As a boy in European boarding schools during the early 1950s, I noticed that some of the lizards were similar to those at home in Oregon, and some of the bird songs also sounded the same. A decade later, while working in Egypt, I found a skink, which is a type of lizard, that was similar to the western skink at home—the young of both had bright, blue tails. I also discovered that the desert gerbil was in many ways similar to Ord’s kangaroo rat of the Great Basin in the western United States. In 1967, while working in Nepal, I heard a great green barbet (a bird), which sounded so much like the western tanager in the coniferous forests of Oregon that, for a moment, I forgot where I was. Moreover, the jungle cat, Himalayan weasel, and the Nepalese golden jackal are similar in habits to the bobcat, long-tailed weasel, and coyote of North America.
Wherever I have been—from Oregon to Alaska and Canada, from Egypt to Nepal, Japan, Eastern Europe, Malaysia, Mexico, Chile—I have seen the similarities of Nature. And yet, as a scientist, I was trained to focus on Nature’s differences, which I suppose should come as no surprise because American culture is primarily a divisive one that tends to focus on our differences as a collective people rather than on our similarities. In some respects, we are still a nation of settlers from many different cultures, staking our own claims, and competing for resources through the “money chase.”
Today, as I look around a world at war in one way or another, from the conflicts in Iraq, Afghanistan, Syria, Egypt, and some African nations, to the local insurgency of Mexican drug cartels, or humanity versus Nature, I find the outcome to be the same—an exaggeration of differences and the attendant sense of insecurity we humans let these perceived dissimilarities breed.
I see an increasingly terrified global society because some of its factions focus so narrowly on the perceived, human-created, irreconcilable differences of right versus wrong, of us versus them fostered by the various religious beliefs. Yet I look at the same world and see the seemingly forgotten similarities—the commonalties of life: the basic human needs of love, trust, respect, and dignity, as well as the biophysical principles of Nature that govern the three spheres and all living things therein: the atmosphere, litho-hydrosphere, biosphere.
Consider, for instance, that the citizens of New York in the United States and the citizens of Nairobi in Kenya are almost poles apart, geographically speaking. Given that, one would expect striking differences between them, and there are. But as much as they differ, they also have much in common. If, however, we observe only the differences, we see but a little of what makes us all human. The larger part comprises the commonalities to which we are often blinded by our choice of focus. Therefore, all we are judging is our perception of an appearance, and our observation is always a partial view, despite our knowledge and best intentions, as exemplified by the distribution of mosquitoes.
If we compare ten individuals of the same kind of mosquito found in the city of Kuala Lumpur, which is near the equator on the west coast of the Malaysian Peninsula, with ten individuals of the same kind of mosquitoes found in the city of Cayenne, French Guiana, which is near the equator on the east coast of South America, we would probably classify the two groups as distinctly different species—a classical, clear-cut “either/or” categorization, based on their extreme divergence in appearance. But if we were now to collect mosquitoes from around the world along the equator, what would we find when they were compared? That would depend on how we compared them.
If we compared each group of ten mosquitoes with their nearest neighbor (ten from location A with ten from location B), we would find an astonishing degree of similarity between the two samples. If we then compared ten from location B with ten from location C, and ten from location C with ten from location D, we would find not only continual similarities but also gradual differences. Should we then compare samples of mosquitoes from location A with location D, we would begin to see increased divergence in characteristics.
So, instead of the neighboring samples of mosquitoes being unequivocally this or that because of clearly distinguishable characteristics, they form a continuum of gradually changing characteristics from A to Z. Despite how similar or dissimilar any two samples of mosquitoes may appear, the same examination will demonstrate the shared elements of design, such as the basic structure and function of their wings, antennae, mouth parts, body, and so on. When viewed as a continuum, the mosquitoes form a circle of similarities that reveal the commonalties of design elements necessary if they are all to be aerodynamically capable of flight and sucking blood, among other shared characteristics that make a mosquito a mosquito. Ultimately, the inviolate, biophysical principles that govern all processes simultaneously bind together the universal commonalities while allowing the novelty of differences, such as those found in large populations.
Populations of animals tend to become increasingly generalized when they are released from competition with other species, a process that can either increase the variation among individuals or broaden how an individual uses the habitat. In practice, ecological generalists, which use a wide diversity of resources, are heterogeneous collections of relatively specialized individuals, meaning they exhibit stronger behavioral specialization in how they use the habitat as individuals within the generalized behavioral patterns of the species as a whole. Hence, populations of generalists may tend to be more ecologically variable overall than populations of specialists.1 As well, the Earth’s crust is composed of spatially heterogeneous abiotic conditions that provide a greater diversity of potential niches for plants and animals than do homogeneous landscapes.
For example, in one study the richness and diversity of trees and shrubs was significantly greater in sites with high geomorphological heterogeneity than in sites exhibiting little change in either the terrain or the types and conditions of the soil, such as texture, mineralogy, and organic matter. Variations in aspect and the soil’s patterns of drainage were especially important predictors of biotic diversity. Hence, geomorphologic heterogeneity plays a major role in determining species richness. Because diversity of the biotic (living) and abiotic (non-living) components of an ecosystem are intricately linked at the scale of the landscape, conservation of geomorphological heterogeneity may have significant implications for long-term strategies in caring for our natural environment, to the benefit of maintaining biodiversity in all its forms.2
The ultimate commonality in today’s world, however, may well be the variability of our changing climate. Climate has been dynamic throughout the various scales of geological time, and it will continue to be the main driver of our planet’s story of novelty within and among the three spheres. Because climate is still the primary mechanism through which the distribution of species and ecosystem processes is controlled, new 21st century climatic conditions may promote the formation of heretofore-unseen associations of species and other ecological surprises. By the same token, the disappearance of some existing climatic conditions will increase the risk of extinction for species with narrow geographic distributions or climatic tolerances, and it will disrupt other communities.
Novel climates are projected to develop primarily in the tropics and subtropics, whereas disappearing climates will be concentrated in tropical montane regions and the pole-ward portions of continents. As well, some extant climates will disappear, and new ones will appear. Consequently, species with limited abilities to disperse will experience the loss of existing climate and the occurrence of novel ones.3 As the climate is altered, so are the biophysical cycles. Nevertheless, the commonalities of life will remain—including the growing necessity of letting go our insane human conflicts in favor of nurturing one another with dignity and compassion so that social-environmental sustainability can become a global reality for all generations.
1. Daniel I. Bolnick, Richard Svanbäck, Márcio S. Araújo, and Lennart Persson. Comparative Support for the Niche Variation Hypothesis That More Generalized Populations Also Are More Heterogeneous. Proceedings of the National Academy of Sciences 104 (2007):10075–10079.
2. (1) Michael R. Burnett, Peter V. August, James H. Brown Jr., and Keith T. Killingbeck. The Influence of Geomorphological Heterogeneity on Biodiversity I. A Patch-Scale Perspective. Conservation Biology 12 (1998):363–370; (2) William F. Nichols, Keith T. Killingbeck, and Peter V. August. The Influence of Geomorphological Heterogeneity on Biodiversity II. A Landscape Perspective. Conservation Biology 12 (1998):371–379; and (3) Cheryl Palm, Pedro Sanchez, Sonya Ahamed, and Alex Awiti. Soils: A Contemporary Perspective. Annual Review of Environment and Resources 32 (2007):99–129.
3. The discussion of climate is based on: John W. Williams, Stephen T. Jackson, and John E. Kutzbach. Projected Distributions of Novel and Disappearing Climates by 2100 A.D. Proceedings of the National Academy of Sciences 104 (2007):5738–5742.
Text © by Chris Maser 2012. All rights reserved.
This essay is exerpted from my 2009 book, “Earth in Our Care: Ecology, Economy, and Sustainability,” Rutgers University Press, New Brunswick, NJ. 304 pp. If you want more information about this book or want to purchase it, visit “BOOKS” on my website.