Fun Plant Tricks with Smell

Have you ever been drawn in by a smell? The aroma of cookies fresh out of the oven, the fragrance of perfume, or the tantalizing scent of a flower? Smell can be a powerful motivator for all kinds of animals, from humans to lizards to insects. Recently, scientists here at the University of Utah unraveled the unusual secret of how one plant uses smell to its advantage.

The Plant
Meet Macrozamia lucida. This Australian wonder is a cycad, a primitive kind of plant that has been around since before the dinosaurs. If you're thinking it looks like a pine cone, you're right! Cycads, like pine trees and junipers, are gymnosperms, which means that they have seeds but not flowers. Instead, they produce cones.

Irene Terry, a biologist at the University of Utah, recently set off to explore just how Macrozamia lucida makes its way through life - particularly, how it reproduces. Like humans, individuals of this species are either male or female. To reproduce, male sexual cells (pollen) must reach and combine with female sexual cells (ovules). For a long time, people thought that the wind moved the pollen from the male cycad cones into the female cones, but in 1999, Terry discovered that small insects, called thrips, were responsible for carrying the pollen from plant to plant.

The Insects
This particular species of thrips spends its life inside the male cycad cones, laying eggs and munching on Macrozamia lucida pollen. The female cones, with no pollen in them to eat, aren't appealing to the thrips. But the plant needs the insects to move some pollen into the female cones so that it can reproduce. How does the plant get the thrips to do that?


The Trick
The answer, it turns out, has to do with the power of smell. The plants let off a special chemical that, in small doses, smells wonderful to the thrips and attracts them. In high doses, though, the chemical is toxic to the thrips and repels them. So, to make sure the insects don't just spend all their time eating pollen in the male cones, every afternoon the male plants burn some of their stored sugars to create energy and heat themselves up. The extra-hot male plants release a high dose of the chemical, driving the thrips away. Many of them fly towards the females, which have an attractively low dose of the chemicals even as the males are too strong. Later, the male plants cool off, and the thrips return to their tasty homes. The whole cycle starts again the next day "until the males wear out and the females are happily pollinated," Terry says.

Have you ever been manipulated by smell? What smells attract you? What smells would you avoid?

The Great Tarantula Rescue

There's some creepy crawly stuff going on at the Museum these days! UMNH insect scientist (or entomologist) Christy Bills delivers this report from the field:

"Knowing there are tarantulas on the site where the new Utah Museum of Natural History facility will be built [starting next year], I thought it would be exciting and important to try to locate and rescue those tarantulas that would otherwise be displaced.

Using a local independent researcher, Zach Valois, I learned how to identify and lure tarantulas out of burrows. There are many burrows at that site because it's often a very hot, dry place so rodents, snakes and invertebrates hide underground to stay cool and keep from drying out.

It's interesting to try to identify what might be living in different burrows. This is especially challenging because some creatures will utilize burrows that were made and abandoned by other animals. However, some burrows are characteristic of the animal that lives in it. Tarantula burrow openings are usually the diameter of a silver-dollar and are tidy and lined with silk.

There are many black widows at the site and their burrows are strewn with a messy and coarse webbing. Black widows are also untidy housekeepers and their burrows are usually littered with insect bits.

In the course of looking for tarantulas, I discovered that the invertebrate night life on that particular hill is ever-changing and always exciting. When I encounter large invertebrates, I often take them home to keep alive. I've found 7 Jerusalem crickets and dozens and dozens of wolf spiders. I've only brought a couple of those home though! Their bites are fairly venomous.

I've only located three tarantulas on the site: 2 roaming males and one female in a burrow. The female has mated with at least one of the males. I missed whether she mated with the second because while I was distracted, she ate him. No telling if mating occured beforehand! I'm looking forward to the spiderlings in the spring!

The female wolf spiders that I have have also been mated and their egg sacs could be formed any day now. The interesting thing about that is that the mother spider will carry the babies on her back for awhile.

The Jerusalem crickets are doing well on a diet of dog food and oatmeal. When I learn to differentiate the genders, I will attempt mating a pair. They are such peculair insects that I'm excited to show them to people. Most people have never seen them even though they are fairly common, probably because they are solitary, nocturnal and they like to live underground.

I'm hoping to keep many invertebrates from the site alive so they can be displayed in the upcoming insect zoo the Museum will be opening next summer! Hooray for bugs from Utah!"

What creepy crawlers have you seen in Utah?

The West On Fire

Have you heard about the wildfires blazing in southern California? A record 500,000 people have evacuated their homes in the San Diego area, and President Bush has declared the situation a major disaster.

So far, the area these fire have burned is about 12% greater than the record-breaking Milford Flat Fire, which made news as it blazed across south-central Utah this summer. While that fire closed large stretches of I-15 and burned several buildings, it didn't even come close to doing as much damage as the San Diego fires have caused so far. What's the difference?

There are two main ways in which the California fires are different from even the biggest fires in Utah: people and wind.

People
Imagine what the Milford Flat fire might have been like if the whole population of Utah lived in that area! When fires travel into human-occupied areas they can cause big problems as they destroy property, force evacuations, and sometimes take lives. The more people around, the more problems. San Diego County, where the majority of the California fires are clustered right now, has a population of almost 3 million people. By contrast, the entire state of Utah has a population of about 2.5 million. The dense population in the San Diego area is part of why the fires are causing so much disruption.

Wind

Utah may have its share of blustery days, but they're nothing compared to the Santa Ana winds racing across southern California. According to a UCLA meteorologist, "Santa Ana winds are dry and warm (often hot) winds in the Southern California area that blow in from the desert." These winds develop from September through March, and usually flow fast and furious for a few days at a time. They help fires start by drying out the surrounding vegetation, and once a fire is going, they can fan the flames and help it spread.

Studying the Science
Each major wildfire is unique, of course, and individual fires can be hard to predict. Researchers all over, including some here at the University of Utah, are trying to find ways both to model what happens once fires start burning, and to anticipate when they're likely to start. In the meantime, we'll keep facing this force of nature as it comes.

Should people be allowed to live in areas prone to wildfires? What experiences with fire have you had? Click "comments" below and let us know!

Figuring out Fall Foliage

If you happen to go outside this month, you might notice that the trees around town are doing something predictable, yet strange: they're changing colors! Leaves fade from brilliant green to red, orange, and yellow, then droop to brown as they litter the ground. This happens ever year, but why? Where do the colors come from?

As winter approaches, the nights get longer. That signals trees to start shedding their leaves, which (unlike the twigs, branches, and trunks) aren't adapted to withstand the cold of winter. To make that happen, the tree gradually cuts off the supply of fluids to the leaves. Without a constant supply of sugars and sap, the chemicals in the plant start to change.

First, chlorophyll decays. Chlorophyll is a chemical that absorbs sunlight and turns it into energy through a process called photosynthesis; it's also what gives leaves their green color. During the spring and summer months, the plant produces lots of chlorophyll, but in the fall production slows down and what's there starts to fade.

As the amount of chlorophyll in a leaf decreases, other colors that were hidden in the leaf all along start to show up. These are the yellow and gold hues, and they're caused by a set of chemicals called carotenoids. At the same time, another set of chemicals, anthocyanins, turn the leaves red and crimson as they're produced in the leaves.

Eventually, the leaves, cut off from the fluids in the rest of the tree, dry up and fall off. They'll provide food and insulation for the tree as they decompose around it. The tree is now ready for winter!

"Knocking-out" Mice Genes: The Nobel Prize come to Utah

Have you heard of the Nobel Prize? It's one of the greatest honors a scientist can receive - an international prize awarded each year in five subjects, recognizing world-class achievements. This week, the selection committees are announcing the prizes for 2007, and a scientist from Utah has won!

Mario R. Capecchi is a professor of Biology and Human Genetics here at the University of Utah. He won a share of this year's Nobel Prize in Physiology or Medicine for work he did manipulating the genes of mice. Back in the late 1980s, Capecchi and his colleagues created a technique for inactivating or "knocking-out" individual mice genes. That means that they could "turn off" a particular gene and see what happened. (For a more detailed description of the technique, visit the Genetic Science Learning Center's page on the subject).

So what's special about Capecchi's work? The technique he helped develop is useful because it helps scientists understand the role of individual genes. By knocking them out one at a time, scientists can study their effects on all aspects of life, including growth, aging, and disease. According to the Nobel Foundation, the technique "has already produced more than five hundred different mouse models of human disorders, including...diabetes and cancer." The hope is that all this information will lead to new and better cures and prevention. "It's applicable to all diseases, because all of them have a genetic component,"added Capecchi in an interview this week.

Want to learn more about genes? Visit the Genetic Science Learning Center for online lessons about all things gene-related.

Solving The Mystery of Gryposaurus

Terry Gates - better known as Bucky - is a paleontologist here at the Utah Museum of Natural History. Today, there's hot news about a dinosaur he named. Here's what he had to say about the whole experience:


"I study the duck-billed dinosaurs that lived in southern Utah around 75 million years ago (during the Late Cretaceous period). For decades, paleontologists knew that there were duck-billed dinosaurs hidden in the sediments of what is now Grand Staircase-Escalante National Monument, but their identity remained buried. That is, until a volunteer from the Raymond M. Alf Museum in California found a skull within the Kaiparowits Formation of the Monument.

The Alf Museum needed help collecting the large skull from the steep and rugged landscape, so in August 2004 UMNH preparation lab manager Eric Lund and I helped the Alf Museum bring it to UMNH. Everyday I visited Eric as he cleaned the fossil in our preparation lab, trying to decipher any information possible from the bones that he had exposed. (Check out Eric’s blog entry for a description of that process).

It wasn’t until we got our hands on a piece of bone that had eroded from the skull that I was able to tell what kind of duck-billed dinosaur this was. Every known species on Earth has a genus and species name; for instance, the genus name for humans is Homo and the species name is sapien. In the same way, all dinosaurs have a genus and species name, and members of the same genus have characteristics in common. The portion of the skull that I found inside a box of eroded bone was exactly the piece of evidence I needed to quickly identify this specimen’s genus. The species of the genus Gryposaurus share several characteristics that are only present on those animals, most noticeably a prominent hump on the nose bone – and that’s what I found.

Now that I knew the genus, I had to figure out the species name. That was more difficult and I had to wait until preparation of the skull was nearly complete before I could proceed with detailed study. Once Eric completely exposed the skull (after two years) I was finally able to meticulously compare the shape of bones on this skull to that of other known species of duck-bills. I traveled to museums all over the U.S. and Canada (including Bozeman, MT, New York, NY, Drumheller, Alberta, Canada, Toronto, Ontario, Canada, and Ottawa, Ontario, Canada), in order to see a broad spectrum of dinosaurs that might help me identify our mystery species.

In the end, I found that there are several differences in the skull found in southern Utah compared to other species of the genus Gryposaurus. Because of these key differences, I named a new species, Gryposaurus monumentensis, meaning “Hooked nose lizard from the monument”.

The process of naming a new species is not easy. First I had to do weeks of research, then spend weeks writing a description of the new species for other scientists. Finally, I submitted the research paper to a scientific journal for publication. More time passed for editing, revisions from other paleontologists, and final editing from the journal. When you count all those phases, it took literally months to name a new species, which explains why it has taken three years since the excavation of the skull for the name to become official. Yet, in the end, all of the work is worth the effort because each new species opens the door a little wider on the ecology and lives of prehistoric animals, and allows us to ask deeper and deeper questions about an ancient world."

Have a question for Bucky about his work? Click "Comments" below and ask him yourself!

Meeting the “Duck” of the Grand Staircase

Eric Lund is the Paleontology Lab Manager here at the Utah Museum of Natural History. Today, there's hot news about a dinosaur he helped uncover. Here's what he remembers about the process:

"The hadrosaur skull was discovered in 2004, in Grand Staircase-Escalante National Monument, by a group from the Raymond M. Alf Museum of Paleontology in California. When I saw the skull in the field there wasn’t much to see, my first impressions were dulled by the lackluster plaster jacket that covered much of the exposed bones. However, we were dealing with a dinosaur skull, so no matter how much of it was there, it was pretty freakin’ awesome!

The day of the helicopter lift there was an air of excitement beaming from every person who was present. For me, there was some apprehension behind my excitement; a myriad of ‘What If’ questions ran through my head: What if the Helicopter can’t lift the block? What if the jacket isn’t strong enough? What if the helicopter pilot drops the specimen too early? All my uncertainties soon faded to jubilation as the helicopter crested the horizon with the skull safely nestled in the dangling cargo net below. I watched with amazement as the helicopter pilot expertly placed the specimen back on the ground. I think everyone exhaled a collective sigh of relief to see the job done. The skull then made the five hour journey up to the Utah Museum of Natural History, where I would get to spend the next two years preparing it for display.

Cutting open the plaster jacket back in the lab, I soon realized just how much work I had ahead of me; there was a lot of rock surrounding the bone. I cautiously began by removing the loose debris from the surface, and to my amazement much of the surrounding matrix practically fell off the bone. I quickly progressed removing much of the bulk that surrounded the bone. That was until I discovered the deeper matrix pockets were harder than cement, forcing me to use the mini-jack to break through the matrix. As the name of the tool implies it is a hand held jackhammer, and with a little elbow grease chunks through the matrix quite easily. I took things in stride and tediously removed the matrix chip by chip until the skull reached its present state. After spending two years preparing the skull, it makes me very proud to see it on display in the Museum for all to see."

To read more about naming this new species of dinosaur, check out what paleontologist Bucky Gates has to say about it!

Got questions for Eric about preparing the skull or working in a dinosaur lab? Click "Comments" and ask him yourself!