It may seem counterintuitive to thank God for an animal species’ extinction, but new research suggests that the catastrophic elimination of larger mammoth species produced manifold benefits for the planet, other animals, and humans in particular.
The mighty mammoths that inhabited Siberia, Alaska, and Canada represent the land largest mammals to have lived in recent times. Though most species of mammoths were no larger than the Asian elephant—maximum size 11 feet (3.3 meters) tall at the shoulder and 12,000 pounds (5,400 kilograms) in weight—the Songhua River Mammoth (see figure 1) reached heights at the shoulder of 17 feet (5 meters) and attained weights of 24,000 pounds (11,000 kilograms).
The dwarf mammoths persisted until about 3,600 years ago. The larger mammoths, however, experienced a catastrophic population collapse about 15,000 years ago and by 8,000 years ago were completely extinct. The specific cause of the mammoth extinction is still the subject of considerable debate among scientists. Some suggest a comet impact in the northern hemisphere altered the mammoths’ habitats. Others argue that human predation wiped out the mammoths. Some claim a dramatic change in climate (see figure 2) at the close of the last ice age was responsible for the demise of the mammoths. Still others say disease was the culprit. Perhaps the correct answer is some combination of all four.
Irrespective of the cause of the mammoth extinction event, scientists Chris Doughty, Chris Field, and Adam Wolf, all of the Carnegie Institution for Science at Stanford University, recently published a paper in which they claim the event had a positive outcome for the human race.1 First, the researchers point out the conclusive evidence proving that mammoths, like elephants, fed on the leaves and branches of young trees. This explains why the northern portions of North America, Europe, and Asia—largely populated by mammoths—were well-pruned and largely free of forests previous to 15,000 years ago. Further, it explains why birch trees in those regions experienced a population explosion at the same time mammoth populations plummeted.
Next, Doughty, Field, and Wolf determined the outcomes resulting from the expanded forests of birch trees. The primary impact was a drop in the albedo of the northern continental landmasses. (“Albedo” is a scientific term referring to how much light a planetary, lunar, or asteroidal surface reflects.) The lower albedo meant a greater amount of heat absorbed from the Sun. In summer, birch tree leaves, being darker than grasses, absorbed more solar radiation. In winter, the trunks and branches of birch trees shaded the highly reflective snow (see figure 3). Consequently, the expansion of birch forests raised the average mean temperature of the world by at least 0.2° Fahrenheit (0.1° Centigrade) and the average mean temperature of the northern continental landmasses by at least twice that amount.
The increased temperatures and greatly expanded birch forests combined provided habitats for higher populations of forest animals (such as beavers, deer, moose, and wolves). Those forest animals, and the birch trees themselves, yielded important resources for the recently arrived humans in what are now Siberia, Alaska, and Canada.
Doughty, Field, and Wolf demonstrate that though humanity lost the mammoth, apparently we gained something much better. Furthermore, we gained that “something” at the best possible time and location. The mammoths’ demise and subsequent benefits appear to be too well-designed for an accident or thoughtless product of human hunting habits. I’d suggest that Doughty, Field, and Wolf’s paper illustrates, inadvertently, the faith of Job when he declared, “The Lord gives and the Lord takes away, Blessed be the name of the Lord.”
Other related resources:
- C. E. Doughty, A. Wolf, and C. B. Field, “Biological Feedbacks between the Pleistocene Mega-Fauna Extinction and Climate: The First Human-Induced Global Warming?” Geophysical Research Letters 37 (2010) L15703, doi:10.1029/2010GL043985.