What exactly kills organisms during mass extinction? Analysis of more than 50 thousand sunk marine organisms had a simple answer: the general physiology.
Matthew Klefem University of California at Santa Cruz and Jonathan Payne of Stanford University (both — USA) reviewed a number of factors that can affect the viability of the species (habitat, habitat, etc.), and took into account the overall physiology of the species. Some organisms (such as sponges) can have a major environmental impact on their chemistry (for example, if it's acidic environment, the cells will be the same.) Others (for example, many clams) have a buffer: they control the cellular response to changes in the environment, that is, themselves determine which chemicals will enter the cage.
Based on these data, the researchers conducted a regression analysis and tried to assess how certain personality traits might affect the survival of the organism in various other factors during the six mass extinctions.
Most of the factors did not have sustainable impact. But in the two scenarios (one of them was the Permian extinction — the worst out of) ability to stand apart from the environment was very important.
How does the change in the environment, from which there is no defense of the body, can kill him? Well, for example, the Permian extinction, presumably, was caused by massive volcanic eruptions. Dramatically increased the level of carbon dioxide in the atmosphere are having trouble breathing, formed in the ocean dead zones with low oxygen content. It has also led to a decrease in pH (acidification) of the ocean, which is why shells and skeletons, based on — carbonates, began to dissolve.
This is not the first work in which the speculation is that the mass extinction was not a series of random killings, and was of a truly comprehensive. By the way, ocean acidification, along with the formation of dead zones observed today …
The study is published in the journal Geology.