by Alim Ates (4Bb, text), Christine Baader and Nicole Heuss (photos)
Don Salvatore is back in town. The “science exciter”, as he calls himself, from the Boston Museum of Science held another talk at our school about biology straight out of our backyard. Being from Boston, a city that I usually associate with Martin Scorsese-type gangster movies, he seems like a very nice and smart man, who wants to make science fun for everybody, and I think he absolutely succeeds. The presentation was a collection of “backyard biology stories” that were all really fun and very weird.
The first story was about ladybugs and why they are called that way. He said that indeed almost only female ladybugs exist. But why is that the case? It is because of a bacterium called Wolbachia that lives inside the ladybugs. The Wolbachia can only be transmitted through the egg cells of the females. It kills the male eggs, so it can spread itself further with the female eggs. But the unhatched male eggs don’t go to waste. The freshly hatched females eat them as their meal. Pretty weird, right?
The next subject was the dragonfly larva which is unexpectedly ugly and looks scary. It has an arm-like mouth, which it can extend to catch pray much bigger than itself. It reminded me a lot of the mouth of the Xenomorph from “Alien”, but I think that’s just me. The dragonfly larva has other peculiarity. It is one of the only animals which breathes through its butt and can even use that as a means of acceleration. This reminded me of Daniel Radcliff in “Swiss Army Man”, but I have to stop with these movie references.
The sprigtail has another weird way getting around. You can find thousands of these tiny insects in the woods or in the snow, Don Salvatore described them as almost looking like pepper sprinkles. They can jump incredibly high with the help of a little lever on their torso. The 15cm altitude might seem small, but in relation to humans it would be like jumping over the Eiffel Tower.
Don Salvatore also told the story of the snow owls living on the grounds of the Boston airport. They come south from Canada every winter. In Canada, they live and hunt in open fields and the closest thing to that they could find in the Boston area seems to have been the airport. It was always thought that they came down south because the food supply became very small; but one day, the little daughter of a biologist remarked that the owls were in great condition and didn’t look like they were starving at all. No one had ever thought of that, and new research found that they left the north because of territorial battle. So, stay in school, kids, and one day you can correct your father’s lifetime work, too.
We humans already get cold when we walk through the refrigerated section of the supermarket, let alone through the snow. The wood frog always has to do that and developed a mechanism to prevent getting frozen. Normally, the ice crystals kill the cells when it gets cold. The wood frog, however, produces a chemical that crystalizes the ice outside the cells, the cells constrict and stay unharmed by the crystals. With this method the frogs can survive the coldest winters.
After that, Don Salvatore told us about the many ways bacteria and animals take advantage of plants. The E. coli. bacteria, for example, senses if a tree is hurt and sets plasmids free. These make the tree produce sugar, so the bacteria have an unlimited food supply. The caterpillar has another way of tricking plants. Its poop tells the plant that it is being attacked by a fungus. Because the plant can only defend itself against one thing at a time, it stops producing poison against insects and starts producing poison against fungus. So, the caterpillar doesn’t have to worry about being poisoned and can go on eating. Poor plants.
The last story, Don Salvatore had in store for us, was one about the fireflies called “photinus”. These little insects glow beautifully at night, and children in America love catching them, as he told us. The fireflies use their flash patterns as a mating signal. The light of the flying males is the signal for the females sitting on the ground. If a female sees a pattern she likes, she repeats it, the male gets to her, and they mate. That seems easy, but there is another player in the game. Another type of firefly called “photurus” deliberately attracts the males by flashing the same way. When the male joins it, being extremely happy finding a partner, the “photurus” kills and eats it. So, for the fireflies it’s a matter of life and death, while children are having fun running around trying to catch them.
Then Don Salvatore ended his talk hoping to have spawned our interest in what is happening in our backyards, and he succeeded. He told these amazing stories about how awesome plants and animals can be and how their unseen life unfolds right in front of our eyes. The next time you see a bug or walk past a tree, it might be worth taking a closer look.
Statements der Klasse 1BM
Ich nehme mit, dass Lebewesen, die auf den ersten Blick uninteressant erscheinen, wie zum Beispiel Bäume oder Bakterien, viel mehr können, als ich gedacht hätte. Mich hat besonders erstaunt, dass Bäume miteinander kommunizieren. Sabine Schär
Ich fand es beeindruckend, wie ausgeklügelt und komplex die Überlebensstrategien dieser Lebewesen sind. Jonas Ruszkowski
Am Interessantesten fand ich die Schneeeule, weil mich Insekten nicht so interessieren. Cem Kalkandelen
Die Sachen waren sehr gut erklärt, sehr vereinfacht und gut erklärt. Ausserdem war das Englisch gut verständlich. Lars Scheuber
Man hat durch den Vortrag erfahren, was alles in einem Garten passiert. Dass Bäume gewisse Chemikalien produzieren und abgeben, um sich vor Insekten zu schützen, wusste ich vorher nicht. Jelena Gasser
Es war interessant, so viele neue Dinge über die Tiere in der unmittelbaren Nähe zu erfahren. Am besten hat mir der Teil mit den Marienkäfern gefallen, als er uns erzählt hat, dass es mehr weibliche Marienkäfer als männliche gibt. Der Grund dafür ist ein Parasit, der die männlichen kennzeichnet und nachher zerstört. Caroline Breuer
Die Wissenschaft beschäftigt sich damit, wie und warum die Natur so funktioniert, wie sie es tut. Es war sehr spannend zu sehen, was für Strategien die Tiere nutzen, um zu überleben. Bavatharani Phaskharan