A Snail’s Tale of the Past

Amino acid geochronology, a forty-year-old technique with limited application, has now been expanded to plumb the mysteries of the Ice Age thanks to an interdisciplinary British study of the snail. What do snails, amino acids, and ice ages have to do with each other?

Amino acids are the building blocks of proteins. In living organisms they are present only in one of two mirror-image forms. After death, those amino acids undergo racemization, no longer maintaining their single form but becoming a mixture. This process happens more slowly in the cold. The racemization rate varies not only with temperature but also with humidity, acidity, and characteristics of the matrix in which the amino acids are preserved. Because amino acid dating depends heavily on environmental conditions, it can only be used when the environmental conditions are actually and exactly known.

The amino acid degradation rate can vary dramatically in decomposing materials and in substances containing catalytic minerals. Therefore, the researchers sought and found a protected protein shelter in the operculum of fossilized snails. (The operculum is the “lid” on the shell opening.) Dr. Kirsty E. H. Penkman, lead author, explains, “The amino acids are securely preserved within calcium carbonate crystals of the opercula. This crystal cage protects the protein from external environmental factors, so the extent of internal protein degradation allows us to identify the age of the samples. In essence, they are a protein time capsule.”

Because the crystalline structure protects the amino acids from extraneous influences, the team is confident that only temperature changes have influenced that rate of racemization. Therefore, they match up amino acid racemic ratios to the “known” environmental history regarding the Quaternary Period in which the “last” ice age occurred. They then match whatever fossilized plants and animals and even human anthropological debris that are found near the snails to the corresponding “ice age” or “interglacial period.”

Penkman explains, “This framework can be used to tell us in greater detail than ever before how plants and animals reacted to glacial and interglacial periods, and has helped us establish the patterns of human occupation of Britain, supporting the view that these islands were deserted in the Last Interglacial period.”

Because the amino acid degradation varied according to the layer the sample came from, the researchers are assuming that those samples came from particular “ice ages” or “interglacial periods.”

The racemic ratio data obtained from 470 snail fossils correlated with stratigraphic data obtained by other means. Therefore the method is asserted to be a reliable way to link the two sorts of information. In other words, because the amino acid degradation varied according to the layer the sample came from, the researchers are assuming that those samples came from particular “ice ages” or “interglacial periods.”

The problem with this new technique lies in its foundational assumptions. All time-measuring techniques must be calibrated against a reliable standard. Here, the protein-based chronometer is calibrated according to uniformitarian assumptions about earth’s icy past. In other words, each degradation ratio corresponds to a particular layer, and the dates claimed for that layer are then assigned to the degradation ratio.

The Quaternary Period of earth’s history is believed by secular geologists to be the past 2.6 million years. (They maintain that “snowball earth” underwent a series of very long ice ages spread over billions of years but assert that a more recent cycle of ice ages and interglacial periods occurred in the Quaternary Period.) They believe that humans evolved around 190,000 years ago and endured some of this icy time. They say that the last glacial period ended about 10,000 years ago. The evidence of Ice Age glacial recession seen in the world today is assigned to this final phase.

Since uniformitarian ideas about geology preclude the possibility of a recent catastrophic global Flood1 and one single Ice Age triggered by it, secular geologists propose that multiple ice ages have happened. Their presuppositions about the earth’s age are used to interpret ice cores from Greenland and Antarctica, deciding how thick each year’s ice accumulation is. Since oxygen isotope ratios vary according to temperature when oxygen gets trapped, oxygen isotope ratios are assigned to layers of ice or deep sea sediment to build a timeline.

It is notable that the amino acid ratios do correspond with the oxygen isotope ratios in various strata. The researchers seem to have found a fossil which protects trapped amino acids from all but thermal changes. Since both racemization ratios and oxygen isotope ratios are sensitive to temperature, the fact that the ratios correspond makes sense.

Uniformitarian geologists have never come up with an adequate explanation for the Ice Age or for multiple ice ages.

The problem is in the calibration of these findings with historical time. Uniformitarian geologists have never come up with an adequate explanation for the Ice Age or for multiple ice ages. Many theories have been proposed, and some have even been cast aside and resurrected later. The currently popular idea—the astronomical theory—is one of those.

Astronomical ice age theory is based on observable changes in earth’s tilt and orbit. The earth wobbles on it axis, the shape of its orbit varies slightly, and the orbital path itself shifts over time. These variations are insignificant within the biblical age of the earth. But if those variations are extrapolated over billions of years, the earth’s orbit would vary between its elliptical shape and a circular orbit. Since those variations would alter all the parameters that produce our familiar seasons, they propose those variations would cause hot enough times to evaporate ocean water and cold enough times to produce ice ages.2 The popularly accepted duration of the ice age cycles of the Quaternary Period come from this extrapolated astronomical data.

Since oxygen ratios and amino acid racemization are both temperature sensitive, they correspond and vary according to the seasonal and climatic changes they were exposed to. But neither tells us anything about the duration of those variations, and neither confirms the notion of multiple ice ages over millions of years.