As a result of the increase in vegetation at the end of the ice age, pollen may have been produced to such an extent that it disturbed the sense of smell of mammoths. A new study shows that this caused the extinction of these giant animals, but not all scientists agree with this argument.
The increase in vegetation due to the warming of the earth probably resulted in the release of a lot of pollen in the air and caused allergic reactions in animals. This may have disturbed the sense of smell of the animals and prevented their natural interaction with each other. The inability to smell each other during the breeding season could have prevented the mammoths from finding a mate, thus leading to a drastic population decline and eventually their extinction.
In their study, published in the journal Earth History and Biodiversity, the researchers write: “One of the possible mechanisms of animal extinction during climate change could be the disruption of the sense of smell due to the development of allergies when the vegetation changes. The aim of this study is to propose a new evolutionary mechanism for the extinction of mammoths and other animals based on the disruption of their communication.
woolly mammothsMammuthus primigenius) lived in the Pleistocene era (2.6 million to 11,700 years ago). Most mammoths disappeared about 10,000 years ago, although a small population of them survived in Wrangel (a remote island in northeastern Russia) until 4,000 years ago.
Researchers think a combination of inbreeding, hunting by humans, and changing vegetation went hand in hand to cause mammoth extinction. But there are ongoing debates about the role of each of the mentioned factors in the extinction of mammoths.
Woolly mammoths probably became extinct due to a combination of environmental and human factors
According to the authors of the new paper, allergies can disrupt several life functions of mammoths. Animals use their sense of smell to find food and mates, to find their way during migration, and to avoid predators, so disruption of mammoths’ sense of smell may have led to their extinction.
One way to test whether mammoths were allergic is to examine their stomach contents for increased plant growth and release of allergenic pollen. Around the tissues of some mummified corpses, there is pollen or plant material left that can help identify past triggers. To determine whether these chemicals actually caused an allergic reaction in the mammoths, the researchers suggest testing for immune system proteins that the body produces during allergic reactions.
One of the main proteins associated with allergic reactions is immunoglobulin E, which is produced in the gut and then excreted in the feces, so testing fossilized mammoth feces could be a way to determine whether mammoths had serious cases of hay fever. According to the new study, no research has investigated the effects of the said protein in ancient mammalian samples.
read more
Some experts are not convinced that allergies played a significant role in the mammoths’ demise. For example, Vincent Lynch, an associate professor at the University of Buffalo in New York, says, “This idea is so far-fetched that I’m not sure how we can prove it.” However, according to Lynch, ancient DNA samples show that the last surviving woolly mammoths had lost the ability to smell certain plants.
The reconstructed genome of a mammoth from Wrangel Island shows mutations in genes associated with the ability to detect the smell of flowers, suggesting that the last mammoths could not detect the smell of flowering plants. However, until the authors’ ideas are empirically tested and confirmed by further research, the accepted belief will continue to be that a combination of environmental and human factors caused the extinction of the mammoths.
