Wyoming is known to most visitors for its striking beauty framed by vast plains and canyon but scientists also love it too for its treasure trove of data—encompassing paleontology, geology, microbiology and now, climate change. Remnants of a staggering hyperthermal event (Paleocene-Eocene Thermal Maximum/PETM) occurring 56 million years ago and lasting 180,000 years have been fossilized and preserved in the Bighorn Basin.
Buried deep within the sediment, scientists have uncovered teeth from a variety of mammals that illustrate just how warming temperatures can drive body size change. Based on soil composition and other factors such as carbon cycles, mammals had to adapt to harsh environments releasing body heat to stay cool. Moreover, environments once rich in vegetation and water became tropical or subtropical causing native mammals to migrate and/or become smaller so they could function more efficiently. As body size changed so did tooth size which offers insight into what we call dwarfing. For example, Sifrahippus—forerunner of the modern-day horse—shrank by 30% during the height of the PETM, (the first 130,000 years), then rebounded in size growing even bigger—possibly as much as 75% during the last 45,000 years of the PETM. At its smallest, the tiny equid weighed about 8 pounds in comparison to a modern miniature Shetland Pony which weighs between 150 and 250 pounds.
Understanding biological responses to these severe changes in climate can provide us with insights into global warming, which we are currently experiencing.
Global warming is a gradual increase in the Earth’s surface temperature, oceans and atmosphere while climate change is a prolonged change in the Earth’s climate or the climate of a region or city with lasting and sometimes deadly effects. According to NASA, the Earth’s temperature has been increasing by 1 degree Fahrenheit over the last 100 years and will increase by the same amount over the next 100 years. However, the Environmental Protection Agency (EPA) projects a rise of 2-11 degrees over the next 100 years—a significant difference.
Besides rising temperature, climate change results in rising sea levels and decreasing snow and ice cover. According to NASA, the warming climate will likely cause more severe floods, droughts, hurricanes and heat waves.
While scientists don’t know yet whether mammals will react exactly the same way, we do know that birds are showing signs of getting smaller. For those who think global warming and climate change don’t exist—dwarfing shows us otherwise.
Read more about the research here.
By Rose-Marie Brandwein