The Universe Within (29 page)

The biologist
Stephen Stearns and his colleagues crunched
these data and were led to a humbling insight. There is a very big difference among people in different parts of the world. In the developed world, with its access to medical care, food, and technological wizardry, most evolutionary pressure is on aspects of fertility: when we have offspring and how many we have. In the developing world things are very different: passing on one’s genes is about mortality, particularly that of children. In one world, evolutionary success is derived from the age at which people have babies; in the other, such success is derived from survival itself. Socioeconomic, cultural, and technological differences mediate the ways evolution acts in human populations.

In our past, long-term success came from spreading one’s genes and traits, often in response to changes to the environment. The major source of information passed from one generation to the next was written in
DNA. The situation now is not so simple. The American scientist
Norman Borlaug and his wife had three children, five grandkids, and six great-grandchildren. We can look at his entire
family tree and assess the extent to which his
genetic traits have been passed from generation to generation. If we transport to the future, we could assess the success of his biological traits in the gene pool: hair color, ability to curl his tongue, susceptibility to diseases, and so on. But how much will traits like those really matter for our future as a species? In addition to passing on his genes, Borlaug was the widely acclaimed father of the “
green revolution,” whose work on corn and wheat increased their pest resistance and yield. He is responsible for bettering or saving the lives of millions of people around the world. His ideas live in the ways others have used them and improved them and in an entire planet changed by his genius. From the people saved by
agricultural and medical breakthroughs to the lives changed by great literature, philosophy, and music, the success of our species resides inside the offspring of our minds.

Like a sixty-year-old person on actuarial charts, the habitable Earth is three-quarters of the way through its calculated
life expectancy. Earth is about 4.57 billion years old, and the laws of stellar physics tell of another billion years before the sun expands to the point that it bakes the possibility for life off the planet. Looking back, life got going quickly after Earth’s formation—within a paltry few hundred million years. Bodies took roughly 2.5 billion years to come about. Then, one after another, heads, hands, and consciousness arose in ever more rapid succession. As in
Moore’s law, which famously describes the doubling power of silicon chips every twenty-four months, the biological world has witnessed exponential rates of change: it took most of the expected life span of our planet for the origin of a big-brained species using
stone tools; then merely thousands for the origin of the Internet, gene cloning, and schemes of geo-engineering the atmosphere of the planet itself. Planetary and biological change have brought about a transformative moment—one in which ideas and inventions shape our bodies, the planet, and the interactions between them. Before our species hit the scene, trillions of
algae took billions of years to transform the planet; now change is driven by single ideas traveling at the speed of light.

Ours is a species that can extend its biological inheritance to see vast reaches of space, know 13.7 billion years of history, and explore our deep connections to planets, galaxies, and other living things. There is something almost magical to the notion that our bodies, minds, and ideas have roots in the crust of Earth, water of the oceans, and atoms in celestial bodies. The stars in the sky and the fossils in the ground are enduring beacons that signal, though the pace of human change is ever accelerating, we are but a recent link in a network of connections as old as the heavens.

Excellent works for a general audience on the history of the universe, planet, and life grace the literature. Carl Sagan’s
Cosmos
(New York: Ballantine Books, 1985), while superseded by decades of scientific discovery, remains one of the clearest and most evocative accounts of the universe and its connection to us. The story from the big bang to the formation of the planet has been told by several scientist-authors, including Lawrence Krauss,
Atom: A Single Oxygen Atom’s Journey from the Big Bang to Life on Earth … and Beyond
(Boston: Back Bay Books, 2002); and Neil deGrasse Tyson and Donald Goldsmith,
Origins
:
Fourteen Billion Years of Cosmic Evolution
(New York: Norton, 2005). Richard Fortey, with his characteristic elegance, covers the history of the planet in
Earth
:
An Intimate History
(New York: Knopf, 2002). Fortey’s book joins Tim Flannery’s
Here on Earth: A Natural History of the Planet
(New York: Atlantic Monthly Press, 2011), Michael Novacek’s
Terra: Our 100-Million-Year-Old Ecosystem—and the Threats That Now Put It at Risk
(New York: Farrar, Straus and Giroux, 2007), and Curt Stager’s
Deep Future: The Next 100,000 Years of Life on Earth
(New York: Thomas Dunne Books, 2011) as forward-looking and richly described histories of the planet and the processes at work on it. For general and lively overviews of the history of life, see Richard Dawkins’s
Ancestor’s Tale: A Pilgrimage to the Dawn of Evolution
(New York: Mariner Books, 2005), Andrew Knoll’s
Life on a Young Planet: The First Three Billion Years of Evolution on Earth
(Princeton, N.J.: Princeton University Press, 2004), and Brian Switek’s
Written in Stone: Evolution, the Fossil Record, and Our Place in Nature
(New York: Bellevue Literary Press, 2010).

Using the predictions of evolutionary and geological history to find fossils means employing the tools of historical
geology, especially the fields of
stratigraphy,
sedimentology, and
structural geology. Generally speaking, stratigraphy
works to piece together the layers of rock in Earth to understand their ages and their relationships to one another. Sedimentology centers on elucidating the conditions that led to the formation of rocks such as the
sandstones, shales, and siltstones that occasionally contain the fossils of interest to paleontologists like myself. Were the rocks originally deposited by the action of lakes, streams, or oceans, or by some other earthly process? Structural geology seeks to make sense of the movements and forces at work on the rocks relative to one another during the millions of years from their deposition as sediments to their presence as layers today. General references on these
fields abound. For a captivating primer that requires absolutely no prior knowledge, see Marcia Bjornerud,
Reading the Rocks: The Autobiography of the Earth
(New York: Basic Books, 2005). Fortey’s
Earth
also fits into this category. See also Walter Alvarez’s excellent
The Mountains of St. Francis: Discovering the Geological Events That Shaped the Earth
(New York: Norton, 2008).

Bill Amaral’s insight into the fossil-bearing potential of the Triassic-age rocks in Greenland began with the
Shell Oil Guide to the Permian and Triassic of the World
. The library discard saved from the trash was K. Perch-Nielsen et al., “
Revision of Triassic Stratigraphy of the Scoresby Land and Jameson Land Region, East Greenland,”
Meddelelser om Grønland
193 (1974): 94–141. This reference ultimately led Bill,
Chuck, and
Farish to the elegant sedimentological work of Lars Clemmensen, a Danish sedimentologist. These papers—L. B. Clemmensen, “Triassic Lithostratigraphy of East Greenland Between Scoresby Sund and Kejser Franz Josephs Fjord,”
Grønlands geologiske undersøgelse
(1980), and L. B. Clemmensen, “Triassic Rift Sedimentation and Palaeogeography of Central East Greenland,”
Geological Survey of Greenland, Bulletin
, no. 136 (1980): 5–72—became a kind of Rosetta stone because they revealed the fossil potential of the rocks and their similarity to those of eastern
North America (described in P. E. Olsen, “Stratigraphic Record of the Early Mesozoic Breakup of Pangea in the Laurasia-Gondwana Rift System,”
Annual Reviews of Earth and Planetary Science
25 [1997]: 337–401). This was a eureka moment in the library.

Coming to grips with the past inside the rocks is as much about practical matters—food, boot selection, and learning to see—as about great ideas at stake. The first of these considerations is derived from one of
Napoléon’s insights: armies run on their stomachs. You can have the best scientific preparation on the planet, but if the food is terrible, things can go awry very quickly. When a field crew eats well and meals become an event to anticipate, folks can endure privations of weather, boredom, and the drudgery of failure that a new fossil hunt brings. Long days spent wet and cold, finding nothing, can be rescued by comfort foods awaiting people when they return to the tent at night. Before departing for the Arctic, we prepare by dehydrating many of our own vegetables and fruits to devise menus that have a diversity of tastes, textures, and smells. Come to my lab in April before a field season and you might smell
kiwis, strawberries, or San Marzano tomatoes in the dehydrator. We even bake bread in the field, knowing that the smell of a rising loaf can not only sell a house but also soothe a surly field crew. In the field, the bread tastes like the finest French baguette. Unfortunately, our creations, having the consistency and density more of a building material than of an edible substance, would be an insult if served at home.

We knew few of these tricks the first season in 1988. The meals were all prepackaged dehydrated affairs with fancy labels to make one salivate and sumptuous names such as veal scallopini, chicken marsala, and turkey tetrazzini. After two weeks of gorging on these bags in the field, we noticed that they all tasted the same. A depressing confirmation came when I read the ingredients lists: all our fancy dinners were essentially the same meal with a different label, in a different-colored bag, with a different-shaped pasta. Revealing this discovery to my colleagues did not help matters; the ensuing run on hot sauce and spices left us with no way to vary tastes. Needless to say, I lost a lot of weight that year.

Our recipes for dehydrated meals can be found at
http://tiktaalik.uchicago.edu
. They do the trick after a day of slogging through tundra or clambering over scree, use a minimum of fuel and water during preparation, can be modified for everyone from a vegan to a ravenous carnivore, and aren’t heavy to pack or ship. You can even serve the meals at home to company you never wish to see again.

For a good nontechnical introduction to the geological history of eastern North America, see Chet Raymo and Maureen E. Raymo,
Written in Stone
(Hensonville, N.Y.: Black Dome Press, 2007). The story of
Lull’s dinosaur in the
bridge abutment can be found in Edwin H. Colbert,
Men and Dinosaurs
(New York: E. P. Dutton, 1968).

The Greenland discoveries are described in F. A. Jenkins Jr. et al., “A Late Triassic Continental Fauna from the Fleming Fjord Formation, Jameson Land, East Greenland,” in
The Nonmarine Triassic
, ed. S. G. Lucas and M. Morales (Albuquerque: New Mexico Museum of Natural History and Science, 1993), 74; F. A. Jenkins Jr. et al., “A New Record of Late Triassic
Mammals from the Fleming Fjord Formation, Jameson Land, East Greenland,” in Lucas and Morales,
Nonmarine Triassic
, 94. The most important of the mammals we found is described in F. A. Jenkins Jr. et al., “Haramiyids and Triassic Mammalian Evolution,”
Nature
385 (1997): 715–18.

General references on the origin of mammals and the relevance of little teeth to our own branch of the evolutionary tree can be found in Zofia Kielan-Jaworowska, Richard L. Cifelli, and Zhe-Xi Luo,
Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure
(New York: Columbia University Press, 2004); and Z.-X. Luo, “Commentary on Mammalian Dental Evolutionary Development,”
Nature
465 (2010): 669.