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A study published this week in Nature Communication revealed new knowledge on the evolution of penguins. The work, carried out by experts from more than 30 institutions around the world, makes it possible to understand how they adapted to the marine environment.
Over time, these animals have developed all of the Features morphological, physiological and behavioral characteristics that make it one of the most specialized that exist today and which allowed them to colonize some of the most extreme environments on Earth.
Penguins appeared more than 60 million years ago. Although they are usually associated with Antarctica, long before the formation of the polar ice caps they had already lost the ability to fly and they had developed the ability to dive powered by their wings.
Previous studies have provided information on the evolution and diversification of these animals, but they were limited by sampling problems (e.g. the number of lineages included) and by the non-inclusion of extinct species. Because nearly three-quarters of known penguin species are represented only by fossils, samples of extinct animals are crucial to understand their evolution and their adaptation to the environmental context.
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Adaptation of penguins to the aquatic environment
The study authors analyzed genomic data of all extant and recently extinct lineages and combined them with information obtained from fossils, in order to reconstruct the evolutionary history of penguins.
Research shows that the diversification of these animals was driven by the climatic oscillations overall between cold and warm periods. Due to these climatic changes, the populations of different species first decreased and then spread throughout the Southern Ocean.
“The evolution rate and ambient temperature are negatively correlated in the case of penguins”explains to Sinc Chengran Zhou, from the Beijing Genomics Institute (BGI), one of the authors.
“This suggests that species at high latitudes may have faster rates of evolution than those at low latitudes. Polar penguins were likely forced to take shelter farther north during ice ages, and then recolonized Antarctica. during interglacial periods.To add.
These results suggest that the selective pressures of an extreme polar environment, combined with climatic oscillations, favored the evolution and diversification of high latitude species and could have favored their adaptation to cold environments.
The keys: thermoregulation, oxygenation, diving…
The researchers examined the evolutionary process of specific genetic sequences among penguin lineages. Thus, they identified a set of genes involved in thermoregulation, oxygenation, diving, vision, diet, and body size that may have facilitated adaptation to the aquatic environment. Analyzes suggest that the ancestors penguins have adjusted their color vision and visual sensitivity to better adapt to the blue light of the ocean environment.
These findings improve understanding of how penguins made the transition to the marine environment, successfully colonizing some of Earth’s most extreme environments.
“Penguins have adapted to an ever-changing world over the past 60 million years, even in the face of climatic changes spectacular. Some species in the polar regions, like Adélie penguins for example, have faster evolutionary rates and can colonize diverse and extreme environments, so we can remain optimistic about their future.”Zhou told Sync.
“However, we must be very attentive to the growing threat of climate change anthropogenic and keep in mind that although penguins have the ability to adapt to new environmental contexts, there are very few places suitable for them, so the threat of extinction is always present”Zhou concludes.
Character font: Iole Ferrara Romeo / SINC Agency
Reference article: https://www.agenciasinc.es/Noticias/Asi-se-adaptaron-los-pingueinos-al-entorno-marino