January 25, 2022 5:39 pm

The quiet life of the Sicilian dwarf elephant, secret of its longevity

The islands are natural laboratories exceptional for the study of evolution. Its characteristics of geographic isolation, which hinders the migrations of species, the limitation of physical space that often prevents the presence of predators – which require large areas of land to hunt – or the limitation of the food resources of island ecosystems, make up some evolutionary patterns common in the fauna that live in them.

The term ‘island rule’ confirms the tendency to gigantism or dwarfism of the species that evolved on the islands.

One of these phenomena is the enanismo or the gigantism. Very often on the islands we observe species larger or smaller than their continental counterparts, especially in terms of mammals and dinosaurs.

Mid-nineteenth century, Charles Darwin and Alfred Wallace They were already interested in this phenomenon after their trips to various islands in the world, which was where they obtained evidence that they later used to propose the teory of evolution.

A peculiar evolutionary pattern

In 1973, building on Foster’s earlier work, the evolutionary biologist Leigh Van Valen coined the term `island rule´ —often translated as ‘insular law’ or ‘island effect’ – which confirmed the tendency to gigantism or dwarfism of the species that evolved on the islands.

One of the emblematic species of this ‘island effect’ is the Sicilian dwarf elephant, (Palaeoloxodon falconeri). It is an extremely small Compared to today’s elephant species, it was about one meter tall and weighed about 250 kilos.

The Sicilian dwarf elephant was about one meter tall and weighed about 250 kilos

This dwarf elephant lived in Sicily during the Pleistocene, between 500,000 and 200,000 years ago and is known by the Fossil remains that have been found in different sites on the island.

Palaeoloxodon falconeri it is a descendant of the continental species Palaeoloxodon ancient, much larger in size (up to five meters high at the withers and 5 tons in weight).

Now, an article published in Scientific Reports led by research staff from the Catalan Institute of Paleontology Miquel Crusafont (ICP), center attached to the Autonomous University of Barcelona (UAB), in collaboration with different international research institutions, describes the characteristics of the ‘life history’ of this species.

The study concludes that the Sicilian dwarf elephant grew very slowly, reached sexual maturity around 15 years and had a long life expectancy of at least 68 years.

This concept refers to the characteristics of the different events that occur during the life cycle of an animal, such as its growth rate, age of sexual maturity or longevity.

The study concludes that the Sicilian dwarf elephant grew very slowly, reached sexual maturity around 15 years and had a long life expectancy of at least 68 years.

“Traditionally it had been considered that this species had a rapid development, which reached sexual maturity early and had a short life,” explains the researcher Meike Koehler, who is leading the investigation. “Our work shows that the life history of this elephant was much slower,” he notes.

Know its life cycle through the fangs

The research team has analyzed the paleohistology ―The internal structure of fossils― of the molars and defenses (what we popularly call ‘fangs’) of this species.

“The different events of the life cycle of an organism are recorded in its bones, such as what happens with the growth rings that we observe in the trunks of trees”, explains Köhler.

The fossils are cut into thin slices approximately 0.1 mm thick, for analysis under the microscope. growth stop lines o LAGs (acronym in English for `Lines of Arrested Growth´) that allow to identify the growth and latency periods of the animal.

Small continental species tend to have faster life histories: they grow fast, reproduce early, and die young; but the opposite happens on the islands

In general, small continental species tend to have more life histories. acceleratedThey grow fast, reproduce early, and die young. “But the opposite happens in the islands,” explains the co-author of the research. Salvador Moyà.

Unlike what happens on the continents, the change in body size of the species that live on the islands is not associated with a faster life history.

“We have found that the Sicilian dwarf elephant had a much slower life history than its sister taxon Palaeoloxodon ancient and the huge African savanna elephant ”, says Moyà. “The slow pace of this animal is the key to its longevity. Maybe humans can learn something from them! ”, The researcher jokingly concludes.

Source: SINC

Rights: Creative Commons.

Reference-www.agenciasinc.es

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