Tag Archives: phylogenetic analysis

Researcher Discovers Mitochondria Share an Ancestor with SAR11

Billions of years ago, an astounding evolutionary event occurred: certain bacteria became obliged to live inside other cells, thus starting a chain of events that resulted in what is now the mitochondria, an organelle found in all eukaryotic cells.  A recent study by researchers at the University of Hawaiʻi at Mānoa and the Oregon State University (OSU) provides strong evidence that mitochondria share a common evolutionary ancestor with a lineage of marine bacteria known as SAR11, arguably the most abundant group of microorganisms on Earth.

“This is a very exciting discovery,” said Michael Rappe, Associate Researcher at the Hawaiʻi Institute of Marine Biology in the School of Ocean and Earth Science and Technology (SOEST) at UH Mānoa.  “The results that we present make sense in a lot of ways: the physiology of SAR11 makes them more apt to be dependent on other organisms, and based on the contemporary abundance of SAR11 in the global ocean, the ancestral lineage may have also been abundant in the ancient ocean, increasing encounters between this bacterial lineage with the host of the original symbiosis event.” (more…)

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What Triggers Mass Extinctions? Study Shows How Invasive Species Stop New Life

*Collapse of Earth’s marine life 378 to 375 million years ago holds key*

An influx of invasive species can stop the dominant natural process of new species formation and trigger mass extinction events, according to research results published in the journal PLoS ONE.

The study of the collapse of Earth’s marine life 378 to 375 million years ago suggests that the planet’s current ecosystems, which are struggling with biodiversity loss, could meet a similar fate. (more…)

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