The story of the Buesching mastodon is imprinted on its ivory

The story of the Buesching mastodon is imprinted on its ivory

The story of the Buesching mastodon is imprinted on its ivory

There they are worse fates than ending your days fighting for your own reason for being. And the raison d’être of the Buesching mastodon was reproduction. The line connecting him with his ancestral past extended not only beyond what his elephantine brain could have conceived, but beyond what any brain could have conceived until radiometric dating identified the birth of planet Earth at a cosmic moment 4,000 years ago. 54 billion years.

Geologists argue over what is truly the first trace of life on Earth. But saying that living things have been around for about 4 billion years will be a good round estimate. Since then, natural selection has done its work. Only the strong survived long enough to hand over their genes to the next generation. And boy, was he strong. Two tons of rippling muscle over a skeleton of the same weight, all powered by another four tons of visceral organs. And prey. Two huge tusks, each three meters long and weighing 40kg.

It is these tusks that best tell the story of the Buesching mastodon. For more than 13 millennia after their last, fateful encounter with another bull – one that turned out to be stronger, or smarter, or just luckier – they were discovered in 1998, along with the rest of their nearly complete skeleton, in peat bogs. near Fort Wayne. , Indiana. Their biographers, Joshua Miller and Daniel Fisher, have been studying them ever since and have just published their latest findings*.

The fangs are giant teeth. And teeth contain calcium phosphate. This is the stuff that makes them strong. But calcium is in the same column of the periodic table as strontium, a rarer element, so the two are chemically similar — so similar (and strontium so rare) that natural selection never bothered to learn the difference. If the prey assembly process finds a strontium atom, it incorporates it as if it were calcium, without any harm.

This harmless mistake gave Dr. Miller and to Dr. Fisher much of what they needed to write the life story of their mastodon. Strontium comes in two isotopes (atoms of different weights). The proportion of these in plants of the type that mastodons ate depends on their proportion in the underlying rocks. Like trees, prey have annual growth layers. And the rocks of the American Midwest are so well studied that their strontium ratios are well known. Thus, the pair were able to track with reasonable confidence the whereabouts of their mastodon when a pertinent piece of prey was growing.

When he was there, he was given a second pair of isotopes – this time from oxygen atoms. Water molecules with the heavier version of oxygen are more reluctant to evaporate, so the ratio of the two isotopes in rainwater depends on the temperature and therefore the season. And the oxygen from the rainwater also ended up in the mastodons through their forage.

Where then. And when. Reluctant to remove for isotopic analysis more than the bare minimum of material from his precious sample, Dr. Miller and Dr. Fisher focused on the years when the animal was between 11 and 16 and between 31 and 34. But they had other information like We go. Nutritional stress shows up in the appearance of the growth layers, as does damage from fighting other mastodons.

Previous studies suggest that male mastodons lived when young with their mothers, brothers, aunts and cousins, in matriarchal groups similar to modern elephants. The Doctor. Miller and Dr. Fisher didn’t bother wasting precious ivory confirming this. Instead, they started with the rebellious teenager.

The adolescent Buesching mastodon, they found, was year-to-year extending its range into the midwestern states of Illinois, Indiana, Ohio and Michigan, but showed no seasonal preference for a specific location. He was also stressed by his teenage years. At the very least, his fangs suggest he wasn’t eating as well as he could have been.

At the height of his powers as an adult, however, all signs of stress disappeared. Now it was migrating seasonally – returning in early summer to a much smaller area near the center of its range that appears to have served as a breeding ground.

And he was combative. Damage to the fangs suggests that, from the age of 26, he was getting into regular scraps at this time of year. These may reflect musth—periods of aggressive temperament experienced by modern male elephants. If they do, it suggests that it must have evolved a long time in the past. The last common ancestor of modern mastodons and proboscids lived about 25 million years ago.

Whatever the details, he found his match in the eighth year of these jousts. All the procreative instincts ingrained in her genes by the successful reproduction of her ancestors over the ages—a weak heart never won a fair lady—culmiated at the moment of her death. One of his opponent’s fangs pierced his right temporal fossa, a thin blade of bone on the side of his skull, severing an artery. It left a hole almost 5 cm in diameter, visible to this day. That was the end of it. But the successes of previous seasons would likely have made him put his genes into the next generation, so the job is done.

Nothing, however, lasts forever – even the lines of creatures as powerful as mastodons. Paleoanthropologists differ on when the peopling of the Americas began, but all acknowledge the emergence of a culture called Clovis, with its array of effective stone tools and weapons, particularly spearheads. This started right after the final and fatal fight of the mastodon Buesching.

Clovis’ weapons changed the rules of engagement between humans and local wildlife. Mastodons, along with their proboscid cousins, mammoths, and a whole range of other large American mammals, from saber-toothed cats to armored glyptodonts, did not long survive contact with this supreme embodiment of 4 billion-year-old selection. of the gene pool. All gone, their genetic lines severed forever. But not forgotten. At least, not while biographers like Dr. Miller and Dr. Fisher ply their trade.

*PNAS, landscape use of male mastodon changed with maturation (Late Pleistocene, North America), JH Miller et al.

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