Research reveals new species are evolving fastest in Antarctica

January 24, 2019 by Anastasia Casagrande, Museums Victoria
Dr. Tim O'Hara in Marine Vertebrate research laboratory holding a specimen jar containing brittle stars. Credit: Museums Victoria

New research published in Nature overturns previous theories about how the stunning biodiversity of the oceans evolved, with important implications for conservation.

The study, titled "Contrasting processes drive ophiuroid phylodiversity across shallow and deep seafloors," was led by first author Dr. Tim O'Hara, senior curator of marine invertebrates at Museums Victoria.

Biologists have long speculated that evolution is sped up by relatively high tropical temperatures, with development being slower in cooler and . However, this research finds that evolution does not follow one course, but rather depends on the geological, climatic and biological history of each ecosystem. Evolution proceeded differently in shallow and deep seas.

Speciation was found to be highest in the coldest region: Antarctica. These waters are still apparently recovering from extinction events of tens of millions of years ago, when ice sheets began to dominate and plummeted. New species that evolved as a result are still in the process of diversifying, and are doing so rapidly.

By contrast, although diversity in tropical deep seas (deeper than 200 metres) is high, it is not an environment that is rapidly producing new species, but rather accumulated its rich biodiversity over millions of years. Tropical deep seas are a refuge for ancient fauna, or "living fossils," mainly due to relatively stable conditions over time.

Ophiuroidea, brittle star. Collected and photographed during the Museums Victoria and partners 'Sampling the Abyss' voyage on the RV Investigator. Credit: Museums Victoria

To study patterns of evolution across the world's oceans, the team focused on the evolution of deep-sea '' (Ophiuroidea). These strange, spiny echinoderms with a typically circular body and five long, flexible arms, are abundant on the seafloor globally. Although they will be unfamiliar to many, their abundance makes them the perfect group for studying large-scale patterns of how marine life arose and spread around the planet.

The researchers utilised data collected on 2017's pioneering "Sampling the Abyss' voyage aboard CSIRO Marine National Facility research vessel Investigator, led by Museums Victoria. The month-long expedition explored the abyssal ocean depths off the eastern coast of Australia for the first time. Dr. O'Hara was Chief Scientist on the voyage, and this publication is the first major paper to be published as a result of the voyage.

DNA was used to reconstruct a comprehensive picture of how brittle stars have evolved across the Indian and Pacific Oceans in the southern hemisphere. Dr. O'Hara explained, "Museum collections are a treasure house of preserved biodiversity collected from thousands of scientific expeditions. Sequencing the DNA from these specimens can unlock the history of life on our planet. The digitisation and DNA sequencing of is providing a new way of looking at how life has evolved and spread around the globe."

Map showing geographic distribution of samples. Credit: Museums Victoria

The deep sea is the world's largest ecosystem, an ancient ark of relics from the dinosaur era, where "living fossils" exist at the same time that new species are fast evolving. These environments require as much protection as more famous and familiar habitats, like coral reefs and mangroves. Yet a lack of knowledge about in these dark waters has made it unclear how best to protect and preserve these environments from human exploitation like fishing or deep-sea mining.

Dr. O'Hara and his team's paper is the result of what he hopes will be the first stage of a global project to shed further light on processes of in precious deep sea environments, and how we can best project them.

Explore further: Faceless fish among weird deep sea Australian finds

More information: Timothy D. O'Hara et al. Contrasting processes drive ophiuroid phylodiversity across shallow and deep seafloors, Nature (2019). DOI: 10.1038/s41586-019-0886-z

Related Stories

Faceless fish among weird deep sea Australian finds

May 31, 2017

Faceless fish and other weird and wonderful creatures, many of them new species, have been hauled up from the deep waters off Australia during a scientific voyage studying parts of the ocean never explored before.

Scientists discover new life in the Antarctic deep sea

May 16, 2007

Scientists have found hundreds of new marine creatures in the vast, dark deep-sea surrounding Antarctica. Carnivorous sponges, free-swimming worms, crustaceans, and molluscs living in the Weddell Sea provide new insights ...

Past deep-water dynamics in the western tropical Pacific

August 29, 2018

Dr. Hokuto Iwatani and Dr. Moriaki Yasuhara from School of Biological Sciences and Swire Institute of Marine Science, The University of Hong Kong), in collaboration with scientists at Rutgers, the State University of New ...

Recommended for you

Archaeologists discover Incan tomb in Peru

February 16, 2019

Peruvian archaeologists discovered an Incan tomb in the north of the country where an elite member of the pre-Columbian empire was buried, one of the investigators announced Friday.

Where is the universe hiding its missing mass?

February 15, 2019

Astronomers have spent decades looking for something that sounds like it would be hard to miss: about a third of the "normal" matter in the Universe. New results from NASA's Chandra X-ray Observatory may have helped them ...

What rising seas mean for local economies

February 15, 2019

Impacts from climate change are not always easy to see. But for many local businesses in coastal communities across the United States, the evidence is right outside their doors—or in their parking lots.

The friendly extortioner takes it all

February 15, 2019

Cooperating with other people makes many things easier. However, competition is also a characteristic aspect of our society. In their struggle for contracts and positions, people have to be more successful than their competitors ...

3 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Bart_A
1 / 5 (5) Jan 24, 2019
Real research reveals that species are not evolving (in the macroevolutionary sense). So claiming that it is faster or slower is meaningless.
torbjorn_b_g_larsson
5 / 5 (2) Jan 25, 2019
Real research reveals that species are not evolving


Erroneous, non-sourced claim: evolution is the studied process of life [ https://en.wikipe...volution ]..
SciTechdude
5 / 5 (1) Jan 25, 2019
"Real Research" meaning religious bullshittery you are pretending is science. Everyone is evolving as we live, if you survive to pass on your genes to your children, they will be evolved to better survive in your lifetime environment.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.