In honor of strawberry season, I decided to investigate the history of this humble yet delicious fruit.
Since wild strawberries (frangaria) have invaded my garden, I thought I might live near the strawberry domestication ground zero, but it turns out that wild strawberries are incredibly common–their range includes much (perhaps all) of North and South America, Hawaii, Europe, and Asia, including the Himalayas and Japan. (It does not appear that they are native to Australia or Africa, but I might have just missed some.)
F. daltoniana, Himalayan strawberry
Wild strawberries, if you’ve never spotted one, are much smaller and more modest than their commercially-available cousins. The French began trying to domesticate wild strawberries by planting them in their gardens back in the 1300s–Charles V’s (1364 to 1380) royal garden had 1,200 strawberry plants. The plants seem to have increased in popularity over the next couple of centuries, but never became very significant–perhaps because the garden strawberries kept crossing with their wild cousins, preventing significant domestication.
In the 1600s, F. virginiana–the Virginia strawberry–spread across Europe after its introduction from eastern North America. (Virginia, I assume.) In 1712, a French spy, Amédée-François Frézier, brought back a third wild strawberry, this one from Chile. Amusingly, the name “Frezier” actually comes from the French for “strawberry”:
A story relates the surname is derived from the fact that Julius de Berry, a citizen of Anvers (i.e. [{Antwerp]]), was knighted by Charles the Simple in 916 for a timely gift of ripe strawberries.[2] The Emperor gave the Fraise family (the surname was corrupted as “Frazer”) three “fraises” or stalked strawberries for their coat of arms.
At any rate, in 1766, the French discovered that crossing F. virginiana and F. chiloensis resulted in a plant with large, tasty berries: the ancestor of our modern domesticated strawberry.
Strawberries and roses are close cousins within the Rosaceae family; blackberries and raspberries, from the Rubus genus of the Rosaceae, are their somewhat more distant cousins.
Humans–Homo Sapiens or Anatomically Modern Humans–have been around for about 200,000 years. We have only recently–for the past few thousand years or so–begun making a serious effort at recording human history and figuring out what happened before our own times.
Most of what we know about major migrations and changes among human populations come from three major sources: written records, archaeology, and genetics.
Written records are (usually) the easiest to work with. We know when the Spaniards discovered Cuba because we have written records of the event, for example. Unfortunately, written records go back only a few thousand years–covering a teeny portion of human history–and can be highly unreliable. After all, we thought the entire world was only 6 thousand years old for a while because a book that seemed to say so.
Archaeology lets us peer much further back than written records, but with much less detail. We don’t know a lot, for example, about the folks who made Aurignacian tools–what they called themselves, what sort of rituals they had, what they hoped or dreamed of. Without those details, it’s hard to care much about one culture or another. After a while, pots blend into pots, stone tools into stone tools.
Can you tell which one is Aurignacian, and which is Gravettian?
(Oh, I threw in a Mousterian tool, as well. Those were made by Neanderthals, not H. sapiens.)
I can’t, either.
It is difficult to tell whether a change in artifacts between one layer and the next reflects a change in people or a change in technology. The proliferation of steel artifacts in the archaeological record in Mexico circa 1500 reflects an influx of new people, but the proliferation of television sets in the future-archaeological record of my area merely reflects a technological development. Finding a lot of mass graves in an area is, of course, a tip-off that invasion and replacement happened, but invasions aren’t always accompanied by easily identified mass-internments.
This is where genetics comes in. If we can find some skeletons and sequence their DNA, and then find some later or earlier skeletons in the same area and sequence their DNA, then we can get a pretty good idea of whether or not the later people are descended from the earlier people. This probably doesn’t always work (if the people in question are under some kind of selective pressure–which we all are–then their descendants might look genetically different from their ancestors simply due to evolution rather than replacement,) but it is a pretty darn good tool.
As I discussed back in “Oops, Looks Like it was People, not Pots,” archaeologists have fiercely debated over the decades whether the replacement of Narva Pots with Corded Ware Pots circa 3750 ago represented a population replacement or just a change in pot-making preferences:
Luckily for us, genetics has now figured out that the Corded Ware people are actually the Yamnaya, aka the Proto-Indo-Europeans, and that they expanded out of the Eurasian Steppe about 4,000 years ago, replacing much of the native population as they went.
So it’s starting to look like there were quite a few conquering events of this sort.
From, A recent bottleneck of Y chromosome diversity coincides with a global change in culturefrom A Handful of Bronze Age Men Could have fathered two-thirds of Europeans
In general, if you see a lot of mtDNA and only a little Y-DNA, that means there were a lot of women around and only a few men. And that generally means those men just killed all of the other men and raped their wives and children.
Which appears to have happened on a massive scale throughout much of the world around 10,000-4,000 years ago.
Just off the top of my head, recent large-scale migrations and at least partial replacements include the arrival of Indians in Australia around 4,230 years ago; replacement of the Thule people by the Inuit (aka Dorset aka Eskimo) around 1,000 ago; successive waves of steppe peoples like the Turks and Mongols invading their neighbors; the Great Bantu Migration that began about 3,500 years ago; the spread of Polynesians through areas formerly controlled by Melanesians starting around 3,000 BC; displacement of the Ainu by the Japanese over the past couple thousand years; etc.
Replacement of the Thule by the Dorset, from The genetic prehistory of the New World ArcticPaths of the great Bantu MigrationMap is in French. Negative numbers are years BC; positive numbers are years CE.
And of course, we know of many more recent migrations, like the one kicked off by Columbus.
So it looks like people have moved around a lot over the past 10,000 years.
Terms like “bronze age” are a little problematic because people adopted different technologies at different times. So the “bronze age” began around 5,300 years ago in the Middle East, 4,000 years ago in Ireland, and skipped the Inuit entirely (they basically went straight from stone and bone tools to guns.)
Agriculture emerged in the Middle East circa 11,500 years ago; followed by the wheel, 8,500 years ago; carts, 6,500 years ago; and domesticated horses about 6,000 years ago. These technologies made the world ripe for warfare–riders on horseback or in chariots were great at conquering, and agricultural settlements, with their large population centers and piles of food, were great for conquering.
Our conventional views of prehistory are tainted, I suspect, by a mis-perception of time. This is probably basically a quirk of perception–since we remember yesterday better than the day before yesterday, and that day better than last week, and last week better than last year, we tend to think of more recent time periods as longer than they really are, and older time periods as relatively shorter. Children are most prone to this; ask a child to make a numberline showing events like “Last week, my last birthday, the year I was born, and the year mommy was born,” and you’ll tend to get a very distorted number line. Grown ups are much better at this task (we can count the time-distance between these events,) but we’re not perfect.
We show this same tendency when thinking about human history. Our written documents barely go back past 3,000 years, and as far as most people are concerned, this is the beginning of “history”. Nevermind that humans have been around for 200,000 years–that’s 197,000 years of human history that we tend to condense down to: humans evolved, left Africa, and invented agriculture–then came us. We tend to mentally assign approximately equal chunks of time to each phase, which leads to things like people thinking that the Basques–who speak a language isolate–are an ancient, archaic people who hail directly from the first humans, or Neanderthals, or somesuch. Neanderthals disappeared around 40,000 years, and the Indo-European language expansion probably cut the Basques off from their fellow-language speakers about 3,000 years ago. Of course, the Basques could have been cut off since the Neanderthal age, but that’s a jump of 37,000 years (or more) on very little evidence. Likewise, we tend to assume that people just spread out from their original African homeland, got to where they were going, sat down, and never moved again. With the exception of Columbus and his European co-ethnics, everyone is sort of assumed to have gotten where they are now about 100,000-40,000 years ago. (Or the equivalent time period for people who think humanity is much younger or older than it is.)
But the emerging picture is one of conquering–lots of conquering, at least in the time periods we’ve been able to get details on. But go back more than 10,000 years or so, and the records start petering out. We’ve got no writing, far fewer artifacts, and even the DNA breaks down. The technology we’ve developed for extracting and sequencing ancient DNA is amazing, but I suspect we’ll have a devil of a time trying to find any well-preserved 40,000 year old DNA in the rainforest.
So what did the human story look like between 200,000 and 10,000 years ago? Have humans been conquering and re-conquering each other from the beginning? Is it ethnic group after ethnic group, all the way down? Or did lower population density in the pre-agricultural era make it easier to spread out and avoid one’s neighbors than to bother fighting with them? Certainly armies would have spread much less slowly before the domestication of the horse and invention of the chariot. (Not to mention that they require quite a bit of food, which is a tough sort of thing to get in large, easily-transportable form if you’re a hunter-gatherer.)
Certainly prehistoric peoples slaughtered (or slaughter) each other with great frequency–we can tell that:
It doesn’t take a lot of technology to go put a spear into your neighbor’s chest. Even bands of chimps go smash other bands of chimps to bits with rocks.
The authors propose that a genetic component found in Horn of Africa populations back-migrated to Africa from Eurasia ~23 thousand years ago. … For a time, there was a taboo against imagining back-migration into Africa; in a sense this was reasonable on parsimony grounds: Africans have most autosomal genetic diversity and the basal clades of mtDNA and Y-chromosomes; a model with Out-of-Africa is simpler than one with both Out-of and Into-Africa. However, we now know that pretty much all Africans have Eurasian ancestry, ranging from at least traces in theYoruba and Pygmies (to account for the Neandertal admixture) to intermediate values in East Africans, to quite a lot in North Africans.
Eurasian admixture in Africa seems to be general, variable, and to have occurred at different time scales. It’s still the best hypothesis that modern humans originated in Africa initially and migrated into Eurasia. However, it is no longer clear that Africa was always the pump and never the destination of human migrations.
Whether this was “conquering” or just wandering remains to be discovered.
As for me, my money’s on horses and agriculture making warfare and dispersal faster and more efficient, not fundamentally changing our human proclivities toward our neighbors.
It’s no secret that sperm counts have been dropping like rocks over the past 70 years or so (though the trend may have recently leveled out.)
” Sperm counts in the 1940s were typically well above 100m sperm cells per millilitre, but Professor Skakkebaek found they have dropped to an average of about 60m per ml. Other studies found that between 15 and 20 per cent of young men now find themselves with sperm counts of less than 20m per ml, which is technically defined as abnormal.” — from The Independent, “Out for the count: Why levels of sperm in men are falling“
While environmental effects (like smoking,) have effects on sperm counts in adults, these appear to be basically small or short-lasting. The biggest, longest-lasting effects on sperm counts appears to be the unterine environment where the future-low-sperm-count-male’s testicles were developing. Improper fetal testicle development => low sperm count for life. Eg,
“A man who smokes typically reduces his sperm count by a modest 15 per cent or so, which is probably reversible if he quits. However, a man whose mother smoked during pregnancy has a fairly dramatic decrease in sperm counts of up to 40 per cent – which also tends to be irreversible.”
What elsecould make a uterine environment hostile to testicular development?
How about too much estrogen?
I’ve posted before about Diethylstilbestrol, (or DES,) is a synthetic nonsteroidal estrogen. Between 1940 and 1971, DES was given in large quantities to pregnant women to prevent miscarriages. Unfortunately, it turns out that pumping babies full of unnaturally high levels of estrogen might be bad for them–DES was discontinued as a medication for pregnant women because it gave their daughters cancer, (an actual epigenetic effect) and the sons appear to have high rates of transgender, transexual and intersex conditions.
Quoting the Wikipedia:
“In the 1970s and early 1980s, studies published on prenatally DES-exposed males investigated increased risk of testicular cancer, infertility and urogenital abnormalities in development, such as cryptorchidism and hypospadias.[38][39]
“… Research on DES sons has explored the long-standing question of whether prenatal exposure to DES in males may include sexual and gender-related behavioral effects and also intersex conditions. Dr. Scott Kerlin, a major DES researcher and founder of the DES Sons International Research Network in 1999, has documented for the past 16 years a high prevalence of individuals with confirmed prenatal DES exposure who self-identify as male-to-female transsexual, transgender, or have intersex conditions, and many individuals who report a history of experiencing difficulties with gender dysphoria.[45][46][47][48]
“… Various neurological changes occur after prenatal exposure of embryonic males to DES and other estrogenic endocrine disrupters. Animals that exhibited these structural neurological changes were also shown to demonstrate various gender-related behavioral changes (so-called “feminization of males”). Several published studies in the medical literature on psychoneuroendocrinology have examined the hypothesis that prenatal exposure to estrogens (including DES) may cause significant developmental impact on sexual differentiation of the brain, and on subsequent behavioral and gender identity development in exposed males and females.”
Here is an excerpt from a paper, published in, I think, the early 40s.
Since the image quality is low, I’ve done my best to type it up for you:
“Experimental Intersexuality: The Effects of Combined Estrogens and Androgens on the Emryonic Sexual Development of the Rat
“RR. Greene, M. W. Rurrill and A. C. Ivy
“Department of Physiology and Pharmacology, Northwestern University Medical School, Chicago, Illinois
“In previous publications the authors have reported and described in detail the effects of large doses of sex hormones on the embryonic sexual development of the rat. Androgens, when administered to the pregnant female, cause a masculinization of the female embryos (Greene, Burrill and Ivy, ’38, ’39 a). The female type of differentiation of most sexual structures is inhibited and a male type of differentiation of those structures is stimulated. Administered estrogens cause a femininization of the male embryos (Greene, Burrill and Ivy, ’38, ’40) in that they inhibit the masculine type of differentiation of some sexual structures and, instead, cause a female type of differentiation.
“…The experimental demonstration that estrogens do have a profound effect…”
What are external sources of estrogens in modern life?
Birth control pills. I know FTM trans folks birth control pills for the hormones in them. (They are often cheaper and easier to get than hormones specifically prescribed for trans folks, especially if you have a female friend.)
Can those hormones stick around in a mother’s body even after she discontinues taking the pills?
Fat and estrogen appear to be correlated:
“Other conditions that cause low estrogen levels in younger women include excessive exercise, eating disorders and too little body fat.” (source)
“Excess estrogen in the body causes weight gain around the abdomen and upper thighs. … Weight gain caused by estrogen starts a vicious cycle. Excessive body fat produces the aromatase enzyme that synthesizes estrogen, thus creating more estrogen in the body, which then promotes additional weight gain, and so on, says Hofmekler.” (source)
“Researchers have found a correlation between estrogen and weight, particularly during menopause, when estrogen levels drop, but weight tends to rise. But since fat cells can produce estrogen, the issue facing researchers is how to target the estrogen receptors that will boost energy and manage hunger and not contribute to menopause-related weight gain.” (source)
“For postmenopausal women, estrogen levels increase with increasing BMI, presumably because conversion of androgens to estrogen in adipose tissue is a primary source of estrogen…” (source)
Since Americans have been getting fatter over the past century, I’d expect estrogen levels to be up, but I’ve found no studies on the subject so far. (Also, the Wikipedia claims there’s no evidence that birth control pills make people fat.)
However, I have found quite a bit of evidence that giving synthetic estrogen to animals makes them fatter:
(Stilbosol is another name for DES, as you may note in the ad’s upper right hand corner.)
Since the picture quality is bad, I’ll try to type it up for you:
Ralph:
“Ralph has been feeding cattle in New York state for 20 years. He runs 300 head a year through his feed lot, buying mountain (?) calves at 400 pounds and finishing them to about 1,000 pounds. …
“”I lean very heavily on college tests and they’re in favor of Stilbosol. The first time we tried it, back in 1955, I noticed a very definite improvement in appetite.
“”Stilbosol is a ‘must’ in our feeding operations. It has added to our profit. If it didn’t, we wouldn’t be using it.””
Dan:
“We bring our cattle into the lots around 600 pounds. Feed for about 150 days. … We feed to all weights (950 to 1150 pounds) and take a little chance from time to time and feed t heavier weights,” Dan stated.
“We get about 2.75 lbs. daily gain. And I figure Stilbosol accounts for (unreadable) to 1/2 lb. of that daily gain. …
“Does Stilbosol make us money? There’s no doubt about it! Stilbosol has revolutionized the cattle business. I guess it’s the only good break through in the last ten years.”
Bill:
“”I tested Stilbosol. Took a bunch of 315 Montana yearlings and split them up. One group was actually lighter than the other. The only change I made in their rations was the addition of Stilbosol. The lighter group received Stilbosol. I figured that the lot fed Stilbosol gained over 1 1/2 lb. per day more than the lot which had no Stilbosol.
“”With all the competition, a man can’t afford to pas up anything that will lower his cost of grain. Stilbosol is one of them.””
John:
“We were trying to find the cheapest, most efficient ration. One group of calves received a ration containing Stilbosol. Another received a similar ration without Stilbosol. The group receiving Stilbosol had a feed conversion of (I can’t tell the number, but it’s clearly a single digit followed by .4). The group receiving no Stilbosol had a feed conversion of 10.35. The Stilbosol group gained 2.49 pounds per day. The group that did not receive Stilbosol gained 2.13 pounds per day.
“With Stilbosol, we figure our cost of grain to be substantially lower than similar rations without Stilbosol.) “
Four farmers wouldn’t lie to us, would they?
Interestingly, eating large quantities of beef while pregnant was one of the things that The Independent article (linked at the top) noted was correlated with low sperm counts years down the road in the all-grown-up-fetuses.
Of course, people who eat more beef may just weigh more, or have some other factors besides adulterations in the cattle feed.
DES was also put in chicken feed, for the exact same reasons as cattle feed, until it came out that DES causes cancer in humans. It was discontinued as a feed additive in the late 70s.
These days, I don’t know what–if anything–they’re using to finish cattle, but we may note that the vast majority of cattle are still finished in feedlots where they get much fatter than they would naturally. (That is, by wandering around eating grass like they normally do.) Feedlot cattle are, to put it bluntly, unnaturally fat.
Now I’m going to do a little math. The Independent article was published in 2010, and states that the article on falling sperm rates was published 19 years prior, or in 1991. The study therefore compared men in the 1940s to men in the 1980s and 1990. Men in the 1940s were fetuses before the age of feedlots, birth control pills, DES, or DES-fed cattle and chicken. Young(ish) men in 1990, by contrast, were born between 1950 and 1970–all within the era of feedlots, BCPs, DES, and DES-fed cattle and chicken.
If it is true that sperm counts have stabilized since the 90s, that is a point potentially in favor of my theory, since after the 70s, DES was basically gone.
They say that about 1 in 200 people alive today is descended from Genghis Khan (or one of his brothers, if he had any.) Obviously most of the Great Khan’s descendants are in Asia; what about the rest of the world?
“Tracking [Y chromosome] mutations allows scientists to create a family tree of fathers and sons going back through time. … Two-thirds of modern European men are found on just three branches (called I1, R1a and R1b). Our results show that these branches each trace their paternal ancestry to a surprisingly recent individual (shown as red dots in Figure 1). By counting the number of mutations that have accumulated within each branch over the generations, we estimate that these three men lived at different times between 3,500 and 7,300 years ago.”
Female genetics–mitochondrial DNA–show no such feature. “… when looking at this maternal tree, there is no similar explosion. This indicates that whatever factors were responsible for this pattern were specific to men.”
This seems reasonably strong evidence that we aren’t just looking at something that could be explained away as founder/bottleneck effect, because I would expect such an effect to act equally on males and females. However, I don’t know if anyone has adequately addressed the question of patrilocality.
On a potentially related note, another study came up with this graph of Y chromosome diversity over time
Now if you ask me, these look like they’re describing the same phenomenon, but the dates are supposedly different.
A couple of thoughts:
1. I really really wish they’d made the Y Chromosome graph bigger and spread it out more so I can actually see what’s going on. According to the article summarizing the paper, the Siberian population did not suffer a decrease in Y chromosome diversity at this time, but I can’t tell it from looking at the graph.
2. Wow, look at the African Y chromosome diversity drop and then never fully recover. The Near East Y-diversity (the orange part) shoots up much higher than it was initially after the drop, as does the European. If the suspicion that farming was the cause of the drop is correct, then it looks like African Y chromosomes never quite recovered–consistent with the theory that African horticulture has traditionally been easy enough for women to do, leading to polygyny, leading to a few males dominating most of the women and the other males being excluded, etc. See, eg, West African Marriage and Child-Rearing Norms vs. African American Norms. (I’ve got another post on the subject, but it’s not going up for a few more weeks.)
3. What’s been happening to mtDNA diversity in the past few thousand years?
So was it agriculture? Or were did agriculture just make people sitting ducks for horse-born invaders? Or perhaps both?
In honor of strawberry season, I decided to investigate the history of this humble yet delicious fruit.
In the 1600s, F. virginiana–the Virginia strawberry–spread across Europe after its introduction from eastern North America. (Virginia, I assume.) In 1712, a French spy, Amédée-François Frézier, brought back a third wild strawberry, this one from Chile. Amusingly, the name “Frezier” actually comes from the French for “strawberry”:
