A group of scientists at Arizona State University have developed a really nice tool for instantly calculating the divergence time between any two groups of organisms—or individual species.
As we all know—or should know, especially if you’ve read Richard Dawkins’s The Ancestor’s Tale—every species on earth is related to every other, for we all share common ancestors. Closeness of relationship is in fact defined as how long in the past this common ancestor lived. More closely related species share more recent common ancestors. And haven’t you wondered, for example, how closely related you are to a mushroom? I know I have.
So go over to Time Tree and write in any pair of species. The application (also available for iPhones, though I can’t imagine why) will tell you not only how closely related are your species of choice, in terms of when their common ancestor lived, but will also give you all the species and references involved in the calculations, and the type of molecular data used to do the calculation.
Here’s one example. When I was an undergraduate, people were arguing about whether the giant panda (Ailuropoda melanoleuca) was more closely related to raccoons (procyonids) than to bears (ursids). I can’t remember why they thought that—perhaps because the raccoon and other procyonids have eye masks like pandas. Anyway, the issue was settled with molecular analysis, described in a Nature paper by Vince Sarich whose title is a model of scientific concision: “The giant panda is a bear.”
Now you can settle this argument simply by looking at divergence times. Here’s the start: comparing pandas and raccoons on TimeTree. This is how the results look:
TimeTree is great for settling those thorny pub arguments! Go see when you had a common ancestor with squirrels or ferns.
h/t: Matthew Cobb