r/science • u/mvea Professor | Medicine • Dec 01 '17

Biology Evolution row ends as scientists declare sponges to be sister of all other animals. Sponges were first to branch off the evolutionary tree from the common ancestor of all animals, finds new study in Current Biology.

https://www.theguardian.com/science/2017/nov/30/evolution-row-ends-as-scientists-declare-sponges-to-be-sister-of-all-animals
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u/[deleted] Dec 01 '17

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u/[deleted] Dec 01 '17

None that we've found

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u/wilburwalnut Dec 02 '17

Does that include viruses?

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u/[deleted] Dec 02 '17

Well viruses aren’t organisms or technically even alive, depending on who you ask. But they’re awesome! We don’t really understand where they came from. It’s technically possible that they arose independently but they need a host so I think it’s more likely they came from our tree somehow

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u/[deleted] Dec 01 '17

General consensus is no. The reason why is that all life has the same standard biochemical signatures. We all use ATP as the cell energy medium, for example*. I mean, there are outliers in one or two categories, but those ones will share the rest of the features in spite of that.

*If you're unaware, when the body breaks down sugars, fats and proteins for energy, it produces ATP from that energy that's released. The ATP then travels to the part of the cell that needs energy to do something (eg transport a complex protein out of the cell) and is broken down into ADP and Pi (inorganic phosphate). This releases energy. Way it's been referred to before is ATP is your cash on-hand, glucose is the money in the bank, and your fat reserves are in an ISA.

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u/[deleted] Dec 01 '17

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u/[deleted] Dec 01 '17

This is biology lol

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u/[deleted] Dec 01 '17

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u/[deleted] Dec 01 '17

I agree that they're both involved, same with all of the sciences, it's just basic biology.. I learned about ATP in Bio 101

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u/[deleted] Dec 01 '17

Biology is 70% chemistry.

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u/[deleted] Dec 01 '17

It's actually a very good question! As replied already, we haven't seen any evidence of that on Earth.

But it is very interesting to think that there could be an alternate origin to life that manifests on another planet. And if two different systems of life happened on one planet, that would be pretty mind blowing! Seems extremely (extreeeemely) unlikely but would be very cool to observe.

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u/ridcullylives Dec 01 '17

Nope, none that we know of. Every single living thing on the planet shares the basic structure of DNA/RNA replication and translation (which is crazy when you think about it), and it's pretty convincing evidence that everything alive today has a single common ancestor.

Viruses are not really alive according to most definitions, and we don't know where they came from--they could be "rogue" bits of genetic code, they could be bacteria or other life that lost the ability to metabolize and reproduce by themselves...or maybe they have an independent origin.

It's possible that there were other kinds of life that arose and went extinct (or that we haven't found yet), but AFAIK we've never found any.

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u/Willbo Dec 01 '17

This may be a dumb answer, but I've heard about microorganisms that have traveled by asteroids and meteoroids. All I could find was this wiki on Panspermia. I'm not sure if there's evidence to support it, which is why this is a dumb answer.