New research adds to penguin story

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Researchers recently offered the most comprehensive examination to date of penguin history.

Penguins are short-legged, flightless seabirds that live primarily in the southern half of the world.

Researchers studied the genomes of 20 living penguins species and subspecies. While more than three-quarters of known penguin species no longer exist, the researchers also included in their study 50 fossil species using skeletal data.

The researchers said the penguins came from a common ancestor shared with a group of seabirds including albatrosses and petrels. Penguins first developed the ability to dive, like a puffin, then lost the ability to fly as they adapted water.

The oldest known penguin is Waimanu Manningi, from New Zealand. It is believed to have lived 61 million years ago.

Daniel Ksepka of the Bruce Museum in Greenwich, Connecticut, co-authored the study, which was published in Nature Communications.

“We know penguins evolved from flying birds, but that happened over 60 million years ago and we need to look to the fossil record to piece together where, when and how that happened. is produced,” he said.

Ksepka noted that penguins are attractive animals. He added that they “are ridiculously charming creatures. They love, they fight, they steal, and because of their funny righteousness posture it’s really easy to imagine them having the same motivations as people.”

Motivation is a term that denotes a cause or reason for doing something.

The study proposes that changes in global temperatures and major ocean currents have been important drivers of penguin evolution.

Penguins live mainly in the southern hemisphere. The Galapagos penguin is the only one found north of the equator.

Theresa Cole of the University of Copenhagen was the study’s lead writer. Cole said the research revealed a number of genes likely involved in physical changes known as adaptations.

These adaptations include genetic mutations that alter the way penguins view the world. Penguin vision is more sensitive towards the blue end of the color spectrum. Blue light penetrates deeper into the ocean than light at the red end of the spectrum.

Genes that help birds detect salty and sour tastes are active in penguins. But the genes that help detect bitter, sweet and salty tastes are turned off. These may no longer be necessary as penguins find food in cold, salty water and usually swallow prey such as fish, shrimp and squid whole.

Penguins show changes in their wing bones and a reduction in their flight feathers. Penguins also have reduced air spaces in the skeleton and the ability to store more oxygen in their muscles for long dives.

Penguins were once much larger than today’s species. An ancient species, Kumimanu biceae, lived in New Zealand between 55 and 60 million years ago and was about 1.8 meters tall. The tallest modern species, the emperor penguin, is about a meter tall.

I am John Russell.

Will Dunham reported this story for Reuters. John Russell adapted it for VOA Learning English.

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words in this story

species – nm biology: a group of animals or plants that are similar and can produce young animals or plants

fossil nm something (like a leaf, skeleton, or footprint) that comes from a plant or animal that lived in ancient times

adapt – v. to change (something) so that it works better or is better suited to a purpose

ridiculously adv. to an extreme extent

charming – adj. very pleasant or attractive: full of charm

posture – nm the way your body is positioned when you sit or stand

spectrum – nm a color continuum formed when a beam of white light is scattered

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