\u201cRevisiting Darwin\u2019s Hypothesis: Does Greater Intraspecific Variability Increase Species\u2019 Ecological Breadth?\u201d was published in the January issue of the American Journal of Botany. Authors Colby Sides \u201912<\/strong>, Brian Enquist \u201991<\/strong>, and Colorado College Biology Professor Jim Ebersole found their connections through CC and collaborated on the work, which became Sides\u2019 undergraduate thesis.<\/p>\n Having also been Enquist\u2019s advisor in the early \u201990s, Ebersole knew that the other two had similar research interests and connected Sides with Enquist, now professor of ecology and evolutionary biology at the University of Arizona.<\/p>\n Sides\u2019 work tested a key Charles Darwin prediction: \u201cIn the mid-1800s, Darwin hypothesized that those species which show larger variation should be found in broader environments. That had not really been tested or proven,\u201d Ebersole said.<\/p>\n Sides spent much of the summer of 2011 collecting and analyzing plant samples from six communities ranging from 9,000 to 12,000 feet in elevation in the area around Crested Butte. He was based at the Rocky Mountain Biological Laboratory in nearby Gothic, where Enquist has been running various experiments for the past 10 years.<\/p>\n Sides measured the area, then dried his leaf samples from 20 species including recognizable Rocky Mountain subalpine flowers such as the glacier lily, bluebell, lupine, and shrubby cinquefoil. He then weighed the samples to evaluate the mass of each, allowing him to calculate specific leaf area that correlates to other plant traits. His results show that those species with more variation in specific leaf area occurred at a wider variety of elevations.<\/p>\n \u201cThe data demonstrate the importance of within-species variation that has been left out of some models,\u201d said Sides, noting that many studies focus on the average measurement of a trait for a species, not its variability. \u201cIt\u2019s really incredible how variable a species can be, and if they vary a lot they can spread themselves over a bunch of different environmental conditions. It can determine where a species can exist,\u201d he explained of his research results.<\/p>\n \u201cThis shows why species occur at specific altitudinal ranges and then drop out as you go up the elevational gradient,\u201d Ebersole said. The work is particularly important because it\u2019s not just about what is happening in Gothic. \u201cWe are saying it looks like this would be true in general.\u201d<\/p>\n It\u2019s also significant for making predictions, Enquist said. \u201cWhat we see along the elevational gradient enables us to make inferences as to what may happen to these populations as climate may change in the future.\u201d<\/p>\n
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