Tuesday, November 25, 2014

As A Bird - It's No Turkey

Mr. Carlson and Herb Tarlek had to deal with the
aftermath of bombing Cincinnati with live turkeys.
The line about turkeys being able to fly is one of the
most famous in TV history. But he should have at least
questioned whether they could fly, there are more than
50 species of flightless bird alive as we speak.

In a famous 1978 episode of the TV sitcom, WKRP In Cincinnati, station manager Arthur Carlson releases turkeys from a helicopter to a waiting crowd below as part of a holiday publicity stunt. The birds crashed to the ground (off camera), as intrepid reporter Less Nessman described the carnage. You can find the entire episode here; it’s as funny now as it ever was.

This comedy had a 1940’s parallel in real life, when the town of Yellville, Arkansas dropped Thanksgiving turkeys off the courthouse roof for several years in succession, and then from low flying planes. They didn’t seem to have any qualms about the flight problems of the domesticated turkey.

In contrast, the North and South American wild turkeys would have survived the stunts. In the genus Meleagris, there are several species of wild turkey, and they can and do fly short distances. In fact, they spend their nights perched in the low branches of trees from Maine to Peru.

The Aztecs introduced the Spanish to Southern Mexican turkeys (Meleagris gallopavo gallopavo), who took them back to Europe in the 1520’s. The Spanish trade capital at the time was Turkey, and from there turkeys spread all across the continent by the 1550’s. Therefore, the English called them turkeys, because they thought the birds originated in Turkey.

The Meleagris g. gallopava birds brought back to Europe were domesticated and became the eating turkeys of today. They were bred for large breast muscles, and being raised in domestication caused them to lose much of their flying musculature; the domesticated turkey is flightless and mimics a bowling ball when released from a helicopter.

Here’s proof for you city folks that turkeys can fly.
Their perch is bird-like, drawing up one leg. This might
be to conserve heat, or to change their outline and
make them look like a plant in order to avoid predation.
Truly, that is one hypothesis… I mean it….really I do.
In animals, only birds have a vertical extension (keel) on their breastbone to allow for attachment of the large breast muscles required for flight. Birds are also the only animals to have fused collarbones, called a furcula. This bone attaches to the muscles important in the down stroke of wings, and also helps to pump air into the lungs - we know this structure as the wishbone. The furcula is more massive in the middle, and can flex and act like a spring during flight.

We use the furcula as a sign of good luck, but for domesticated turkeys it is just an unfortunate reminder that they used to have a fighting chance at avoiding a gravy bath. It's ironic that breeding to increase the size of their flight muscles is exactly why the domesticated turkey can’t fly.

Over many generations, the domesticated turkey’s muscles have become too big to allow it to fly and its legs have becomes shorter, so it has a hard time running. In fact, they are so large and cumbersome that they can’t even mate; they are inseminated artificially in order to breed them further. Many have been bred for white plumage, so that the small pin feathers left after plucking are harder to see.

But the noble turkey (Benjamin Franklin suggested the turkey as our national bird) can trace its line back to about 1100 CE, with the Spanish entering the picture about 400 years later. But new evidence suggests turkeys were raised in captivity much earlier than either of these estimates.

A recent study based on excavations of Mayan ruins shows that as early as 300 BCE there were male, female, and juvenile M. gallopava within the settlements, and some reduced flight morphology suggests that they had begun to be domesticated by that time. What is more, the native turkeys in southern Mexico were M. ocellata, not M. gallopava (from northern Mexico and America), suggesting that trade in the animals with the north had already commenced by this time period.

All this traveling suggests that by the time the pilgrims landed in Massachusetts they were already familiar with the turkey, and its inclusion in the first Thanksgiving feast was probably not a surprise to them. There is no evidence that turkey was the served at the first Thanksgiving, but it makes sense; both cultures were familiar with the bird. American Indians even had tribes named for turkeys and believed that their feathers had mystical powers; Central American Indians had turkey gods.

I find it a little odd that the turkey was revered as a god, considering its looks – that is truly a face only a mother could love. It has appendages and little growths everywhere. If a turkey spins its head around when startled, it could slap itself silly! But as nature proves again and again, everything has a purpose – or did.

You can see the differences between wild turkeys and those bred 
for lots of meat. True, the domesticated version is puffed up in
a display, but he is much bigger weighing twice as much as 
the wild version on average (16-50 lb.s/7.25-22.5 kg for domestic).

The fleshy appendage around the head a throat of many bird species is called the wattle. In turkeys, the wattle hangs from under the beak and down the throat, but in pheasants it is located around the eye and cheek. Another name for this structure is the dewlap, and many animals have these. Even your grandmother might have a dewlap under her chin or upper arms!

The wattle is a mark of sexual dimorphism in many birds (di = two, and morph = shape). The males and females look different in species that are sexually dimorphic. It is hypothesized that birds’ wattles are a form of ornament for mate selection. A male with a larger wattle may be seen as more fit and a may have more reproductive success. The hypothesis states that a large ornament is energetically costly, so only the strongest, most disease resistant males will be able to survive the cost of a large ornament and still live to reproduce.

In terms of the female turkey, picking a male with a bigger wattle would be the same as picking a male with stronger genes. Indeed, a 2010 study in pheasants showed that there were different immune genotypes (MHC, major histocompatibility complex) associated with wattle size. The functional difference between the different MHC genotypes is not known, but they did show a significant difference in the genotypes of males with larger wattles, and those are the more highly preferred mates, so it may also represent stronger MHC types.

But domesticated turkeys don’t worry about selecting mates or appearing healthy, all decisions are made by the breeder, so why do they still have wattles? It may be because their breeding is anything but true natural selection, but it may also be that the wattle has another function. Being highly vascularized (having many blood vessels), the wattle can release body heat by placing a large amount of blood close to the surface, thereby acting as a physiologic control.

Use this picture to memorize the parts of the turkey’s
head.  Cousin Eddie asked Clark to save him the neck
in National Lampoon’s Christmas Vacation, but I doubt
that anyone ever specifically for the snood! There are
no snood recipes - believe me, I looked.
On top of a turkey’s head and down its wattle are smooth surfaced growths called caruncles. At the base of the wattle are larger growths called the major caruncles (not very imaginative). The exact function of the caruncles is not known, but they are significantly larger on males than on females, so sexual ornamentation might be one of their functions. Together, the wattle and caruncles are also a mood detector. When threatened or ready to mate, the wattle on a tom turkey will turn bright red.

The strangest part of a turkey’s head is the snood. The English word “snood” was around long before the English were aware of turkeys. It referred to a decorative hair net or bag worn by women on the back of the head to confine their hair. The resulting mass of hair does look something like the snood that hangs over a turkey’s beak, and this might be where the name came from (see below).

While many animals have wattles, and several different kinds of fowl have caruncles, the turkey is the exception in that it is the only animal with a snood. Its functions may be similar to those of the wattle and caruncles, as they are much larger in males than in females. The snood length in males is linked to testosterone levels, and males are more likely to dominate or steal food from shorter snooded (just made up that word) males than long snooded (there it is again) ones.

I haven’t found any documentation that the turkey
snood is named after the hair snood, but it makes sense.
The snood as a garment makes a comeback every 100
years or so, now they are all the rage in McDonalds and
abattoirs (slaughterhouse) –turkeys with snoods are
processed by workers wearing snoods!

But turkeys are rarely served with the head intact, and eating them is what we are most interested in at Thanksgiving. Like chickens, turkeys have both dark and white meat. The difference in color is due to the makeup of the muscles and how they store and use energy.

The red meat of mammals and the dark meat of birds are similar in that they contain high amounts of myoglobin. The muscles that have myoglobin are for prolonged use; muscles used most of the time require lots of oxygen to make lots of ATP. Myoglobin is to muscles cells what hemoglobin is to red blood cells; it is a molecule that binds and holds oxygen. In the muscle cell, the myoglobin will release the oxygen as needed to allow the muscle to make more ATP and then use that ATP for contraction.

Myoglobin is highly pigmented, so the muscles look darker (redder). When denatured by temperature, the myoglobin turns a tan to dark brown color, giving the cooked meat its look.

Myoglobin is structurally similar to hemoglobin, in that it
looks like one of hemoglobin’s subunits. Each subunit in
hemoglobin can carry one oxygen molecule, but act in
cooperative behavior; the first one is hard to bind, the
second is easier and so on. Myoglobin stores oxygen within
the muscle cell. The more you exercise that muscle, the
more myoglobin it will produce.

White meat, on the other hand, has much less myoglobin. Why? The muscles with white meat (like flight muscles) need energy in short bursts, perhaps to evade predation. To do this, they need less oxygen most of the time, but need lots of glucose some of the time. Therefore, they have less myoglobin but more glycogen (a storage form of glucose) so they can react quickly, rather than waiting for the blood to bring more glucose. The glycogen makes the cooked meat look white and glossy.

So, we have a big bird (did you know that Big Bird’s costume is made of turkey feathers painted yellow?) providing us with a big meal on a big holiday. Next week, we look at three stories of fungus-like protists. Can you believe that they are responsible for Irish priests in America and video game theory, and that they can be ranchers with hired cowhands?

Baratti, M., Ammannati, M., Magnelli, C., Massolo, A., & Dessì-Fulgheri, F. (2010). Are large wattles related to particular MHC genotypes in the male pheasant? Genetica, 138 (6), 657-665 DOI: 10.1007/s10709-010-9440-5

Thornton, E., Emery, K., Steadman, D., Speller, C., Matheny, R., & Yang, D. (2012). Earliest Mexican Turkeys (Meleagris gallopavo) in the Maya Region: Implications for Pre-Hispanic Animal Trade and the Timing of Turkey Domestication PLoS ONE, 7 (8) DOI: 10.1371/journal.pone.0042630
For more information or classroom activities, see:

Sexual dimorphism –

Myoglobin –


Wednesday, November 19, 2014

A Meal More Powerful Than The NFL

Biology concepts – genetic code, neurotransmitters

A turkey dinner with all the fixins can lead to a
satisfying nap. But the meal usually takes a little
longer than this to have an effect. This fellow might
be more affected by last night’s activities than today’s
Turkey dinner at Thanksgiving brings the family together, celebrates the bountiful harvest, and puts you to sleep just as the NFL games are ready to start. Many people think that if you eat less turkey and fill up on the other goodies you can escape the post-Thanksgiving meal sleepiness. Other people look forward to eating seconds and thirds and then stretching out on the couch for a long nap, forcing Aunt Ethel to sit in the chair with the spring that surprises you every once in a while.

The culprit, or the hero, in this eat and sleep saga is said to be the tryptophan in the turkey. Other people think that it is simply how much you eat, not the turkey's tryptophan, but it isn’t quite that simple. What is tryptophan, and is it indeed responsible for the snoring that follows Thanksgiving dinner?  Some background will help.

Tryptophan is an amino acid, one of the twenty standard building blocks of proteins. Each amino acid has a similar basic structure, as shown in the picture below. The central carbon has an amino group (NH3) on one side and a carboxylic acid (COO-) moiety on the other; hence the name – amino acid. The third side group is a simple hydrogen (H), while the fourth side (R) refers to any of several different side groups and is what makes one amino acid different from one another.

Tryptophan is an aromatic amino acid, meaning that its side group contains a six-sided carbon ring structure (each corner represents a carbon). It also has a second ring group of four carbons and a nitrogen. As such, it is the largest and most massive of all the standard amino acids. However, tryptophan is the least abundant amino acid in plant and animal proteins; it accounts for only 1-1.5% of the total number of amino acids in proteins.

Amino acids are the building blocks of proteins. The NH3
is the amino part and the COO is the acid part. The R is
different for each amino acid. On the left, you see that
tryptophan’s R group is a big structure with two different
rings (each angle where two lines meet stands for a carbon,
they just don’t write in each “C”). Two lines means a double
bond. In producing the protein, the COO of the last amino acid
added gets connected to the NH3 of the next amino acid to be
connected. Which amino acid it is determine by the mRNA
and the genetic code.

Tryptophan’s large structure and intricate rings make it costly to produce in terms of ATP invested. In fact, it takes so much energy to make that we have stopped making tryptophan all together. Tryptophan is abundant in a number of food sources commonly available to humans, so over evolutionary time we have turned it into an essential amino acid. True, it is essential for life, but here the word “essential” means that we MUST get it from our diet, we cannot produce it ourselves.

Of the 20 standard amino acids, 10 are essential in humans (9 that we must eat and 1 that we make from an essential amino acid), but bacteria make them all just fine - although the parents of newborns may wish it wasn’t so. Gut bacteria make tryptophan or use the tryptophan we eat. They transform it into molecules they need to survive, but the byproducts of these reactions are skatole and indole – these are the precious little molecules that give dirty diapers that wonderful smell!

Tryptophan is different from many other amino acids in another way as well; it gets no respect from the genetic code. Each amino acid is coded for by a group of three RNA bases, together called a codon. Since there are four different bases in mRNAs (A, C, G, and U – remember that T is used in DNA but not RNA), then there are 64 different codons (4 x 4 x 4). This is more than the 20 amino acids that the codons code for, so most amino acids have two or three codons that signals that they should be added to the growing peptide. But tryptophan is encoded by only one codon (UGG).

It may make sense that an amino acid that is not used often in proteins might rate only one codon, but the amino acid methionine is used much more often than tryptophan, and it's only coded for by one codon as well (AUG). You know nature must have a reason why tryptophan has a single codon, we just don't know it yet.

The genetic code is how mRNA codons (3 bases sequences)
get translated into a signal to build proteins from specific amino
acids. The first base of the codon is represented by the biggest
letters (ACGU), the middle base is the middle size letters, while
the third position (wobble position) is usually where you see an
amino acid coded for by more than one codon. For instance,
serine is coded for by UCU, UCC, UCA, or UCG. But tryptophan is
only coded for by UGG. Three codons signal the protein to stop
growing, called stop codons (UAG, UAA, and UGA).
Even though it is used sparingly in proteins, tryptophan is an essential amino acid - don’t eat enough of it and you die. This is because tryptophan’s most essential functions have nothing to do with protein synthesis or structure – tryptophan is important to your brain function. The crucial neurotransmitter, serotonin, is synthesized only from tryptophan.

It takes two enzymes to turn tryptophan into serotonin (also called 5-HT).  First is tryptophan hydroxylase; hydroxylase means it splits water, here it adds an OH to tryptophan. Next, the amino acid decarboxylase removes a carboxylic acid (COOH), producing serotonin.

Amongst the many functions of serotonin are a few that are not brain related. Serotonin is released by enterochromaffin cells that line your gut to tell your gut to move. The movement helps push the food along your digestive tract, but serves a protective function.

If you eat something toxic, the enterochromaffin cells produce more serotonin – your gut moves much faster, and you get diarrhea. If even more serotonin is made and released, it moves through the bloodstream to your stomach and esophagus and causes you to vomit.

But it is in the CNS that serotonin has its significant activities. As a neurotransmitter, it is responsible for controlling how electric messages are passed from one neuron to another. When serotonin is released in the synapse (the gap between the upstream and downstream neurons) and is taken up by adjacent neurons, it produces a sense of well-being.

Where one neuron ends and others begin there is
a gap called the synaptic cleft. Different types of
neurons use different neurotransmitters, of which
serotonin is one. It is released into the synapse, and
adjacent neurons with serotonin receptors can be
stimulated to conduct a nerve impulse. The serotonin
is broken down in the synapse by MAO’s and taken
back up to produce more serotonin.
It isn’t surprising that depressed individuals often have low blood levels of tryptophan, as well as reduced serotonin. Classic treatments for depression include increased tryptophan intake, monoamine oxidase (MAO) inhibitors, and serotonin reuptake inhibitors (SSRI). With more tryptophan, you make more serotonin – problem solved. On the other hand, MAO’s break down serotonin, so their inhibitors enhance the action of tryptophan. SSRI’s prevent the reuptake, this leaves serotonin in the synapse longer. Both types of drugs make tryptophan more likely to be taken up by downstream neurons.

Unfortunate, but interesting, is the study showing that the suicidal thoughts that sometimes accompany anti-depressant therapies (TESI – treatment enhances suicidal ideation) use may be related to polymorphisms in one form of the tryptophan hydroxylase enzyme that starts the serotonin production from tryptophan.

When non-suicidal patients were compared to those with TESI or those who were suicidal without treatment, a pattern emerged. Only those with TESI showed a polymorphism pattern in the tryptophan hydroxlyase 2 (TPH2) gene. This polymorphism had previously been associated with suicide victims and major depressive disorder. It seems that a slight alteration in function of TPH2 due to a single nucleotide change can contribute to the genetic background of treatment induced suicidal thoughts.

The feeling of general well being induced by serotonin also participates in the sleep/wake cycle. So is tryptophan – through serotonin – responsible for the post-Thanksgiving nap? Well… yes and no, it's an accomplice in a larger conspiracy.

Serotonin is use to produce the hormone melatonin, and melatonin promotes sleep, so you could say turkey dinner promotes sleep. But turkey doesn’t have that much tryptophan! Tofu has much more tryptophan than turkey, but you don’t get a post-Chinese takeout urge to sleep, so what gives?

Melatonin is made from serotonin in the pineal
gland. Sunlight stimulates the suprachiasmatic
nucleus (SCN) which inhibits the pineal from
making melatonin. As the sun goes down,
inhibition is reduced, more melatonin is made
and released from the pineal, and sleep is
The melatonin effect has to do more with how much of everything else you eat at Thanksgiving dinner, especially carbohydrates. Here is how it works – eating lots of carbohydrates causes a release of insulin into the blood (to reduced blood glucose levels). Another function of insulin is to promote the uptake of some amino acids (but not tryptophan) into muscle cells. This leaves the blood higher in tryptophan as compared to other amino acids than it would normally be.

The brain takes in amino acids through a neutral amino acid transporter, which now finds more tryptophan than other neutral amino acids, so the brain level of tryptophan goes up. More tryptophan in the brain, more serotonin – more serotonin, more melatonin. More melatonin = nap time! So if you want to avoid the post-Thanksgiving nap, eat the turkey and skip the mashed potatoes.

You didn’t know how much tryptophan controlled your daily life, did you? Well, there’s more. Tryptophan is also important in synthesizing niacin, a.k.a. vitamin B3 or nicotinic acid. Niacin is important in production of NAD/NADH for energy metabolism, for production of steroid hormones and balance of lipid forms in the blood, and as an anti-convulsant.

The tryptophan-niacin connection is made stronger by recent evidence that high dietary tryptophan can prevent epileptic seizures in mice. In this study, a whey protein called alpha-lactoalbumin (ALAC) was found to have much tryptophan, much higher levels than in most proteins. Feeding epileptic mice ALAC resulted in reduced numbers of seizures.

So even if you don’t want to sleep or think happy thoughts, you still need to eat food that contain tryptophan or niacin. And many of those foods are plants, because plants use tryptophan to control their own activities. Tryptophan is easily converted to auxins, a type of plant hormone. Auxins are responsible for several different plant behaviors, namely the falling leaves in autumn and ripe fruits all year long.

Here is an interesting attempt to get kids to read
history. During the spring, captive warriors were
killed by cutting out their hearts, then their skin was
flayed off their body, and the priests would wear them
around for 20 days. This was meant to celebrate the
god who sacrificed himself to allow a new growing
season to begin. This time period corresponds
 to when they would have had the lowest amount of
 tryptophan in their daily die. No - I wouldn't want
to be an Aztec sacrifice!
Having dietary choices for tryptophan is good, and plants provide our major source. However, cooking grains and corn reduces usable tryptophan and niacin levels dramatically, so poorer environments where corn is the staple food need also to have additional dietary sources of tryptophan. A deficiency of this amino acid leads to some disturbing conditions. Low tryptophan leads to low serotonin levels and agitation, insomnia, and depression. A study in the Archives of General Psychiatry stated that chronically low levels of tryptophan led to relapses of purging behaviors in bulimics.

More amazingly, studies in the 1970’s to 1990’s suggest that low tryptophan levels can lead to increases in religious fanaticism. Several studies from a single author correlate the Aztec human sacrificial ceremonies to the times of year when their diets depended more on foods that had less tryptophan. Think of all the lives that could have been saved by tofu!

But turkey is more than just tryptophan. You have to love an animal that has caruncles, a wattle, and a snood! What's a snood? Come back next week.

Musil, R., Zill, P., Seemüller, F., Bondy, B., Meyer, S., Spellmann, I., Bender, W., Adli, M., Heuser, I., Fisher, R., Gaebel, W., Maier, W., Rietschel, M., Rujescu, D., Schennach, R., Möller, H., & Riedel, M. (2012). Genetics of emergent suicidality during antidepressive treatment—Data from a naturalistic study on a large sample of inpatients with a major depressive episode European Neuropsychopharmacology DOI: 10.1016/j.euroneuro.2012.08.009

Russo, E., Scicchitano, F., Citraro, R., Aiello, R., Camastra, C., Mainardi, P., Chimirri, S., Perucca, E., Donato, G., & De Sarro, G. (2012). Protective activity of α-lactoalbumin (ALAC), a whey protein rich in tryptophan, in rodent models of epileptogenesis Neuroscience, 226, 282-288 DOI: 10.1016/j.neuroscience.2012.09.021

For more information or classroom activities, see:

Genetic code –

Neurotransmitters –


Wednesday, November 12, 2014

A Goat For Thanksgiving

Biology concepts – cornucopia, goat, nutrition, sustainability, browser/grazer, Cassandra hypothesis

The image on top is the traditional cornucopia, filled with
foods or riches. The bottom image is the version form the
Hunger Games movies, filled with survival gear and weaponry.
Boy, did they go the other way with that idea. I prefer a
different Horn of Plenty, the Dizzie Gillespie album from 1953.
Thanksgiving is a traditional time to remember the work of planting and tending, and to be grateful for the harvest. In a larger sense, it’s a time to be grateful for life’s unending bounty, both the good and the challenging.

As a symbol of the gifts of the Earth, the ancient Greek cornucopia (comes to us as the Latin cornu = horn, and copiae = plenty) has been adopted as a symbol of this holiday in the USA. Not every country has a specific date set aside for celebrating the harvest, but almost every culture has a version of the cornucopia.

Looking at the horn of plenty in a little more detail, we will see that it fits more nicely with the American holiday tradition, and perhaps the American future.

From Greek mythology, there are a few stories about how the horn of plenty came to be. My favorite is that when Zeus was born, he had to be hidden from his father Chronos. Dad had a nasty habit of eating his young, so Zeus was whisked away to a mountain cave on Crete where he was suckled by Almathea, a lesser god that took the form of a goat.

Zeus, being the he-man god that he was, accidentally broke off one of Almathea’s horns while playing. Of course he blamed it on his sister ….. wait, that’s what used to happen at my house. No, Zeus felt bad about his rude feat of strength, so he enchanted the horn so that it would provide Almathea with whatever she desired. I imagine that for a goat that would be anything edible, and goats will eat almost anything.

Other versions of the myth say that Almathea was a nymph that fed goat’s milk to Zeus and he subsequently blessed one of the goat’s horns to provide her with unlimited bounty as a way of thanking her – but either way it didn’t end well for for the goat. A teenage Zeus showed his appreciation by killing and skinning the goat. The skin was used to make his shield, the aegis, and is shown in many depictions of Zeus. But the horn was still around, spewing forth sustenance for the holder.

This is from the 1555-1556 painting, Infancy of Jupiter, by
Giorgio Vasari. It shows the god being suckled by the divine
goat Amalthea. Notice we said Jupiter, not Zeus. Roman and
Greek myths often stole from one another, the same stories
can be found in each traditions; only the names have been
changed to protect the copyright.
This brings us to the goat horn and the American Thanksgiving. The goat just may have been a part of the first Thanksgiving, and it may have implications for future Thanksgivings, speaking biologically.

The first Thanksgiving wasn’t too much of feast; it looked nothing like the table we look over as we watch football and stuff ourselves. The pilgrims had it rough, but they were thankful for the harvest that they did manage and the wisdom that the native Americans had passed on to them about finding food in their new home.

They might have had some turkey, but they certainly didn’t have a big steak. The pilgrims had not brought any cows with them on their journey, and they weren’t native to this country. They may have had some pork, as they did have a few pigs, but they may also have had another meat – goat.

It's true, goats are not native to the Americas. No, the Rocky Mountain goats (Oreamnos americanus) that grace the crags and cliff faces so majestically are not really goats, they’re actually members of the antelope family. And it turns out that they aren’t even native to the Rocky Mountains, at least not the lower Rockies. They were originally found in Alaska, and were introduced to Colorado, Montana, and South Dakota much later.

Check out the nutritional values for goat meat. If you, unlike
most Americans, can stomach the idea, you should be adding
it to your diet in place of some other red meat.
The pilgrims had at least some goats with them in 1621, they were remarked upon in one person’s journal. They certainly used them for milk and cheese at the first Thanksgiving, but they may have eaten goat meat as well. Does that sound weird to you?

True American’s don’t eat goat to any great degree. But in this instance, we’re the exception. Over 70% of all the red meat consumed worldwide is goat! I don’t remember trying it, but I am sure going to try and procure some now – not just for the novelty of it, goat meat (sometimes called chevon) is really good for you.

Chevon has greater vitamin and lower fat content than other red meats, even fewer calories and fat than chicken. People around the world haven't necessarily known about the nutritional value of goat meat for centuries; goats lived there and they ate them. Even south of the border in Mexico and Latin America they eat lots of goat (and I don’t just mean the cryptozoologic chupacabra).

All across Asia they eat goat, especially northern China, but as many of my Chinese friends say, the only thing with four legs the Chinese won’t eat is the kitchen table. Andrew Zimmern, he of the bizarre foods shows, says that goat is like soccer - it’s popular everywhere but the US.

Despite the fact that we don’t eat it nowadays, our story tells us that goat might have a bit more to do with Thanksgiving that one might think. Is there more – you bet. Along with their meager harvest and maybe some roast goat, the pilgrims enjoyed native American foods, things that were grown, hunted and/or gathered.

The black trumpet mushroom lives in Europe across to Asia.
Avery closely related species lives in North America, still
called the black trumpet or horn of plenty. Recent studies
show that in America, the black trumpet lives in a symbiotic
relationship with several pine trees. This is interesting, since
goats are now being fed pine bark to make their meat taste
better. Everything is connected.
In southern Virginia, this would certainly have included many different species of mushroom. And wouldn’t you know it, one of the most bountiful mushrooms in this region is named Craterellus cornucopioides, or Craterellus fallax. Also called the black trumpet or the horn of plenty mushroom.

I have read that native American Indians didn’t eat a lot of mushrooms, but they did use them for medicines and as symbols. But the European pilgrims were certainly mushroom eaters, so it is likely they made good use of the horn of plenty mushrooms. I can see a big bowl of mushroom stuffing gracing the tables of the first Thanksgiving.

Maybe the Indians were on to something when they used the mushrooms in their medicine. Recent studies of the black trumpet mushrooms show have medicinal effects. A 2012 study indicated that several mushrooms related to, and including the black trumpet mushroom have the ability to regulate blood sugar levels so as to prevent hyperglycemia. I know my diabetic wife would be interested in that, even if she doesn’t like to eat mushrooms.

In addition to this, the same study showed that the mushrooms also have antioxidant activities. They could scavenge iron ions that can do damage to cells as well as oxygen radicals that can devastate cellular function, see this post for a discussion of oxygen radicals and antioxidants.

A newer 2014 study show that the black trumpet has significant anti-inflammatory properties. An alcohol extract of the black trumpet was able to prevent inflammatory cytokine and nitric oxide production in macrophages that were stimulated with LPS, a potent inflammatory agent.

We have seen that goat plays a role in the American Thanksgiving, perhaps in the symbol we use for the harvest, perhaps as a meat source, and even perhaps in the mushroom stuffing. Now we can see how it may represent the future as well.

Evolution is amazing. Some ruminants evolved as grazers, while
others became browsers. That way, they can live in the same
areas and they both still have enough to eat. Goats are browsers,
so they have to digest things that even cows can’t digest.
Goats are browsers, not grazers. This means that they don’t eat grasses down to the roots; they also feed on what ever is around. They eat bark, twigs, leaves, license plates, homework, just about anything laying around. As such, they have a smaller effect on the environment than do grazing livestock, like bovines. Cows can strip a pasture clear of grass and its roots, and this takes time to replenish.

So goats are better for the land, you can raise more goats on the same amount of land as cows, and you don’t need to grow as much grain for them to eat. The commercials should really be saying, “Eat More Goat.” Goat numbers in the US have doubled in the past few years, but they still pale in comparison to those of bovines. Given the nutritional and environmental advantages of goats, maybe they could use a marketing slogan – “Goat, the other green meat.” Maybe not.

All this environmental talk leads us into the last discussion for our Thanksgiving post. Is the horn of plenty really a good symbol for the Earth today? Are the resources of Earth limitless and will keep pouring forth no matter what we do to our home?

This is the issue in an argument about population growth referred to as the Cornucopia vs. Cassandra hypothesis. The cornucopia position is one that says that the Earth will be able to sustain human population no matter how much it grows, while the Cassandra hypothesis states that the Earth’s resources are limited and that uncontrolled population growth is untenable.

Alan AtKisson wrote Believing Cassandra in 1999. He
explains how working for sustainability is necessary but
possible. Global sustainability is explained via anecdote and
good science, unfortunately, his method for reaching
sustainability is abbreviated ISIS, not so good for late 2014.
I recommend the book highly.
Cassandra was another character from mythology. Apollo gave her the power of prophecy in hopes becoming her boyfriend, but she spurned his advances and he took revenge. He left her with the power to predict the future, but cursed her so that no one would believe her predictions. Ouch, that “hell hath no fury like a woman scorned” line might have to be amended to include Greek gods.

The argument seems odd to me. Of course the Earth can take what ever we throw at it, but we can’t. Population growth and climate change are untenable only to us. Life will change and go on, but we won’t be here to see it.

The key is to manage the growth so that we don’t destroy the Earth for ourselves and for the rest of the living organisms that we depend on. And we depend on them all in one way or another. Maybe we should give thanks that we still have time to embrace the goat. OK, that sounds bad too.

Next week - does Thanksgiving turkey really put you to sleep?

O'Callaghan YC, O'Brien NM, Kenny O, Harrington T, Brunton N, & Smyth TJ (2014). Anti-Inflammatory Effects of Wild Irish Mushroom Extracts in RAW264.7 Mouse Macrophage Cells. Journal of medicinal food PMID: 25136763

Liu YT, Sun J, Luo ZY, Rao SQ, Su YJ, Xu RR, & Yang YJ (2012). Chemical composition of five wild edible mushrooms collected from Southwest China and their antihyperglycemic and antioxidant activity. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 50 (5), 1238-44 PMID: 22300772

For more information or classroom activities, see:

Cornucopia in myth –

First Thanksgiving meal –

Browser versus grazer –

Cassandra and population growth –