Face to face with evolution
Face to face with evolution
AJC readers relish being put to the test
By MATTHEW GROBER - Atlanta Journal Constitution, Feb 14, 2004
• What do you know about evolution?| QUIZ
I am overwhelmed. More than 2,200 people took my evolution quiz on ajc.com last week. More than a dozen contacted me directly with questions or comments. And that's great news.
As we in Georgia discuss public school science standards and the proper place of evolution studies in the classroom, I've been thinking about folks who are past school age. These are people who must take an active part in discussions and policy. To what extent do everyday people understand key points about evolution?
I developed this quiz to touch on key misunderstood aspects of evolution.
Now I have the opportunity to comment on these issues, after folks have had some time to chew on them. I think the chewing is important. Education is certainly about getting the facts straight, but it is also about learning to evaluate and process those facts, and then integrate them into an expanding understanding of "life, the universe and everything."
I thank everyone for participating and I thank some colleagues for reviewing this article in an effort to keep my facts straight.
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Question 1. True or false: The design of animal systems (eyes, ovaries, spleens, etc.) is perfectly adapted to each animal's environment because of the millions of years over which natural selection has worked on existing variation.
Answer: False. Most said true (67 percent). Adaptations are not perfect because they are made from whatever materials are available. There is no premeditated choice of what will come to pass, just a variety of existing options, with some that work and persist.
The reproductive system of women is a telling example. Sure it works pretty well, but it's riddled with design flaws. The egg ruptures from the side of the ovary (ouch) and is set afloat in the body cavity to find its way to the fallopian tube, which is not directly connected to the ovary. Sure, signals are sent out to guide it, but why leave the egg afloat when it's easy enough to make a tube that directly connects to the ovary? Because of this "imperfect" design, sometimes the egg develops inside the tube, a dangerous location.
These descriptions give the impression of the duct tape and hacksaw approach rather than intelligent design. Selective forces are dynamic. So, given the less than optimal building materials and the dynamic forces of selection, living organisms aren't perfectly designed, but they work well enough to persist. Life is all about persistence.
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Question 2. True or false: The concept of evolution (change over time) was first put forth by Charles Darwin in his now famous book on The Origin of Species.
Answer: False. Most said true (57 percent). Evolution was not Darwin's key contribution. Geologists and biologists before Darwin noted that the Earth and its inhabitants change over time. They contributed to Darwin's thinking. What set Darwin apart, in biology and in history, was that he provided a mechanism -- natural selection -- for how evolution worked. In so doing he gave us a way to understand and, in fact, test hypotheses about the pattern and process of evolution. The reason we still accept and investigate the idea of evolution via natural selection is because his proposed mechanism has undergone many tests and has fared remarkably well.
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Question 3. True or false: Many of the early naturalists (1600s to mid-1800s) whose work cataloged and classified species on Earth were working for the greater glory of God and did not believe forms could change over time.
Answer: True. Most said true (74 percent). Science and religion need not be antagonistic forces. Science is a method for discovering and testing the rules that govern the physical world. It has no hold on our metaphysical views, nor do most religions preclude the pursuit of knowledge regarding the generation of biological diversity. Significant scientific discoveries have come from people who hold a wide range of religious views.
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Question 4. The best estimate of the age of the Earth is:
A. 6,000 years
B. 250 million years
C. 50,000 years
D. 4.5 billion years
Answer: 4.5 billion years (4 percent said 6,000 years; 14 percent said 250 million; 1 percent said 50,000 and 81 percent hit the nail on the head). Bottom line here is that there's been plenty of time for selection to act. Sometimes you need a lot of time, while in other cases (like bacterial resistance to antibiotics -- see below) evolution can occur on a much shorter time scale.
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Question 5. When an antibiotic is used too often in the treatment of some bacterial infections, the bacteria can develop a
resistance to the antibiotic. A key reason for the development of antibiotic resistance is:
A. Bacteria compete with humans for access to resources
B. Bacteria reproduce more rapidly than humans develop antibiotics
C. In order to succeed, many bacteria come genetically equipped to deal with all types of antibiotics
Answer: The best answer is B. (7 percent said A; 36 percent B; 57 percent C). The bacteria in question see humans as their resources, so that eliminates A. C may seem reasonable, but bacteria can't come equipped to deal with all types of antibiotics, because other organisms are in the process of evolving new antibiotics to keep themselves from succumbing to these bacterial pests. Scientists are studying these promising species to learn their antibiotic secrets. B -- What we're really talking about is generation time, not chronological time. Evolution comes about by selection acting over many generations. Bacteria reproduce in as little as 20 minutes, so they can produce dozens of generations in a single day. If bacteria, like people, reproduced two to five copies of themselves every 50 to 70 years, we wouldn't have to worry about them.
But some bacteria can make two to five copies before lunch.
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Question 6. True or false: Apart from understanding animal and perhaps human origins and relationships, the study of evolution has provided discoveries of great economic value to human societies.
Answer: True. Most people said this was true (84 percent). Folks nailed this one, but what are the significant contributions? Some would say increased production in domesticated livestock, but that was really going quite well before we understood natural selection. There's Darwinian medicine (selection in a vial in the quest of evolving new chemical / biological therapies), but it is still in its infancy. Understanding the origins of the HIV or SARS virus and how they change are questions answered by scientists with a sound understanding of evolution. Understanding the origins and mechanisms of insecticide resistance in insects plays a major role in farming practices. Last but not least, knowledge of the fossil record is very important in oil exploration.
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Question 7. True or false: One problem with studying evolution is that you can't test scientific hypotheses concerning plants
or animals that have long been extinct.
Answer: False. Most people said this was false (66 percent). It is very straightforward to test hypotheses using the fossil record. The idea that birds and dinosaurs were related was first proposed in the late 1800s and recent fossil discoveries in China (e.g., "feathered dinosaurs") have now allowed us to test this 100-plus-year-old idea. Another example is how our ideas about whale evolution have changed with the discovery of more fossils. Finally, our ideas about relationships between animal groups that have been based on the fossil record are generally supported by DNA data, an independent test of these hypotheses.
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Question 8. True or false: Since fish (as a group) appear in the fossil record before humans, then all fish species must be more ancient than the human species.
Answer: False. Most people said this was false (79 percent). Since I spend most of my time studying fish, I am overjoyed with this result! In short, although some fish evolved millions of years ago and have not changed much since then (like sharks), there are species of fish, like some minnows, that are recent arrivals. It is relatively easy for freshwater fish to get "trapped" in a secluded environment (like when a river doubles back on itself and in time leaves a small isolated pond in its wake). So groups of fishes continue to be reproductively isolated in small populations, and this is generally recognized as a key step in at least one pathway toward the evolution of a new species.
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Question 9. True or false: Genetic mutation is the primary way by which variation is generated in animals.
Answer: False. Most people said this was true (70 percent). Mutation can generate lots of genetic novelty and is the ultimate source of variation. However, for most animals on earth, sex generates more variation than mutation. You can think about the generation of variation like the movie business. Mutation would be like a new idea or plot line. It arises spontaneously and is most often not useful, but on rare occasions is successful. In sexual reproduction, recombination takes these new ideas and combines them in a variety of ways with a smorgasbord of existing ideas and techniques. "Mutation" may generate a new plot line (e.g., coming of age) but recombination then "produces" a hundred variations on that theme (from "the Graduate" to "American Pie").
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Question 10. In answering these questions, I went to the following places for information:
A. The Web
B. Books
C. Both the Web and books
D. I did not look for any new information (answered based upon what you already knew)
98 percent of respondents did not look up any new information in completing their quiz.
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Question 11. When I answered these questions, my views on evolution were:
A. It is a robust scientific theory on the level of gravity or plate tectonics
B. It is a fable constructed by fringe scientists to discredit religious dogma
C. it is a developing hypothesis that still requires rigorous testing before we can accept any part of it.
71 percent went with the robust theory, 5 percent see evolution as a fable, and 23 percent are still dubious. I guess I can live with these numbers, but hope that this article will begin to make a difference here.
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So what did I take home from this process? First, I hope that people who took this quiz have begun to appreciate arguments and facts from scientists. People took the time to complete the quiz, and they have taken the time to discuss the questions and answers. And that was my goal. If you want more information, a good place to start is the understanding evolution Web site at evolution.berkeley.edu. You may also access more than 111,000 articles in scholarly journals over the past 30 years.
Yet, what I really took home from this quiz was a question. I wondered why some people have difficulty discussing and appreciating biological evolution. I went to Zoo Atlanta last week to take a picture with a fellow primate (big thanks to the staff). I spent some time observing a beautiful, rare gorilla, while the ape watched me.
I also watched an orang mom and her baby. I reflected on our biological similarities. We are made of the same stuff (mostly carbon, nitrogen and phosphorus). We are all a small subset of vertebrates (which are dominated by fish) notable for having traits such as hair and lactation (mammals). Within mammals we share much anatomy, behavior and DNA sequences with our fellow primates (see the photo on the @issue section front).
In some very fundamental way, they are as much a part of us as we are a part of them. Maybe the problem with issues of biology education isn't our inability to understand the pattern and process of evolution, but rather our inability to understand ourselves.