Posts Tagged ‘biology’

Twittering with Aliens

One of the staples of television and movie science fiction is the universal translator that allows humans and aliens to communicate fairly easily. But the reality is that we aren’t even currently able to automatically translate all human languages reliably. If we do someday run into an alien race, will we be able to communicate?

The difficulty of conversing with aliens isn’t limited to learning vocabulary, grammar, and body language. We humans all can (on average) produce and hear the same range of sounds. If the aliens we end up meeting use sounds or visual cues outside the human range of perception, we would be entirely dependent on computers to help us communicate.

Fortunately, scientists are currently studying the language of some of the aliens already among us. I’m not talking about extraterrestrials, but rather non-human animals like whales, elephants and birds. Parrots have been a popular focus of study, since it’s long been known by scientists and pirates alike that parrots can imitate human speech.

Three Birds on a Boardwalk

Are they talking about us?

But observing how parrots mimic human speech patterns doesn’t tell us how they normally communicate.

U.C. Berkeley ecologist Steve Beissinger and his colleagues have been studying a single population of Green-rumped Parrotlets (small parrots) in Venezuela for 26 years. In a project lead by Cornell ornithologists Jack Bradbury and Karl Berg, analysis of data collected from carefully placed video and audio recorders have allowed them to observe how wild parrotlets learn their “names” and socially interact with each other.

It turns out that young parrotlets learn their contact call – the sounds that serve as a personal identifier or “name” – from their parents. The call is modified a bit by individual chicks so that each has a “name” that is both unique and related to their parents’ own “names”.

But this isn’t a language that humans can imitate. The sounds are actually much too fast for us to follow. As Berg describes it, the fairly simple peeps we can hear are actually much more complex sounds :

“The parents can make 20 contact calls in the time it takes you to sneeze.” When slowed down for our ears, a parrotlet’s single peep sounds more like eh-ehhh-gehhhlll-grrr-whoeeeeee. [. . . ] “You can’t make sense of their vocalizations just by listening. You can’t imitate their calls like you can whistle a songbird’s tune,” Berg says. “The only way we can study them is by converting their calls to spectrograms, then running these through computer programs” that search for subtle similarities [. . . ]“

This video has the calls first in normal time, then slowed down so human ears can detect the difference between different contact calls so you can hear the difference for yourself:

Nestling Vocal Signatures from Karl Berg on Vimeo.

Berg and colleagues have suggested that their research may provide insight into human language acquisition during infancy. But it seems to me that their methodology could be used to help decipher the “talk” of non-terrestrial species as well. How could they neglect to mention that?

While their parrot communication research has taken years, I would think that it would go much faster with a species that is both more intelligent than a parrot and interested in helping us to learn to understand them.

And I’m wondering if there will come a time when we are able to use our translation devices to talk to Earthly non-humans in their own tongue, rather than “uplifting” them so that they speak in ours.

More information:

For more about the research on Venezuelan parrotlets, listen to the 22 July 2011 Science Podcast or read the podcast transcript.

There is also a video of cute parrotlet nestlings being fed by their father, who uses contact call “names” to greet them.

You can download software – Raven and XBAT – developed by the Cornell Lab of Ornithology Bioacoustics Research program for the analysis of acoustic signals.

Original articles:

Morell V. “Why Do Parrots Talk? Venezuelan Site Offers Clues.” Science 22 July 2011: 398-400. doi:10.1126/science.333.6041.398 (subscription required)

Berg KS et al. “Vertical transmission of learned signatures in a wild parrot, Proc. R. Soc. B. 13 Jul 2011 doi: 10.1098/rspb.2011.0932 (subscription required)

Top image: Three Birds on a Boardwalk by LancerE, on Flickr

Bottom image: Body parts I – What are you looking at? by Sami__, on Flickr

Forever Young

Today is my birthday, so age is a bit on my mind, and so is youth. People have been looking for centuries, at least, for the Fountain of Youth. We’ve made some advances, generally no longer old at forty and ancient at sixty, but no such magical elixir has been found.

Whole species, though, have found their own permanent youth. Some species have done it on their own, while we’ve done it to other, and maybe even to ourselves as a species, though not individually.

Neoteny (also called pedomorphism) is the retention of juvenile traits in adults. Physical traits that are usually considered to be neotenous include: large eyes, wideset eyes, less hair, flat face, small nose, small jaw, and small teeth. These tend to be the physical traits that separate us from our closest ape relatives.

They are also traits that seem to be hardwired into us as cute: babies, puppies, cartoon characters (the cat from Shrek with his cute face on), even the standard depiction of “gray aliens.” Besides the traits already listed, large floppy ears and curly tails are considered to be neotenous traits in animals.

We’ve bred these traits into our companion animals too: think about toy dogs in terms of retaining juvenile features. The physical traits may have started out as coincidence. Behavioral neotenous traits include playfulness and ability to learn, key elements determining trainability. I’m certain that both intentional and unintentional selection for cute traits has also occurred in the domestic species most closely associated with people.

Then there’s the axolotl. This rare salamander is native only to two lakes in Mexico. Salamanders are amphibians, so like frogs they have a purely aquatic gilled juvenile stage, then metamorphose into an air-breathing terrestrial adult form. The axolotl never transforms, keeping the gilled aquatic form even after sexual maturity.

Wild-type axolotl
(Photo by Stan Shebs)

Why? One hypothesis is that the lakes were safer than the surrounding land, so there was strong evolutionary pressure to stay in the aquatic form. The neoteny is now genetic, species-wide, but once in a while an axolotl spontaneously goes through metamorphosis into a fairly normal looking adult salamander. Metamorphosis can also be triggered by treating the axolotl with hormones.

There’s the science. So where’s the science fiction?

Well, the human response to these traits really does seem to be hardwired. That suggests that when and if we meet other intelligent species, our responses to them may vary depending on how close to this expression of cuteness they are. A floppy-eared large-eyed cute alien might be more successful at interacting with us than those with the opposite traits. That idea isn’t at all far-fetched: cute wild species get a lot more money and effort for conservation than ugly ones.

We’ve bred other species, and quite possibly ourselves, for neotenous traits. What might happen if we did it on purpose, with intent? Could we increase our own peak learning age range (like the childhood years when the brain best picks up languages) by doing so, and would it come with increased physical neoteny?

And axolotls are science fictional looking all by themselves, don’t you think?

Leucistic axolotl
(Photo by Only Alice)

(W)hole Hearted

In preparation for this month’s post, I’ve been reading up on the heart. The post was inspired by my friend, Francesca Forrest’s, recommendation that I read The Sublime Engine: A Biography of the HUMAN HEART by Stephen Amidon and Thomas Amidon, MD. NPR had done a piece on the book discussing the man that toured Europe with a hole in his chest that allowed folks to see his heart hard at work deep within his chest. I was intrigued. Read the rest of this entry »

No Lorax Neccessary?

I am the Lorax. I speak for the trees. I speak for the trees, for the trees have no tongues. And I’m asking you sir, at the top of my lungs – that thing! That horrible thing that I see! What’s that thing you’ve made out of my truffula tree?

Find yourself a patch of forest. Sit among the trees and if you’re quiet (and a breeze is blowing) you’ll hear whispering and moaning. Folktales and legends say it’s the trees speaking to us. As Dr. Seuss’s Lorax points out, trees can’t really speak to us directly – at least not using words.

But even if they can’t speak, trees can indeed communicate. Back in 1982 Ian Baldwin, currently director of the Max Planck Institute for Chemical Ecology, published a paper showing that young trees that were damaged as if attacked by hungry insects increased production of tannins and several other chemical compounds. Those chemicals were known to inhibit growth and foraging of insect larvae and so presumably helped defend the trees from further attack.  They also discovered that undamaged trees in the same enclosure  started producing similar compounds. Baldwin and his colleagues concluded that the damaged trees were releasing volatile compounds into the air. Those chemicals served to warn the undamaged trees of potential danger, and induced them to begin to mount their own defenses.

Since then. advanced molecular analysis and genetics have been used to study the so-called “talking tree” phenomenon in more detail. Plant leaves release a number of different chemicals, from simple small molecules like ethylene to more complex compounds like methyl jasmonate. These compounds diffuse through the air, and if they come in contact with the leaves of responsive plants, those plants respond with changes in chemical synthesis and growth.

Plant roots also secrete a number of different communicating chemicals. These compounds aren’t able to travel as far through the soil as volatile compounds can drift through the air. Instead they locally fight of insect pests and battle nearby plants for growing room. Those chemical signals are also in the process of being deciphered, and that information is already being used to genetically engineer pest-fighting crops.

While the forms of chemical plant communication we currently are aware of are essentially  non-directed shouts of “Danger!” or “Stay away!” rather than conversations, a recent public Q&A session with Ian Baldwin touched on some more speculative possibilities.

So what about fiction?

SF has a number of examples of tree-like aliens (such as Orson Scott Card’s Pequeninos or the lonely female tree beings in Jack Skillingstead’s “Rescue Mission”) and fantasy creations like Tolkien’s Ents, but I couldn’t come up with any stories with scientifically plausible talking trees.

One big problem is intelligence – or more specifically the lack of it. To truly converse an entity must be able to think, and there is nothing that suggests that trees or other plants have any means of doing that. But once that hurdle is crossed (genetically engineered nervous systems, perhaps?), I think there’s a plausible leap to be made from the current simple modes of Earthly plant communication to full-fledged chemical conversation.

I wonder what they’d say?

More technical information:

Top image: Oak trees in October. Perhaps they are discussing the cooling weather? Photo by me.

Middle image: Methyl jasmonate. According to Baldwin, “Heavier compounds with less volatility, such as terpene alcohols, methyl jasmonate (MeJA), aromatic compounds including methyl salicylate (MeSA), and green-leaf volatiles (GLVs), are more likely to function as signals over longer distances, because their comparatively slower dispersal allows development of plumes of higher concentrations that may be carried farther as intact parcels by turbulent flow.”

Bottom image: “A Criminal Lead By Three Watchmen”, an illustration from Baron Ludvig Holberg’s 1741 novel Niels Klim’s Journey Under the Ground,  involving a visit to the Planet Nazar, which is inhabited by walking and talking trees

Co-Dependency, the Natural Way

Species don’t exist in a vacuum. That is, if you go nearly anywhere on this planet, you’re not going to find just one form of life. You’re going to find several, all filling different niches and frequently interacting with each other. (I say nearly because I don’t know whether the extremophile bacteria in the Earth’s crust are one species or several. I’m betting there are a range of them in any given location, given how resilient and diverse life is.)

The most familiar relationship between species is probably that of predator and prey. There’s the lion and gazelle, the wolf and the caribou, the anteater and the ant. We’re familiar with parasitism too—one species feeding off another without killing them first. It’s as easy to cast Earth parasites as villains as it is to cast predators. Parasites are often widely known, affect humans, have historical impact, or get handy evil-sounding names. Examples of the first three categories are fleas, mosquitoes, intestinal worms, ringworm, lice, and insect-born diseases such as malaria. Examples of the last one include strangler figs, vampire bats, and the zombie ant fungi that have been in the news lately.

Stargate’s Goa’uld, Spider-man’s Venom, and the xenomorph from Alien are examples of fictional parasitic antagonists. There’s a list of other made-up parasites on Wikipedia, though it’s probably incomplete. That said, I think we could go further. I’m not sure I’ve seen a bio-apocalypse or bio-thriller with protozoa or insects as a vector, though I’ve seen them with bacteria and viruses. And we shouldn’t forget the parasites that don’t affect humans. Some insects, such as wasps, lay eggs in other animals. A number of vines choke the life out of their supporting plants. Who knows what other kinds of parasites might evolve on other planets? Or if an alien parasite could use the strangling or egg-seeding techniques on humans?

Discussion of parasites leads us into other types of symbiotic relationships. (Yes, parasitism is a form of symbiosis.) There’s mutualism, where both species benefit. There’s commensalism, where one species benefits and the other is neither helped nor harmed. There’s also amensalism, where one species inhibits or kills off another but isn’t affected itself. Penicillium mold does this with some bacteria, for instance, and some plants produce substances that kill off competing plant life.

Mutualism can involve trading resources (think of nitrogen-fixing bacteria in plants), trading a service for a resource (pollinators, remora and sharks, animals dispersing seeds), or trading services (clownfish and anemones, ants nesting in trees). Humans are in mutually beneficial relationships with the bacteria in their intestines, and with domesticated animals.

Examples of commensalism include the cattle egret, which feeds off the insects stirred up by grazing cattle; barnacles, which attach to animals and plants as well as rocks and ships; plants that use other plants for support, such as orchids or moss; and hermit crabs, which use shells as housing.

Of course, the plants, animals, fungi, protozoa, and bacteria that engage in symbiotic relationships continue to evolve. They become better parasites, or better killers of parasites, or better nitrogen producers, or better protectors of their symbiotes. They’ll change size or shape or color or biochemistry. A change in one often means a change in the other. Symbiotes may even suffer a disability if their counterpart is removed. Lichen wouldn’t even exist if you separated the fungi and algae that form it, and removing a symbiote from an ecosystem could cause a cascade of species deaths and ultimately destroy the ecosystem.

Some questions that may spark a story or two:

  • What happens if you introduce an alien (let’s say, truly alien) species that becomes a parasite or other symbiote to a native organism?
  • Could you bioengineer a lifeform to enter into a symbiotic relationship with a plant/animal that needed a boost? Could you turn parasitism into mutualism?
  • Could you alter a symbiote’s genes to give it freedom? Would there ever be a circumstance where you’d want to do that?
  • What if one intelligent species was oppressing its equally intelligent symbiote for, say, eating insects instead of plant matter or having a strange physiology?
  • Since symbiotes tend to co-evolve, pick a possible resource or service that a species could provide, the crazier the better, then create a species that would make use of it. Remember that it will likely also be providing a service or resource for the other species. (E.g., a mollusk that feeds off electricity produced by electric eels; a plant that grows on a herbivore’s head and acts as a sound amplifier; an insect that cultivates a particular plant so that its eggs can hitch a ride on the seeds)

Love and Brains

Wikipedia goes into a very long definition of love; it has a series of topics revolving around the main one.  Some of these overlap with the other kinds of love, but since this is Valentine’s Day, I am focusing on the love generally related to dating. In anthropologist Helen Fisher‘s book, Why We Love: The Nature and Chemistry of Romantic Love, she breaks love down to three overlapping stages. These are lust (I am tossing an additional link for libido in here for your reading pleasure),  attraction, and attachment. Most of my research after browsing the main topic included the chemical aspects of interpersonal love.  Based on the neuroscience studies the list of chemicals involved in love include: nerve growth factor, testosterone, estrogen, dopamine, norepinephrine, serotonin, oxytocin, and vasopressin.

The Biology of Love - Calamities of Nature by Tony Piro

The Biology of Love - Calamities of Nature by Tony Piro

If recent neuroscience research into love is any indication, the biologist above is ready to talk commitment. “Couples who have been together for several years show increased brain activity associated with (the hormones, oxytocin and vasopressin) these chemicals, when they look at pictures of their partner. Oxytocin is produced when couples have sex and touch, kiss and massage each other – the hormone makes us more trusting, helps overcome “social fear” and is important for bonding.” (Pickrell, John, Middleton, Lucy, and Anderson, Alun, “Introduction: Love.” New Scientist (Online). September 2006. 04 . Web. February 2011. 14.0)

Crazy In Love:

In the brain, romantic love shows similarities to going mildly insane or suffering from obsessive compulsive disorder. Studies show that when you first fall in love, serotonin levels plummet and the brain’s reward centres are flooded with dopamine. This gives a high similar to an addictive drug, creating powerful links in our minds between pleasure and the object of our affection, and meaning we crave the hit of our beloved again and again.

Lust is driven by sex hormones such as testosterone, which can go off-kilter too. As can levels of the stress hormone cortisol, and the amphetamine-like chemical phenylethlyamine, increasing excitement. (Pickrell, Middleton, and Anderson)

Love and Hearts:

I did not want to leave the heart out on Valentine’s Day.

“Does the heart fall in love, or the brain?”

“That’s a tricky question always,” says Ortigue [assistant professor of psychology and an adjunct assistant professor of neurology, both in The College of Arts and Sciences at Syracuse University]. “I would say the brain, but the heart is also related because the complex concept of love is formed by both bottom-up and top-down processes from the brain to the heart and vice versa. For instance, activation in some parts of the brain can generate stimulations to the heart, butterflies in the stomach. Some symptoms we sometimes feel as a manifestation of the heart may sometimes be coming from the brain.”

Love and Pain:

Researchers in the pain center at Stanford University Medical Center recruited a group of students in the first nine months of a relationship to test the pain relieving effects of love when dealing with mild pain stimulus. The students brought pictures of their significant other and an attractive acquaintance. Their brains were scanned as the pictures were alternated while a computer-controlled thermal stimulator placed in the palm of their hand was heated to cause mild pain. Word association tasks were included to test a non-romantic distraction against the pictures.

Results showed that both love and distraction did equally reduce pain, and at much higher levels than by concentrating on the photo of the attractive acquaintance, but interestingly the two methods of pain reduction used very different brain pathways.

“With the distraction test, the brain pathways leading to pain relief were mostly cognitive,” Younger said. “The reduction of pain was associated with higher, cortical parts of the brain. Love-induced analgesia is much more associated with the reward centers. It appears to involve more primitive aspects of the brain, activating deep structures that may block pain at a spinal level — similar to how opioid analgesics work.

“One of the key sites for love-induced analgesia is the nucleus accumbens, a key reward addiction center for opioids, cocaine and other drugs of abuse. The region tells the brain that you really need to keep doing this,” Younger said.

“This tells us that you don’t have to just rely on drugs for pain relief,” Aron said. “People are feeling intense rewards without the side effects of drugs.”

While I was exploring this topic for today’s post, I mentioned my quest for knowledge to my LiveJournal readers. I asked two questions. What did they know of the effects of love on the brain, and had they read any fiction that used this particular area of science for plot points? Ayoub Khote, Sophy Z. S. Adani, and Patricia Esposito get credit for sending me links and giving me an overall reminder of what chemical production is stimulated by love. Please do check out the links in this post. I am sure you will find some interesting reading material.Feel free to discuss any of the linked articles here.  Speaking of reading, none of my friends could offer fiction recommendations. I was disappointed. You can help, though. Have you read a story involving this topic? If so, please share a name or a link. A

Science Fiction: The Musical?

If you want to make the world a smarter place, it’s not always enough to create an image, post to a blog, or even write a book. Sometimes, if you really want to get inside people’s minds, you have to set your message to music. That’s right; it’s time to send in the earworms!

Disclaimer: The following playlist may or may not make the world a smarter place, but at this point, we’ll take all the help we can get…

Losing An Arm and A Leg

London Zoo - Animal Adventure - Donkeys - Danger signImagine that you are working on a home improvement project and, being a bit of a klutz, something goes horribly wrong: a slip of the saw and you’ve lost the tip of a finger. Is there any hope of regaining your lost digit?

While there young children reportedly have the ability to regrow amputated fingertips, in adults it’s possible with special medical treatments (or maybe not even that). Cut off your whole finger – or (stars forbid) an entire arm – and unless it can be reattached, it’s gone for good.

While lobsters can regenerate their claws, and many lizards can regrow their tails, humans and other mammals have notably poor limb regeneration abilities.

The notion  that such an “animal” ability could somehow be transferred to people has been a part of science fiction since its early years.  A good example of this is Romeo Poole’s 1926 short story “A Hand from the Deep”, which has a Doctor Whitby experimenting with crayfish extracts on an unsuspecting patient:

“The theory is nothing very new. As early as 1906 it was observed that when a limb is amputated at the middle of a bone, the bone starts to grow out again, but increases only about one-fiftieth of an inch in length before it is halted by some other influence. You know also, of course, about the little warts of so-called ‘proud flesh’ that apparently try to replace the original muscular tissue in case of injuries, but which are misshapen or misplaced. What Whitby was trying to get at, as I see it, was to so control these misdirected efforts of nature as to produce a new and perfect limb.
“The human body is already able to repair damaged bones by rebuilding small particles of the bony tissue; it is also able to replace muscle, nerve and even finger-nail tissue, although in somewhat imperfect forms. Whitby was trying to induce it to build a lost member in perfect form.
“It seems that Whitby has been experimenting for years with the ductless and other glands of shellfish in pursuance of this theory of regeneration, and we have upstairs the living proof that he was able to prepare a glandular extract that changes the bodily cell-structure as well as influencing the building-up processes of nature; but it appears that he near succeeded in isolating the one influence from the other, both being present in his preparation.

Of course there are terrible side effects to the treatment; quite improbably the patient starts turning into a crustacean himself.

Later science fiction tales usually assume as a matter of course that “autodocs” and other advanced medical treatment technology will make limb regeneration almost routine procedure, albeit often a slow and painful one.

California Tiger Salamander, Ambystoma californiense IIBut wouldn’t it be better for future humans to be able to do that on their own?

The only vertebrates able to regenerate entire arms and legs as adults are some species of salamanders.   After a limb is amputated, cells are mobilized to to start healing the wound.  In humans, scar tissue forms.  In newts, on the other hand, cells migrating to the wound site form a structure called the apical epidermal cap (AEC) . Cells under the AEC begin to proliferate and create a tumorlike mass called a blastema which eventually will grow into the newt’s new limb.

If humans could be given that ability,  you could create a superhero (or supervillain) or a super soldier. It’s no surprise that some research in limb regeneration is funded by the US Department of Defense.

But the exact molecular signals that direct salamanders limbs to regrow are still being sorted out.  And it’s not at all known whether similar mechanisms would function the same way in mammals (like humans) if they were somehow transplanted.

There was an interesting paper last year that suggested the removal of a single gene in mice can stimulate scarless wound healing. But despite the wildly speculative headlines, the study did not actually even try to look at whether the mutant mice could regenerate digits or limbs. Mouse limb regeneration – let alone human limb regeneration – is still firmly in the realm of science fiction.

Red on SaleAre there aspects of limb regeneration that haven’t been fully fictionally explored?  What would be the implications if all ordinary people had that kind of wound healing ability for society and medicine?

The wound healing ability in axolotls has also allowed scientists to surgically induce the formation of extra limbs.  What if humans had that ability as well?

Additional Reading and Watching

Video: Newt Limb Regeneration from the HHMI 2006 Holiday Lectures — Potent Biology: Stem Cells, Cloning, and Regeneration

Video: Superhero Science: Limb Regeneration

Gardiner David M and Bryant Susan V. Regeneration Basics. UC Irvine Limb Regeneration Lab.

Interview with Jon Mogford, Program Manager of the Defense Sciences Office at DARPA (2009) [Military projects on wound healing]

Whited Jessica L and Tabin Clifford J. “Limb Regeneration Revisited” Journal of Biology 8:5 (2009)

Bedelbaeva Khamilia et al. “Lack of p21 expression links cell cycle control and appendage regeneration in mice” Proc Natl Acad Sci 107(13): 5845–5850 (2010)
[note that the "appendage regeneration" refers to closure of a hole punched in the mouse's ear]

Illingworth, Cynthia M. Trapped fingers and amputated fingertips in children. J. Ped. Surgery 9:853-858. (1974)

Top Image: London Zoo – Adventure Animal – Donkeys – Danger Sign by ell brown on Flicker
Middle Image: California Tiger Salamander, Ambystoma californiense II by marlin harms on Flickr.
Bottom Image: “Red on Sale” by Artiii on Flickr