On the subject of communities and their resources, this Thursday the 30th Michael Pollan is speaking at the the Granada Theatre on State St. He has written multiple books about topics like the sustainability of our food supply chain. The talk is being co presented with doctors fromSansum Clinic and Cancer Foundation of Santa Barbara so it should touch on multiple topics. For people who were interested in ecological communities and resource allocation, he is well known for talking about the food supply chain and the sustainability of our food sources. The talk is at 8pm and tickets are 19$. If live talks aren't your thing, here are a couple videos of him speaking about food production, in varying times depending on what you have patience for.
With the increasing global population, feeding the world in the future is going to depend on efficient food production and distribution. This kind of food sustainability will matter more than ever if we reach the human population carrying capacity, currently unknown but estimated many times.
Left: An unbanded grackle ignores the photographer. Right: Horchata forages for trash
Pictures by Michelle Gertsvolf
A few class sessions ago, we were talking about the different relationships between different species. What caught my attention was the talk of symbiosis, or mutualism. In this +/+ relationship, both species benefit from the interaction. I began to wonder, can humans be included in this sort of relationship? While by no means neccasary to either species, the humans at the Santa Barbara Zoo do benefit a bit from the resident Great-Tailed Grackle population.
As part of my research under Dr. Corina Logan, I go to the Santa Barbara zoo every week to observe the resident Great-Tailed Grackle population. We had captured and banded eleven of these grackles over the past two quarters, and tested their intelligence with some basic tasks such as stone-dropping and object manipulation. Now after these grackles had been released, we observe them in the wild to see if the 'smarter' birds according to the tests end up with more nests and chicks (currently it's breeding season - a few of the grackles already have hatched eggs and it's adorable!)
I noticed something interesting though. The grackle's primary source of food is what they steal from human zoogoers. During lunchtime, the food court is a flurry of bird activity as grackles zoom from their nests to grab french fries and back. I wonder, is this a sort of mutualistic relationship? Humans get a cleaner zoo while grackles get food for their young. Perhaps it's not very significant, but it sure is interesting.
Last week's visit to campus point gave us a look at intertidal organisms (and a chance to get out of the classroom!) A good place to check out the tide schedule for Santa Barbara is here. Remember that the lower the tide, the more of the lower intertidal organisms will be accessible for you to view. Minus tides are especially great, though there are not so many in the spring. A superb website with lots of information about intertidal environments and species there was written by Genny Anderson at SBCC and you can see it here. John has posted a few really good articles here on our CCS Bio Blog so check those out as well!
The Following is a post taken from my own blog which I originally made for a writing class last quarter. I thought it might be of interest to some of you, so feel free to look through and also check out some of the other posts on my site.
More often than not when learning science, we are taught to ignore the context underlying major discoveries. We are told to memorize details without seeing the big picture; however, the stories behind these great advances can be extremely compelling. To me anyways, one of the most intriguing trends in the stories underlying scientific exploration is that often times the most critical advances in understanding come not from rigorous experimentation (as so many of us are misled to believe), but from insights and revelations formed via intense observation of natural processes.
The greatest scientific minds throughout history are remembered for predictions rooted in realizations that had never occurred to anyone else before them. Based only on the movements of stars in the sky, Copernicus postulated the structure of our solar system. Newton hypothesized gravity by observing falling objects and Darwin created the Theory of Evolution by collecting specimens and fossils separated in form by time and geography. In the same manner, a great German anatomist once predicted the cellular basis for the sensation of touch.
Freidrich Sigmund Merkel
In 1864, after bureaucracy put a stop to his adventurous dream to become a sailor in the German navy, a youthful Friedrich Sigmund Merkel began studying to be a physician. The son of intelligent and wealthy parents, Friedrich’s free thinking was encouraged in his pursuit of a scientific education. Early in his learning, however, he firmly assured his mother that out of all of the sciences, he would never become an anatomist; a statement completely invalidated by his lasting impact on the field he so adamantly rejected early on.
The ambitious scientist’s fascination by the invention of the microscope lead to many revelations. He published works on the iris musculature of the eye, papers about the connections of the chest muscles, and manuscripts outlining benefits of microscope use for anatomy. Then, in 1875, Merkel first observed and described “Tastzellen”, or touch cells. Merkels’ newly discovered cells would make an enormous impact on the physiology of touch, or mechanosensation, but his original term has been substituted for a new name. “Merkel Cells” forever commemorate the enormous impacts of the famous Anatomist.
In mammals, Merkel cells are dispersed throughout all of the skin. While, in the majority of the body, the cells surround the base of hair follicles; the areas that are highly sensitive to touch use Merkel cells concentrated in tiny lumps called touch domes. In both cases, these specialized skin cells form connections with sensory neurons projecting to the brain. While it is true that your skin is the largest body organ, containing over 30 billion cells, very few of them actually connect with the nervous system in any way. Most just form protective layers which will eventually be shed off of your body.
In a manner resembling other great scientific discoveries outlined above, having only the observation that his cells form synaptic connections with underlying neurons, our insightful Friedrich Merkel predicted that his tastzellen were likely responsible for the sensation of touch.
Modern science now defines several classes of mechanosensation including painful touch, heavy pressure, vibration, stretch, and more. Other cell types have been explored for roles in these sensations, and evidence has been built for the Merkel cell’s involvement in the discrimination of “light touch”. These cells likely give us the basis for discriminating between textures and finding small edges.
How can these skin-derived, or epithelial, cells send all this information to our brains? Non-neuron cells are known to play parts in the tongue for taste detection, and also in the inner ear in our ability to hear. The common feature of these signaling epithelial cells is their ability to quickly change their electrical charge, or depolarize, in the same way that our neurons do. However, unlike neurons, epithelial cells do not form complex signaling networks or project to the brain or spine. When the correct stimulus is present, these cells open channels in the surrounding membranes to allow charged ions to flood the cell. This rapid change is carried all the way to the site where the receptor cell meets a sensory neuron, at which point; the depolarization is carried along the length of the neuron towards the brain.
Now, a major question is begging to be asked. How do these receptor cells, in our case, Merkel cells, discriminate between different types of stimuli? Each receptor cell must have a specialized receptor molecule on its cell membrane, either acting as an ion channel itself or else with the ability to cause a separate ion channel to open. In many cases of sensory transduction, vision, taste, smell, these ion channels are well known. However, in most cases of touch mechanosensation, the identity of these critical players was not known. What we do know is that both isolated Merkel cells and the ones in living tissue display electrical current changes when slightly moved by a probe. This means that a molecule on the membrane of these cells must respond to mechanical force by allowing charged ions to enter the cell.
Hair Follicle and Touch Dome Merkel Cell Neurite Complexes
The Piezo family, a family of large membrane proteins, is one of the largest proposed ion channels with over 30 regions of the protein passing through the membrane (most have only 7 such regions). Over the last year, groups around the world have been investigating the role of one such Piezo protein family member, named Piezo2, as the ion channel involved in Merkel Cell touch sensation in mice.
Mice typically prefer textured ground conditions in their cages. When given a choice between a textured surface and smooth ground, mutant mice without working Piezo2 protein don’t show the same preference. By tagging one end of the protein with a fluorescent marker, they can use microscopes to observe Piezo2 expressed only at the tips of the neurons closest to the Merkel cells and in the Merkel cells themselves. Studies of electrical current changes, or electrophysiology, in Merkel cells and the sensory neurons demonstrate that the mutant mice cells do not respond to mechanical force as do the cells with working Piezo2.
The enormous body of evidence continues to build for Piezo2’s responsibility as the mechanically activated ion channel in mice. While studies in mice are not always indicative of answers for humans, our two species’ versions of the proteins are fairly similar. Future studies will determine whether or not the protein plays the same role in the human being, but if so, the identity of the channel responsible could have major impacts on the medicine of touch and pain. It is astounding to me that just now, 150 years after Friedrich Sigmund Merkel began his studies as a physiologist, we are finally beginning to understand the molecular basis for his most important prediction and the cells that bear his name.
I can imagine that bower birds are a behavioral ecologist's dream. Though these birds generally not the flashiest looking (there are 20 species), they are known for their courtship display, in the form of elaborate nests, or bowers. The following videos show different species of bowerbirds, each with its own variation of courtship.
Warning: mating does occur in these videos, please watch at your own discretion
BBC David Attenborough:
BBC Vogelkop Bowerbird:
National Geographic World's Weirdest:
I also found a National Geopgraphic article (Trivedi, 2004) that talked about how female satin bowerbirds have complex taste in mates and use different criteria to choose a mate depending on their age. More naïve bowerbirds are easily attracted by colorful displays, while older bowerbirds depend on the mating routine itself. Of course, the best males will get it all...
My lab manager recommended that I listen to this podcast, so Rachel and I listened to it while doing Chemistry homework. It's an hour long, but is honestly such an experience, with topics ranging from political unrest, conservation efforts, and breeding programs in the Galapagos. My favorite part of the whole segment is the part about the goats.
There were 250,000 invasive goats on the islands that had been introduced 500 years ago. These goats were destroying the ecosystem there, eating everything and putting the tortoises in danger. So, after much debate, Project Isabella was launched. On Isabella island, thousands of goats roamed free, and authorities decided to take a small helicopter and fill it with shooters, finding and chasing these goats until they could take them all out. With these operations, Isabella island was 90% goat-free. But the problem was that the remaining 10% were smarter, and knew to hide when they heard the helicopter. They needed a solution to this. The idea of a Judas goat was brought up. They captured a few goats, put a tracker on them, and released them back on the island. Goats are naturally herd animals, so the Judas goat would find other goats, and the gunmen now knew their location. More and more goats were being killed while the Judas goat was allowed to live on, but they encountered another problem. When the Judas goat became pregnant, it wasn't social anymore and wanted to be isolated. So, they decided to engineer the perfect Judas goat by sterilizing it, and then pumping it with hormones so it would be in heat for 180 days rather than a few weeks. This way, the goat was luring the males out into the open so they could then be shot. Within a few years with the Judas goat, the goats on Isabella island were completely eradicated.
Yesterday I was walking on the
beach and by Isla Vista I saw a very small sea lion pup (it was about the size
of a pug dog) resting on an indentation of a cliff wall.It was very cute with big eyes.It seemed calm and at times it closed its
eyes.After reading about prematurely
weaned sea lion pups last quarter and what to do about them if you see them, I
put in a call to the Santa Barbara Marine Mammal Center.It was about 6:00 pm.They never called back and the tide rose
until the sea lion pup had to go back into the water.Initially, it kept trying to avoid the water
but it had no where else to go.
This morning I still never heard back from the
Marine Mammal Center, but I left a message that the sea lion pup had left. I called the statewide distressed marine
mammal hotline (415) 289-SEAL to ask them what I should do in a situation like
this. Here’s what they said. Report the animal to the hotline. Leave the seal lion pup alone. Do not attempt to help it or take it to an
animal shelter. It is illegal to
transport a marine mammal and the fines can be up to $20,000. Sometimes
the shelter will even report people to the authorities who bring in stranded
pups to their facility! The woman
said that usually the first time people do this, they are given a warning but
they will be fined if they ever do it again.
This woman, who works at a marine mammal center, says that she never
picks up a stranded marine mammal after 6:00pm because it is getting too
dark. She also said that strandings this
year are so numerous that some facilities are full and cannot accept more
animals. She said that yesterday, the
facility that she works for picked up 20 stranded animals. She said that there is only a 50-50 chance
that a sea lion pup will survive anyway if it is admitted to a shelter. Many are dehydrated and malnourished and the
additional stress of being put in a shelter is hard on them.
I went walking on the beach today to see if I could find the sea lion pup. I walked from the lagoon to Sandpiper Golf Course (slightly past Coal Oil Point). I didn't see the sea lion pup that I saw the day before, but I did see six dead sea lion pups or yearlings on the beach. I hope that the stranded sea lion pup I found is strong enough to survive on its own.