Undeniable (2 page)

You've probably heard a great deal about Darwin. You may not have heard so much about Wallace. He was a naturalist who spent a great deal of time in the field studying and collecting specimens of flora and fauna. He traveled in the Amazon River basin and in what is now Malaysia. Through his far-flung geographic and intellectual explorations, Wallace formulated his theory of evolution independent of Darwin, and described an important aspect of the evolutionary process, often still referred to as the “Wallace effect” (more about that in chapter 12). Wallace recognized humans as just one part of a much broader living world. Quoting from his 1869 book
The Malay Archipelago
, “… trees and fruits, no less than the varied productions of the animal kingdom, do not appear to be organized with the exclusive reference to the use and convenience of man…” In Victorian England, such a point of view was controversial to say the least.

Darwin had the earlier start. Wallace was just eight years old in 1831 when the twenty-two-year-old Darwin had a remarkable opportunity as an energetic young man to go to sea aboard the HMS
Beagle
. He realized that if humans could turn wolves into dogs, then new species could come into existence by the same means naturally. He also saw that populations do not grow and grow indefinitely, because their environment will always have limits on the resources available. Darwin connected these ideas by observing that living things produce more offspring than can survive. The individuals compete for resources in their respective ecosystems, and the individuals that are born or sprout with favorable variations have a better shot at survival than their siblings. He realized that, left unchecked, the process of natural selection would result in the great diversity of living things that he would go on to observe.

Recognizing the two scientists' convergent views, colleagues arranged for Wallace and Darwin to present a paper together at a meeting of the Linnaean Society in London in 1858. The paper was based on a letter that Wallace had written to Darwin, along with an abstract for a paper that Darwin had written in 1842. The revolutionary impact of the joint presentation was not immediately obvious to all of those in attendance. Thomas Bell, the president of the Linnaean Society, infamously reported that no important scientific breakthroughs had occurred that year: “The year which has passed has not, indeed, been marked by any of those striking discoveries which at once revolutionize, so to speak, the department of science on which they bear…”

The publication of
On the Origin of Species
in 1859 created a sensation and proved President Bell spectacularly wrong. It also made Darwin far more famous than Wallace, as Darwin remains to this day. His ability to articulate the theory of evolution is still astonishing.
On the Origin of Species
remains a remarkable and remarkably readable book, readily available in hardback, paperback, and online a century and a half later. In it, Darwin gives us example after example of evolution and explains the means by which it happens, providing both the facts and the mechanism in one volume.

Evolution is one of the most powerful and important ideas ever developed in the history of science. It describes all of life on Earth. It describes any system in which things compete with each other for resources, whether those things are microbes in your body, trees in a rain forest, or even software programs in a computer. It is also the most reasonable creation story that humans have ever found. When religions disagree about just creation, there is nothing to do but argue. When two scientists disagree about evolution, they confer with colleagues, develop theories, collect evidence, and arrive at a more complete understanding. Every question leads to new answers, new discoveries, and new smarter questions. The science of evolution is as expansive as nature itself.

Evolution goes a long way toward answering the universal question that ran through my brain as a kid, and still does: “Where did we come from?” It also leads right into the companion question we all ask: “Are we alone in the universe?” Today, astronomers are finding planets rotating around distant stars, planets that might have the right conditions for supporting life. Our robots are prospecting on Mars looking for signs of water and life. We're planning a mission to study the ocean of Jupiter's moon Europa, where there is twice as much seawater as there is here on Earth. When we go seeking life elsewhere, the whole idea of what to look for, and where to look for it, will be guided by our understanding of evolution. Such a discovery would be profound. Proving that there is life on another world would surely change this one.

The great questions of evolution bring out the best in us: our boundless curiosity, and our boundless ability to explore. After all, evolution made us who we are.

 

2

THE GREAT CREATIONISM DEBATE

For those readers who might be deeply religious, welcome. I very much hope you make it through this chapter. It's about my recent debate with a creationist in the Commonwealth of Kentucky, which in many ways was the impetus for me to write this book. Our issue was whether or not creationism is “viable” (the term agreed upon) as an explanation of … well, of anything. I emphasize that I did not disparage anyone's religion. I did not mention anything about
The Bible
. I had no reference to Jesus from the city of Nazareth. But I was, and remain, concerned about the extraordinary claim that Earth is extraordinarily young, which is an assault not just on evolution but on the whole public understanding of science.

Having a few thousand people make use of a few million dollars to promote their point of view is not unusual. This is actually what a great many not-for-profit organizations do, including the Union of Concerned Scientists, the National Center for Science Education, and my own Planetary Society. It's also part of how government policies are developed and put into law. In the case of creationism however, certain not-for-profit groups set out to indoctrinate our science students in their central idea: that the first book of
The Bible
's assertion that Earth is only six or ten thousand years old (the exact number depends on their interpretation) is supported by scientific evidence. Such an idea is laughable and could be easily dismissed were it not for the political influence of these groups. In general, creationist groups do not accept evolution as the fact of life. It's not just that they don't understand how evolution led to the ancient dinosaurs, for example, they take it another step and deny that evolution happened at all anywhere, let alone that it is happening today. They want everyone else in the world to deny it, too, including you and me.

Inherent in this rejection of evolution is the idea that your curiosity about the world is misplaced and your common sense is wrong. This attack on reason is an attack on all of us. Children who accept this ludicrous perspective will find themselves opposed to progress. They will become society's burdens rather than its producers, a prospect that I find very troubling. Not only that, these kids will never feel the joy of discovery that science brings. They will have to suppress the basic human curiosity that leads to asking questions, exploring the world around them, and making discoveries. They will miss out on countless exciting adventures. We're robbing them of basic knowledge about their world and the joy that comes with it. It breaks my heart.

I got the chance to write this book after expressing my concern about the future of the U.S. economy on an Internet Web site called
BigThink.com
. I pointed out that without young people entering science fields, especially engineering, the country will fall behind other nations who do educate their kids in real science rather than the pseudoscience of creationism. Subsequent to that, I was challenged to a debate by Ken Ham, an Australian-born evangelical leader who has managed to oversee the construction of an amazing building that he calls the Creation Museum in Kentucky. His organization is called Answers in Genesis. He claims that his interpretation of
The Bible
is more valid than the basic facts of geology, astronomy, biology, physics, chemistry, mathematics, and especially evolution.

After a few months of mulling it over, I agreed to go to the Creation Museum and take the guy on head-to-head, or lectern-to-lectern. I chose to participate in this debate to raise awareness of the creationist movement and its inherently deleterious effects on our society, as it dulls our resolve to tackle big scientific challenges like producing energy for the burgeoning human population. Perhaps it's not surprising that along with his other extraordinary claims, my opponent doesn't feel that he or his followers should be concerned with climate change.

We were each given time to make our case before the audience. Mr. Ham holds to a fascinating pair of doublespeak phrases: “observational science” and “historical science.” He says that there's a difference between things that happen while you're alive and watching and things that happened before you were born. So for him, anything in the fossil record is subject to question. For him, any astronomical observation is automatically irrelevant, because the stars are older than any person that could have observed them. Perhaps a mischievous deity put them all there in a flash. Using the word
science
in these Orwellian ways is unsettling. As a science educator, I also find this practice deeply irresponsible.

When it was my turn, I hammered away at Mr. Ham's claim that there was a big ole flood and that all the animals we see today are descendants of the few pairs that Noah and his family were able to save on a big boat, the ark of Biblical myth. By the way, neither
The Bible
nor Mr. Ham offers any insight into the fate of every surface-dwelling plant during this supposed episode.

I started by discussing stratigraphy, the layering (strata) of the rocks that make up Earth's crust. I could not help but point out that the Creation Museum building sits atop millions of years of limestone layers. The famous landmark Mammoth Cave is right there in Kentucky not far away. On the way to the event, I had no trouble finding a piece of limestone with a small shelly ancient sea creature fossil clearly visible. It was just off the shoulder of Interstate 69. I showed the audience photos of the Grand Canyon, including the striking Muav limestone, the Temple Butte formation, and the Red Wall limestone. They are 505 million, 385 million, and 340 million years old, respectively. What's so striking about them is how distinct they are from one another. Clearly there were three different spans of time during which these three very-different-colored deposits were formed.

I made the significant paleontological point that in each of these strata, there exist certain fossils that are specific to that time. Impressions of creatures like trilobites that lived in the more distant past are found in the lowermost layers. Creatures like ancient mammals that lived in the most recent times are found in the topmost layers. And creatures that lived in between are found in the in-between layers. There is no place, not one single example, of a fossil from one layer trying to swim its way up into a more recent deposit. If there were a great flood and every living thing was drowning all at once, we would expect one of them somewhere to be caught trying to save its life. There is not one instance of this in any stratum anywhere on Earth. If you find one, you will turn science on its head. You will be famous. Believe me, people are looking.

Early in my presentation, I talked about the ice cores, long cylinders of ice extracted by researchers from ice sheets (in Greenland and Antarctica, especially). There are samples with 680,000 layers of snow-ice. Every year a layer of snow falls. It gets compacted by each subsequent year's precipitation. I asked how there could be 680,000 layers, if there weren't 680,000 seasons of snow (in other words a period of 680,000 years). I explained that in Ham's natural history, you'd have to have 170 winter-summer seasons every single year, for every time Earth went around the Sun. Such a turn of events is just not possible.

Did you know that there are bristlecone pine trees in the western United States that are significantly older than 6,000 years? If you put a tree under water for a year, you kill it, and that's exactly what would have happened according to the creationists' literal reading of Noah's flood. There is a tree in Sweden called Old Tjikko that is apparently 9,550 years old. I, and apparently most of the online audience, was thinking: For cryin' out loud Mr. Ham, what sort of weird world do you live in? If a tree is 9,000 years old, the Earth is not 6,000, etc.

As a lover of math, this was a fun one: Mr. Ham claims there were 7,000 kinds of animals on Noah's ark; there are about 16 million species extant today (that's my very conservative estimate based on recent surveys of life). To get from 7,000 species 4,000 years ago to 16 million today, we'd need to find 11 new species every day. Not every year! And not 11 individual animals! Eleven new species would need to be identified every single day! It's a multiplication and division problem. Not difficult, but very difficult to refute.

It was fun for me also to point out that this brand of young-Earth creationism claims that kangaroos came from a huge ship, the ark, which is supposed to have safely run aground on Mount Ararat in modern-day Turkey. It's a respectable peak—5,165 meters (almost 17,000 feet)—and it's snowcapped. It's not clear to me how all the animals and humans made the arduous descent. The kangaroos, both of them, are supposed to have made it down the mountain, ran or hopped from there to Australia—and no one saw them. Furthermore, if they took a reasonable amount of time to make the trip, you'd expect some kangaroo pups or joeys to have been born and some adults to have died along the way. You'd expect some kangaroo fossils out there somewhere in what is now Laos or Tibet. Also, they are supposed to have run across a land bridge from Eurasia to Australia. But there's no evidence of such a bridge or any kangaroo fossils in that area, not any.