Ups and downs of biodiversity after mass extinction
The climate after the largest mass extinction so far 252 million years ago was cool, later very warm and then cool again. Thanks to the cooler temperatures, the diversity of marine fauna ballooned, as paleontologists from the University of Zurich have reconstructed. The warmer climate, coupled with a high CO2 level in the atmosphere, initially gave rise to new, short-lived species. In the longer term, however, this climate change had an adverse effect on biodiversity and caused species to become extinct.
Until now, it was always assumed that it took flora and fauna a long time to recover from the vast mass extinction at the end of the Permian geological period 252 million years ago. According to the scientific consensus, complex ecological communities only began to reappear in the Middle Triassic, so 247 million years ago. Now, however, a Swiss team headed by paleontologist Hugo Bucher from the University of Zurich reveals that marine animal groups such as ammonoids and conodonts (microfossils) already peaked three or four million years earlier, namely still during the Early Triassic.
The scientists chart the temperature curves in detail in Nature Geoscience, demonstrating that the climate and the carbon dioxide level in the atmosphere fluctuated greatly during the Early Triassic and what impact this had on marine biodiversity and terrestrial plants.
The blood of an icefish isn’t red. Instead, its blood runs white.
Kristin O’Brien is a biologist at University of Alaska Fairbanks, who studies an unusual family of fishes called icefishes. They’re found only in the Southern Ocean surrounding Antarctica. They are unique because they are the only vertebrates in the world that lack the oxygen-binding protein hemoglobin, which is the protein that transports oxygen throughout the body and gives blood its red color. In other words, the blood of an icefish isn’t red. Instead, its blood runs a cloudy white. “I think these animals are among the most fascinating creatures on Earth,” Dr. O’Brien said
Image Credit: Wikimedia Commons
A lot of you are aware of Joel Sartore’s Biodiversity Project, but more importantly, a lot of you aren’t.
Sartore, a long time contributor to National Geographic, started the project with a modest goal: To show the world what it risked losing. Over 1,800 specimens have been photographed thus far. A considerable amount of the funding comes from Nat Geo and organizations concerned with wildlife preservation, but you can also purchase a print yourself to help out! I recommend you pick out your favorite one and hang it in your home/apartment/dorm/cardboard box.
When you focus on the response to climate change at the macro level, the ecosystem level, you get a better understanding of what is one of the major drivers of that biodiversity loss: forced migrations. And even here, the numbers may be larger than one would expect, as a new assessment by NASA and Caltech published in the journal Climatic Change shows that by 2100 some 40 percent of “major ecological community types” – that is biomes like forest, grassland, tundra – will have switched to a different such state.
Science Bulletins: Down and Dirty Biodiversity
The soils in tundra, grasslands, tropical forests are very different, but they have one thing in common; they all host an astounding diversity of life. Inhabiting these underground worlds are millions of species, which play vital roles in maintaining soil health and preserving the balance of their ecosystems. In the latest Bio News from the Museum’s Science Bulletins program, a new study shows that biodiversity underground is much greater than previously thought, with a direct relationship to life on the surface. View the story in AMNH’s Hall of Biodiversity until December 14, 2011 or online. For background information, educational resources, and more, visit the Science Bulletins Web site at http://www.amnh.org/sciencebulletins/.
Science Bulletins is a production of the National Center for Science Literacy, Education, and Technology (NCSLET), part of the Department of Education at the American Museum of Natural History.