sterile for the rest of their lives. Pair ...
• 2,629

### Why is overpopulation not an issue on a floating island where people can live for a long time

The drug helps preventing aging related diseases and deaths, but does nothing to avoid fall related deaths. And if you live on a floating island, exposed to winds which will be stronger than at ground ...
• 245k

### Viable alternatives to lignin and cellulose for cell walls and wood?

Polycarbonate. https://en.wikipedia.org/wiki/Polycarbonate#Construction_materials lexan sheets There are many types of plastic. Above is polycarbonate; the stuff is strong, light and durable. ...
• 283k
Accepted

### Viable alternatives to lignin and cellulose for cell walls and wood?

The space of possible structural chemicals, as AlexP observed, is Quite Big. Cellulose is a polysaccharide, for example. Chitin is another, and is used for the cell walls of fungi. You don't have any ...
• 62.8k

### Viable alternatives to lignin and cellulose for cell walls and wood?

Chitin or Keratin From Wikipedia: Chitin $(C_8H_{13}O_5N)$ is a primary component of cell walls in fungi, the exoskeletons of arthropods such as crustaceans and insects, and the radulae, cephalopod ...
• 44.4k

### programing genetic memory (or; the hard way to get your kids to clean their room.)

Epigenetics In mammals, there is evidence that the environment of a parent affects what instincts and biological traits are passed down at better than random rates as purely evolutionist views would ...
• 67.3k

### programing genetic memory (or; the hard way to get your kids to clean their room.)

The ability to speak is genetically programmed into humans. That is why most everyone on the planet speaks some language. It is also why your dog and cat cannot speak to you. Some apes can be taught ...
• 44.4k

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