Volume 18, Issue 25
The extinction of the dinosaurs has been a mystery that has gripped the attention of people of all ages, from children with plastic dinosaur figurines to adults eagerly awaiting the release of the next Jurassic Park film. Recently, scientists have uncovered some clues that may help lead to obtaining the full story of how the dinosaurs went extinct, but these clues lie in a much more familiar animal than dinosaurs: birds.
Birds trace their ancestry all the way back to the dinosaurs. Many, including chickens, can trace their ancestry to a specific species of dinosaur, Archaeopteryx. Scientists have now begun to classify birds as being related to either ancient ground-dwelling or tree-dwelling species. They also discovered that the tree-dwelling birds, discovered via fossils, all became extinct due to the asteroid that killed the other dinosaurs 66 million years ago. In other words, all the birds that we see outside today, from cardinals to penguins, can be traced back to only ancient ground-dwelling birds. What does this tell us about the mass-extinction event that killed the dinosaurs? It also killed all the trees!
This deforestation is further confirmed by the species of ferns that exist today. Paleobotanist Antoine Bercovici of the Smithsonian National Museum of Natural History in Washington, DC studied the spores and pollen of ferns found in rock layers that formed in the years after the asteroid impact. He discovered that all these ferns could be traced back to only two species of ferns. This indicated that there was a mass extinction of ferns species, resulting in rapid recolonizing by the two surviving species of ferns. Bercovici says this is seen today as well “when ferns recolonize lava flows in Hawaii or landslides after volcanic eruptions.”
This new evidence may seem small, but it is another piece in the giant puzzle that is the extinction of the dinosaurs. Scientists may now know why tree-dwelling birds living in the Cretaceous period died after the asteroid hit, but they still cannot explain why certain species of ground-dwelling ancient birds also died in this event. Scientists are excited to continue piecing together the evidence that will one day, completely answer the question, “What really happened when the dinosaurs went extinct?”
Pickrell, John. “How did Dino-Era Birds Survive the Asteroid Apocalypse?” National Geographic. National Geographic. May 24, 2018. Web. May 30, 2018.
Volume 18, Issue 24
In June of 2013, the Nicaraguan National Assembly approved of the construction of a canal to be built through Nicaragua by the Hong Kong Nicaragua Canal Development Group. The canal is expected to cost around $40 billion, provide Nicaragua with 250,000 jobs and significantly increase the national GDP. On the surface, one can understand why the government of the second poorest country in the western hemisphere, with nearly 45% of its citizens below the poverty line, may find this deal attractive. However, the canal’s construction, which has already been postponed twice, has raised concerns by conservation scientists, environmental activists, and indigenous Nicaraguans about the environmental and social impacts the canal may have on the country.
The 173-mile long canal is currently projected to bisect Nicaragua starting from the mouth of the Brito river on the Pacific coast, where it will cut through to lake Cocibolca and on eastward through the Tule and Punta Gorda rivers to the Caribbean sea. Lake Cocibolca is Central America’s largest freshwater lake and is not only Nicaragua’s primary source of fresh water, but is also home to a variety of endemic fish species as well as thousands of indigenous families who fish the lake for subsistence. Conservationists fear that the introduction of saltwater from the ocean entering the lake via the canal could disrupt the lake’s ecosystem, threatening not only its biodiversity but also the livelihoods of thousands of people. There is the additional possibility of invasive ocean species being inadvertently transported into the lake from ships passing through and wreaking havoc on endemic populations.
The canal would also cut through the Mesoamerican Biological Corridor, a reserve stretching from southern Mexico to Panama that allows endangered mammals, such as jaguars, to migrate from north to south across their native habitat. Experts at Panthera, a group of scientists dedicated to the protection of large cats, warn that such a disruption could do significant harm to the already small jaguar population (500 individuals) in Nicaragua. Perhaps the most troubling consequence of the canal would be the displacement of some 120,000 farmers and members of the indigenous Rama, Ulwa, Garifuna, and Miskitu communities that live along the canal’s proposed route. This displacement would not only unjustly confiscate land from indigenous groups that have been marginalized since Spanish colonial times, but would also threaten their unique languages and cultures, representing a net loss of human cultural diversity.