Gondwana and Marsupials

Throughout most of the Permian, Earth's land masses had merged into the mega-continent of Pangea. Then, in the Triassic (about 200 million years ago), the Tethys Sea began to form, rifting the northern Continents (Laurasia) from the southern Continents (Gondwana); the latter included South America, Africa, Antarctica and Australia. About 160 million years ago, the northern Atlantic started to open, dividing future North America from Eurasia, and Madagascar broke from Africa, drifting south to join the Antarctica-India land mass.

Marsupials arose in North America during the Cretaceous Period, some 100 million years ago; other mammals had become eutherians (placental mammals) and were beginning to colonize the northern Continents. Just before marsupials spread southward and eastward through Gondwana, the southern Atlantic split Africa from South America and Madagascar rifted from Antarctica, eventually docking off the coast of Africa. About 90 million years ago, India broke from Antarctica, heading toward its collision with southern Asia; South America drifted into isolation 75 million years ago and Australia followed suite 20 million years later.

Marsupials had spread through South America, Antarctica, India and Australia before these latter rifts developed. Those that remained in North America were rapidly displaced by eutherians and, when India merged with Asia, 60 million years ago, the same occurred in that region. South America's marsupials managed to hold on during its prolonged isolation but those in Antarctica succumbed to the climate as that Continent drifted to the South Pole; only those in Australia, free from the competition of eutherians, thrived and diversified. Finally, after Panama lodged between North and South America, some 3 million years ago, the Virginia opossum, our Continent's lone marsupial, spread back from the south.

Recycling and Consumption

Many Americans take part in recycling programs. Every garbage day, they set out their basket of newspapers, soda cans and beer bottles. Yet, despite this important and well-intentioned effort, few take a broader approach to the problem of resource depletion.

Recycling recaptures component materials, reduces the energy needed to produce new items, cuts the space and energy needed for garbage disposal and reduces the destruction and utilization of natural resources. But the recycling step is only part of the solution; we must also be willing to choose products that are made with recycled materials, avoid items whose production threatens natural ecosystems and diminish overall consumption of new products.

Excessive consumption is the primary threat to our natural resources. The demand for new cars, new houses, new clothes and the latest gadgets all take a toll. Of course, this consumption is especially evident in affluent countries, of which the U.S. is king. That basket of recyclables is only a start; we must reduce our population growth and learn to live with less. Otherwise, we will consume our way to desolation.

The Mammal Explosion

Though mammals first appeared in the Triassic, some 200 million years ago, they lived in the shadow of the dinosaurs and remained rather small and inconspicuous creatures. These therians split into eutherian (placental) and marsupial lines in the Cretaceous (100 million years ago) but did not diversify significantly until the demise of the dinosaurs, 65 million years ago.

Then, over the first two Epochs of the Tertiary (the Paleocene and Eocene), mammals exploded in number and variety. During this period (65 to 38 million years ago), primates, bats, the first ruminants and ancestral elephants appeared. Primates diverged into prosimians (future lemurs, lorises, galagos) and ancestral anthropods (future monkeys, apes, hominids) and, in North America, ancestral horses, rhinos and camels evolved. Canids (wolves, fox, dogs) and felines split from a common ancestor and the earliest cetaceans (whales, dolphins) returned to the sea.

While many of these ancestral species bore little resemblance to modern mammals, the stage was set for mammals to dominate earth's ecosystems. The Cenozoic Era (the Age of Mammals) began with this explosion and continues today. Most assume that humans, which finally graced the scene 125,000 years ago, are the culmination of this process; more likely, we are just another species in the web of mammal evolution.

Volcanic Islands

While Greenland, Madagascar and Tasmania rifted away from other Continental land masses, the great majority of oceanic islands are volcanic in origin. Of these, most lie along subduction zones, where one of Earth's tectonic plates is subducting beneath another; in these areas, the crust of the subducted plate begins to melt as it approaches the mantle, producing a line of volcanoes on the overlying plate.

The Aleutians and northern islands of Japan have formed where the Pacific Plate is subducting beneath the North American Plate; in like manner, the archipelagos of Indonesia, southeast Asia (Taiwan, the Philippines, southern Japan) and the South Pacific (Solomon Islands, New Zealand) rise above subduction zones at the margins of the Pacific, Australian and Philippine Plates. The Lesser Antilles, stretching along the eastern edge of the Caribbean Sea, were produced by subduction of both the North and South American Plates beneath the Caribbean Plate.

Iceland, which rose from the sea 16 million years ago, has resulted from volcanism along the mid Atlantic Ridge (where the spreading Atlantic continues to rift North America from Eurasia); indeed, this island nation straddles the two Continental Plates. A third type of volcanic island, produced by a mantle plume, can develop far from any plate margin; the Hawaiian Island chain, the Galapagos Islands, the Azores and Easter Island are examples of such isolated "hotspot" volcanism.

Of course, all of these islands are prone to continued volcanic activity, even after hundreds or thousands of years of quiescence; only hotspot islands that have been transported away from the mantle plume (by movement of their oceanic plate) are immune to reawakening. Earth's landscape continues to evolve and humans are finally around to observe it!

Rock Rabbits

Anyone who has been hiking above timberline in the Western mountains has likely heard the loud, high-pitched call of the pika. Resembling a chunky, large-eared hamster, pikas are actually members of the rabbit family; a variety of species are found across the globe and are also known as coneys or rock rabbits.

Favoring rocky slopes and boulder fields, pikas spend much of the day foraging for alpine vegetation which they add to their sheltered haystacks; once the plant material dries out, they take it into their burrows for bedding and nourishment. When not gathering food, these cold-loving mammals perch on boulders to survey and protect their territory. Despite their small size, pikas remain active through the winter, relying on lichen and matted alpine plants if their hay supply runs out.

Usually mating by mid spring, females give birth to 3-4 young after a four-week gestation and nurse them for another month. By then, the young pikas are on their own and, if not killed by golden eagles, hawks, coyotes or weasels, will be full grown by the end of summer. Adult females often raise a second litter after the first group leaves the den.

Storm Trains

Last evening, a cold front stretched from the Central Plains to southern Michigan, separating warm, humid air, to its south, from cooler and drier air behind the front. Not associated with a potent storm system, the front was relatively stationary, drifting very slowly to the south and east.

Disturbances along the front produced thunderstorms and, as they mushroomed into higher levels of the atmosphere, these storms were nudged eastward by strong, upper level winds that paralleled the front. In concert, another storm would develop at the disturbance; this ongoing process produced linear bands of thunderstorms which, moving eastward, dropped heavy rains across the same locations.

Such "training" can lead to copious rainfall and local flooding. Two to three inches per hour fell in the Greater Kansas City area while parts of lower Michigan received nearly five inches of rain. Meanwhile, wildfires plague the Southwest and parts of the Southeast remain mired in a multi-year drought.

Geologic Basins

Novice geologists who visit a region such as the Permian Basin of West Texas might be surprised to find that the area does not resemble a broad valley. Geologic basins refer to the shape of the deep sediment formations and to their deposition in a structural bowl of ancient Precambrian or early Paleozoic bedrock. In the case of the Permian Basin, a thick layer of Permian sea sediments collected within such a basin; now covered over by Mesozoic and Cenozoic strata (which have been sculpted into the West Texas landscape by wind and water erosion) the deeper Permian rocks are tapped for their rich oil and gas deposits.

Further north, the Michigan Basin is often confused with the glacial-carved basin of Lake Michigan (a shallow surface feature). Rather, centered over Lower Michigan, this geologic basin extends from western New York to eastern Wisconsin and from Upper Michigan to northern Ohio. This broad bowl of Precambrian bedrock has gradually filled in with Paleozoic and Mesozoic sediments; as layers were added over a span of 400 million years, the basin closed in from the periphery and the youngest deposits (Jurassic in age) lie in the central part of Lower Michigan. Lakes Michigan, Erie and Huron, the varied topography of Michigan and Niagara Falls are all erosion-produced surface features of the Basin.

In northeastern Wyoming and southeastern Montana, the Powder River Basin is famous for its vast supply of low-sulfur coal. Derived from swamplands of the late Cretaceous and early Tertiary Periods, this coal is near the surface of a wide geologic basin that underlies the region and includes deposition layers that date back to the Precambrian Era. Unlike the other examples discussed above, Powder River is also a topographic basin, a broad valley that has been eroded from the surrounding landscape by the River and its tributaries; indeed, this erosion of soft, overlying Tertiary deposits has made the Powder River coal especially accessible.

Canadian Rescue

Cool, dry air pushed into Missouri over the past 48 hours, courtesy of a Canadian cold front. Displacing the hot, muggy air that enveloped us for most of the week, it was a refreshing and invigorating change. Yard work was a pleasure and the desire for exercise returned. One could almost imagine that the leaves were beginning to turn or that the rumble in the distance came from the University's marching band. Even the scent of neighborhood cookouts suggested pregame tailgates.

Then I remembered: we still have to get through July and August! An escape to Colorado and a planned trip to Newfoundland should ease the burden. Life can be tough.

Evening on the Floodplain

Cool, dry air, clear skies and a flooded landscape characterized the Missouri River Valley last evening. A raft of flotsam had collected behind the Perche Creek bridge, attracting a pair of red-headed woodpeckers that hopped among the logs, picking off insects. A flock of cliff swallows, temporarily evicted from their homes beneath the bridge, gathered on nearby power lines.

Out in the Eagle Bluffs Conservation Area, shallow pools covered most of the fields and the permanent waterways lapped against the levees. Waterfowl had dispersed across the flooded valley and were represented by only a few Canada geese and a mother wood duck with her maturing brood. Great blue herons, like posted sentries, guarded the shallows and turkey vultures soared low above the fields, searching for stranded fish. Indigo buntings sang from roadside saplings while lark sparrows and horned larks scoured the gravel for windblown seeds.

A lone red-tailed hawk circled above the refuge, perhaps over-whelmed by the numerous cottontails that emerged from thickets as dusk enveloped the floodplain. Mammals were otherwise limited to a few deer on distant meadows and the occasional muskrat that motored across the lakes. While the extensive flooding produced scenic vistas and a peaceful landscape, it had clearly sent many creatures to higher ground.

The Nature of God

Once hominids were intelligent enough to wonder, the concept of God was born. By then, the Universe was already 13.6 billion years old.

Since that time, God has been the target of man's hope and the refuge from his fear. Early human civilizations worshipped numerous gods, each associated with specific needs and threats. Rituals, designed to appease these divine powers, became an integral part of their culture. Modern, Western religions, though monotheistic and based on a humanized God, were established before the scientific revolution and retain a focus on ritual.

Science cannot prove nor disprove the existence of God but it does lend perspective to man's interpretation of the natural world. We now know that the Earth is not flat; it does not lie at the center of the Universe, nor at the center of our galaxy, nor even at the center of our solar system. We have come to understand the natural forces that shape our planet and the evolutionary processes that produced our species. There is, of course, still room for faith in a Divine Architect, but I am inclined to believe that God is Nature; I reject the vindictive, judgemental, ritualized God of Western culture.

Colorado's Jays

Five species of jay inhabit Colorado. All are noisy, aggressive and omnivorous birds but each is associated with a unique life zone; as is usual in nature, the borders of their range tend to overlap.

Blue jays, common throughout eastern and central North America, spread into Colorado via the South Platte and Arkansas Valleys and are now common along the Front Range urban corridor; they are easily found along wooded streams and in residential areas. Scrub jays inhabit foothill shrublands and lower canyons throughout the State, generally at elevations between six and seven thousand feet. In the higher foothills and mountains, Steller's jays are found, favoring the ponderosa parklands and Douglas fir forests that dominate the vegetation of the Montane Zone (roughly 7-9000 feet); they may be seen as high as timberline in summer and occasionally descend to the Plains in winter.

Gray jays, also known as Canadian jays, prefer the high forests of the Subalpine and Hudsonian Zones, between 9000 and 11,500 feet. Inquisitive and rather tame, they often visit picnic areas and ski resorts, seeking handouts or grabbing leftovers. Finally, pinyon jays favor the dry, open country of southern and western Colorado where, as their name implies, they roam among pinyon-juniper woodlands; unlike the other jay species, they tend to move about in sizable flocks and, from a distance, are often mistaken for crows.

Steam Bath

Less than a week past the summer solstice, I'm ready for September. Hot, humid weather has settled into Missouri, with highs near 90 and dew points in the seventies. Though I appreciate seasonal change, such conditions sap my energy and I long for the next wave of cool, Canadian air.

Of course, there's still plenty to see and explore on these muggy, summer days. The mimosas and elderberries are in bloom, insects are peaking in number and variety and frequent thunderstorms keep the weather interesting (though their rains boost the humidity). While I admire the swifts and swallows that thrive in this Midwestern steam bath, I'll limit my outdoor jaunts to the early morning and evening hours. Man may have evolved in such a climate but I feel out of place.

A cold front is due by the weekend and the humidity should drop significantly. Until then, I'll get some reading done and appreciate my indoor job.

Pine Mountain

In southeastern Kentucky, two high ridges, separated by the Cumberland River Valley, parallel the Virginia border. These prominent spines are part of the Cumberland Mountains, the southeast edge of the Appalachian Plateau and the westward extension of the Allegheny Front. The more southern ridge is Cumberland Mountain which harbors the famous Cumberland Gap, just outside of Middlesboro, Kentucky.

The northern ridge, extending from Whitesburg, Kentucky southwestward into Tennessee, is known as Pine Mountain; after flowing along the south side of this ridge, the Cumberland River cuts through to its north side at Pineville and continues westward to Cumberland Falls and Lake Cumberland. Pine Mountain State Resort Park, just west of Pineville, is an excellent place to explore the ridge; it is the oldest Park in what is arguably the finest State Park system in the country. Numerous trails lead across the south face and atop the high spine of Pine Mountain, passing waterfalls, a natural bridge and scenic rock formations; "chained rock," reached by a short walk or a long hike, yields a spectacular view of the nearby mountains and valleys.

Further east, via KY 1254 off U.S. 119, Kingdom Come State Park sits atop Pine Mountain; at an elevation of 2800 feet, it is the highest of Kentucky's State Parks. Centered on Raven Rock, a giant outcrop of sandstone, the Park is accessed by a fine network of trails which lead across the mountain slopes and out to several overlooks. The Little Shepherd Trail, which follows the crest of Pine Mountain for 38 miles (from U.S. 421 to U.S. 119), crosses through the Park.

Even further east, the Bad Branch State Nature Preserve spreads up the south face of Pine Mountain. Reached via KY 932 (off U.S. 119, 7 miles southwest of Whitesburg), the refuge is renowned for Bad Branch Falls, a 60 foot cascade. Energetic and conditioned hikers may also want to set their sights on High Rock, atop the Pine Mountain ridge.

Clifton Gorge

Slicing through the farmlands of southwestern Ohio, Clifton Gorge is a scenic wonderland for naturalists. Though its rugged walls of Silurian dolomite were deposited 400 million years ago, the gorge itself was carved by a torrent of glacial meltwater near the end of the Pleistocene, some 12,000 years ago. Documenting this history, the shaded walls of the chasm harbor relict, periglacial vegetation, including hemlock, Canadian yew, arborvitae and mountain maple.

Stands of chinquapin oak cover south-facing hillsides and over 340 species of wildflower have been found in the gorge. Numerous springs and seeps produce ideal conditions for the sixteen species of fern that grace the rocky walls and provide ideal habitat for salamanders (8 species live here). Red squirrels are common in the hemlock areas and, as one might expect, a large variety of songbirds are drawn to this chasm, which offers protection in winter and a cool retreat in summer.

Hikers will find an excellent trail network at Clifton Gorge; these footpaths skirt the rim, snake down the rugged walls and run along the canyon floor, following and crossing the Little Miami River, where slump blocks of dolomite rest along and within the stream. Dedicated in 1973, Clifton Gorge State Nature Preserve merges with John Bryan State Park, which encompasses the western portion of the gorge. Access to both areas is off State Route 343, between Yellow Springs and Clifton; a parking lot off Jackson Street, on the west edge of Clifton, is closest to the scenic "Narrows" of Clifton Gorge.

A Feast of Froglets

On our visit to the Forum Nature Area, yesterday, my wife and I found a zillion froglets along the marshy shores of the flooded, seasonal lake. While most appeared to be young leopard frogs, they were difficult to observe, springing from the wet vegetation like hordes of grasshoppers. Within the shallows, other frogs were in various states of metamorphosis, from tadpoles with legs to froglets with tails. Once they transform from a reliance on gills to the use of lungs, the froglets emerge from the water to feed on insects, diving back when danger is sensed.

These swarms of froglets highlight the abundance of life in our rich, unspoiled wetlands and provide natural entertainment for adults and children alike. More importantly, they offer a feast for the herons, snakes, snapping turtles, mink and raccoons that prey on these amphibians. Those that survive will grow rapidly through the summer, doing their part to control the wide variety of insects that inhabit and breed in the wetland. As autumn approaches and the waters cool, the adult frogs will settle into the bottom muck until the warm days and heavy rains of spring revive the marsh.

The Cost of Oil

The price of oil has surged in recent months, producing hardships for individuals and businesses alike. The cause for this phenomenon appears to be mulifactorial: increasing worldwide demand (especially in developing nations), political unrest in oil producing countries, limited refinery capacity, speculation and a diminished U.S. dollar are all playing a role. But, despite the pain levied on consumers, we are, in many ways, beginning to appreciate the true cost of using oil as fuel.

Though I have some personal doubts regarding the degree to which human industry is responsible for global warming, there is little doubt that we are have produced 100% of the environmental pollution; the procurement, transport and burning of fossil fuels have contributed significantly to the pollution and destruction of natural habitat. Recognizing that high oil prices and consumer stress are providing an opportunity, U.S. oil companies are renewing their efforts to drill in ANWR and other environmentally-sensitive areas. But, as we and they know, the benefits from such a policy change would not be realized for years and, by then, the worldwide demand would absorb any increased production.

There is evidence that the higher cost of oil is beginning to change our lifestyle. Auto use is down, train cargo transport is up, mass transit ridership is increasing and the shift to clean, renewable energy sources is getting a much-needed boost. Hopefully, such trends, combined with conservation measures, will end our long love affair with fossil fuels.

Turtle Tots

It seems to be a good year for aquatic turtles in mid Missouri. Our visits to the Forum Nature Center, in Columbia, have turned up a large number of small painted turtles and red-eared sliders this season; local flooding may have drawn some of these reptiles from more permanent lakes and ponds in the area.

After wintering in the muddy bottoms of lakes and ponds, aquatic turtles emerge by April and mate in mid spring. Pregnant females leave the water in June to lay six to thirty eggs in a depression that they dig near the shoreline (larger, older females generally lay the most eggs). If not eaten by raccoons or other scavengers, the young turtles hatch in mid-late August and head for the water. Over the first few years, they are primarily carnivorous, feasting on insects, other invertebrates and small fish; as they mature, they become omnivorous, adding carrion and aquatic plants to their diet. Those that do not fall prey to herons, mink, otters, snakes, large fish or snapping turtles will reach sexual maturity in 5-6 years.

Painted turtles and red-eared sliders are common throughout much of the Midwest, especially along the primary river valleys. Like most of their cousins, they enjoy basking on logs or mats of vegetation; active from late March into October, they may also surface during prolonged warm spells in the winter months.

Altitude Sickness

Many Americans will head to the National Parks and mountain resorts of the West this summer and, unfortunately, some of their vacations will be marred by altitude sickness. This common malady is triggered by an impaired ventilatory response to hypoxemia, an increased blood flow to the brain, increased blood pressure in the lungs and an altered acid-base state, especially in the brain and spinal fluid. The risk for developing all forms of altitude sickness is increased by a past history of altitude-related illness, a rapid ascent (>1000 feet/day), a home elevation under 3000 feet, age under 50 years and by strenuous activity prior to acclimation; the altitude at which one sleeps (while in the high country) also correlates with the risk level.

Acute mountain sickness, the most common and least serious form of altitude-related illness, is generally characterized by a mild headache, nausea, fatigue, dizziness and insomnia; in addition to the risk factors listed above, obesity predisposes to this disorder. Symptoms of acute mountain sickness develop over 2-3 hours and often persist for 2-3 days. Preventive measures include a slow ascent, adequate hydration (including a reduced intake of caffeine and alcohol), limited physical exertion for the first few days and the use of acetazolamide (a prescription medication that should be started 2 days before reaching high altitude).

More severe forms of altitude sickness include high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE). The former, caused by fluid accumulation in the lungs, usually develops after rapid ascent to 10,000 feet or more and tends to occur within 48 hours. HACE, caused by brain swelling, is relatively rare and generally develops at elevations above 14,000 feet; a gradual onset of headache, confusion and ataxia (impaired coordination) is typical. Both HAPE and HACE are medical emergencies, treated with rest, oxygen administration, a descent to lower altitude and professional intervention. Persons planning high altitude climbs should discuss the preventive use of nifedipine or dexamethasone with their physician.

Floodplain Roulette

During most of our history, humans have been a nomadic species, living in temporary camps as we followed game and explored our planet. Early man surely noticed that many rivers lie on broad, flat plains but he had little reason to wonder about the evolution of that landscape. Though he often camped along rivers for water, food and transport, he was free to move on when floods developed.

Modern man has come to understand the natural history of rivers; he knows that glaciation, climate fluctuation and periodic flooding have all played a role in the formation of their floodplains. Yet, drawn by the many benefits that rivers provide, including the rich soil of their valleys, he has chosen to build permanent settlements on these ancient channels, relying on dams and levees for protection. Unfortunately, his brief life span (and the relatively short history of record keeping) cause him to underestimate the extent and power of massive, periodic floods.

Once again, we are witnessing destruction and misery along the Mississippi Valley. "I've never seen the water this high," a farmer laments; but he is in his fifties and the river has molded its floodplain over hundreds of thousands of years. It is time that we respect the lessons of natural history; the evolution of our landscape continues and we stand it its way at our peril!

The Yellowstone Time Bomb

Yellowstone National Park, renowned for its scenic vistas, abundant wildlife and geothermal wonders, is a relatively recent addition to the American landscape. Formed by a massive volcanic explosion 2 million years ago (at the onset of the Pleistocene Ice Age) and by subsequent eruptions 1.2 million and 600,000 years ago, the Park's magnificent topography stretches across the broad, remnant caldera of those volcanic blasts. When will the next eruption occur? A look at the spacing of previous eruptions is certainly unsettling.

Yellowstone's geysers and hot springs attest to the continued presence of a "hot spot," a mantle plume close enough to the surface to generate these hydrothermal features. And recent Park surveys have confirmed a gradual bulging of the region's crust. Whether the risk of a major eruption has been reduced by previous volcanism and by subsequent movement of the North American Plate remains uncertain.

Like the San Andreas Fault and the Cascade Volcanoes, Yellowstone is a potential natural catastrophe that will eventually occur. Our brief life spans shelter us from the long view of geologic history and tend to make us oblivious to the risks inherent in our planet's ongoing evolution. The explosion of the Toba Volcano, in Sumatra, 74,000 years ago, nearly wiped out the human species; a fourth eruption of Yellowstone could be just as disastrous!

Islands of Water

Mention islands and most of us think of land masses that protrude above lakes and oceans. But, in desert regions, isolated mountain ranges produce the opposite effect, yielding pockets of moisture in a sea of dryness. Reaching high into the atmosphere, these "sky islands" are bathed by cool air and receive "upslope precipitation" from all directions. As a result, the mountain slopes are cloaked by bands of vegetation, corresponding to the change in climate that occurs with increasing elevation.

Such islands of water are common throughout the western U.S., especially in the vast, dry terrain between the Sierra Nevada and Rocky Mountain chains. Requiring an annual precipitation of 15 inches or more, a zone of juniper and pinyon pine begins above elevations of 5500 feet. Nearing 7000 feet, one encounters open woodlands of ponderosa pine and, on shaded slopes, forests of Douglas fir. Aspen and lodgepole pine begin to appear above 8000 feet, mixing with Englemann spruce, limber pine and subalpine fir at higher elevations. At timberline, which ranges between 10,500 and 12,000 feet (depending on latitude) pockets of bristlecone pine are often found.

Of course, the wildlife population varies with the life zones and many species demonstrate vertical migration, moving higher during the warmer months and descending to lower elevations in the winter. Some of the better areas to explore sky island ecosystems include the La Sal Mountains (east of Moab), Mt. Lemmon (east of Tucson), and Mt. Wheeler in Great Basin National Park, on the border of Utah and Nevada.

A Prime Time Death

The recent, unexpected death of Tim Russert, a renowned and beloved TV journalist, brought deep sorrow to his family, friends, colleagues and viewers. The death of a relatively young, vibrant person is always disturbing and, the better we know him, the more it triggers our own sense of mortality.

Religious people, of which Mr. Russert was one, often accept these tragedies as part of God's plan; in their view, God delivers both happiness and pain. Pure fatalists, on the other hand, harbor the conviction that "when your time is up, there's nothing you can do about it."

Those of us in the medical profession witness many early deaths in the course of our career. While many are due to trauma or to unpreventable illness, a significant percent result from poor lifestyle choices or from underlying, treatable conditions. A fatalistic view of life overlooks or denies the control that we have over our health and, thus, over our longevity. Tobacco use, excessive alcohol consumption, illicit drug use, obesity, a sedentary lifestyle, lack of sleep, excessive stress, uncontrolled hypertension and the avoidance of seat belts are all examples. We are not solely at the mercy of fate!