Human threats to the amphibian tree of life

March 27, 2018 by Jim Shelton, Yale University

A new study by researchers at Yale and George Washington University examines the human threats to the amphibian family tree and calls for a rethinking of conservation priorities to preserve species diversity and evolutionary heritage.

Amphibians represent an important bellwether of global change, scientists say, due to their particularly high sensitivity to disturbances in their environment. There are more than 7,000 amphibian species on Earth, including frogs, toads, caecilians, newts, mudpuppies, and hellbenders.

"Amphibians are a globally endangered group for which threats from global change are outpacing our ability to safeguard species," said Walter Jetz, lead author of a paper published online March 26 in the journal Nature Ecology & Evolution. Jetz is an associate professor of ecology and evolutionary biology at Yale and director of the Yale Center for Biodiversity and Global Change.

Jetz and co-corresponding author R. Alexander Pyron of George Washington constructed the first comprehensive family tree for nearly all amphibious species alive today. The researchers used the data to examine historical diversification patterns of amphibians as well as species' level of isolation on the family tree, also called evolutionary distinctness.

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Revising a mammal branch on tree of life

Researchers return a subspecies of giant elephant-shrew from the Congo Basin to full species status

Date: August 2, 2017

Source: California Academy of Sciences

Summary:

One small mammal is experiencing a triumphant return to its long-ago spot on the tree of life. Scientists have elevated a subspecies of giant sengi, or elephant-shrew, to full species status aided by genetic information gathered from the California Academy of Sciences' vast mammalogy collection.

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Mysterious fossils find place on the tree of life

By Helen Briggs BBC News

11 January 2017

A strange animal that lived on the ocean floor 500 million years ago has been assigned to the tree of life, solving a long-held mystery.

The creature has eluded scientific classification since the first fossil was discovered 175 years ago.

The extinct hyolith has a cone-shaped shell, tentacles for feeding and appendages that acted as "feet".

It belongs to an invertebrate group that includes animals such as the horseshoe worm, say scientists.

Joseph Moysiuk, of the University of Toronto, made the discovery after analysing more than 1,500 specimens dug out of rocks in Canada and the US.

"Hyoliths are small cone-shaped sea dwelling animals. They are known from all around the world, mostly from fossils of their shells," he told BBC News.

"They appear in the fossil record about 530 million years ago and survived until about 250 million years ago.

"But the question of where hyoliths actually fit into the tree of life has been somewhat of a mystery for the last 175 years, since they were first described."

The research, published in the journal Nature, analysed soft tissue preserved in "very special fossils" from a site in Canada known as the Burgess Shale.

In the past, hyoliths have been interpreted as being related to molluscs, which are common today and include squid, clams and snails.

The new research suggests the animals are in fact more closely related to a different group of shell-bearing organisms, known as lophophorata, which includes brachipods (lamp shells), among others.

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Turtles and dinosaurs: Scientists solve reptile mysteries with landmark study on the evolution of turtles

Date:

November 24, 2014

Source:

California Academy of Sciences

Summary:

A team of scientists has reconstructed a detailed 'tree of life' for turtles. Next generation sequencing technologies have generated unprecedented amounts of genetic information for a thrilling new look at turtles' evolutionary history. Scientists place turtles in the newly named group 'Archelosauria' with their closest relatives: birds, crocodiles, and dinosaurs.

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Study of sea anemones leads to new branch in the tree of life

A deep-sea animal with tentacles more than six and a half feet long was once thought to be one of the world's largest sea anemones, but has now been reclassified as belonging to a new order of animals and is not a sea anemone at all.

This animal, previously called Boloceroides daphneae, was discovered in 2006 in the deep east Pacific Ocean and labelled as one of the largest sea anemones in existence. But a new DNA-based study led by the American Museum of Natural History shifts it outside of the tree of life for anemones. Instead, researchers have placed it in a newly created order—a classification equal to carnivoria in mammals or crocodilia in reptiles—under the sub-classHexacorallia, which includes stony corals, anemones, and black corals. The new name of the animal, which lives next to hydrothermal vents, is Relicanthus daphneae.

Relicanthus daphneae is a classic example of convergent evolution, the independent evolution of similar features in species of different lineages.

"Even though this animal looks very much like a sea anemone, it is not one," said Estefanía Rodríguez, lead author of the report published in the journal PLOS ONE, and an assistant curator in the Museum's Division of Invertebrate Zoology. "Both groups of animals lack the same characters, but our research shows that while the anemones lost those characters over millions of years of evolution, R. daphneae never had them. Putting these animals in the same group would be like classifying worms and snakes together just because neither have legs.

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TREE OF LIFE: You really must play with this (or at least that's what Max told me)

http://www.onezoom.org/mammals.htm

Strange Organism Has Unique Roots in the Tree of Life

Talk about extended family: A single-celled organism in Norway has been called "mankind's furthest relative." It is so far removed from the organisms we know that researchers claim it belongs to a new base group, called a kingdom, on the tree of life.

"We have found an unknown branch of the tree of life that lives in this lake. It is unique! So far we know of no other group of organisms that descend from closer to the roots of the tree of life than this species," study researcher Kamran Shalchian-Tabrizi, of the University of Oslo, in Norway, said in a statement.

The organism, a type of protozoan, was found by researchers in a lake near Oslo. Protozoans have been known to science since 1865, but because they are difficult to culture in the lab, researchers haven't been able to get a grip on their genetic makeup. They were placed in the protist kingdom on the tree of life mostly based on observations of their size and shape.

Read on:  http://www.livescience.com/19955-ancient-protist-kingdom.html