Tlaloc_Temporal

Yeah, hydrocarbons are probably going to be really good energy storage for airplanes and gas turbine generators. Outside of that, I don’t see much use for a rare, dirty, hot, energy source. Rockets I guess.

This is a bit of an issue when what they want out of the oil is the energy. If you have enough energy to make oil, why not just use the energy directly?

I’d much prefer those over cursive characters. I can tell those apart when written by hand.

One of my default phone keyboards had them. Either an old bersion of Gboard, or the Samsung keyboard.

Ah, a definition of life in Namibia for a grade 12 course. Quite the scientific authority you have there.

Here’s a short paper (Origins of Life and Evolution of the Biosphere 32, 387-393, 2002) that refutes your position that a single definition of life is definitively agreed upon.

Here’s a paper (Synthese, 2012) on how a definition of life is impossible and pointless.

There is a species of dog that infects other dogs as a parasite. There are viruses with larger genomes than some bacteria. Obligate parasites and endosymbiotes often lose large portions of their genome and depend on their hosts for their vital functions. Nature doesn’t care about are definitions, and biology hates hard cutoffs.

Sure, I agree with most of that. Dwarf planets not being planets feels intentionally confusing though, and the definition is basically Major/Minor planet anyway. A planet having hydrostatic equilibrium is such an elegant and applicable limit, yet the current definition specifically counts only bodies that clear orbits (how is poorly defined) around this star. It’s a bad definition in several ways, and many astronomers have already complained about this. Many use planet anyway, particularly planetary scientists.

It’s all about how useful the word is, and putting the limit at our star and a vague idea being the biggest thing in one general area feels more like it’s gatekeeping the word “planet” rather than facilitating understanding or discriminating something useful. Planets can change class simply by drifting closer or farther away from the sun, or even be temporarily demoted by a rogue planet.

most would agree that the best definition would be the one that has the biggest consensus amongst biologists, and maybe more precisely microbiologists.

This is precisely the part I disagree with. Consensus isn’t truth, and better definitions are likely possible. Not that consensus even exists here, the specific definition of life is controversial and several definitions are used in different areas. Homeostatic reproducers, replicators, entropy pumps, chemical system that evolve; it’s almost as bad as double-slit interpretations.

And most such definitions you’d find would include “self-replication” as a necessary trait.

Replication? Sure. Self-replication? That’s either an incredibly arbitrary limit seeminly designed to specifically exclude viruses, or isn’t applicable to anything except perhaps the entire tree of life as a whole. Where is the line of “self” drawn? As a human, you can’t replicate yourself, you need other organisms to collect energy for you and to make some proteins for you, and a sexual partner. Tapeworms need their hosts to digest food for them; cuckoos need other birds to feed and raise their chicks; E.coli needs other organisms to feed them and maintain a suitable environment; clonally transmissible dogs need another dog for all nutrients, and protection; and viruses need cells to provide the replication hardware. Some viruses even have some of the genes necessary for DNA copying and protein synthesis, and can be infected by smaller viruses themselves.

It’s the zip file, it can’t do anything until a system unzips it. The resulting program can be really small and still do a lot, especially if it modifies another program.

I disagree. At one time, consensus was the Earth was the center of the universe, that the world was just a few thousand years old, that life just sprung into being sometimes, that unwashed hands were perfectly fine to perform surgery with, that some peoples were much closer to other animals than some other peoples, that the universe was static, that light was continuous, and that Ceres was a planet.

Consensus is nice, but usefulness is the gold standard. Is holding metabolism and a complex proteome as the limit of life --excluding viruses, preons, and mechanical reproducers-- useful to expanding our understanding of life and how it functions? Is taking replicators as the most important distinction a necessary step to understanding the origin of life and how we can engineer it ourselves? Will the ability to manipulate certain chemicals and not others help us describe the world? Are edge cases explained better with a genomic, proteomic, or metabolomic base?

I do know that we have a lot left to learn, and I would be very surprised if our current definition of life is fully sufficient for the next century of life sciences.

Another example; mammals probably developed pregnancy using an Autoimmune virus’ genes in the placenta to prevent the fetus from being destroyed by the immune system.

And yet, that wasp will die out in a single generation if it’s host disappears. It does most of it’s own processing, but it’s existence is still contingent on a specific host species. Does that make parasites less alive than other life?

Many insects go through a phase of their lives without a mouth or stomach. They can’t eat at all and quickly starve. Are they less alive?

Most life would die out if the sun stopped shining. Does that make chemotrophic organisms more alive than phototrophic life?

Chemotrophic life still needs chemicals to eat, and are completely useless without them. Does that make a Boltzmann Brain the most alive thing possible, coming into existence without any outside action whatsoever?

Plants depend on the sun for energy, animals depend on plants for carbohydrates, we depend on animals and plants for carbs and proteins, mayflies depend on stored energy from their larval stage, parasites depend on other organisms for transportation, food, protection, parenting, and even homeostasis. Viruses depending on other cells for reproduction doesn’t seem out of place to me.

Complex organisms can also drastically change from point mutations, although such changes are more likely to kill the organism as they grow more complex. Viruses are so incredibly simple and make so many copies that this doesn’t matter.

Many organisms can hybridize, which can make drastic changes with much less chance of fatal errors. Plants especially like this; see farmed maize vs wild maize or the entire brassica genus.

Viruses also hybridize though, and can do so much more drastically. Most of the critical genes are in the host, so virus genomes are free to do whatever, and because they highjack other genomes a very small change can radically alter their behavior.

They had a huge amount of diversity between the Cambrian and the Carboniferous periods, then all but a single order (Nautilida) died out when land animals became a thing, and only a single genus survived the Triassic extinction. They went on to flurish globally until only 20 million years ago, when specifically seals appeared. Nautiloids went extinct everywhere seals existed, leaving the only living species in the Indo-Pacific.

Their shells have a tendency to float huge distances, with some floating for over a decade. So not only are they a “living fossil”, their shells are found even when they are not.