Martian Genes: Alien or Just Weirdly Familiar?

Certainly they would not match any known life - even if they appeared similar at macro scale.

We can now sequence of the entire genome of microbes. The simplest have thousands of genes.
We are so good at this now we can tell how far back in history two organisms diverged "simply" by looking at the number of genes that have changed.

There would be little correlation with the genes of Earth life.
 
Richard Townsend said:
If bacteria evolve on Mars right now, would we recognise their genes as alien, or just a different accent for life?
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“Right now”?

It took 600 million years for life to arise on Earth from inanimate matter. We have no idea if that’s a typical timeframe; it’s n=1 for all the life we’re familiar with. But it’s safe to say that it will take a long time, on the scale of geological eras. So, if Mars is sterile now, we’re not going to see Martian life emerge in our lifetime. (By ‘lifetime’, I mean the lifetime of our species, not us individually.)

If there’s already life on Mars, then there’s two possibilities: it’s indigenous to Mars, or it’s terrestrial life that has transferred to Mars via impact debris (panspermia). If we find life on Mars, it should be quite obvious to which of the two possibilities it belongs. Regardless of the category, it will be sub-surface where it’s warmer and wetter with less radiation. Indigenous Martian life (ie. it arose and evolved on Mars) is perfectly plausible as Mars has a very wet and Earth-like history.

As for the idea of “Martian genes”…

If life exists elsewhere in the Solar System, the most plausible expectation is microbial-like life that is functionally analogous - but not identical - to terrestrial bacteria or archaea. There is no requirement that extra-terrestrial life use DNA, RNA, or terrestrial nitrogenous bases, provided it can still satisfy the core functions of heredity and evolution. Heredity can be implemented in multiple chemical ways. However, carbon-based chemistry is overwhelmingly favoured due to its versatility and stability, and the ready availability of carbon throughout the Solar System.
 
Hercules Rockefeller said:
“Right now”?

It took 600 million years for life to arise on Earth from inanimate matter. We have no idea if that’s a typical timeframe; it’s n=1 for all the life we’re familiar with. But it’s safe to say that it will take a long time, on the scale of geological eras. So, if Mars is sterile now, we’re not going to see Martian life emerge in our lifetime. (By ‘lifetime’, I mean the lifetime of our species, not us individually.)

If there’s already life on Mars, then there’s two possibilities: it’s indigenous to Mars, or it’s terrestrial life that has transferred to Mars via impact debris (panspermia). If we find life on Mars, it should be quite obvious to which of the two possibilities it belongs. Regardless of the category, it will be sub-surface where it’s warmer and wetter with less radiation. Indigenous Martian life (ie. it arose and evolved on Mars) is perfectly plausible as Mars has a very wet and Earth-like history.

As for the idea of “Martian genes”…

If life exists elsewhere in the Solar System, the most plausible expectation is microbial-like life that is functionally analogous - but not identical - to terrestrial bacteria or archaea. There is no requirement that extra-terrestrial life use DNA, RNA, or terrestrial nitrogenous bases, provided it can still satisfy the core functions of heredity and evolution. Heredity can be implemented in multiple chemical ways. However, carbon-based chemistry is overwhelmingly favoured due to its versatility and stability, and the ready availability of carbon throughout the Solar System.
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A different mod? Wow! Well met!
 
Richard Townsend said:
If bacteria evolve on Mars right now, would we recognise their genes as alien, or just a different accent for life?
Click to expand...
Depends on whether panspermia is really a thing.

If it is, then they'd look familiar to us; they'd likely be based on DNA/RNA. They'd probably look something like (and be as different to most Earth life as) archaea.

If not, all bets are off. Could be anything. Could be self replicating salt crystals, and biologists would argue for decades over whether they are really alive or not.
 
billvon said:
Depends on whether panspermia is really a thing.

If it is, then they'd look familiar to us; they'd likely be based on DNA/RNA. They'd probably look something like (and be as different to most Earth life as) archaea.

If not, all bets are off. Could be anything. Could be self replicating salt crystals, and biologists would argue for decades over whether they are really alivQe or not.
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Yes material from mars has reached us. Be cool if it turned out Mars "seeded" earth.
 
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