Putting the Fun Back in Fungus

Como Zoo: The Giraffe's Adaptations

The giraffe has some highly unusual and specific adaptations, among which at least one that demonstrates how evolution must work with the "materials at hand" rather than being able to come up with more elegant engineering solutions. Richard Dawkins explains one such compromise in the following video.

https://www.youtube.com/watch?v=cO1a1Ek-HD0

A word about Dr. Dawkins. He has had some controversial things to say on subject matter that technically lies outside of science. Feel free to agree or disagree with his opinions on non-scientific topics. But when it comes to evolutionary biology, Dawkins is in fact a leading light (his brilliant book "The Selfish Gene" is seminal), and he is not expressing opinion but explaining biological facts.

One fact about giraffes--again, something that points toward common descent--that is surprising is that they have the same number of vertebrae in their necks as humans and most other mammals. You can see from the photo of the model giraffe that one reason for that is that the bones are elongated. Human cervical (roughly, "neck") vertebrae are short, compact, and closely nested. You can see that this is not the case with giraffe cervical vertebrae. Again, this is typical of what evolutionary processes must do--make do with materials at hand. It might have been an advantage to have more, smaller bones in terms of flexibility (and in fact, in snakes this adaptation DID occur), but just because an organism might benefit from some feature does not mean it will get it. Novel features are largely determined, initially, by chance,and those differences that confer a survival and reproductive advantage spread throughout the species population. Over geological time (thousands of years), advantageous features accumulate, bringing about usually gradual (rarely, less gradual) change.

Other adaptations that enable the giraffe's unique body plan include those related to the circulatory system. Consider the problem--getting an adequate blood supply all the way up that long neck into the brain, and, if the giraffe, say, has to bend down to get a drink, the pressure can't, oh...make its little noggin explode? So the giraffe has evolved some unusual hydraulic equipment, which top-notch science writer Natalie Angier explains in the October 7 2014 New York Times:

Also of interest is the giraffe’s exceptional cardiovascular system. A large giraffe can stand 20 feet tall — the height of a second-story window — with its neck accounting for roughly a third its span and its long legs the same. The multitiered challenge, then, is how to both pump blood very high and retrieve it from far below while avoiding burst capillaries in the brain or blood pooling around the hooves.

As part of the Danish Cardiovascular Giraffe Research Program, scores of scientists have traveled to South Africa to study giraffe physiology. They have measured blood pressure at different sites and found readings that range from high to ridiculous — up to five times human blood pressure — yet with none of the organ damage commonly seen in hypertensive patients.

Instead, the giraffe has extremely thick blood vessel walls to prevent blood from leaking into surrounding tissue, while rugged, inflexible collagen fibers in its neck and legs help keep the blood traffic moving, rather as the tight antigravity suits worn by astronauts and fighter pilots will maintain blood flow under the most extreme gravitational shifts. A complex mesh of capillaries and valves store and release blood in the neck, allowing the giraffe to bend over for a drink of water and then raise its head again quickly without fainting; when the giraffe is standing still, sphincters at the top of the legs limit circulation to the lower extremities, to minimize the risk of fluid buildup around the hooves.

Researchers were also surprised to find that contrary to old textbook wisdom, giraffes do not have unusually large hearts for animals their size. “It’s half a percent of body mass, and that’s the same as we see in a cow, dog or mouse,” said Christian Aalkjaer of the department of biomedicine at Aarhus University in Denmark.

Moreover, Dr. Aalkjaer and his colleagues have determined that the giraffe’s cardiac output — the amount of blood pumped into circulation each minute — is modest, proportionally lower than it is in humans. That finding could help explain why giraffes rarely run for very long: Their hearts can’t deliver oxygen to their muscles fast enough to power extended aerobic exertion.

Lizard Island Observation Game Helps Kids "Think Like a Scientist"

I confess that I have no played this game myself yet--I'm not much of a gamer--but I'm looking forward to trying this out. From what I read and understand, it seems like a fun tool to aid biology understanding. This is what an article ( http://www.gamepolitics.com/2014/08/20/lizard-island-observation-teaches-children-think-scientists) says about the game:

Lizard Island Observation sends players on an adventure to search micro islands for brown anole lizards. Players must find, catch, tag, and measure each one they find. Along the way, players can tap on various island life to learn more about it. All of these facts, questions, and answers are recorded in a field notebook.

The game is also tailored for use with non-readers or children with learning disabilities because it offers the option to have the text read aloud. The game is recommended for children in grades K-5. A school version of the game will also have lesson plans and assessment tools for teachers and homeschoolers.

The game is available here, on iOS and Android, for $4.99: www.buddingbiologist.com

Fossil Sites Within A Day's Drive

http://www.mycountyparks.com/county/Floyd/Park/Fossil-Prairie-Park-Preserve-and-Center.aspx

http://ashfall.unl.edu/

http://www.smithsonianmag.com/evotourism/evolution-world-tour-ashfall-fossil-beds-nebraska-6171451/

I first learned about Ashfall Fossil Beds State Historical Park in Royal Nebraska, from an article in Smithsonian’s magazine called Evolution World Tour, in the section titled: “ Ashfall Fossil Beds, Nebraska,” which said:

Prehistoric rhinoceroses and horses died of volcanic ash inhalation 12 million years ago – their fossils are studied now as a perfect example of natural selection.

I confess I had no real idea how far Royal Nebraska is from Minneapolis where I live, so I used Google Map and discovered it’s about six and half, seven hours, depending on the route. I selected a route through Sioux Falls, South Dakota, because I figured me and my partner would want to stay overnight someplace with decent but not terribly expensive hotels, and I was curious to see the Great Plains Zoo in Sioux Falls.

The drive in my then-new Kia Rio (jealous much?) was…I’m going to say “serene” here. It’s not fair to call it boring, because it has a real beauty to it, but it’s not a dramatic beauty like pounding surf; it’s a quiet, static kind of beauty. Lush rolling hills, sheets of cornfield extending to the horizon, sky sky and geez there’s more sky. But this is not an unpleasant drive, and the right MP3 player music mix really helps.

About the Great Plains Zoo (http://www.greatzoo.org): This is not a bad zoo by any means, but for those of us who have grown accustomed now to the more animal-friendly habitats at the Minnesota Zoo, and the increasingly better habitats at Como Zoo, it seems comparatively stark and unintentionally mean-spirited. There are rhinos there, and that was a big part of the draw for me. I was really interested in seeing a live African one on the same trip as I saw its distant Nebraska cousin’s fossilized bones. Circle of life? Something.

But the paddock for the rhinos was rather small and while the animals were in no way mistreated or neglected, I couldn’t help feeling a wave of the same sort of sadness that used to overtake me at Como Zoo, seeing, say, the polar bear in an enclosure not much larger than my apartment. Como has moved to correct much of that last-century cruelty; I hope all zoos are able to find the resources to follow suit.

Oh. And the MAIN reason for going to this zoo was their alleged axolotl. It’s a marine salamander, extinct in the wild, and from only one small region of Mexico. A real freak show, this salamander—it reaches sexual maturity while still a “tadpole,” so it keeps its frilly lion’s mane of gills and lives an entirely aquatic life. It’s an example of what’s called “neotany,” and some scientists have speculated that humans might also, in their evolutionary history, have benefited from some neotany, because baby chimpanzees and bonobos look “more human” than the adults of those species do.

At any rate. Axolotl. All kinds of cool. Nowhere to be found, despite it’s having appeared on their website of animals to see. We asked around and they no longer have an axolotl, which at the time disappointed me quite a bit. But I fixed that by getting my own this spring. Her name is Rose (Axol Rose) and she’s doing great. Take that, Great Plains Zoo!

The actual Ashfall park is in a remote-but-easy-to-find location, set among rolling hills mostly covered in cornfields. It’s nice, new, and modern, with a newish interpretive center that does a great job of explaining, for example, the evolution of horses represented at the site. And the main attraction is a huge barn- or hangar-like structure that shelteringly covers the actual site. The site is an active dig, and you can observe paleontologists carefully digging among the amazing riot of shapes.
Mike Voorhies, the paleontologist who made this discovery with his wife Jan back in the 1970s, was onsite, still digging and answering questions. I can’t promise that everyone will be so lucky as to have the actual number one expert on Ashfall present to, with great generosity, respond to a series of questions, but if it happened to us, maybe it’s not SO unusual.
A long way to come just to see a graveyard? I suppose the case could be made. But I thought it was awesome, and like in some great myth for me the bones seemed to come alive and I could imagine the rhinos and camels and horses and other animals alive in that very different time when Nebraska—NEBRASKA!—looked more like the African plains.

The OTHER fossil site possibly worth driving to is still a fair distance, but only about a third as far as Ashfall: Fossil Prairie in Rockford, Iowa. It’s approximately two and half hours from Minneapolis, in the northeast corner of Iowa. I took advantage on the trip of seeing and staying at the Frank Lloyd Wright hotel in nearby Mason City, but other more modest accommodations are also available in the area if you plan to make an overnighter out of the trip.

The thing about the fossil center (fossilcenter.com) is NOT that it is site to spectacular specimens like in Ashfall, but that they are abundant, easy to find, and available for collection. These are fossils from the Devonian, all marine animals, so you won’t find any dinosaurs or mammoths or anything, but there is-for me, at least—a special thrill that comes from finding shells and coral and other animals that have been dead for almost half a billion years. I went the morning after a very heavy thunderstorm, and the torrents of rain washed the soil and sand away from some areas, leaving behind a number of exposed fossil shells. I described it as “beachcombing the Devonian,” and I found it thrilling.

Trips are sometimes complicated to arrange, and seldom entirely convenient. They can cost money, and they for sure cost time—some of it being pretty bored. All I can say is, if you plan right and are open to it, these mega-field trips are totally worth the effort for the budding paleontologist and her parents or friends.
Final note: I stopped somewhere along the way, on my drive down to the Fossil Center, that I will have much more to say about in a later post, but wanted to put here as a further enticement to make the trip. At about the one-third mark or so, in Owatonna, Minnesota, is the Reptile & Amphibian Discovery (RAD) Zoo, and it’s well-worth the stop as long as you’re buzzing nearby. As I said, more on that later, but take a peek:

http://www.theradzoo.com/

Plants

Squiggle finally learns what "tardigrades" (or "waterbears") actually are:

"Tardigrade!" shouted Ollie.

"What now?" asked Squiggle, a little startled by the way a loud, unfamiliar word had shattered the silence of a lazy Sunday afternoon.

"That's the word of that thing that one of Mr. Li's students is doing something on for her science fair project...look, there's a book on tardigrades on his desktop, on the short pile."


Kids & Teachers TARDIGRADE Science Project Book: How to Find Tardigrades and Observe Them through a Microscope by Michael Shaw (you can find it here at Amazon.com: http://www.amazon.com/Kids-Teachers-TARDIGRADE-Science-Project-ebook/dp/B009D7VHXK/ref=sr_1_1?s=books&ie=UTF8&qid=1407356021&sr=1-1&keywords=tardigrade).

Squiggle excitedly hopped off the bookshelf--well, hopped as only a small, not very thin and not very coordinated worm can hop--and shimmied on up to the computer's keyboard. She had to know what these "tardigrade" critters were, what they looked like, and why the fuss. She did a search and came up with this site:



http://tvblogs.nationalgeographic.com/2014/03/19/5-reasons-why-the-tardigrade-is-natures-toughest-animal/

And after that, she even found a plushy doll version of the so-homely-cute waterbears:

http://www.giantmicrobes.com/us/products/waterbear.html