"Some early analyses pointed out that spiders with orb webs didn't form a group they appeared in different places along the tree," Giribet said. "But the genes that were being used weren't enough to elucidate the evolution of a very diverse group like spiders, so most people dismissed many of those results."
In recent years, however, sequencing technology has dropped dramatically in cost, meaning researchers who once were able to study only a handful of genes can now examine the entire genome of a particular organism.
"The technology has changed what we are able to do in terms of the questions we can ask and the questions we can answer," Giribet continued. "Even just five years ago, we were spending thousands of dollars to sequence 3,000 genes. Today, we're spending just a few hundreds of dollars to sequence millions, which is almost an entire genome.
In the case of Giribet and Fernndez, the technology allowed them to sequence genes from 14 different spiders, creating the largest genomic data set for the study of spiders.
"This paper is at the forefront of how these large data sets are being analyzed, and how we are now constructing phylogenies using molecular data," Giribet said. "We can now test all possible pitfalls of phylogenetic interference to make sure our results are as accurate as possible."
Though his hunch, Giribet said, is that the two orb-weaver groups evolved independently, he's now designing a study that will examine the genetics of as many as 150 spider species to test that hypothesis.
While the two groups create very similar webs, he said, their strategies for using them, how they manufacture silk, and even the silk used to construct them are very different. While one group passively uses their web to catch prey, some species in the other use it like a net, holding it between their legs, and trapping insects with it. <
|Contact: Peter Reuell|