Please, accompany me back to that most uncomfortable of times – high school. Specifically high school biology class, sans the ubiquitous frog dissection. Lesson: Evolution. I apologize to those from backwards school districts that have tried to strike evolution from the curriculum (Kansas circa 1999, I mean YOU) for you will not have an accurate reference for our flashback moment.
A long, long time ago,
I can still remember…
(Stolen from the opening lines of Don McLean’s 1971 hit American Pie)
*atmosphere shimmer* *harp music*
Now then, here we have the two competing evolutionary theories of the early to mid 1800s. Charles Darwin’s theory of natural selection, which eventually became the underpinning of On the Origin of Species, and Jean-Baptiste Lamarck’s theory of transmutation or the heritability of acquired characteristics.
Examples of Darwin’s theory of natural selection include the Peppered moths of pre versus post-industrial England, or more commonly the Galapagos finches.
Lamarck’s theory on the heritability of acquired traits is most commonly illustrated with a figure depicting giraffes stretching to reach high leaves. This prolonged and persistent stretching supposedly strengthens and lengthens the neck, thus the offspring of these giraffes will be born with longer necks. Over time the result would be the impressively lengthy necks we see today.
illustration by The Scientifican
This is approximately the stage at which your most venerable and august science teacher pointed out that while Lamarck’s theory may seem unquestionable absurd in modern times, it simply serves to illustrate just how far the sciences progressed in the last 150 years.
Well, most venerable and august science teacher. Pie on your face! Lamarck was not that far off the mark. What, you say? You thought this was a legitimate science blog publishing interesting, yet accurate, snippets and factoids? Well it is. You doubted me? I’m hurt.
Anyway, now I will tell you just what in the hoo-hah I am talking about. Relatively recent discoveries in the field of epigenetics
From Wikipedia: epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence – hence the name epi- (Greek: επί- over, above, outer) -genetics. It refers to functionally relevant modifications to the genome that do not involve a change in the nucleotide sequence. Examples of such changes are DNA methylation and histone modification, both of which serve to regulate gene expression without altering the underlying DNA sequence.
have provided evidence for the possible inheritance of things like behavioral traits and response to environmental conditions in the parental generation. Changes in DNA due to nutrition, stress, chemical exposure, or other environmental conditions were originally thought to be “reset” with every successive generation (these changes generally occur in the non-reproductive “somatic” cells as opposed to the germline). However, recent discoveries are showing that this theory may not be entirely accurate. Studies in mice and observational studies/surveys in humans show that exposure of the parental generation – or even the grandparents – to certain conditions affects the physiology of the offspring even after that condition has been removed. For example, men exposed to famine in preadolescence in the 19th century had grandsons that were more resistant to cardiovascular disease. By the time these grandparents had their children, who then had the grandchildren…the famine was long over, but changes in gene expression persisted. Note: changes in expression not changes to the actual genetic sequence or code: changes to the sequence are traditional Darwinian evolution).
So, Lamarck’s giraffes may not be true, but certain parallels exist. Darwin’s theory of natural selection has clearly NOT been disproven, but evidence suggests that traits acquired during the adult life of the parents can persist in the offspring (we’re not talking amputations or neck lengethening here – epigenetics only). One has to remember Lamarck came up with his theory without the advantage of known molecular mechanisms and extensive studies of genetics and evolution.
Imagine my devastation when I learned there are no green animals! Sure there are parrots, frogs, chameleons, grasshoppers, nasty poisonous snaksiesss, iguanas, some turtles, and my dog on a boat. But they ain’t green! It’s all an optical illusion and/or seasickness (side note: the aforementioned dog is a friggin’ Labrador who gets seasick and does not swim).
all illustrations by The Scientifican
Don’t believe me? Perhaps you trust the Howard Hughes Medical Institute more than a random blogger (silly you!). Green Animals.
But perhaps you prefer to read my account of this unfortunate lack of verdant varmits (you know you do!).
Technically I should say there are no green pigmented animals. Obviously from the brief list I mentioned earlier, there are plenty of animals that appear green. However the color is not due to biological pigmentation, but rather combinations of coloration strategies including chromatophores and structural coloration. Chromatophores are both pigment-containing and light-reflecting cells that come in hues of white, yellow, red, blue, and black/brown while structural coloration is exactly what it sounds like, and the colors of each cell are due to microscopically structured or textured cell surfaces that reflect differing wavelengths of light (click the links for more detailed information).
Now, as any properly educated kindergartner will tell you – green is not a primary color. Notice that chromatophores and structurally colored cells are both capable of producing yellow and blue (structural coloration is also the source of iridescence, by the way). By layering and combining these cells birds, butterflies, reptiles, amphibians, and the Incredible Hulk can all produce something that appears green. In fact, it really is green…but it is not green pigmentation.
Hop on over to Wikipedia if you want to learn more about Animal Coloration!
That indelible creation of Lewis Carroll, the Red Queen, has marched her way out of Wonderland and invaded the realm of evolutionary biology. Madness! (Actually she invaded in the 1970s, but who’s counting?) Like my illustrations? Let me know if I should continue! (Disclaimer: my artistic abilities are limited by a lack of talent).
illustration by The Scientifican
On to the topic at hand: What is that despotic figment of a nonsensical author’s imagination up to? As tyrannical as she might be, the Red Queen proves to be a prescient commentator on evolutionary biology.
Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that! - The Red Queen, Through the Looking Glass
Now, being a creation of Lewis Carroll we obviously cannot expect her to say what she means. Please allow me to translate.
What is termed the Red Queen Hypothesis in biology is a principle or theory stating that for an evolutionary system, constant adaptation is needed to maintain it’s position relative to those systems with which it is simultaneously co-evolving. In short, it basically just means that when one system/organism (a garden slug, for example) evolves to have an advantage (perhaps a resistance to being salted) the other organisms or systems that interact with the slug (the person wielding the salt) must adapt to nullify the advantage of the salt-resistant slug. Otherwise your vegetable garden will be replete with slugs and you will have no tomato sandwiches this summer!
Nasties worldwide are developing resistance to common pesticides and antibiotics, and now plants are in on the action. Perhaps it is time to change our strategy? The chemicals are obviously losing their edge. Our move.
I know, I know. Italian words meaning beautiful lady, accompanied by “of death.” Lucrezia Borgia.
Nope. Although I would be surprised if our 16th century (or 15th, she had the indecency to live in 2 centuries) femme fatale was unfamilar.
The subject, my pretties? Poison. Atropa belladonna, to be precise. A favorite of poisoners across the centuries, Atropa belladonna a.k.a. the Deadly Nightshade is undoubtedly one of the most toxic plants in the western hemisphere. However, it is arguably not the deadliest member of the nightshade family (Solanaceae). That dubious honor lies with the humble potato (Solanum tuberosum), the plant responsible for the deaths of approximately 1,000,000 Irishmen during the period of 1845-1849. The Deadly Nightshade, while not responsible for decimating the population of an entire country in the span of only 4 years, is entirely capable of doing-in the wayward berry picker.
Technicalities aside, symptoms of belladonna poisoning all too frequently include falling off one’s perch, biting the dust, and giving that bucket a resounding kick. All parts of the plant are poisonous (the root being the most toxic) and include tropane alkaloids with anticholinergic active agents (including Atropine, incidentally). The deadly symptoms result from disruption of the parasympathetic nervous system‘s control over things like, oh…breathing and heart rate.
Interestingly, albeit unsurprisingly, several of the non-death symptoms (hallucinations, dilated pupils) are prized by recreational risk takers. Wine at the bacchanalia , the wild festivals of Bacchus/Dionysus, is believed to have been spiked with belladonna to yield the frenzy and hysteria associated with the gatherings. Italian and Spainish women once made use of the antimuscarinic properties of the plant to dilate their pupils. Apparently it was once popular appear as if one were perpetually ‘trippin on E’ [high on ecstasy/MDMA (3,4-methylenedioxy-N-methylamphetamine) for my straightlaced readers]. (Psst! It’s also an ingredient in a witch’s flying potion)
So if, for some strange reason, you wish to acquire this most potent of herbs (perhaps you have a Facebook invite a bacchanalian festival?), you must venture forth on Walpurgis night – for only then has the devil retired to prepare for the witches’ sabbath and left his charge untended. But take care in taking belladonna, lest you harvest her cousin the mandrake (also a member of the Nightshade family) and give up the ghost in the devil’s back garden. Do you expect him to FedEx you to the pearly gates or something?
Preemptive clarification: Epicurean meaning the enjoyment of fine food and dining, not the teachings of our 3rd Century BC friend Mr. Epicurus
At first blush, the similarities between the modern epicurean movement and sadomasochism may not be entirely obvious. The link, my friends, is that saucy mistress – the Chili Pepper. Unlike her more salacious colleagues earning their wages in the seedy dungeons of the red-light district abusing patrons’ pain receptors, Madame Pepper is a class act. Patrons of her establishment are greeted with courtesy, seated, plied with beverages, and given cause to thoroughly enjoy themselves. Mme Pepper, you see, is a bit sadistic. Not until well into their visit do patrons begin to notice a sneaky burning sensation creeping up behind them, but by then it is too late. They are in the clutches of Madame Pepper, and they will grovel at her feet, clutching at her skirts, in unrelenting anguish. Mme Pepper is unsympathetic and her patrons leave the Hall of Pain eyes streaming, nose burning, mouth alight, and yet – strangely satisfied.
Madame Pepper is a member of the Clan of Capsicum, an ancient and powerful clan with the unnerving ability to produce capsaicin and related capsaicinoids via her secondary metabolism (see An Apple a Day for a related story) in an attempt to ward off the twisted modern epicurean (among others). Back in the mists of time when an ancient ancestor of Madame Pepper realized the family was under attack, she devised an ingenious plan to manipulate the nociceptors (pain receptors) of her enemies.
The Devious Plan
As all strategists will tell you, you must exploit the weaknesses of thine enemy. Here, the chink in the proverbial armor lies with the body’s own peripheral nervous system. A unique protein, originally expressed in order to sense and regulate body-temperature, can be manipulated to respond to the ministrations of Madame Pepper. The protein, unimaginatively named TRPV1 is a receptor protein present in the outer membrane of cells. When this protein is activated, it sends signals to the cell indicating that the temperature is much too high and results in a painful burning sensation – incentive to stop doing whatever is causing this pain. Interestingly, when it comes to pinpointing the cause of this pain, the cell is essentially blind. It knows the forces are at the gates, the castle is under siege, the red telephone is ringing in the oval office – but the caller ID is blocked!
Enter….Madame Pepper: “Double, double toil and trouble;
Fire burn, and caldron bubble”
With her wily witch’s ways, Madame Pepper has cooked up a potion to hijack that gullible receptor with her capsaicin. An unwitting double agent, when Madame Pepper approaches the castle gates, Mr. TRPV1 relays false information to the king. The castle is on fire! Evacuation commences, the gates are left unguarded, and Madame Pepper waltzes into the Great Hall. By the time the fire department arrives and Mr. TRPV1 is arrested for pulling the fire alarm under false pretenses, Madame Pepper has already won. The castle is lost, the throne usurped, and Madame Pepper is standing over the whimpering king with a riding crop.
….but the King, being a fan of John Mellencamp, knows that Sometimes love don’t feel like it should and he keeps calling up Mme Pepper leaving her too many voicemails saying Come on baby, make it hurt so good.
Until Mme Pepper gets a restraining order, this is the tale of Epicurean S&M.
Beltsville, MD – USDA Research chemist Dr. Jae B. Park operates in intriguing research program looking for biologically active plant compounds that might be used in the treatment of human diseases.
Anyone who happens to browse the “Health” or “Science” sections of a major news publication is bound to run across articles linking the newest super fruit to increased lifespan, reduced cancer risk, or increased cognitive clarity. Lately the newest spate of articles concerns the possible health benefits of downing a cup (or several) of coffee. Although the supposed benefits of each new fruit/vegetable/legume differ, they all share a central theme – phytochemicals.
Phytochemicals are often produced as secondary metabolites (molecules produced by the metabolism that are not absolutely essential to the survival of the organism). These metabolites can be in the form of pigments, toxins, or chemical signals for communication (look for a future post on that!) and may differ significantly from plant to plant, species to species, or between life stages of the same plant. Occasionally, these chemicals have purported health benefits when incorporated into a balanced diet or sometimes even applied topically.
In his research program, Dr. Park investigates along 4 main lines of inquiry:
1) Purification and/or synthesis – in order to be used in disease treatment, phytochemicals must be reliably extracted or produced synthetically.
2) Bioavailability – the degree to which the molecule is actually absorbed or utilized by the body. Some things just pass straight through!
3) Cellular and molecular mechanisms – how do these plant compounds actually work and affect living cells?
4) Construction of databases relating plant, phytochemical, and bioavailability data to human chronic diseases.