Leilan
Current Event Posting #2
Science
"A Tiny Horse That Got Even Tinier as the Planet Heated Up" by James Gorman
New York Times
Published February 23, 2012
Length: 2 pages
When the word "prehistoric" is brought up, the first thing that comes to mind is usually the dinosaur and the grim ending they all faced around 65 million years ago. It is unlikely that an asteroid will be the thing to strike down all life on Earth, as was the case with the prehistoric lizards we all came to know through Jurassic Park. Instead of a killer rock from outer space, climate change may be the most pressing environmental danger of our time--something that we are getting more and more familiar with in our daily lives. As James Gorman wrote, "rising seas, killer storms, droughts, extinctions and money wasted on snowblowers" are all signs that the temperature of the Earth as a whole is rising. Though there weren't any expensive snowblowers around 56 million years ago to clog up the atmosphere, the Earth was warming up at that time as well. This had an interesting effect on the size of the mammals of the era, scientists say, observed through the size pattern on a certain animal known as Sifrhippus.
Sifrhippus, also known as the first horse, makes an interesting study of the effects of global warming on mammals. By studying the skeletal structure of this prehistoric horse, scientists Ross Secord, Jonathan Bloch, and their team of researchers were able to directly tie the shrinking in size of the Sifrhippus to the warming of the planet. During a period of global warming which lasted about 175,000 years, in which temperatures rose by 9 to 18 degrees Fahrenheit, the little horse got 30 percent smaller over the first 130,000 years; the weight of the horse went from 15 pounds at its largest to only 8.5 pounds at the smallest.
Secord speculates that the reason for this change seems to be natural selection, because a smaller mammal has an “easier time [shedding] excess heat.” The question stands: will the horses or other mammals around today begin to shrink as well? Unlikely, as the current warming period is over hundreds of years, not thousands, as it was in Sifrhippus’ case, and the fact that the tiny horse was the size of the domestic cat. Does this mean that your cat will shrink? Again, that is far-fetched, but trends have been noticed in birds that are reducing in size in response to global warming. However, that broaches the disturbing question: “Can mammals keep up?”
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