Nav: Home

Life in Antarctica's ice mirrors human disease

June 10, 2019

The cooling of the Southern Ocean surrounding Antarctica, which began approximately 35 million years ago and gave rise to its present icy state, has for decades been considered a classic example of climate change triggering rapid adaptation.

Using tens of thousands of genes mapped from across the genomes of a group of Antarctic fishes called notothenioids, a team of researchers is now challenging this paradigm, revealing that the massive amount of genetic change required for life in the Antarctic occurred long before the Antarctic cooled.

These genetic changes not only have major implications for understanding the evolution of Antarctica's unusual animals, but also highlight that some key adaptations used by fishes mirror the genetics of human bone diseases such as osteoporosis.

"Many species have evolved traits that are adaptive in their environment but are similar to disease states in humans," says Jake Daane, lead author of the study (Northeastern University). "We use this natural variation to better understand genetic mechanisms of disease."

The team found evidence of an increase in mutation rate during the evolution of Antarctic fishes prior to the onset of icy waters in the Southern Ocean that corresponded with a severe reduction of bone mineral density.

"Antarctic notothenioids don't have swim bladders to adjust their buoyancy in the water column. Rather, they use reductions in bone density to help them 'float' in the water column at low energetic cost," says co-author Bill Detrich (coauthor, Northeastern University). "What is a genetic disease state in us is a means of survival in these fishes."

"The genetic changes we found are severely pathological in humans, including some that have been considered not compatible with life," added Alex Dornburg (coauthor, North Carolina Museum of Natural Sciences). "Finding that notothenioids use the same genetic pathways to achieve buoyancy in water represents a tremendous opportunity for human health research."

To test the function of the genetic changes identified, the team further used advances in gene editing to engineer genetically modified zebrafish embryos with the same mutations as Antarctic notothenioids. As these zebrafish grew, they displayed the same loss of bone as observed in the Antarctic species.

"Our research is revealing Antarctic notothenioids to be important models for human disease. In addition to low bone density, Antarctic fishes also have evolved other apparently pathological conditions, including the loss of kidney glomeruli and red blood cells," says Matthew Harris (coauthor, Boston Children's Hospital and Harvard Medical School).

Harris added, "These biomedically-relevant processes can be studied to reveal the genetic mechanisms behind these 'disease' states and their accommodation in these fishes. The results should lead to deeper understanding of how we might treat comparable disorders in humans."

Rather than evolving these unusual adaptations in the face of major environmental upheaval, the team found that much of this genetic variation was already in place before the Antarctic cooled. This finding challenges how we consider adaptation versus standing genetic diversity to predict the response of modern populations to contemporary climate change.

Antarctic notothenioids were in the right place at the right time to capitalize on the transition to an icy Antarctic millions of years ago. However, their future is uncertain.

"Notothenioids are of high ecological, economic and medical importance, however, many species can't tolerate warming of more than a few degrees," says Thomas Near (coauthor, Yale University). "In an ironic twist of fate, forecasts of climate change now warn that this unique radiation of fishes could become decimated over the next century. It is up to us to prevent such a tragic loss."
-end-
The paper, "Historical contingency shapes adaptive radiation in Antarctic fishes," was posted as an Advance Online Publication on Nature Ecology & Evolution's website 10 June 2019, and appears here: https://www.nature.com/articles/s41559-019-0914-2.

North Carolina Museum of Natural Sciences

Related Climate Change Articles:

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.
Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.
Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.
Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.
A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.
Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
Predicting climate change
Thomas Crowther, ETH Zurich identifies long-disappeared forests available for restoration across the world.
More Climate Change News and Climate Change Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Space
One of the most consistent questions we get at the show is from parents who want to know which episodes are kid-friendly and which aren't. So today, we're releasing a separate feed, Radiolab for Kids. To kick it off, we're rerunning an all-time favorite episode: Space. In the 60's, space exploration was an American obsession. This hour, we chart the path from romance to increasing cynicism. We begin with Ann Druyan, widow of Carl Sagan, with a story about the Voyager expedition, true love, and a golden record that travels through space. And astrophysicist Neil de Grasse Tyson explains the Coepernican Principle, and just how insignificant we are. Support Radiolab today at Radiolab.org/donate.