The organisms were anchored to a boulder 900 meters beneath the ice, living a cold, dark existence miles away from the open ocean.
Life finds a way. That way may be uncomfortable, brimming with struggle, and demand an unsightly appendage or two, but as Jeff Goldblum reminds us, "Life will not be contained, life breaks free, it expands to new territories, and it crashes through barriers painfully, maybe even dangerously, but, uh, there it is."
To crash through those barriers, however, creatures must find the requirements for life waiting on the other side: namely, liquid water, a source of energy, and biogenic elements such as carbon and nitrogen. While terrestrial life has found some environments too hostile to call home, it's also evolved mind-boggling adaptations that allow it to access those three essentials in some bizarre places.
For example, the denizens of hydrothermal vents—such as the yeti crabs, scaly-foot gastropods, and Pompeii worms—dwell too deep in the ocean for sunlight to reach. Because their food chains can't rely on photosynthesis, they're supported by microbes that utilize a process called chemosynthesis, which converts chemicals from the vents into sugars and, in turn, useable energy.
Similarly, the Atacama Desert is a place so dry and barren that scientists compared it to the rusty dunes of Mars. Yet, even here, life has found a way in the form of microbes who wait patiently for those fleeting spits of rainfall to replicate.
And a new study, published in Frontiers in Marine Science, has proven Goldblum correct, uh, yes, once again. The study details the discovery of unusual creatures in one of the most unsympathetic environments on Earth's most inhospitable continent.
A cold dark place to call home
The Antarctic sessile creatures photographed on their home boulder.
Credit: Frontiers in Marine Science
Researchers made the discovery while drilling boreholes on the Filchner-Ronne Ice Shelf. Antarctica's ice shelves are giant, permanent floating ice sheets connected to the continent's coastlines, with the Filchner-Ronne shelf being one of the largest. Using a hot-water drill system, they bore through roughly 900 meters of the ice looking for sediment samples. Instead, they discovered a boulder. Two hundred sixty kilometers away from the ice front, the rock was nestled in a world of complete darkness at -2.2°C. And on it, they found sessile organisms.
"This discovery is one of those fortunate accidents that pushes ideas in a different direction and shows us that Antarctic marine life is incredibly special and amazingly adapted to a frozen world," Dr Huw Griffiths, the study's lead author and a biogeographer of the British Antarctic Survey, said in a press release.
Sessile creatures are defined by their inability to move freely. They live their lives anchored to a substrate—in this case, the aforementioned boulder. Common sessile animals found in coastal tide pools include mussels, barnacles, and sea anemones, yet none of these were present beneath the Antarctic shelf. Instead, the researchers discovered a stalked sponge, roughly a dozen non-stalked sponges, and 22 unidentifiable stalked organisms.
Previous boreholes had revealed creatures living in these murky waters, but they had always been free-moving predators and scavengers such as jellyfish and krill. It's not too surprising to find such animals under the ice shelves as their mobility allows them to seek out food that may drift beneath.
But sessile organisms depend on their food to be delivered to them. That's why they are so bountiful in tide pools; tides and currents are the DoorDash of the ocean world. It's also why the researchers found the sponge's Antarctic lodgings so astounding. Because they live 1,500 kilometers upstream from the nearest source of photosynthesis, it's unknown how a food supply reaches these sponges or whether they generate nutrients from some other means, such as glacial melt or carnivorous noshing.
"Our discovery raises so many more questions than it answers, such as how did they get there? What are they eating? How long have they been there? How common are these boulders covered in life? Are these the same species as we see outside the ice shelf or are they new species? And what would happen to these communities if the ice shelf collapsed?" Griffiths added.
To answer those questions, researchers will need to revisit the sponges to collect samples and study them in more depth. We'll also need to explore further the vast reaches of the Antarctic continental shelf. According to the release, counting the previous boreholes, scientists have only studied an area roughly the size of a tennis court to date.
Life will not be contained
As science discovers life in more and more unusual places, it's also considering more and more that life has not been contained to our pale blue dot. For example, the recent discovery of microbial life in the Atacama Desert has reignited hope that evidence of past life will be found on Mars. NASA's Perseverance Rover recently land on Mars to begin analyzing soil samples from the Jezero Crater to test that hypothesis.
Looking to the future, NASA's Dragonfly rotorcraft aims to explore the Saturn moon of Titan. The icy moon has a makeup similar to early Earth's, so the vehicle will study the moon's atmosphere and surface for signs of chemical evidence for life. And the ice-covered surface of Europa could hold twice as much water as Earth and a bevy of hydrothermal activity that could harbor life within our solar system.
Here life is, uh, and there it may be.
The island rule hypothesizes that species shrink or supersize to fill insular niches not available to them on the mainland.
- Brookesia nana, the nano-chameleon, may be the smallest vertebrate ever discovered.
- The "island rule" states that when new species migrate to islands, they may shrink or grow as they evolve to fill new ecological niches.
- It remains unclear whether the island rule can explain the nano-chameleon or nature's other extreme miniaturizations.
The newly discovered nano-chameleon (Brookesia nana) is the latest contender for the title of the world's smallest reptile and amniote vertebrate. Found in a mountainous region in northern Madagascar, the males of this diminutive species sport a body size of 13.5 mm, meaning one could comfortably stand on the end of your finger.
Its wee challenger is the Jaragua dwarf gecko (Sphaerodactylus ariasae). These pocket-change-sized geckos—the genus is often pictured snogging the minted portraits of past presidents—come in at 16 mm from nose to tail. They were discovered in 2001 on Isla Beata, a small, forested Caribbean island just south of the Dominican Republic.
The title of the world's smallest, however, is difficult to award thanks to sexual size dimorphism. As Dr. Mark Scherz, herpetologist and evolutionary biologist, pointed out on his blog, nano-chameleon females are significantly larger than their male counterparts or Jaragua dwarf gecko females. "As a result, whether or not the new species is considered the smallest amniote in the world depends on whether we define that based on the male or female body size, or the midpoint of the two. It turns out this is quite a common problem in other species with size dimorphism as well, such as frogs," Scherz writes.
Beyond their shrimpy stature, these and other miniaturized species have another thing in common: They live on islands. That fact may explain why evolution has pushed them to shrink in a world full of giant competition.
Bigger isn't always better
The New Zealand little spotted kiwi evolved to be small to fill an ecological niche. Before the arrival of humans, its island ecosystem contained no land mammals to prey on these flightless birds.
Credit: Wikimedia Commons
Because of their geographic isolation, islands can have powerful effects on the evolution of their residential species. The massive Komodo dragon prowls its namesake island. The Barbados threadsnake is thin enough to slither through a straw. And the fossil record recounts a history of unusually sized and bedecked creatures who established homes far from the mainland, such as the Hoplitomeryx of the Mikrotia fauna.
One hypothesis for evolution's insular experimentation is "the island rule." The rule states that after establishing themselves on an island, smaller species will tend to evolve into oversized versions of their mainland ancestors. Meanwhile, larger species will tend to evolve into smaller variations. These processes are known as insular gigantism and insular dwarfism, respectively. They do this to fill the ecological niches available to them, which often differ from those they filled on the mainland.
The rule was first formulated by evolutionary biologist Leigh Van Valen and based on a 1964 study by mammologist J. Bristol Foster—which is why it is also known as Foster's rule. Since then, many observational studies have corroborated the island rule, and there is even evidence to suggest that new species introduced to islands will, for a time, evolve more rapidly to fill available niches.
A flock of migrant birds, for example, may find an island's lack of mammalian and reptilian predators opens the ground-living niche once forbidden to them. Such birds would then be free to grow larger, forage below the canopies, and lose the ability of flight.
This appears to be the origin story for New Zealand's flightless birds including the giant moa, which, at six-feet tall, is the tallest bird on record. This megafauna enjoyed all the benefits of being large and in charge: fewer predators, wider ranges, access to more and varied foods, and the ability to better survive trying times. The species enjoyed island life until roughly 600 years ago, when humans arrived on the scene and hunted them to extinction.
Conversely, large species may find island living restrictive as there's less room or food when compared to their mainland nurseries. Because of this, evolution may select for smaller body sizes as such bodies require less energy, and therefore fewer resources, to survive and reproduce.
This is the theory behind the miniaturization of the Channel Islands pygmy mammoths. As the story goes, in the search for food, a herd of Columbian mammoths embarked on a journey to the super island Santaroasae. Over time, the island was cut off from the mainland. Food became scarce, and smaller mammoths had an easier time surviving and reproducing, thus passing on their Shrinky-Dink genes. Thanks to a lack of oversized predators, such evolution proved fruitful, and in less than 20,000 years, the giant Columbian mammoths evolved into a new species—the (relatively) pint-sized, 6.5-foot-tall pygmy mammoths.
To be clear, the island rule doesn't state that any species that washes ashore must go either Lilliputian or Brobdingnag. It only states that if an ecological niche becomes available and improves survival and reproductive success, then such a change is likely.
Thanks to that island living?
Such constrained growth may be the cause of the Jaragua dwarf gecko's bantam evolution. The gecko eats tiny insects and may be filling a niche that's unavailable on the North American continent with its many, many insectivores. In fact, the island rule may explain why islands are so rich with endemic species—particularly the Caribbean, which is considered a biodiversity hotspot.
Of course, scientific rules are only provisional, and scientists are prepared to revise or completely disregard a hypothesis should new evidence appear. In a field as new as biogeography, the question of whether the island rule is truly a "rule" remains an open and hotly debated question.
One systematic review found empirical support for the island rule to be low, while another analysis argued the rule is simply a recognition of "a few clade-specific patterns." The latter's authors conclude that "[i]nstead of a rule, size evolution on islands is likely to be governed by the biotic and abiotic characteristics of different islands, the biology of the species in question and contingency."
That brings us back to the newly discovered nano-chameleon. While it seems to follow the island rule—Madagascar being an island known for its rich biodiversity—there is a wrinkle. The species' closest relative lives right next door. Brookesia karchei is near twice the size of the nano-chameleon but ranges in the same mountains on mainland Madagascar.
If the nano-chameleon evolved to fill an ecological niche, why didn't those same environmental pressures miniaturize the karchei chameleon? If not the island rule, what did lead to the nano-chameleon's smaller size? As is often the case in science, further evidence may one day answer these questions.
Participation in community science programs has skyrocketed during COVID-19 lockdowns.
The rapid spread of COVID-19 in 2020 disrupted field research and environmental monitoring efforts worldwide. Travel restrictions and social distancing forced scientists to cancel studies or pause their work for months.
Our work relies on this kind of information to track seasonal events in nature and understand how climate change is affecting them. We also recruit and train citizens for community science – projects that involve amateur or volunteer scientists in scientific research, also known as citizen science. This often involves collecting observations of phenomena such as plants and animals, daily rainfall totals, water quality or asteroids.
Participation in many community science programs has skyrocketed during COVID-19 lockdowns, with some programs reporting record numbers of contributors. We believe these efforts can help to offset data losses from the shutdown of formal monitoring activities.
Nature's Notebook is a community-based science project that invites participants to track seasonal changes in plants and animals.
Why is uninterrupted monitoring important?
Regular, long-term tracking of phenomena such as plant and animal abundance, composition and activity is critical for understanding change. It enables researchers to see the impacts of natural disturbance events, such as wildfires, and human activities, such as construction and development. Long-term studies offer insights into patterns and processes that can't be derived from shorter studies, and help experts make better predictions about the future.
Interruptions in monitoring make it harder to accurately assess changes. If those disruptions coincide with extreme events, such as a major hurricane, experts miss opportunities to understand the full impacts of those events.
The U.S. has several long-term ecological monitoring programs, including the National Ecological Observatory Network (NEON), the Long Term Ecological Research Network and federal inventory and monitoring programs. Many state and local government agencies carry out similar activities. The pandemic has significantly disrupted all of these programs.
Reasons to engage the public in science
Community science is a strong complement to formal research. By engaging willing volunteers, community programs yield much more data and cover larger areas than professional scientists can achieve on their own.
We help manage two popular biodiversity-themed community science programs in the U.S.: eButterfly, a program for tracking butterfly sightings, and Nature's Notebook, a program for tracking seasonal activity in plants and animals. Scientists have used data contributed by participants in these programs to verify information collected by satellites, determine the conditions associated with flowering in different species of plants, and predict how climate change will shift plant species' ranges in the future.
Observations contributed to other community science programs have helped to document new insect species, discover exoplanets and even find cures for rare diseases. Globally, millions of people participate in thousands of projects, resulting in data valued at more than US$1 billion annually.
Community science programs also benefit participants. Joining a community science program can make people more science-literate and help pull back the curtain on how scientific work is done. It also deepens their sense of place and increases their understanding and appreciation for the plants and animals they monitor. We have frequently heard from our participants that making observations has enabled them to see and experience much more in places they know well, and to enjoy those places all the more.
Community science to the rescue
As offices and schools closed in the spring of 2020, many Americans turned to community science programs in search of stimulating and meaningful activities for children and adults alike. And despite COVID-19 restrictions, volunteer data collectors have persisted through the pandemic.
In a recent analysis of activity in biodiversity-themed community science programs during COVID-19 lockdowns, we found that participation generally held steady or increased in the spring of 2020. Two popular programs, iNaturalist and eBird, both grew. Participation in Nature's Notebook and eButterfly declined slightly, though volunteers still logged many critical observations. What's more, community science volunteers in these programs and others have kept at it even as lockdowns have relaxed.
Plant ecologist Chad Washburn explains how the Naples Botanical Garden in Florida uses citizen science research to study plant distribution, flowering times and range.
How good is community data?
One common question about community science projects is whether data collected by volunteers is reliable. This is a valid concern, since many program participants are not formally trained as scientists.
Organizations that run community science programs typically go to great lengths to ensure data quality. To avoid recording erroneous observations, project leaders provide extensive training and support materials. They also construct data entry apps so that volunteers can't mistakenly input dates in the future, and flag inconsistent reports for review. Several biodiversity-themed programs, including iNaturalist, eBird and eButterfly, engage expert reviewers to evaluate and verify reports.
According to a 2018 review by the National Academies of Science, Engineering and Medicine, on average, volunteer contributors yield reliable data points about 75% of the time. For some programs, such as Nature's Notebook and eBird, accuracy is over 90%.
SciStarter is a database that volunteers can use to find community science opportunities across the U.S. throughout the year.
How to get involved
Your observations can help fill critical gaps that COVID-19 closures have created. Contributions to iNaturalist, eBird, eButterfly or Nature's Notebook are welcome any time of the year, but spring is an ideal time to contribute observations to biodiversity-themed programs to help document plant and animal response to changing seasonal conditions. For example, participants in Nature's Notebook will help document whether springtime plant and animal activity is early amid the ongoing effects of climate change.
The 2021 City Nature Challenge, an effort using iNaturalist to document urban biodiversity in brief, focused events, will run in late April and early May in cities worldwide. Another event, Global Big Day – a single day focused on celebrating and recording birds worldwide – is scheduled for May 8. Even if you've never thought of yourself as a scientist, you can help scientists collect data that expand our understanding of the Earth and how it works.
Theresa Crimmins, Director, USA National Phenology Network, University of Arizona; Erin Posthumus, Outreach Coordinator and Liaison to the U.S. Fish & Wildlife Service, University of Arizona, and Kathleen Prudic, Assistant Professor of Citizen and Data Science, University of Arizona
First picture of worldwide bee distribution fills knowledge gaps and may help protect species.
Twelve different species of bees swarming a flowery meadow. Etching by J. Bishop, after J. Stewart.
Credit: Wellcome Collection, CC BY 4.0
How many bee species are there? Wait a minute: honeybee, bumble bee, erhm… five? Five hundred? Five thousand? Not even close: the total is well over 20,000 – which means there are more species of bees than of birds and mammals combined.
There's no shame (nor surprise) for bee civilians like you or me in not knowing that. What is surprising, is that even scientists who specialise in bees didn't quite know how those species are distributed all over the world. Until now.
By combining and filtering more than 5.8 million public records of bee occurrences, a team of researchers from China, the U.S., and Singapore have built up the very first comprehensive picture of bee diversity worldwide. And that picture presents a few surprises, both for laypersons and specialists.
Bee ignoramuses will be surprised to learn that the United States is the throbbing heart of bee diversity. The U.S. has far more bee species than any other region on Earth. And by the fact that large tracts of Africa and the Middle East remain terra incognita, in terms of apiary diversity.
Relative bee species richness in the New World. Note the low density in the Amazon Basin.
Credit: Current Biology, open access
In general, there are more bee species in the Northern Hemisphere than the Southern and—confirming previous hypotheses–more in arid and temperate climates than in the tropics.
That goes against the common pattern in biology known as the 'latitudinal gradient', which predicts that species diversity (of most plants and animals) increases towards the tropics and decreases towards the poles. Bees are an exception, with a higher species concentration away from the poles (in what scientists call a 'bimodal latitudinal gradient').
To give that difference some visual immediacy, imagine a graph with one hump in the middle (i.e. the latitudinal gradient) versus one with two humps, one on either side of the middle (i.e. the bimodal latitudinal gradient). In other words: dromedary (one-hump) versus camel (two-hump).
It seems counter-intuitive that bees would thrive better in arid deserts than in lush tropical jungles; but that's because trees–the dominant vegetation type in the tropics–provide less bee food than the plants and flowers that grow elsewhere.
Three ways of measuring species richness in the Americas: (A) richness of polygons, (B) sPCA and (c ) turnover. All suggest a large, distinct bee fauna in the southwestern U.S.
Credit: Current Biology, open access
Also, bees don't like it too wet, unlike their cousins the ants, whose populations peak in the humid tropics. The researchers think humidity may play a role in limiting bee distribution by spoiling pollen resources.
The relative absence of bees from the tropics has consequences for pollination, which in those regions is performed by a wide variety of alternative species: wasps, moths, and even cockroaches.
Previous datasets of global bee distribution were either inaccurate, incomplete, or difficult to interpret. This world map clearly establishes that bees prefer dry and temperate zones to wet and tropical ones. For bee scientists, it provides a much-needed baseline to predict the geographic distribution of bees and interpret the relative richness of species.
While much work needs to be done to fill additional knowledge gaps, this baseline is an excellent starting point, not just for greater understanding, but also for better conservation. Because bees are not just for making honey. In many countries, they're the top pollinator species. And they typically visit 90 percent of the leading crop types.
Carpenter bee (Xylocopa latipes) pollinating a flower in the Indian state of Kerala.
Yet over the past decades, bee populations have been crashing. In the U.S., honeybee populations have declined by 60 percent between 1948 and 2008. In Europe, 12 wild bee species are critically endangered.
That trend is potentially disastrous for agriculture. More than $550 billion in annual global crops are at risk from pollinator loss. The loss of bees as pollinators would lead to a collapse in crop yields and even entire ecosystems.
Better understanding bees increases our options for protecting them. This study will help pinpoint bee diversity hotspots in otherwise poorly examined parts of the world and help predict how bees will react to climate change–for example when certain regions will get wetter weather.
Protecting bee diversity is especially important and urgent in developing countries, where many of the knowledge gaps are located, and where many crops rely on native bee species for pollination.
Strange Maps #1060
Got a strange map? Let me know at firstname.lastname@example.org.
Exceptionally high-quality videos allow scientists to formally introduce a remarkable new comb jelly.
- Gorgeous simplicity characterizes the comb jelly recently discovered by National Oceanic and Atmospheric Administration Fisheries.
- The small denizen of the deep was spotted three times beneath the waters off Puerto Rico.
- Though it's unusual to formally identify an animal strictly based on video observations, the quality of NOAA's video made it possible in a case where there's no better alternative.
Usually, when scientists announce the discovery of a previously unknown animal, they have a specimen of the new arrival in hand. That's not the case, though, with Duobrachium sparksae, an amazing and beautiful ctenophore encountered 3,910 meters beneath the ocean surface about 40 kilometers off the coast of Puerto Rico. No one has met Duobrachium sparksae in person — we know of its existence only through several high-definition videos. ("Ctenophore" is pronounced teen-a-for, by the way.)
Says NOAA Fisheries' Marine Biologist Allen Collins in a NOAA press release, "It's unique because we were able to describe a new species based entirely on high-definition video."
It's also unique because it's such an exquisitely elegant organism.
Meet cute beneath the waves
The first encounter humanity had with the jelly occurred on April 10, 2015, when Deep Discoverer (a remotely operated vehicle or ROV) came across the gelatinous wonder. Fortunately, the ROV sports cameras that were sufficiently high-definition to clearly capture Duobrachium sparksae's fine details.
The animal was first noticed in a video feed by Mike Ford of the shoreside science team working in NOAA's Exploration Command Center far away, outside of Washington, D.C. The ROV was working the Arecibo amphitheater canyon. What Ford saw was, in his words, "a beautiful and unique organism."
Deep Discoverer's cameras produce externally high-resolution images, and are capable of measuring objects as small as a millimeter.The comb jelly's body is about 6 centimeters in size, and its tentacles are about 30 cm long.
While video-based animal identification can be controversial, there was little choice in this case. "We didn't have sample collection capabilities on the ROV at the time," says Collins. "Even if we had the equipment, there would have been very little time to process the animal because gelatinous animals don't preserve very well; ctenophores are even worse than jellyfish in this regard."
Credit: Nicholas Bezio/NOAA Office of Ocean Exploration and Research
Describing Duobrachium sparksae
All told, three individuals were observed by the scientists in three separate encounters with the ROV. The image at the top of this article is from the second encounter. The fact that three separate examples were easily spotted leaves scientists hopeful that the creature is not a rarity in the seas.
Ford describes what they saw:
"The ctenophore has long tentacles, and we observed some interesting movement. It moved like a hot air balloon attached to the seafloor on two lines, maintaining a specific altitude above the seafloor. Whether it's attached to the seabed, we're not sure. We did not observe direct attachment during the dive, but it seems like the organism touches the seafloor."
The role that Duobrachium sparksae plays in its ecosystem is not yet understood.
Finding a place in the family
The manner in which light refracted prismatically off the jelly's cilia combs immediately placed it in the ctenophore family as a start.
Collins explains, "We don't have the same microscopes as we would in a lab, but the video can give us enough information to understand the morphology in detail, such as the location of their reproductive parts and other aspects."
"We went," says Ford, "through the historical knowledge of ctenophores and it seemed clear this was a new species and genus as well. We then worked to place it in the tree of life properly."
The videos—the only "specimens" there are of Duobrachium sparksae—are now publicly accessible as part of the Smithsonian National Museum of Natural History Collection.