The Rise of C4 Plants

By Kevin McFadden

Imagine a happy place where you’re laying out in the Caribbean sunshine on a beach with a mojito in hand. You jump into the crystal clear blue bathwater of the sea, then you lay down in your chair under an umbrella and doze off thinking about delicate and beautiful New England winters… you wake up and look over at a little saltbush that hasn’t been consuming delicious beverages, cooling off in the sea or taken cover under an umbrella to take a nap. In fact, this poor plant hasn’t moved an inch. First off, let’s hold the phone here. The truth is, this plant is loving life and it took over 3 billion years of evolution for it to become so happy! Saltbush is one of many plants who has adapted to warm, sunny, and dry conditions.

Long ago, when atmospheric carbon dioxide levels were high and oxygen levels were low, an enzyme called Rubisco started being made in plants which is an important driver in the Calvin cycle, without which food can not be made. Continue reading

Extinction through time; were humans a factor in the past, too?

By Gloria Lima

It’s known that humans have played a large role in the extinction of many organisms. But does this mean we are the only cause? How is it possible for us to tell if we are the only factor or if we simply play a large role in the whole ordeal? Paleoecology offers clues, starting with which organisms went extinct, and which survived. We can look to paleontological data for patterns, like the body size of extinct species, or how those species interacted with their habitats.  By comparing fossil and modern animals, it is then possible to see how the organisms in the past interacted with their environments, by looking at the ecology of their surviving relatives.

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Image courtesy of Smithsonian Magazine.

Much of what we know about extinction comes from carbon dating the remains of extinct animals. An example is seen in the article “Patterns of generic extinction in the fossil record.” The authors looked at many fossils from a wide range of genera to see if there was a common pattern in extinction among the organisms. If there was a trend, it’s then possible to see whether the environment played a large role in the extinction, compared to the biology of the organisms. If so, this could mean that the climate caused a change in the environment before the organisms were able to adapt to it. Continue reading