December 9, 2022 | David F. Coppedge

Can DNA Last 2 Million Years?

A new claim about ancient DNA deserves some scrutiny.
Why did evolutionists double their maximum lifetime of DNA so quickly?

 

The study of “environmental DNA” (eDNA) is a rapidly advancing field. Archaeologists and paleontologists have made great strides in recovering pieces of genetic code from soil, permafrost, caves, and many other locations. For instance, these scientists look for DNA in “rainwash” from forests to determine what lives at the tops of the trees without having to climb up there to look:

Rainwash eDNA provides minimally invasive method to assess tree canopy invertebrate diversity (Universität Duisburg-Essen via Phys.org, 7 Dec 2022).

This mixture of beetle, fungus, ant, and oak DNA—to name just a few—is subsequently analyzed by eDNA metabarcoding: The method captures even the smallest traces of genetic information, amplifies them, and enables the precise identification of each species present in the sample.

Other applications of this burgeoning field include searching for eDNA in sea water, soil samples and in the human microbiome. The data give scientists clues to the identity of organisms living in those ecological niches.

Art of mammoth and mastodon types found at La Brea Tar Pits, California. (DFC)

Ancient DNA

Once lost from the organism, eDNA begins a steady process of decay. For a time, though, the DNA—even if fragmented—can be recovered and sequenced. How long can it survive before it becomes useless? The news media are announcing a new record.

DNA from 2 million years ago is the oldest ever recovered (New Scientist, 7 Dec 2022). Michael Marshall writes, “DNA bound to mineral particles in ancient sediment reveals that north Greenland once had spruce forests populated by hares, reindeer and even mastodons.” He says this doubles the old record of a million years for ancient DNA reported in 2021. Marshall assumes the consensus date for the formation where the DNA was recovered, and only comments briefly about why it could last so long:

The DNA didn’t come from fossilised organisms, but was instead bound to mineral particles in the sediment layers. This helped preserve the DNA, because enzymes couldn’t get to it to break it down, says team member Karina Sand at the University of Copenhagen in Denmark.

Enzymatic breakdown, however, is only one cause of DNA decay. Cosmic rays, radon (along with other environmental radioisotopes), chemicals and atmospheric changes can also accelerate the decay process. It’s understandable that permafrost can keep DNA intact for longer, like putting food in the freezer, but a lot can happen in a million years: climate change, for instance! DNA decays from temperature alone even in permafrost, because molecules vibrate in response to temperature. No DNA repair processes would be available in eDNA after the organism dies.

Artist conception of the environment of the ecological niche where the mastodon lived based on species recovered from eDNA. Credit: Beth Zaiken (bethzaiken.com). Compare with photo of northern Greenland today, below.

Since Nature published the scientific paper about the ancient DNA, let’s first look at their press releases about it.

Oldest-ever DNA shows mastodons roamed Greenland 2 million years ago (Nature News, 7 Dec 2022). Assuming the reported date of 2 million years, Ewen Callaway writes colorful prose about the ancient land of mastodons that left traces of their genetic code behind. It must have been more temperate back then.

The northeastern tip of Greenland is a lonely, barren place, home to the odd hare and musk ox, and few plants. Two-million-year-old DNA sequences — the oldest ever obtained — recovered from frozen soil suggest that the region was once home to mastodons and reindeer that roamed a forested ecosystem unlike any now found on Earth.

“No one would have predicted this ecosystem in northern Greenland at this time,” says Eske Willerslev, a palaeogeneticist at the University of Copenhagen who co-led a study published on 7 December in Nature describing the ancient-DNA findings1.

“It’s pretty awesome,” adds Love Dalén, a palaeogeneticist at the Swedish Museum of Natural History in Stockholm who was not involved in the study. “Not in a million years would you expect a mastodon up there.”

Aerial photo of Greenland (DFC)

OK, now that the hype is done, let’s take a look at the open-access report in Nature.

Willerslev et al., A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA. (Nature volume 612, pages 283–291, 7 Dec 2022). Figure 2 shows the methods used to date the specimens using “Age proxies for the Kap København Formation.”

  • Paleomagnetic analysis is built on deep time assumptions about the dates of magnetic reversals.
  • Dates of “last appearances” of a foraminifera species, a hare and a mollusk. These are also built on deep time assumptions about the rate of evolution and extinction.
  • Cosmogenic age calculations depend on uniformitarian assumptions about exposure to cosmic rays.
  • Molecular dating of a certain tree depends on deep time assumptions about evolutionary rates.
  • The paper compares a reported DNA age from a mammoth (one million years), but the evolutionary assumptions apply to that specimen as well.
  • The paper also makes statements about thermal degradation of DNA (see below).

The chart looks impressive, but if all the dating methods depend on deep time assumptions or uniformitarian assumptions, no amount of precision is possible, and conclusions are only as credible as the assumptions they are built on.

One eye-opening sentence in the paper compares the expected thermal age of DNA at 10° C, which would be 2,700 years, with the concluded age of 2 million years. It’s a difference of 741 to one! (see quote below). The authors justify the long age by assuming that the samples remained frozen and undisturbed all that time. Then they also had to assume that the minerals at the site could have adsorbed the DNA, protecting it from degradation. Even so, those rescue devices seem inadequate to protect the DNA for 2 million years, given all the forces at work to disrupt the bonds of DNA strands.

Whole lotta assuming going on. Read for yourself the manipulation required to get DNA that old. It should have only lasted 2,700 years, which would fit with a Genesis timeline! But they needed the DNA to be millions of years old to fit evolution, so they applied Gumby oil to stretch the time 741 times its expected value. Is that reasonable? Watch:

DNA preservation

DNA degrades with time owing to microbial enzymatic activity, mechanical shearing and spontaneous chemical reactions such as hydrolysis and oxidation. The oldest known DNA obtained to date has been recovered from a permafrost-preserved mammoth molar dated to 1.2–1.1 Myr using geological methods and 1.7 Myr (95% highest posterior density, 2.1–1.3 Myr) using molecular clock dating. To explore the likelihood of recovering DNA from sediments at the Kap København formation, we calculated the thermal age of the DNA and its expected degree of depurination at the Kap København Formation. Using the mean average temperature22 (MAT) of −17 °C, we found a thermal age of 2.7 thousand years for DNA at a constant 10 °C, which is 741 times less than the age of 2.0 Myr (Supplementary Information, section 4 and Supplementary Table 4.4.1). Using the rate of depurination from Moa bird fossils, we found it plausible that DNA with an average size of 50 base pairs (bp) could survive at the Kap København Formation, assuming that the site remained frozen (Supplementary Information, section 4 and Supplementary Table 4.4.2). Mechanisms that preserve DNA in sediments are likely to be different from that of bone. Adsorption at mineral surfaces modifies the DNA conformation, probably impeding molecular recognition by enzymes, which effectively hinders enzymatic degradation. To investigate whether the minerals found in Kap København Formation could have retained DNA during the deposition and preserved it, we determined the mineralogic composition of the sediments using X-ray diffraction and measured their adsorption capacities. Our findings highlight that the marine depositional environment favours adsorption of extracellular DNA on the mineral surfaces (Supplementary Information, section 4 and Supplementary Table 4.3.1.1). Specifically, the clay minerals (9.6–5.5 wt%) and particularly smectite (1.2–3.7 wt%), have higher adsorption capacity compared to the non-clay minerals (59–75 wt%). At a DNA concentration representative of the natural environments (4.9 ng ml−1 DNA), the DNA adsorption capacity of smectite is 200 times greater than for quartz. We applied a sedimentary eDNA extraction protocol on our mineral-adsorbed DNA samples, and retrieved only 5% of the adsorbed DNA from smectite and around 10% from the other clay minerals (Methods and Supplementary Information, section 4). By contrast, we retrieved around 40% of the DNA adsorbed to quartz. The difference in adsorption capacity and extraction yield from the different minerals demonstrates that mineral composition may have an important role in ancient eDNA preservation and retrieval.

These assumptions should be subject to scrutiny. If the Darwin Party did not maintain such a stranglehold on the media, which protects dating methods to preserve Darwin’s timeline, fair-minded and qualified physicists who are Darwin skeptics might make mincemeat of the assumptions used in arriving at the 2 million year date. We invite such interlocutors to comment on this paper.

In the meantime, here’s one challenge to chew on: how much time elapsed between the temperate climate pictured in the artwork above, and the onset of permafrost? Thousands of years? That would have been ample time for the DNA to degrade entirely.

The simplest explanation is that the eDNA is only thousands of years old, not millions. And if that is true, the whole biosphere was wiped out suddenly not that many thousands of years ago. That fits the Genesis creation and Flood timeline. A subsequent ice age, advancing rapidly, would have preserved the environmental DNA for a few thousand years maximum.

Note: Creation scientists believe that a single ice age followed the Flood. Some propose the frozen mammoths and ice age were consequences of the Flood. Others believe the ice age occurred centuries after the Flood Their papers presenting alternative theories are published in peer-reviewed creation journals and should be given a hearing, given the unreasonableness of the evolutionary account.

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Comments

  • Ian P. says:

    The low temperature seems critical to their assumptions regarding DNA preservation, but they also claim Greenland once had a mild climate. The DNA would have degraded much more quickly during the mild period, before the colder temperatures arrived to preserve it. It doesn’t appear the researchers took that into account. I also thought Love Dalen’s comment ironic “Not in a million years would you expect a mastodon up there.” Maybe because it hasn’t been in a million years.

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