In lieu of doing a "year in review" issue this year, EARTH asked our staff and some frequent contributors to write a short commentary on something that grabbed their attention in 2013. We gave everyone carte blanche. What follows is a collection of extremely varied, often very personal insights into how the planet impacted each individual. In this commentary, EARTH contributor and cartoonist Callan Bentley discusses his run-ins with science denialism.
It has long been hypothesized that human ancestors evolved the ability to walk upright — a feature that appeared about 6 million years ago — in response to African landscapes changing from forests to grasslands. Now, a group of scientists has assembled the most continuous timeline of landscape evolution and grassland development over the last 12 million years near the African Rift Valley in northeastern Africa — and the timeline contradicts conventional hypotheses.
What do creationists and climate change deniers have in common? Over the past few years, this riddle has been on our minds a lot at the National Center for Science Education, a nonprofit that has fought for more than a quarter-century to defend the teaching of evolution in the public schools. Now, we’re expanding to defend the teaching of climate change — and with it, science in general.
Our knowledge of the evolution of feathers in dinosaurs is sketchy, at best, but new research on fossilized feathers is painting a remarkably clear picture of what one species, known as Microraptor, may have looked like — a raven with black iridescent feathers. The findings may have implications for the importance of sexual display in the early origins of feathers.
It’s no secret that many of the protests and rebellions in North Africa and the Middle East this year have been dominated by globally connected, young, educated Muslims. One of the stated goals of many of these young people is improving the science and technology programs in their countries. They understand that to compete in the global marketplace, strong science and technology programs are necessary. That bodes well for these countries’ futures.
I had recently moved to a new community and begun a new job. One night I was dining with some potential new friends. Upon learning that I am both a Christian and a passionate student of geology, one of my dinner mates proclaimed, “So, I suppose you believe in evolution, right? Well, I need to let you know that I HATE evolution.” I somehow managed to keep my cool. “And exactly why do you hate evolution?” I queried. “My minister has taught us that it is false Christian teaching,” she retorted. By that time, I could not hold myself back.
It was easy to miss the part where the field trip leader said the outcrop formed during Noah’s Flood. After all, “During these catastrophic flood flows, turbulent, hyperconcentrated suspensions were observed to transform laminar mudflows” sounds like a reasonable description of alluvial fan processes. And “massive marine transgression” sounds scientific enough. But when creationist geologists use those phrases, they take on a very different meaning.
Arizona’s Coconino Sandstone — a deposit seen in the Grand Canyon and elsewhere — plays a central role in the creationist argument that the upper rocks of the Grand Canyon were deposited during Noah’s Flood. In fact, the posters presented by students and faculty of Cedarville University at the 2010 annual meeting of the Geological Society of America (GSA) in Denver, Colo., pushed a consistent narrative: The Coconino did not form in an eolian (wind-blown) environment. Why is this so important? If the Coconino is eolian, it means the Flood did not happen.
The debate over when our ancestors first used stone tools is not over just yet. In August, researchers had reported finding scratch marks on two 3.4-million-year-old animal bones that they said were made by Australopithecus afarensis — the ancestor made famous by Lucy — scraping meat off the bones with sharp-edged stones. If true, that would push tool use back to 800,000 years earlier than previously thought.
Triceratops and its cousin Torosaurus are not hard to tell apart. Both horned dinosaurs had a giant bony frill that rose up behind the head, but Torosaurus’ frill was much longer and was adorned with giant holes that were covered by a thin layer of protein called keratin. Yet Triceratops and Torosaurus may have been more alike than scientists realized: New research suggests that the two animals were actually the same species, with Torosaurus being the adult version of Triceratops.
Modern humans reached the islands of Southeast Asia by approximately 50,000 years ago, but our ancestors’ journey was not easy. Even during times of low sea level, a voyage to some of these islands would have required crossing open water, leaving many scientists to wonder how humans arrived on the most isolated islands.
The only monkeys you’ll find on the islands of the Caribbean today were brought there (intentionally or not) by people. But just a few thousand years ago, thriving populations of primates existed across the Caribbean. The discovery of exceptionally well-preserved monkey bones in the Dominican Republic is helping researchers better understand the evolutionary history of these now-extinct primates.
Last October, scientists formally introduced the world to Ardi the Ardipithecus, the well-preserved skeleton of a 4.4-million-year-old hominin found in Ethiopia. Eight months later, scientists have had time to digest the data from all 11 papers that were published in Science last fall regarding Ardi’s biology and ecology, and there is some dissent.
Did “Clan of the Cave Bear” get it right after all?
Probably not, but at least one aspect of the ice age saga is true: Modern humans interbred with Neanderthals. In fact, for many of us, as much as 4 percent of our DNA may be Neanderthal DNA. That’s the conclusion of a group of 56 scientists who have just announced today in Science that they’ve completed a draft sequence of the Neanderthal genome.
Last month, the Smithsonian’s National Museum of Natural History in Washington, D.C., unveiled its new (permanent) human evolution exhibit: the David H. Koch Hall of Human Origins. The exhibit seeks to answer the millennia-old question, What does it mean to be human?
About 18 million years earlier than they were thought to exist, tetrapods — vertebrates with four limbs instead of fins — walked in what is today Poland. A new study published in Nature describes tracks belonging to a tetrapod in a Polish tidal flat, dating to the Middle Devonian period, about 395 million years ago. The discovery may prompt scientists to completely reassess the environment, origins and timing of early tetrapods.
About a decade ago, I was fortunate enough to hold in my hands a first edition of Charles Darwin’s “On the Origin of Species.” The green cover was cracked and frayed. The cardboard backing protruded through the torn corners. I put the book down and stared at it in awe. The owner of this book was Asa Gray, one of America’s greatest botanists, an important early American supporter of natural selection, and a friend of Darwin’s.