Instant divergence times!

April 10, 2011 • 9:02 am

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:

In contrast, the divergence between giant pandas and grizzly bears occurred 28 million years ago.  Case closed.

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

40 thoughts on “Instant divergence times!

  1. It might interest Ray Comfort to know that not only did Godd not create the banana, but that we essentially were bananas, about 1407.8 Million years ago.

    1. By a striking coincidence, we were also strawberries 1.4078 billion years ago, too — thereby conclusively proving, beyond a shadow of a doubt, that bananas are really strawberries!



      1. … 324.8 chicken & human – which explains why we both taste the same. Oh, I probably should not have admitted to knowing that! …er, well I read it somewhere!

      1. Multicellularity arose multiple times independently (upwards to around 16 (King 2004 Dev Cell)). Plants, animals and fungi are independently multicellular, and animals and plants are about as diverged from each other as two eukaryotes can be.

        That said, the most reliable origin of eukaryotes is estimated at around 0.8-1.2Gya (eg. Berney & Pawlowski 2006 PTRSB; Cavalier-Smith 2006 Biol Direct; PTRSB) ; 1.5 is possibly believable and anything beyond that is just absurd. 1.4 for animals + plants is a possibility if euks existed by then, but I doubt it.

        I wouldn’t trust molecular clocks. Especially given the known sketchy reliability of the author behind the protist divergence times and phylogeny in Time Tree…

  2. That’s a great tool, but I think there’s room for improvement.

    For example, Baihu and I share a common ancestor about a hundred million years ago. But how many generations is that?

    I’m just about old enough that I could have been a grandparent by now if I had had children when I was in college. In that same span of time, there may well be a dozen or more generations separating Baihu from his ancestor that was born the same time as I.

    It’d be nice to get an estimate for how many generations separate the two of us, on each side.



  3. Very nice. Hopefully they’ll add a measure of the precision of the estimate soon (you know, 40Mya plus or minus 39.994Mya).

    1. Troy, it does – in the example Jerry gives there’s only one study, so there’s no variability. It normally gives you the full range of estimates, so you can choose.

      – BTW, the real h/t for this goes to Ed Yong’s Twitter feed. I am a bit bemused why no one I know appears to have heard of Timetree, though the book (free chapter downloads from the site!) was published in 2009 and the original paper announcing the project was published in 2006.

      – Oh, and Jerry, the reason why there’s an iPhone app is so precisely you can settle those pub arguments – instantly. (All it does is connect to the database, so you need an internet connection to use it).

      1. Thank you, Matthew. Very nice indeed that it shows all studies pertaining to a particular request. Still, even if based on a single study, it’s possible to estimate a range (a confidence or credibility interval) of dates consistent with the data. It would be cool to show that too, if only to show to a certain audience that scientific estimates are not “certain”, but admit to a range of uncertainty.

  4. It is cool but failed when I asked for Camelus bactrianus/Camelus dromedarius! No data would you believe it!

    1. They have this message in red under the heading Molecular Time Estimates in the above picture

      *Note: If you would like to suggest a publication for inclusion please send us a PubMed ID or PDF file.

  5. I’ve used this a couple times already for some stuff related to issues in my field, it is pretty cool.

  6. PZ linked to this awhile back. I tried it, but it is not working well, often doesn’t recognize a spcies I try to look up.

  7. I believe it was actually the lesser panda, not the giant panda. We now know that it is indeed more closely related to raccoons than to the giant panda and other bears, and that therefore pandas are not a monophyletic group. TimeTree says that Ailurus fulgens diverged from Procyon lotor 35 Mya. Or perhaps it was thought that, as a group, the pandas were not bears.

  8. great for settling those thorny pub arguments!

    Ha! I broke it!

    Unable to find the taxa [Rotaviral Gastroenteritis]. Please check your spellings.

    It can’t tell me how closely related I am to an icosohedron. Anyone know the answer?

    1. As in herpes simplex capsids, say? It doesn’t seem to recognize viruses.

      Let us say, closer than you are related to a stone then; less than ~ 4 Gy.

  9. This whole thing is an utter failure.

    Homo sapiens versus Canis lupus familiaris: 98.2 Million Years Ago

    Homo sapiens versus Felis catus: 98.2 Million Years Ago

    That’s not going to settle any thorny pub arguments at all.

  10. So mice and bats diverged 98mya, but cats and bats only 84.

    Humans and bats are 98mya as well.

    So it’s as equally valid to call bats flying mice as it is to call bats flying humans? Is that the right deduction?

    What a fun site. Whales and goats are just slightly closer than whales and camels, by the way.

  11. I swear some people evolved from the potato and still share many of its traits.

    I put in ‘homo sapiens’ v. ‘platyhelminthes’ and got an estimate of 800-1100MYA – obviously incorrect since everyone knows the earth is only 6000 years old. Creationism: the *real* instant divergence.

  12. Delightful site. Tried to determine how many times I’d have to reincarnate before I could get back to be an otter, 98.2 million years ago. Just can’t see it happening. Bummer, another bubble burst. 🙂

  13. I have a similar app on my phone called TimeTree. It has some problems but all and all is pretty useful. I will have to download this one and put them head to head.

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