Biomolecular Histology as a Novel Proxy for Ancient DNA and Protein Sequence Preservation

[fossil_lover_2277]

Hi all, I recently published my first paper as a molecular paleontologist (I don’t have a PhD yet). The publication has actual electron microscope images of mammoth collagen protein. The publication proposes using biomolecule histology to predict degree of preservation of ancient DNA and protein sequences. Take a look for yourself, the publication is open access:  https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.9518

Edited December 14, 2022 by fossil_lover_2277

[Mark Kmiecik]

Thank you for making it available.

[Crusty_Crab]

My read is that DNA and proteins are very short lived (~130k-240k years for DNA) and ~800k-1 MYA for proteins. The variation is due to mainly temperature but other geological factors. The key to your paper is using biomolecular histology to differentiate the high and low estimates- that is, using tissue morphology, we can differentiate fossils or tissues that may have been altered over time. Presumably, less altered tissues would be more promising to yield molecular data. Is that a correct interpretation? 

 

Ultimately, the bulk of scientific data suggests DNA is transitory and proteins, while more resilient then DNA, are still relatively short lived on geological time scales. There are many geological factors that may affect the resilience of both molecules but we can use morphology of preserved tissue to refine that data. Going one step further, this means that its unlikely we're going to achieve a Jurassic Park scenario anytime soon since the tissue in amber (or anything Cretaceous) is significantly altered. However, we can start small in trying to isolate molecular sequences from more recent fossils using your concept of biomolecular histology.

 

Please correct me if I'm wrong in any of my observations or conclusions.

[fossil_lover_2277]

31 minutes ago, Crusty_Crab said:

My read is that DNA and proteins are very short lived (~130k-240k years for DNA) and ~800k-1 MYA for proteins. The variation is due to mainly temperature but other geological factors. The key to your paper is using biomolecular histology to differentiate the high and low estimates- that is, using tissue morphology, we can differentiate fossils or tissues that may have been altered over time. Presumably, less altered tissues would be more promising to yield molecular data. Is that a correct interpretation? 

 

Ultimately, the bulk of scientific data suggests DNA is transitory and proteins, while more resilient then DNA, are still relatively short lived on geological time scales. There are many geological factors that may affect the resilience of both molecules but we can use morphology of preserved tissue to refine that data. Going one step further, this means that its unlikely we're going to achieve a Jurassic Park scenario anytime soon since the tissue in amber (or anything Cretaceous) is significantly altered. However, we can start small in trying to isolate molecular sequences from more recent fossils using your concept of biomolecular histology.

 

Please correct me if I'm wrong in any of my observations or conclusions.

Yes, this understanding is generally correct. I will point out that permafrost and cave deposits can greatly affect the ~130-240Ka and~0.8-1Ma timeframes. For example, the furthest back in the fossil record DNA has been recovered now is 2Ma, from permafrost sediments in Greenland. Protein sequences of “Bigfoot” (Gigantopithecus blacki) have been recovered from an early Pleistocene cave in a subtropical region of China.

 

Also, there are examples of protein sequences recovered past 1Ma that aren’t from permafrost or cave deposits, but these are an exception and not the norm. Biomolecule histology is predicted to provide insight regarding such exceptional cases. Also, geologic age is  a big factor affecting preservation, in addition to thermal setting.

Edited December 14, 2022 by fossil_lover_2277