World’s Largest Genome Discovered

On New Caledonia, a species of fern has been discovered with the longest genome (is the entire set of DNA instructions found in a cell.)of any known living organism.

Its genome is 50 times longer than a human’s, 7% longer than the previous record-holder, and 20% longer than the animal with the longest genome. While humans have 23 pairs of chromosomes, this fern has 416. If unraveled, its DNA would stretch higher than Big Ben in London.

Dr. Ilia Leitch from the Royal Botanical Gardens, Kew, remarked on the significance of this discovery, highlighting the diverse nature of plant DNA and its implications for understanding global biodiversity. She also noted the potential to explore the biological limits of genome size.

Twenty-thousand species have had their genomes sequenced and through that we learned that having a large genome isn’t always beneficial. Larger genomes demand more resources for replication, repair, and transcription, and require a larger cell nucleus.

Dr. Leitch explained to Reuters that species with larger genomes are more prone to extinction, similar to how simpler machines tend to be more durable than complex ones.

Previously, the longest genome was held by the Japanese flowering plant Paris japonica, while the African marbled lungfish (Protopterus aethiopicus) has the longest animal genome. The smallest genome belongs to the fungus Encephalitozoon intestinalis, with 2.6 megabase pairs. In comparison, the New Caledonian fern has 168 gigabase pairs, akin to comparing the file size of Tetris to a modern game like The Witcher.

Meteorites From Mars Found on Earth

Eleven million years ago, a meteorite impact on Mars sent fragments to Earth, providing unique insights into Mars’ composition. Scientists at Scripps Institution of Oceanography analyzed these Martian meteorites, collected from locations such as Africa and Antarctica.

These meteorites are the only physical pieces of Mars that we have. Their research is crucial for understanding Mars’ formation and evolution and it also helps inform current ongoing NASA missions like Insight and Perseverance.

Led by geologist James Day, the team focused on nakhlites and chassignites, meteorites originating from a single Martian volcano. These samples, identified by their unique compositions and young age, match the Martian atmosphere data from the 1970s Viking landers.

Published on May 31 in Science Advances, the study revealed that these rocks formed through fractional crystallization in a Martian volcano and included crustal material altered by the Martian atmosphere. These findings enhance our understanding of Mars’ internal structure and offer a glimpse into the conditions of early Earth.

130-Year-Old Assumption Overturned

For over a century, scientists believed that charged particles, or ions, in seawater remained in relatively constant ratios across the ocean. However, a recent study by a group of researchers has debunked this long-standing assumption, raising concerns about the accuracy of previous seawater studies based on it.

Mario Lebrato, station manager and chief scientist at the Bazaruto Center for Scientific Studies in Mozambique, led the team that challenged this assumption about seawater ion proportions. Interestingly, the original aim of their study wasn’t to test this assumption. “Originally, we were trying to understand how plankton grew in different seawater conditions,” Lebrato said. His team collected seawater samples from various parts of the world to analyze plankton growth. Upon measuring the composition of a few samples, Lebrato noticed significant differences in ion proportions between seawater from different sources. “This really triggered the project,” he explained.

To further investigate, his team formed partnerships with international universities, governments, and environmental agencies over seven years. They knew it would be challenging to collect seawater samples worldwide without external assistance or substantial funding. “It’s almost impossible for anybody to organize over a hundred research cruises,” Lebrato said. These partnerships included organizations like the United States National Oceanic and Atmospheric Administration (NOAA) and Environment Canada, as well as small research cruises and individual scientists. Lebrato even received help from organizations that ventured into the Arctic Circle to retrieve seawater samples.

After seven years of research, Lebrato’s team concluded that the original assumption about ion proportions in seawater was incorrect. According to their findings, there were significant deviations in major seawater ion ratios between samples, especially in the open ocean. “Everybody knew it was expected to find deviations from the coast, deviations near the rivers, and deviations in the poles near the ice. But nobody was expecting significant deviations on the open ocean,” Lebrato said.

Scientist have relied on the idea of a consistent ion distribution in the ocean to calculate a multitude of factors, such as ocean temperature and acidity. It addition, it has a large effect on marine biology, affecting things like shell density and dissolution. What this means is that much of the research that has been used to determine potentially large problems like rising ocean temperatures and ocean acidification could have major flaws.

Deep Sea Squid with ‘Headlights’

Australian marine biologists recently captured video footage of a large deep-sea squid attacking their camera over 3,000 feet below the ocean’s surface.

The deep-sea hooked squid, one of the largest species in its habitat, drew attention not for its size but for the glowing lights at the end of its tentacles.

A team from the University of Western Australia’s Deep Sea Research Center deployed baited, free-falling cameras to record deep-sea life.

Chief scientist Heather Stewart, working in the Samoan Passage, dropped the camera to a depth of 5 kilometers before retrieving it.

“We realized we had captured something very rare,” Stewart said, as they reviewed the footage.

They identified the squid as a Taningia danae, known for having the largest bioluminescent organs (photophores) of any known animal. These photophores are part of the squid’s hunting strategy, used to disorient prey with bright flashes of light.

“The squid, about 75 cm long, attacked our camera, mistaking it for prey, and tried to startle it with its bioluminescent lights,” Stewart added.

Professor Alan Jamieson, director of the Minderoo-UWA Deep Sea Research Center, noted the difficulty of observing deep-sea squid in their natural habitat.

“Most records of this species come from strandings, accidental bycatch, or the stomach contents of whales,” Jamieson said.

“Live observations of these squids are rare, making each encounter valuable for understanding their location, depth, and behavior. We had to share this unique sighting.”

The “Ancient Tree of Life” Explained

Scientists have traced the origins of ancient baobab trees to Madagascar, dating back 21 million years, according to DNA studies. Seeds from these trees were later dispersed by ocean currents to Australia and mainland Africa, resulting in distinct species.

The research team, including Dr. Ilia Leitch from the Royal Botanic Gardens, Kew, and Prof. Andrew Leitch from Queen Mary University of London, emphasizes the urgent need for increased conservation efforts. They warn that baobabs may be closer to extinction than previously.

Baobabs, known for their unique shapes and longevity, support a diverse range of animals, plants, and human communities. The study covered eight baobab species, with six in Madagascar, one across Africa, and another in northwest Australia. Researchers call for heightened conservation status for two endangered Malagasy species, including the giant baobab.

The trees, referred to as the “tree of life” or “upside-down tree,” can live for thousands of years, grow to enormous sizes, and store water in their trunks to survive dry seasons. Their fruits are considered a superfood, and their trunks provide fibers for ropes and clothing. The large white flowers attract bats for pollination, and baobabs serve as crucial nesting sites for birds.

This research was a collaborative effort between Wuhan Botanical Garden (China), Royal Botanic Gardens (Kew, UK), University of Antananarivo (Madagascar), and Queen Mary University of London (UK).