In this study, we continuously monitored Egyptian fruit bats for months, recording audio and video around-the-clock. We analyzed almost 15,000 vocalizations, which accompanied the everyday interactions of the bats, and were all directed toward specific individuals, rather than broadcast. We found that bat vocalizations carry ample information about the identity of the emitter, the context of the call, the behavioral response to the call, and even the call’s addressee. Our results underline the importance of studying the mundane, pairwise, directed, vocal interactions of animals.

This is brilliant. They were able to correlate their data analysis of the bats’ vocalizations with the behavior and responses that they observed… so now we know more about how bats communicate! Simply by listening to the vocalization, the context, addressee, and even “the outcome of the interaction can be predicted above chance level”. Fascinating.

From the discussion:

It is important to note that we used one set of acoustic features for classification. However, many other multi-dimensional spectro-temporal representations can be tested. The bat’s brain could thus be using some other representation that encapsulates much more information regarding different social aspects. The bat may be able to classify the context of an interaction with higher confidence, based on some acoustic feature which it evolved to use and is yet to be determined. Our analysis is thus probably only a lower bound on what a bat is capable of extracting from aggressive social vocalizations. For example, we did not include any temporal information in our analysis.

In any acoustic signal, and especially where communication is involved, the time parameter is usually crucial and will add rich layers of information. For example, just imagine taking a piece of human speech, and (a) only looking at the overal speech parameters, versus (b) observing how the speech parameters change during the speech. Case (b) will provide far more information than case (a). I think we will discover over time that bats have a pretty well-evolved communication scheme.

This is fascinating stuff.

∞

I’ve written about the naked mole rat before, about how it seems to be immune to acid.

Well, it turns out it has more tricks up its genetic sleeve.

To compare how the naked mole rat made their proteins, they inserted an engineered gene in the naked mole rat as well as in mice, which allowed them to compare the rate of errors in making proteins. And here’s what they found:

[The naked mole rat] built the engineered protein far more accurately, in other words. Naked mole rats, the scientists found, made anywhere from four to ten times fewer mistakes. Yet the naked mole rats can make their proteins as quickly as the sloppier mice.

This seems to be a fascinating creature the more we study it!

I wonder, though, why other species did not pick up this brilliant piece of evolution. Are there side effects to this that are detrimental, overall, to other species but which don’t affect the naked mole rat? As I said in my earlier post, intriguing.

(Original source, quoted by National Geographic: Jorge Azpurua et al.“Naked mole-rat has increased translational fidelity compared with the mouse, as well as a unique 28S ribosomal RNA cleavage.” PNAS 2013

I wrote a small piece on fair use of our biotechnology on my Tumblr, but since I’m planning to write longer pieces on this blog, I wanted to cross-post it here as well.

Joe Hanson, of It’s Okay To Be Smart, wrote:

Can Biotechnology and Genetic Engineering Save an American Icon?

What I find so interesting is that the techniques being used to save this tree, and one day reintroduce it to the wild, are not that different from those that are used to create genetically modified crops. How does saving a dying species by inserting a gene differ from creating an herbicide-resistant soybean, or rice that produces extra vitamins? I have my opinions, but I want to know: What do you think?

My thoughts are below.

The two are different in only the following way—in one case, we’re using our technology to help another being survive better; in another case we’re using technology to extract more from a being we intend to use as a ‘resource’, in this case food.

I think they’re both fine uses of our technology.

As humans, we have always wanted to modify our surroundings to suit us better. That’s who we are; that’s what defines us as a species and helps us move unflinchingly deeper into the unknown.

It was the same when we invented agriculture; it was the same when we domesticated animals; it was the same when we forced natural selection to go in a certain direction to create “man’s best friend”.

The only difference today is that instead of indirect approaches, we’re learning to make pin-point, particular modifications exactly as we require.

Yes, this is a sensitive topic, and rightfully so. With great power does come great responsibility, and we’re only now learning to harness the power of genetic engineering. I feel we should find it easy to stay on the straight and narrow as long as we remember one rule—no interference for the fun of it. I’ll explain more.

Only organisms capable of photosynthesis are able to produce their own energy. Every other living being must depend on other living beings for energy and sustenance, and we are no different. As long as our genetic engineering endeavours are focussed towards areas that we must harvest for our nutrition, we should be okay. Genetically modified crops are okay—as long as we understand the effects of what we are doing. Edit*: There is a lot of ambivalence towards genetically modified food crops, but the problem isn’t the technology itself, but that we don’t yet understand* the technology well enough to implement it perfectly. Let’s keep at it; we’ll get there.

In addition, being the sole species on this planet with advanced technology, we owe it to our planet-mates to share. Just as in this example of chestnut trees dying from a fungus, when we see an organism dying from infection, and we realize we can help—by all means, we should! We already try to help species that we are afraid will become extinct (often, unfortunately, to our own greedy exploits)–why should that help not include our latest and greatest knowledge?

Let’s just not play with our planet-mates simply because we can. That would be abuse of power, no?

Species that reproduce sexually usually need two partners to reproduce, right? Right. What I didn’t know was, females of some species (that usually reproduce sexually) have apparently been observed to be able to reproduce without a mate—rarely, and when they’re in captivity and away from potential mates.

But now, virgin births have been observed in snakes–in the wild, with males present nearby!

They captured pregnant copperhead and cottonmouth female pit-vipers from the field, where males were present.

The snakes gave birth, allowing the scientists to study the physical and genetic characteristics of the litters. […]

“That’s between 2.5 and 5% of litters produced in these populations may be resulting from parthenogenesis.

“That’s quite remarkable for something that has been considered an evolutionary novelty,” he said.

No insights yet on how and why this happens, though, or what implications it may have.

But this is fascinating, nonetheless.

Found this article recently, where they wanted to check how microscopic worms would do in space. Turns out, they do fine—in fact, they actually live longer in space! Additionally:

“We identified seven genes, which were down-regulated in space and whose inactivation extended lifespan under laboratory conditions,” Szewczyk said in a press release. This basically means that seven C. elegans genes usually associated with muscle aging were suppressed when the worms were exposed to a microgravity environment. Also, it appears spaceflight suppresses the accumulation of toxic proteins that normally gets stored inside aging muscle.

They’re not sure what the biological mechanisms might be behind this phenomenon.

I wonder, though—how much of it can be simple chemistry and fluid dynamics? We know that at small enough length scales (such as those of microscopic organisms) viscosity is a much stronger agent than inertia (governed by mass, and to an extent, gravity). Often, gravitational effects are ignored when doing small scale analyses. How do things change in the actual biology when gravity is really zero, not just as an approximation?

Also from the article:

“Most of us know that muscle tends to shrink in space. These latest results suggest that this is almost certainly an adaptive response rather than a pathological one. Counter-intuitively, muscle in space may age better than on Earth. It may also be that spaceflight slows the process of aging.”

I’m not sure why this seems novel. My thought has always been that muscle atrophy in space is due to lack of use, i.e. adaptation. This is why astronauts take special care to exercise their leg muscles while at the International Space Station. The legs no longer need to support the considerable weight of the human body, and the body efficiently starts optimizing its resources!

But perhaps (and most likely) my lack of knowledge allows me to simplify a phenomenon that a physiologist would find many angles to! I’d love to know those angles though—anyone reading this who can help?