Highlights

• Discovery of immunoglobulins in permafrost paleontology samples.

• Allergens (plant’s metabolites, volatile organic compounds, pollen) induced sex contact inhibition as one of factor animals extinction.

• Disruption of chemical signaling between animals as a factor in animal extinction. The influence of plants and parasites on signaling disruption between animals.

One of the possible mechanisms for the extinction of animals during climate change could be a violation of the sense of smell due to the development of allergies when the flora changes.

During the breeding season, susceptibility to odors is very important for animals. The development of allergies from plant pollen, changes in pollen’s allergic toxicity, pollen’s release period increasing or the emergence of a large quantity of flowering plants during climate change, could lead to decrements in sensitivity to odors in animals during the breeding season.

This may explain the extinction of animals due to a decrease in sexual intercourse. Probably these changes in allergic responses of mammoths at period of climate changes led to a decrease in the mammoth population and, as a result, to their disappearance.