What confuses me about tardigrades is how they are resistant to so many things. Like it would make sense to have resistance to one or two things, but all those things? Why is that even needed? Do they keep ending up in bad situations?
It’s a form of evolutionary cross-tolerance. The mechanisms that tardigrades evolved to handle the hydration/dehydration cycle in moss just happen to be very effective at protecting them from radiation and a bunch of other environments.
That’s not a very satisfying answer until you dig into the biology that makes it happen. The mechanisms that protect cells from environmental stress are useful for many different kinds of stressors.
There is usually some energy cost associated to keeping resistance unless critically needed. Or limited place on genome.
Any organism from virus to human will happily shed over time (generations) any resistance we now consider crucial to survival, just change its environment enough.
You send them with algae and photosynthetic bacteria, which are also pretty robust. Algae is (are?)a mazing. I would not at all be surprised if you sent tardigrades to enough remote planets, that they would find some local equivalent of algae that is mostly digestable. And photosynthetic bacteria were some of the earliest forms of life on earth, likely surviving adverse conditions (I think it's still an open question whether the earliest organisms with metabolism used geochemical energy or photosynthetic energy)
If we're speaking about terraforming, cyanobacteria photosynthesizes, produces oxygen, and is also hardy. Forget the tardigrades, we don't want to fight their descendants when humanity eventually colonizes.
Bonus: the rise in oxygen might kill any existing native life, or make it more like ours.
it's unlikely, as they showed up evolutionarily after preceding organisms and were wholly consistent with evolution of preceding organisms. They are remarkably similar to other organisms, like isopods.
The advantage of panspermia is that when cornered, it can retreat to more primitive life forms, and even basic life molecules. It can't be reasonably unproven, so the onus is on the supporters to prove it.
What confuses me about tardigrades is how they are resistant to so many things. Like it would make sense to have resistance to one or two things, but all those things? Why is that even needed? Do they keep ending up in bad situations?
It’s a form of evolutionary cross-tolerance. The mechanisms that tardigrades evolved to handle the hydration/dehydration cycle in moss just happen to be very effective at protecting them from radiation and a bunch of other environments.
That’s not a very satisfying answer until you dig into the biology that makes it happen. The mechanisms that protect cells from environmental stress are useful for many different kinds of stressors.
> "Like it would make sense to have resistance to one or two things, but all those things? "
It makes sens, and all organisms and creatures would be more than happy to evolve to where they have resistance to everything.
That's a way to remain healthy, strong and spread own genes as much as possible for a long time.
There is usually some energy cost associated to keeping resistance unless critically needed. Or limited place on genome.
Any organism from virus to human will happily shed over time (generations) any resistance we now consider crucial to survival, just change its environment enough.
Tardigrades would be a good candidate for seeding other planets in our galaxy imo
I get what you mean but tardigrades don't photosynthesize, so you still have the problem of what they should eat.
You send them with algae and photosynthetic bacteria, which are also pretty robust. Algae is (are?)a mazing. I would not at all be surprised if you sent tardigrades to enough remote planets, that they would find some local equivalent of algae that is mostly digestable. And photosynthetic bacteria were some of the earliest forms of life on earth, likely surviving adverse conditions (I think it's still an open question whether the earliest organisms with metabolism used geochemical energy or photosynthetic energy)
If we're speaking about terraforming, cyanobacteria photosynthesizes, produces oxygen, and is also hardy. Forget the tardigrades, we don't want to fight their descendants when humanity eventually colonizes.
Bonus: the rise in oxygen might kill any existing native life, or make it more like ours.
Maybe they were
it's unlikely, as they showed up evolutionarily after preceding organisms and were wholly consistent with evolution of preceding organisms. They are remarkably similar to other organisms, like isopods.
The advantage of panspermia is that when cornered, it can retreat to more primitive life forms, and even basic life molecules. It can't be reasonably unproven, so the onus is on the supporters to prove it.
Maybe they are.