Climate change has become a hot-button phrase these days, and has unfortunately has lost a lot of its previous impact. Usually people just roll their eyes and think, “Here comes another nutcase to tell us about the end of the world.”
So, you can relax. This isn’t one of those end-of-the-world lectures. But I am going to tell you about climate change.
Samantha Hopkins, University paleontologist,@@http://directory.uoregon.edu/telecom/directory.jsp?p=findpeople%2Ffind_results&m=staff&d=person&b=name&s=Samantha+Hopkins@@ is working on a project exploring how ecological systems changed as a result of a warming Earth. We all know that the Earth has been even warmer in the past, and the time frame that Hopkins is researching falls between 15 and 30 million years ago: the Miocene Epoch.@@checked@@
“Ignoring the fossil record because it’s incomplete is ignoring a possible, very valuable source of information about what we might expect to happen,” Hopkins said.
The Miocene Epoch falls within the Cenozoic Era @@http://www.pbs.org/wgbh/evolution/change/deeptime/cenozo.html@@(248 million years ago to now), our current era. It spans about 20 million years, from 24 million years ago to over five million years ago. Horses and other hoofed animals evolved during this time. Hominids branched off from chimpanzees. The Cascades, the Andes and the Himalayas were being built, which affected weather patterns. Antarctica had already split off from South America and consequently froze.
But most importantly, global warming occurred.
“(It warmed) up to a temperature that is as warm as where we’re going in the next 100 years,” Hopkins said.
The warming pattern mixed with Antarctica’s frozen state shrank the oceans, exposing land bridges all over the world. A new habitat took over — from tropics to dry, dusty land. And with new land comes new life.
“The question that I’m asking is ‘How does community structure and ecology change with changes in climate?’” Hopkins said.
Oregon has a fantastic fossil record from late Oligocene (33-24 million years ago)@@checked@@ and Miocene Epochs, and Hopkins’ research has made it possible to see what kinds of changes happened to the ancient flora and fauna. She works on mammals — specifically small rodents. But even the most seemingly insignificant critter can tell a paleontologist a lot about the ecology of its environment. For instance, by looking at the bones of the animal’s forearms and shoulders, Hopkins can be confident whether the specimen was some kind of burrowing animal. And from today’s observations of burrowing mammals, we know that they like to live in dry, warm climates where there is little to hide them from predators.
Another thing that was different about the animals in the middle Miocene Epoch was their size. Things were smaller, which Hopkins and other scientists know to be consistent with changes in climate. When you’re big, it’s hard to shed excess heat. Things get bigger in the cold and smaller in the heat.
The cool thing about this project is that it brings together all sorts of scientists. Although Hopkins is well-versed in prehistoric rodents, she needs input from geologists, paleoecologists, biologists, ecologists and other paleontologists to drive her research. This is a project that scientists around the country can contribute to because there are fossils everywhere.
“It is a collaborative endeavor, and it’s good to work with people,” Hopkins said.
At this point in her research, Hopkins and her team have gathered tens of thousands of specimens and are currently slogging through them — cataloging, identifying and examining. Just adding one data point means hours and hours of work. Hopkins isn’t willing to say that all the observed changes are an effect of climate change because ecology and evolution are complicated. Lots of different things can cause a population or community structure to change, and climate is just one of them.
“The best way to say what happens when (the Earth warms) is to look at what happened when (it’s) done this before,” Hopkins said.