Tuesday, October 20, 2015

Name that Tree: Dinosaur Edition

I'd past by this particular tree dozens, if not hundreds of times:

The fan shaped leaves give away its identity. It's a Ginkgo tree, which even a cursory bit of research will tell you that it's one remarkable specimen. Ginkgo trees are unique because they have incredibly ancient lineage. If you warped yourself back in time 200 million year, you'd find dinosaurs, and you'd find Gingko trees. In all this time, the Ginkgo tree hasn't really changed. That's staggering. It stands alone:

When we think about flowering plants, there are about 350,000 living species. And in an evolutionary sense, they’re equivalent to that one species of ginkgo. They’re all more closely related to each other than they are to anything else. But the ginkgo is solitary and unique, not very obviously related to any living plant. One of the points I wanted to draw out in the book is that in the past there were a variety of ginkgo-like plants, but this is the only one surviving.

While Ginkgo's are unique, they're also quite commmon. According to one study, they were 5th most common genus in DC.

While Ginkgo's are common, female versions of the tree aren't. They apparently produce vile smelling fruit that's compared to vomit. Thing is, that awful smell probably appealed to some animal at some point:

It’s the outer part of the seed that produces the smell, and it smells, to put it bluntly, like vomit. More than likely, it reflects some sort of adaptation or modification in its dispersal biology. Probably either now or in the past the smell has been attractive to animals. You hear stories of dogs, for example, eating ginkgo seeds — sometimes with not a terribly happy outcome in that they don’t feel so good afterward. But it must be part of a dispersal system. The interesting question is, are the things that adapted to disperse it still around? Or are they extinct?

There’s this wonderful idea that [Daniel] Janzen and [Paul] Martin published about how many neo-tropical fruits don’t appear to have any dispersers in the contemporary fauna. And their idea was that as many large mammals went extinct about 10,000 years ago, many plants actually lost their most important dispersal agents. So in a sense, the plants have continued to live on, while the dispersers themselves have already gone extinct.

e360: So their theory would say that the ginkgo smell would have attracted dinosaurs to eat it?

Crane: Yes, or more likely some mammals that died out much more recently. But the idea is that the tree now could be out of phase with its dispersal agents.

Imagine that: that Ginkgo has been around so long that it's optimized for life that's long extinct. Amazing. And right in front of me the whole time.

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