"They're having to travel farther to find the food," Boersma said. "The food's just not here. And part of that is climate change. It changes the distribution of prey and it changes then where the penguins have to go to find it. ... It's not as good fishing as it used to be because, of course, we're Hoover-vacuuming the oceans for food for us.
"We're fishing down the food chain and so you're seeing more and more anchovies, sardines for sale. We're eating penguin food, more and more. ... Because the big fish are gone from the oceans. We've already eaten those."
What do population declines among these adorable birdies tell us about our environment?
A sea slug shows off its newly-acquired stingers using bright colors
Solar-powered sea slug (pnas.org)
Consider the plight of Cnidarians (sea anemones, coral, jelly fish), a phylum of aquatic invertebrates with a unique, ingenious weapon: stinging venomous cells. Cnidarians can release stinging harpoons that imbed themselves in an assailant (or prey) and release harmful chemicals that cause paralysis. However, some Cnidarian predators have devised a clever method of retaliating against this defense mechanism. When these cells are ingested, animals like the sea slug (pictured above) recycle these stinging cells for their own use. They even use them against other Cnidarian prey. Recently, scientists discovered that sea slugs are “stealing” other features too, with the discovery of the first photosynthetic animal. This clever sea slug (above) incorporates photosynthetic genes from algal prey into its own system, allowing it to produce chloroplasts and harness the light energy of the sun.
And we think organisms can't have it all... how can nature be so unfair?
Greenwood, P.G. Acquisition and use of nematocysts by cnidarian predators. (2009). Toxicon. Rumpho, M.E. et al. Solar-Powered sea slugs. Mollusc/Algal chloroplast symbiosis. (2000). Plant Physiology.
Bacterial biofilm in a hot spring in Northern Nevada
For a long time, microbiologists thought that bacteria cells acted as individual entities and did not communicate with one another. We now understand that nearly all cells communicate- whether its the stomach cells within our own body or the mass of cells within the hot spring biofilm above.
Biofilms are dense aggregates of billions of cells that stick together to form a mass that we can actually see with our own eyes. One of the most interesting features of biofilms is that they are generally composed of a variety of different kinds of bacteria, working together as a community. In much the way our communities differentiate labor to benefit the whole (garbage collection, food production and trasnport, etc.), these aggregates of bacteria form fluid channels for transport of waste and nutrients and rely on communication to perform these tasks.
Instead of using verbal communication, bacteria cells talk to each other using signaling molecules that are released into the environment. Different bactieral species use different signaling molecules to communicate. Within biofilms, interspecies (between two different species) communication can be very important. Communication allows indivudal bacteria cells to regulate gene expression by sensing cell density, the presence of "intruders" and the availability of nutrients.
Magnetotactic bacteria are oddities with organelles that contain magnetic minerals that allow them to orient themselves along the magnetic field of the earth.
Here at University of Nevada Las Vegas, Dr. Bazylinski is working to learn more about how... and why... these bugs precipitate magnetic material. Scientists believe this magnetic capability helps orient bacteria towards a region called the oxic-anoxic transition zone (a region within water between an area of high and low oxygen concentration). This is believed to be an optimal place for them to find food. But what?!?! Of all the things that microbes can do, I think this is one of the strangest (and coolest).
Watching magnetotactic bacteria gravitate towards a magnet through a microscope is one of the most amazing things... here is a video from Chris of Dr. Bazylinski's lab that shows cells gravitating, in culture, towards/away from a magnet. And is there anything cuter than a miniature magnet?
This gorgeous lichen found a nice home just a few feet from an 80 degree C (175 degrees F) hot spring. Lichen is yet another example of cooperation – because fungi can’t photosynthesize, which is a neat trick in a sunny place, they partner with cyanobacteria (a bacteria that can produce energy via photosynthesis) or algae. In turn, algae or cyanobacteria get wrapped up in fungal threads, providing protection that allows them to grow in some extreme (deserts, bare rock) environments. A big fungus blanket.... cozy!
Rattler snacking on a deer mouse in Eastern Washington.... she rattled the whole time, and it took about 20 minutes for her to fit that fat little mouse into her mouth. WOW.
Cooperation is EVERYWHERE (see below for cooperation between aphids and ants). Scientists think cooperation occurs for two different reasons: (1) Reciprocity: I give you something you need, and you give me something I need (i.e. aphids need protection from predators, ants need carbon-rich honeydew). (2) Kin selection: we’re closely related, so I’ll help you out even though it might hurt me (i.e. ant colonies are dubbed “the super organism” by E.O. Wilson because an ant colony functions as a cooperative unit).
Wenying Shou at the Fred Hutchison Cancer Research center is also interested in cooperation– cooperative systems are difficult to study, so Shou created her own using yeast cells. Unlike some cooperative systems, Shou’s system is obligatory– meaning, the cells have to cooperate or they will die. In her system, each cell (pictured above) is unable to generate a compound necessary for its survival (let’s call these compounds yellow and red) while each cell also over-produces the compound that its neighbor cell needs– in other words, the yellow cell over-produces yellow but cannot produce red. These cells cannot survive alone, they must be close enough to each other to exchange these essential nutrients.
In order to cooperate, each cell pays a cost- it takes energy to over-produce the compound that the other cell requires. This is analogous to each citizen’s “obligatory” participation in the government– we pay taxes, and (ideally) enjoy the common resources these taxes provide (i.e. parks, schools, police).
Not everyone wants to cooperate, however. When a cell, or person, continues to take the common resource but stops contributing to the system (halts excess compound production or evades taxes) we call them “cheaters”. And cooperation begets cheaters. That’s why we’ve developed the IRS, an entire division of the government that stops cheaters via “policing”. Now Shou’s lab asks– what “policing” methods do cells use to combat cheating?
Cancer cells are ultimate cheaters. Imagine the lung cells in your body as cooperators– working together to deliver oxygen to your body. Cancerous cells (cells that have a mutation causing continued, uncontrollable replication) arise in our body every day but our body has “policing” mechanisms to destroy these mutant cells. By studying cooperation and cheaters, we can learn more about how our body polices cheater cells and why these policing strategies sometimes fail.
Shou WY, Ram S, Villar JMG (2007): Synthetic cooperation in engineered yeast populations. PNAS 104: 1877-1882.
