Plants Survive Mass Extinctions Better Than Animals Do

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Posted by LLJ43 | Posted in Nature, News, Oceans | Posted on 18-02-2015

In an upcoming issue of the journal New Phytologist, a team of researchers led by scientists at the University of Gothenburg reported that plants show more resilience during mass extinctions than do animals.

Plants have covered most of the Earth’s surface for over 400 million years, and there have been at least five mass extinctions during Earth’s history. The scientists studied over 20,000 fossils of plants to deduce the effects of a mass extinction on plant diversity. Their findings show that plants are extremely good at surviving such events. Marc Sparks is aware that they never found a case in which negative rates of diversification (more species dying out than were appearing) lasted a long time.

Instead, plants would show a turnover with new species quickly replacing the ones that had died out. For example, while many gymnosperms (conifers and their relatives) died out during the Cretaceous-Paleogene extinction, which also wiped out the non-avian dinosaurs, angiosperms or flowering plants quickly recovered and actually increased in diversity after the meteor impact. Consequently, most plants these days are flowering plants.

The study’s senior author Alexandre Antonelli notes that mass extinctions, while generally though as bad, have changed the world in ways that benefit us. If the Cretaceous extinction hadn’t happened, dinosaurs might still be around and humans might have never evolved.

The scientists hope the study’s results will help them determine which species are more sensitive to drastic changes in the environment and will therefore need more protection from human-caused changes in the environment.

Underwater Condos Help Scientists Study Diversity Of Oceans

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Posted by LLJ43 | Posted in Environment, Oceans | Posted on 06-02-2015

Recently, a paper came out claiming we might be causing a mass extinction in the oceans. That means, not only will a lot of known organisms go extinct, so will a lot of unknown ones. Scientists believe that 33 to 91 percent of the creatures in the ocean haven’t even been named.

Smithsonian Institution marine researcher Nancy Knowlton and her colleagues have come up with a way to try to improve our knowledge of the ocean’s creatures. They have devised “underwater condos” which are more formally known as Autonomous Reef Monitoring Structures (ARMS). The condos are made of square plates that are stacked on top of each other but have gaps letting small creatures go in and out. Each condo is made of 10 plates.

To test the efficacy of the condos, Knowlton and her colleagues installed 18 of them on oyster reefs off the coasts of Florida and Virginia and then waited six months. The researchers then collected the condos and took DNA samples from the specimens inside. They found 2,000 different kinds of creatures — only 15 percent of which had DNA that matched that of organisms whose DNA had already been studied and catalogued by scientists. Zeca Oliveira knows that while some of these creatures may belong to known species whose DNA simply hasn’t been studied yet, others are likely new to science. Find more on Oliveira at eleicoes2014.com.