This week's Radiolab podcast episode- check it out!
In our new hour of Radiolab, Jad and Robert wrestle with a disturbing question: does natural selection favor selfishness? Or can it pay to be nice? We look at the cold calculations of kin selection, talk to heroes who risked their lives for strangers, and look to game theory--where doing good is sometimes a good strategy.
The first story about George Price is heartbreaking, but raises fascinating, questions like- can we quantify and predict altruistic behavior? Can we piece apart its evolutionary origins?
And from a non-science view - how does this make you feel about our human nature?
Also, make sure to check out last month's posting about charitable microbes.
This lil' puff ball (IDed as a Northern Saw-Whet Owl) was found hiding out in the Medicinal Garden on campus at the University of Washington. A quick wikipedia search reveals that this cutie is named after the repeated whistle noise it makes, which they use to find a mate. This guy looked like he was napping when I checked him out in the evening.
Now I'm torn... is this sleepy little owl cuter than our Honduran white bat friends? It's mammal vs. bird now.
Thanks, nature.... for keeping it cute on a Friday.
Remember how, as a kid, you were always so willing to share your newly acquired ice cream with others? Just because you were such a giving child? (Or, more likely, your parents forced you to). That’s the fascinating thing about organisms- why do we share? Perhaps it’s because we’re all stewards of the golden rule. But it seems that the more science looks into it, the more we discover that all organisms – even microbes- are extremely cooperative. Charitable, even.
Antibiotic resistance in hospitals (and elsewhere!) is now a widespread epidemic. For decades, scientists have been trying to figure out how microbes become resistant to antibiotics so quickly.
We have always assumed that most of the cells that survive an antibiotic attack are resistant. However, new research has shown that in many bacterial populations, a few cells are highly resistant to antibiotics but most have a minimal tolerance to the drugs. So how are these weaker cells able to withstand high doses of antibiotics?
Turns out, those cells with high drug resistance are also extremely charitable… always willing to share their ice cream. They produce massive amounts of helper proteins that protect weaker cells in the population. These helper proteins act like steroids, beefing up the weaker cells to help them survive attacks from the drugs we are pumping into our systems.
This strategy also offers another advantage- when the antibiotic goes away, most of the population is already prepared to carry on without the heavy burden of still being antibiotic resistant, which can be a huge cost for organisms.
But why is this strategy advantageous for the charitable cell? Why is helping others such a good strategy?
In honor of Halloween, how about some Hannibal-themed science?
A common theme in biology… males have to work hard to impress the ladies.
But what if mate choice involved tastiness? This might be the case in sagebrush crickets. During copulation, females snack on the wing flesh of their mate, enjoying the benefits of extra nutrients while the male benefits from spreading his genes (A win-win-win?).
Which reminds me to pitch a great book…. Dr. Tatiana’s Sex Advice to All Creation, a Savage Love for some of the most fascinating (and freaky) sex in the natural world.
Johnson, Ivy and Sakaluk. (1999). Behavioral Ecology.
A new species of fish discovered by one of our own, Husky Ted Pietsch, professor of aquatic and fishery sciences. H. psychadelica was discovered in a harbor in Indonesia. Pretty sure this will be the new disturbing image for the "this is your brain on drugs... any questions?" campaign.
Scientists have discovered that bacterial cells may have their own version of a viral “memory”. In complex multicellular organisms (like us), our immune system uses specialized memory cells that can help detect dangerous invaders (like viruses) once our bodies have come into contact with them – these memory cells are what vaccines aim to create in our bodies without making us sick.
Bacterial cells can also fall victim to viruses, which we call phage. Phage look like an alien space craft and their behavior is very alien-like… they attach to the bacterial cell wall, “impregnate” the bacterial cell with their genetic information (Aliens with Sigourney Weaver anyone?), and force the cell to make more of the virus – creepy!
Now we know of an ingenious method bacterial cells use to fight back.
For some time, scientists have known about small repeating chunks of DNA within bacterial chromosomes that seem to help prevent the infection of phage, which they've dubbed "CRISPR" (clustered regularly interspaced short palindromic repeats). But how do they prevent phage infection? Turns out, when viruses "impregnate" bacterial cells with their genetic information, some types of bacteria have incorporated chunks of these viral genes into their own genomes. When that same virus attempts to infect the bacterial cell again, these "memory genes" recognize the viral genetic information as BAD and send out little proteins that act like scissors, cutting up the foreign DNA, in much the same way that our own immune systems tackle viruses once we've been vaccinated.
Could this be a snapshot into the past of the evolution of our very own immune systems?
Vale, P.F., Little, T.J. (2010). Review. Bacteria-phage coevolution.
"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.
Patel, Iverson, Bregman, Schulz (2009) - Current Biology
Although youtube may claim otherwise (this study was actually inspired by a youtube video), scientists had not documented dancing in non-human species.... until now. In a recent study, the sulphur-breasted cockatoo (named Snowball, pictured above) was shown to "spontaneously adjust (to) the tempo of its rhythmic movements to stay synchronized with the beat ". The beat of The Backstreet Boys.
Which confirms what I've suspected all along- birds have poor taste in music.
Percentage of Women Doctoral Scientists and Engineers in
Academic Institutions by Field and Rank in 2003
All Science and Engineering
Biology and Life Sciences
Physical Sciences
Engineering
Math and Statistics
Computer Science
Assistant Professor
41
38.4
24.5
16
29.2
23.3
Associate Professor
31.1
29.4
19.2
11.9
15.9
19.9
Full Professor
17.6
19
6.8
3.8
9.2
12.3
Total
29.8
32.1
14.8
10.3
17.1
18.3
Source: Commission on Professionals in Science and Technology, 2007.
Note: The percentages in the “total” category include instructors and lecturers.
Although the numbers of women receiving degrees in Engineering, Science and Math have increased substantially, the number of women science professors is still low.
Just four years ago, Harvard University president Summers tried to argue why this might be... (1) Women with children can't work 80 hours a week (2) fewer girls than boys have top scores in math and science in high school- and these discrepancies are probably genetic and (3) discrimination within the hiring process cannot possibly play a role because schools that did not discriminate would be able to hire top women within the science field, and we have not witnessed this trend
How do we fix this? A good start might be to re-educate individuals like Summers: (1) Women who desire a family don't typically have the same options as men to work 80 hours a week (biological differences like pregnancy and breast feeding are just the beginning) (2) there is no genetic basis for lower math and science test scores in girls, but changes in early education can help alleviate these discrepancies and (3) discrimination exists within academia, making it more difficult for women (and all minorities) to secure higher level positions.
A bizarre mutualism that you have to squint to observe - aphids are tiny insects that suck phloem (sugars that plants use for food) from a plant like sucking water from a coconut with a straw. They can be devastating to crops and gardens because they are such skillful phloem-stealers. Because of their constant sugar intake, aphid poop is carbon-rich and forms as a translucent bubble clinging to their rear (called honeydew). Aphid poop is so attractive to foraging ants that many species have gone the "extra mile" to secure this resource for their own colony.
Out at the Pot Holes in Eastern Washington, Formica sp. ants are especially adapt at aphid tending. Formica have an incredible defensive adaptation- spraying Formic acid at their enemies! They flip onto their back, lift their little butts and take aim at any threat. Formica nit-pick over their aphids like an overprotective mother- cleaning them with their antennae (research has shown this prevents fungal infections), defending them from predators (we tried poking at a cluster of aphids- and were sprayed with gas and bitten!) and, of course, transporting bubbles of honeydew back to the colony. Amazing!
