Living fossil

[Top Trilo]

There is a species that is called the immortal jellyfish (Turritopsis dohrnii) It could theoretically live forever, if it lived past the general fossil age of 10000 then wouldn't it be considered a fossil, an actual living breathing fossil? Does a fossil have to be dead? Thought this was an interesting subject and want your guys' opinion on it.

[Kane]

By definition, a fossil is the remains of a once living creature. 

Theoretically, if the living creature lived a million years and shed parts (such as through moulting), and those shed parts underwent fossilization, then those would be fossils. 

[Top Trilo]

28 minutes ago, Kane said:

By definition, a fossil is the remains of a once living creature. 

Theoretically, if the living creature lived a million years and shed parts (such as through moulting), and those shed parts underwent fossilization, then those would be fossils. 

This doesn't really work with jellyfish but if an animal lost an arm or a leg, than it would be considered a fossil? And then if it was stitched back together then is it still a fossil? Can something be a fossil at one time and then be not? Its not impossible but almost there. There probably isnt a correct answer for this part, but if it was up to you how would  you call it?

[Jeffrey P]

People have accused me of being a fossil, a living one I suppose. 

[Kane]

Remember, the remains have to undergo fossilization of some sort, so there would be no stitching anything back together any more than an immortal shark could wear one of its shed teeth on a necklace to say it is no longer a fossil if that tooth has been fossilized. 

 

In all cases, the biological material is now "dead" in a fossil, and eventually replaced by minerals. There is no way of reanimating the dead (with apologies to Mary Shelley  ). Even if we could take the DNA of a frozen mammoth and try to grow a piece of flesh in a lab, the mammoth itself is gone, and the source material is still a fossil. 

[Top Trilo]

5 minutes ago, Kane said:

Remember, the remains have to undergo fossilization of some sort

 

Thank you for helping

[Kane]

12 minutes ago, Top Trilo said:

 

Thank you for helping

Hey, that's what we're all here for! How will we know if we don't ask?  

[Norki]

I mean, arguably every single living thing on Earth is a living fossil, since we're all part of the continuation of life through the ages... The "immortality" of these jellyfish isn't much different, fundamentally speaking, than the propagation of other organisms through time which live, donate their cells on to the next generation, and die. It's all just a process of recycling and reproduction, which has been going on in a continuous cycle since the dawn of life on Earth.

 

You sort of have a Theseus' ship situation here, so I think that just for the sake of simplicity, the definition of fossil should be limited to the preserved remains or physical traces of organisms from the distant past.

[LabRatKing]

And the concept of cnidarian immortality is pop culture nonsense that resulted from so-called sci comm bloggers writing about stuff they don’t really comprehend. The interesting tricks we can get inverts to do in the lab don’t work in the real world. This is right along the lines of the myth that all planaria can regenerate or that tardigrades are both immortal and indestructible.

 

But Kane nailed it definition wise.

 

 

[DPS Ammonite]

The definition of a fossil is imperfect. Reports of bacteria millions of years old and probably considered as fossils by most since they are traces of life that may not have appeared to be alive when found occur in the professional literature. Bacteria may have survived millions of years in a suspended animation. There is some controversy if these are the same organisms born long ago that never reproduced for millions of years.

https://www.google.com/amp/s/amp.theguardian.com/environment/2020/jul/28/scientists-successfully-revived-mesozoic-era-microbes-from-the-sea

https://www.newscientist.com/article/dn12433-eight-million-year-old-bug-is-alive-and-growing/

 

https://www.nature.com/news/2000/001019/full/news001019-9.html

 

[LabRatKing]

23 minutes ago, DPS Ammonite said:

The definition of a fossil is imperfect. Reports of bacteria millions of years old and probably considered as fossils by most since they are traces of life that may not have appeared to be alive when found occur in the professional literature. Bacteria may have survived millions of years in a suspended animation. There is some controversy if these are the same organisms born long ago that never reproduced for millions of years.

https://www.google.com/amp/s/amp.theguardian.com/environment/2020/jul/28/scientists-successfully-revived-mesozoic-era-microbes-from-the-sea

https://www.newscientist.com/article/dn12433-eight-million-year-old-bug-is-alive-and-growing/

 

https://www.nature.com/news/2000/001019/full/news001019-9.html

 

This is another misconception. These particular bacteria were not dead, nor fossilized, or in rock. If one reads the actual paper, you will see that in fact these guys were just living in very very old sediments at very deep depths. The revival was “just” that they were able to be cultured in lab conditions...which is the real feat to be celebrated. Another albeit recent example of bad sci comm.

We’ve had similar success with chemotrophs that live inside the voids inside the travertine from various hot springs in Yellowstone. And those specimens were rescued from a consumer grade freezer from the garage of a dearly departed collaborators collection...from samples dated 1982.

[DPS Ammonite]

31 minutes ago, LabRatKing said:

This is another misconception. These particular bacteria were not dead, nor fossilized, or in rock. If one reads the actual paper, you will see that in fact these guys were just living in very very old sediments at very deep depths. The revival was “just” that they were able to be cultured in lab conditions...which is the real feat to be celebrated. Another albeit recent example of bad sci comm.

The OP was asking if living organisms that have existed more 10K years could be considered fossils. Simple definitions of fossils are: traces of organisms that were living more than 10K years ago suggest that long lived organisms could be fossils. If you can prove that a bacteria has remained viable for millions of years and has not split to reproduce then it could be a fossil.

 

See this Merriam Webster Dictionary definition of a fossil:

 

Fossilized means preserved and not always totally mineralized. 

 

 

Edited December 12, 2020 by DPS Ammonite

[Kane]

32 minutes ago, DPS Ammonite said:

The OP was asking if living organisms that have existed more 10K years could be considered fossils. Simple definitions of fossils are: traces of organisms that were living more than 10K years ago suggest that long lived organisms could be fossils. If you can prove that a bacteria has remained viable for millions of years and has not split to reproduce then it could be a fossil.

 

See this Merriam Webster Dictionary definition of a fossil:

 

Fossilized means preserved and not always totally mineralized. 

 

 

I caution my students about relying on dictionary definitions and ask them to cite primary sources. What works for a high school book report does not quite cut it in specialized fields. Lexical definitions are approximations as any linguist knows, and a reader of Bakhtin knows, is liable to constant slippage. 

As @LabRatKing correctly indicated with the bacteria example, these were not fossils. The example is moot.

 

In science, as in math or just about any other discipline, I'm interested in operational definitions. Provide that, and Im all ears. Without that, we are mired in semantics.

[DPS Ammonite]

38 minutes ago, Kane said:

As @LabRatKing correctly indicated with the bacteria example, these were not fossils. The example is moot.

 

In science, as in math or just about any other discipline, I'm interested in operational definitions. Provide that, and Im all ears. Without that, we are mired in semantics.

I agree that a Merriam Webster definition is not great for professional papers. However the basic definition is accurate: “a remnant... of an organism of past geologic ages...“. The definition is nearly the same at the one below from UC Berkeley. Neither say how old a fossil has to be.
 

UCMP at UC Berkeley definition:

“Fossils are the remains of an ancient organism or the traces of activity of such an organism.”

 

Not all the definitions of a fossil require that they are dead or not able to be revived. In its simplest form, a fossil is a trace of life that existed a certain time ago. The OP suggested that 10K was their suggested time. An organism can be both living and a fossil. 

Edited December 12, 2020 by DPS Ammonite

[GallinaPinta]

This reminds me of this quest in one of the old pokemon games where you could find two fossils at a sand storm desert where you could revive only one, whereas the other would be swallowed by the sand. 

[Kane]

Read that again: the remains of an organism. Now read this thread again. This is fairly straightforward. Read carefully, as I tell my students.

[DPS Ammonite]

Remains or traces could mean dried up, distorted and apparently lifeless. If the 100 million year old bacteria were never reanimated they probably would be called a fossil by most people just based on their primitive characteristics.

 

Here is an article about a 32K year old seed that grew into a plant. The seed qualified as a fossil by an ordinary definition of a fossil and yet it was still alive. In other words, the definition of a seed as a fossil that is more than a certain age (in this case the OP states 10K years) does not change just because it can grow into a plant.

 

I answer the OP’s original question, “Does a fossil have to be dead?” as a no. Growing a 32K year old seed supports this statement. @Top Trilo

 

 

https://www.google.com/amp/s/api.nationalgeographic.com/distribution/public/amp/news/2012/2/120221-oldest-seeds-regenerated-plants-science

 

https://www.google.com/amp/s/api.nationalgeographic.com/distribution/public/amp/news/2012/2/120221-oldest-seeds-regenerated-plants-science

Edited December 12, 2020 by DPS Ammonite

[DPS Ammonite]

7 hours ago, Kane said:

Remember, the remains have to undergo fossilization of some sort, 

Fossilization by definition means that an organism has undergone a process and meets a definition as a fossil. If you agree that an organism has to be at least 10 K years old to be a fossil then a 11K year old seed is a fossil and 9 K seed is not regardless of the viability of the seed. Fossilization does not require that an organism’s remains have to be mineralized or changed in any way other than changed in age. So, when someone asks if something is fossilized or not, ask how old it is.

Edited December 12, 2020 by DPS Ammonite

[LabRatKing]

I think the key here is replacement of structure with minerals via geologic and hydrologic chemistry. Key points there being geologic and hydrologic actions as there are numerous biological mineralization processes. Time is important too, but the amount of time is important.

Limestone is a great example as the initial components are hydrologic and biological. Without the geologic and relatively short time, it’s diatomaceous earth. With the geologic and lots of time, it’s limestone.

 

this is an interesting conversation to say the least!

 

[DPS Ammonite]

6 minutes ago, LabRatKing said:

I think the key here

Are you referring to the definition of “fossilization“?

6 minutes ago, LabRatKing said:

Limestone is a great example as the initial components are hydrologic and biological. Without the geologic and relatively short time, it’s diatomaceous earth. 

Diatomaceous earth which comes from silica rich diatoms does not turn into limestone.

[Top Trilo]

thank you guys for telling me your position on this, there wasn't an agreement but I heard several good points that I never even thought of.

[GallinaPinta]

I once believed fossils were anything old and dead but after reading the fossil seed that grew into a plant i think the term may have some live exceptions. Incredible. What about those nematodes that were frozen for 42,000 years that were supposedly thawed back to life by scientists? I found it strange and I still don't 100% believe the story of the thawed nematodes from russia but if it were true then that means there are definitely some live fossils. Never thought a quick read about this would change my definition of fossils

[GallinaPinta]

Here is the news article about the worms. https://www.rbth.com/science-and-tech/332955-ancient-worms-permafrost-scientists

[DPS Ammonite]

8 hours ago, GallinaPinta said:

Here is the news article about the worms. https://www.rbth.com/science-and-tech/332955-ancient-worms-permafrost-scientists

Freezing seems to be a common method of preservation that holds promise to preserve life for long periods of time. Imagine when we have the ability to reanimate the 180 plus whole bodies and heads (including Ted Williams, the baseball player) stored at the Alcor facility in Scottsdale.

https://www.alcor.org

[LabRatKing]

12 hours ago, DPS Ammonite said:

Are you referring to the definition of “fossilization“?

Diatomaceous earth which comes from silica rich diatoms does not turn into limestone.

Depends...the silicates often react with the calcium and magnesium ions, so after that heat and pressure...

wink