If he were still alive today, Charles Darwin would be proud of us. He’d also be 204 years old. But hey, he did coin the idea of survival of the fittest. Maybe he used his insight to discover the secret of eternal life and is currently surviving in great fitness on some tropical island in the Galapagos Archipelago. That’s pretty unlikely, but at least Darwin can rest easy knowing he made a pretty big impact on our world. Charles Darwin, of course, is the father of the theory of evolution. He traveled the world and viewed all different kinds of organisms, wrote a ground-breaking book “On The Origin of Species,” and changed scientific thought forever. He ascertained that all Earth’s species are descended from common ancestors, and through the process of natural selection, have been adapting and evolving and often becoming extinct, since the beginning of life. Simply put: if you can’t adapt to changes, your species is a goner.
So why would Darwin be proud of us? Darwin laid the foundation for a school of thought that we’ve built on exponentially. Darwin’s ideas have touched on a great many aspects of modern-day humans’ lives. Science, of course, has benefited tremendously. In the field of paleontology: the idea of evolution has shed light on fossils, and vice versa. Biologists have learned about what it is that makes a species thrive, and how ecosystems and the species in them become extinct because of natural selection. Human psychology only ultimately makes sense in the context of evolution: we do what we do and think how we think because of that innate drive to survive. It isn’t just science. Literature, technology, music, politics, religion—you name it—the theory of evolution is pervasive in our society, and who do we have to thank for that? Charles Darwin.
Modern science has taken Darwin’s ideas and ran with them. Darwin probably wouldn’t have pictured, 130 years after he died, his ideas being used in application to cutting-edge technology called Ecological Niche Modeling to determine the likelihood of an organism surviving in a particular ecosystem. This is exactly what Dr. Alycia Stigall, a geologist at Ohio University, works on. Dr. Stigall recently presented her work as part of Ithaca Darwin Days, a week-long celebration devoted to Darwin’s legacy organized by the Paleontological Research Institution and Cornell University in Ithaca, New York. The theme for this year’s Darwin Days celebration (February 11-16) is “Evolution and Invasive Species,” focusing on non-native organisms whose presence within an ecosystem causes environmental harm or harm to other species. Invasive species, as Stigall pointed out, are everywhere, even in your backyard. Take the house sparrow, for example. These little guys were native to Britain, but now there are more than 150 million in the United States. Other common invasive species include dandelions, rats, mice, pythons, and zebra mussels. “Darwin,” Stigall said, “actually had a real appreciation of invasive species. Darwin understood human agents of transport, and the speed at which some of these motions can occur.” Stigall took Darwin’s ideas and used them to analyze how invasive species affect ecosystems, but using a novel approach that allows examination over very long time periods. She used patterns from the fossil record of brachiopods to trace how invasive species were distributed during the Late Devonian, one of Earth’s five big mass extinctions. She discovered that extinction itself wasn’t incredibly high during this time, but that speciation, or the origin of new species into ecosystems, essentially came to a halt. So organisms were becoming extinct at relatively the same level as at other times, but new critters weren’t arriving. This was due, in large part, to brachiopod invasion. The species that survived the invasion events were those who could live in diverse environments and were less ecologically specialized. Invasive species themselves, in fact, are just that: generalists, not specialists. “If you can make your living in lots of different ways,” Stigall noted, “then there are many places you can make a living.”
Dr. Alycia Stigall, Ohio University
People around the world are celebrating Darwin’s birthday today, February 12. Dr. Stigall’s study pays homage to Darwin, who, more than most during his lifetime, knew the importance of diversity. Stigall’s study has relevance for species today; even for us humans. If the presence of invasive species results in depressed speciation rates, perhaps being aware of invasive species will help us preserve diversity in the future. “Not only do we need to focus on extinction,” Stigall commented, “but we need to worry a little bit about how the Earth is going to recover. It’s probably going to take a long time, because if we can’t form new species, it will take longer to rebound from the present crisis.” The birthday guy would agree.
Please visit Ithaca Darwin Days for a full schedule of events, and this column for more summary reports during the week.
The Paleontological Research Institution, Ithaca, New York, is pleased to sponsor Paleontology content for This View of Life. Founded in 1932, PRI has outstanding programs in research, collections, and publications, and is a national leader in development of informal Earth science education resources for educators and the general public.