Fireside Chats

This is a special winter opportunity for those living near Columbus, Ohio. It is a rare chance to see displays and the professional scientists who are spending their lives studying about the natural world, both past and present.I spent a few hours making the rounds and will share some of the insights while the memories are still fresh.

Darwin was a recurrent theme at many of the displays. It is the 150th anniversary of the publishing of the Origin of Species. Make sure to get hold of a copy of National Geographic from February 2009.

An ornithologist displayed birdcalls from warblers collected around western Washington and Oregon. Spectrograms were on display which showed the variation of frequency with time. We could press buttons to actually hear the call of males of the species. All of the calls start out the same, but different individuals have different trills at the end of their calls. The map showed the distribution of calls around the region. The males learn their calls from their fathers. The warblers migrate, but return to their home regions. The scientist mentioned that the females of this species are not selective about the particular call of the males they choose to mate with. This is probably good for biological diversity, though it does raise a question about how the geographical distribution of calls can be maintained.

Spectrogram of a Cardinal

Then we spoke to a scientist with recording equipment. My wife was recorded and we could study the time domain view as well as the spectrogram of her voice. We compared this to birds and other animals.

Next, we experienced arachnophobia as we examined live tarantulas and black widows as well as the preserved body of a brown recluse spider. We could see the red hour glass on the black widows and learned that they like to live in basements and sheds, places where the air is undisturbed. We then saw a preying mantiss devouring a cockroach.

We then viewed an amazing journey through gut of a mite. The camera view entered the mouth which had parallel ridges. Down the gullet we travelled through a seemingly endless labyrinth of channels. These images are taken from an actual mite using Synchotron-X-ray-Tomography. This technique allows 3-D reconstruction of structures lying below the surface at the submicron level.

We moved on to look at a microscopic protozoan that lives in pond water. It was magnified 100 times . It rotated around and around using antennae as paddles. We could see legs, two eggs, gills, and eyes. The scientist told us it was stuck in place on a bubble of air. (Damn that surface tension!)

Then I went into the fossil room. I saw something about the size of a head of cabbage. I guessed it was a stromatolite, one of the earilest forms of life on Earth. The scientst told me that it was a kind of sponge that still exists today. It is found in caves in the Carribean. Each layer consists of thousands of individuals living in a colony. They are not sure why there are cabbage leaf-like layers. Many periodicities are measured in the fossil record. Many times, paleontologists are at a loss to explain whether it is seasonal like tree rings or epochal like changes in ocean levels. One scientest did show that the number of days in a year used to be greater during the Devonian. Was this is because the rotational speed of the earth was greater or the orbit of the earth was different? That’s another question for next year.

I was extremely pleased to see a fossil from Caesar’s Creek. I recognized the it from a recent trip documented here. The scientist helped identify all the different kinds of animals. I learned that the lily-like crinoid was really an animal. The rock is indeed limestone.

Ordovician Fossils from Caesar Creek, Ohio

Then Anne and I went into the insect room where our son, Jerry, has been an intern for the last two years. We saw the tiny scielionadea wasps that are almost too small to be seen without a magnifying glass. Jerry had to view them under a microscope to tell male from female. The undergrads and interns often mount the insects on paper, pins or clay, so that the more-experienced scientists can do further studies with microscopic cameras.

Anne Visits the Insect Lab

Doug and Shannon Visiting the Insect Lab

Jerry Holds Forth

Insect Biologists

Sarah

Entrance to Insect Lab

I then visited the plant DNA lab and saw three scientists describing the encoding of life I learned that each cell has almost 6 feet of DNA coiled up in the nucleus. The entire genome is encoded with paired nucleotides designated A, G, T, C. We compared different species of orchids and observed code substitutions. The scientist explained that some substitutions could change how the entire sequence is read, while other substitutions have a minor effect. All of the substitutions are subject to random changes. I asked for an example of how those sequence changes might cause a change in the form of a species. The scientist took in a big breath, and said, “That is the topic of my research. There are two phases of photosynthesis, a daytime and night time phase. I am studying a species whose genome has mutated so that the night time phase of photosynthesis does not work That gene is what is called a fossil gene. And yet the plant survives. It sends out chemical messages from its roots that causes another species of plant to provide essential nutrients.”

Back in the museum, I saw a video of a fresh water clam dangling a protrusion from its bivalve. A darter fish was attracted and actually bit off a small piece. The scientist explained that the continental US has more fresh water mollusk biological diversity than all the rest of the continents combined. However, they require fish to help spread their offspring. I agreed that it was fascinating to observe the many forms of life and the complex ways they find to survive and propagate. I was curious about who would fund the search for knowledge. The scientist explained that the fresh water mollusks were very sensitive to pollution. We risk losing them if we allow our streams and rivers to become polluted. In some cases a stream may have many adults of the species, but the population could still be in collapse if new generations of mollusks were not being produced. They often gather a gravid female and observe how it interacts with fish species in the lab. Then they know what to look for in nature. I asked if it would be possible to train non-scientists to take part in the monitoring of fresh water molusks in nature. He agreed it may be possible, but that it takes a special individual to go snorkeling in shallow rivers and streams to observe these interactions so essential to the preservation of the species.

I finished my tour in the horticultural room. I learned how plants are pressed and preserved. They use white glue like Elmer’s to glue the sample to paper. Large twigs can be sewn or taped. I observed a display entitled “Bark is a Many Splendored Thing”. It was used in many medicinal remedies down through the ages. Today, we take aspirin without thinking of where it originated. Then I got a nice lecture on the reproduction of ferns. I observed the disk shaped spots on the bottom of fern leaves. I could see numerous spores within the circle.

Plant Press

Reproductive Life of Ferns

If you live nearby Columbus, Ohio and would like to find out more about the natural world, then make sure to make it to the open house next winter.