Rumeli Hisarı

Right after I got to Istanbul on this most recent trip, I took a taxi from my hotel down to the Bosphorus, to check out the Rumeli Hisarı, a fort complex built in 1452 by Sultan Mehmet the II in anticipation of the following year’s siege of Constantinople. It’s constructed at the narrowest point on the Bosphorus (660 m wide), with the aim of controlling boat traffic coming from the Black Sea. This narrow spot is today where they have the second of two bridges spanning the Bosphorus. It looks like this:

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It’s in Europe; that’s Asia on the far right of the photo. A few more shots of the fortress’s pattern of towers and interconnecting walls:

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Inside, I was pleased to note the variety of building stones. Here’s a nice porphyritic andesite which was a common constituent of the walls:
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And a folded limestone:

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Here are some yellowish blocks that are weathering away faster than the mortar which holds them in place. There is a Turkish 1-lira coin in front of the dark block near the center, to provide a sense of scale:

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Here’s a similar phenomenon playing out with some bricks used to make an archway, except here the mortar is the more rapidly weathering component:

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Check out this slab of brick… it’s got a curious adornment:

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Zoomed in to show this detail:

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Dog prints! Sometime a long time ago, maybe more than 500 years ago, a brick maker put out slabs of clay to dry, and some long-dead dog walked across it. The dog’s footprints are a kind of “historical trace fossil” that was then incorporated into this ancient structure.

Visiting the Rumeli Hisarı was a pleasant experience. I walked down along the Bosphorus next, peering into its surprisingly clear waters and counting jellyfish, then got a pide at a cafe. I caught another cab back to the hotel, and eventually fell asleep, a victim of jet lag…

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Pine Marten, Adirondacks

Hello everyone,

I’m back in my office after 7 weeks away. I had some great travels this summer, to Turkey, Montana, and New England… and great geological photos to share from each of those locations. I’m going to start off with something non-geological, though: something furry and alive!

Pine Marten

That, my friends, is a pine marten, a smaller relative of the fisher (“fisher cat,” in the local parlance) and a member of the Mustellidae, the weasel family of mammals. They are a vital part of the northern forest ecosystem, but rarely seen. This was the first time I have ever seen one in the wild: Lily and I were camping at Round Pond in the Adirondacks (near Keene Valley, New York), and this fellow was snuffling his way up the tree. When I called Lily over to see him, he froze, hunkered down, and stared at us for more than an hour. Sometime later, I looked back, and he was gone. For me, this was a great encounter… it was one of the few North American critters I haven’t yet encountered in the wild, and it was a pleasure to share the camp with it for a while.

I’ll be posting more regularly (and not just iPhone-uploaded photos) in the weeks to come. It’s good to be back.

Giant ground sloths

In the American Museum of Natural History:

These mylodontids reminded me of Puerto Natales

The Ghosts of Evolution, by Connie Barlow

Over Snowmageddon, I read Connie Barlow’s book The Ghosts of Evolution: Nonsensical Fruit, Missing Partners, and Other Ecological Anachronisms. [Google Books; Amazon]

Barlow isn’t a scientist, but she’s got a scientist in her pocket: Paul Martin of the University of Arizona. In 1982, Martin and Dan Janzen of the University of Pennsylvania published a paper in Science in which they postulated that a lot of the features of some modern plants are best explained by co-evolution with Pleistocene megafauna (mammoths, gomptotheres, glyptodonts, ground sloths, rhinoceroses, horses, etc.). As those animals are now extinct or extirpated from North America, the plants lack their “disperser” partners. As a result, their “over-sized” or “overly-protected” fruits don’t get dispersed, and tend to rot on the ground. Gravity is the main modern dispersal agent, and so they tend to be quite common in floodplains, but not upland areas.

North American examples of these so-called “ecological anachronisms” are honey locust, osage orange, gingko, pawpaw, Kentucky coffee tree, persimmon, and potentially desert gourds. Another great example, from Central America, is the avocado. These plants bear fruits (or fruitlike growths, if they’re not true angiosperms, like the gingko) which are either very large, very tough, or have very large seeds that are not swallowed by modern animals. Barlow claims that these plants are “haunted” by their departed ecological partners, an evocative analogy that gets repeated many times, long after it’s worn out.

The book is interesting and it held my attention. More importantly, it made me look at the trees around me and wonder at the evolutionary forces that sculpted them, forces now absent, though their sculpture remains. These plants surround us, and one you learn to spot them, it’s hard to pass them on the street without pondering their species’ history.

Walking back to my car after structural geology class at George Mason University last week, I saw some of the pods of the honey locust — big leathery things 15 cm long, 3 cm wide, and 1 cm thick. Some had been cracked open by the pounding action of undergraduate footsteps, and I saw inside the green pulp that Barlow described in the book. I remember she described it as “sugary,” so I grabbed an unmolested pod, and stuck it in my bag. That night, at home, my girlfriend and I cracked it open and tried some. It was sweet! Kind of mango-gummy, I’d say. However, the shell is quite bitter, and so if you try it at home, don’t lick the shell. After I accidentally grazed the shell with my lip and then my tongue, I had to spit and rinse my mouth out. It was nasty.

The Ghosts of Evolution isn’t a perfect book. One criticism I would offer is that it’s a bit repetitive, where the original thesis (a fresh, interesting idea) gets beaten into the ground with endless reiteration. Guns, Germs, and Steel fell victim to the same lack of editorial excision, in my view.

Another problem is that Barlow illustrates her plants with a series of “arty” photographs. The composition of these photos is symmetrical and balanced. They convey beauty, but they aren’t really scientific. Also, the sense of scale she provides is a honey locust seed. This may seem an appropriate sense of scale to a North American botanist, but most of us do not have an intuitive sense of the size of a honey locust seed, even if we are told it’s “about 1 cm long.”

Finally, I would say she needs to be more precise about where the science stops and her own enthusiasm for the idea takes over. The desert gourds she discusses are an exemplar of this: She runs with the idea of ecological anachronisms, and tries to apply its principles to a plant she sees in her own New Mexico neighborhood, but it is unclear how much of this discussion is her own extrapolations and how much has been rigorously researched by botanists. On the other hand, she does things that are beautiful without being scientifically significant: like rubbing a honey locust pod over a mastodon tooth in the American Museum of Natural History, and reflecting how that’s probably the first time that’s happened in more than 10,000 years!

All in all, worth reading if you’re into ecology, evolution, the Pleistocene, or botany. Has anyone else read it? If so, what did you think?