Parsis, Travellers, and Human Niches

Irish Travellers, 1954

I.

Why are there many kinds of plants and animals? Why doesn’t the best out-compete, eat, and destroy the others, rising to be the sole dominant species on Earth?

In ecology, a niche is an organism’s specific place within the environment. Some animals eat plants; some eat dung. Some live in the sea; others in trees. Different plants flower and grow in different seasons; some are pollinated by bees and some by flies. Every species has its specific niche.

The Competitive Exclusion Principle (aka Gause’s Law) states that ‘no two species can occupy the same niche’ (or positively, ‘two species coexisting must have different niches.’) For example, if squirrels and chipmunks both want to nest in the treetops and eat nuts, (and there are limited treetops and nuts,) then over time, whichever species is better at finding nuts and controlling the treetops will dominate the niche and the other, less successful species will have to find a new niche.

If squirrels are dominating the treetops and nuts, this leaves plenty of room for rabbits to eat grass and owls to eat squirrels.

II. So I was reading recently about the Parsis and the Travellers. The Parsis, as we discussed on Monday, are Zoroastrians, originally from Persia (modern-day Iran,) who settled in India about a thousand yeas ago. They’re often referred to as the “Jews of India” because they played a similar role in Indian society to that historically played by Jews in Europe.*

*Yes I know there are actual Jews in India.

The Travellers are an Irish group that’s functionally similar to Gypsies, but in fact genetically Irish:

In 2011 an analysis of DNA from 40 Travellers was undertaken at the Royal College of Surgeons in Dublin and the University of Edinburgh. The study provided evidence that Irish Travellers are a distinct Irish ethnic minority, who separated from the settled Irish community at least 1000 years ago; the claim was made that they are as distinct from the settled community as Icelanders are from Norwegians.[36]

It appears that Ireland did not have enough Gypsies of Indian extraction and so had to invent its own.

And though I originally thought that only in jest, why not? Gypsies occupy a particular niche, and if there are Gypsies around, I doubt anyone else is going to out-compete them for that niche. But if there aren’t any, then surely someone else could.

According to Wikipedia, the Travellers traditionally were tinkers, mended tinware (like pots) and acquiring dead/old horses for slaughter.

The Gypsies appear to have been originally itinerant musicians/entertainers, but have also worked as tinkers, smiths, peddlers, miners, and horse traders (today, car salesmen.)

These are not glorious jobs, but they are jobs, and peripatetic people have done them.

Jews (and Parsis, presumably) also filled a social niche, using their network of family/religious ties to other Jews throughout the diaspora as the basis of a high-trust business/trading network at a time when trade was difficult and routes were dangerous.

On the subject of “Madeburg rights” or law in Eastern Europe, Wikipedia notes:

In medieval Poland, Jews were invited along with German merchants to settle in cities as part of the royal city development policy.

Jews and Germans were sometimes competitors in those cities. Jews lived under privileges that they carefully negotiated with the king or emperor. They were not subject to city jurisdiction. These privileges guaranteed that they could maintain communal autonomy, live according to their laws, and be subjected directly to the royal jurisdiction in matters concerning Jews and Christians. One of the provisions granted to Jews was that a Jew could not be made Gewährsmann, that is, he could not be compelled to tell from whom he acquired any object which had been sold or pledged to him and which was found in his possession. Other provisions frequently mentioned were a permission to sell meat to Christians, or employ Christian servants.

External merchants coming into the city were not allowed to trade on their own, but instead forced to sell the goods they had brought into the city to local traders, if any wished to buy them.

Note that this situation is immensely better if you already know the guy you’re selling to inside the city and he’s not inclined to cheat you because you both come from the same small, tight-knit group.

Further:

Under Bolesław III (1102–1139), the Jews, encouraged by the tolerant regime of this ruler, settled throughout Poland, including over the border in Lithuanian territory as far as Kiev.[32] Bolesław III recognized the utility of Jews in the development of the commercial interests of his country. … Mieszko III employed Jews in his mint as engravers and technical supervisors, and the coins minted during that period even bear Hebraic markings.[30] … Jews enjoyed undisturbed peace and prosperity in the many principalities into which the country was then divided; they formed the middle class in a country where the general population consisted of landlords (developing into szlachta, the unique Polish nobility) and peasants, and they were instrumental in promoting the commercial interests of the land.

If you need merchants and goldsmiths, someone will become merchants and goldsmiths. If it’s useful for those merchants and goldsmiths to all be part of one small, close-knit group, then a small, close-knit group is likely to step into that niche and out-compete anyone else trying to occupy it.

The similarity of the Parsis to the Jews probably has less to do with them both being monotheists (after all, Christians, Muslims, and Sikhs are also monotheists,) and more to do with them both being small but widely-flung diasporic communities united by a common religion that allows them to use their group as a source of trustworthy business partners.

Over hundreds or thousands of years, humans might not just move into social niches, but actually become adapted to them–Jew and Parsis are both reported to be very smart, for example.

III. I can think of several other cases of ethnic groups moving into a particular niche. In the US, the gambling and bootleg alcohol trade were long dominated by ethnic Sicilians, while the crack and heroin trades have been dominated by black and Hispanic gangs.

Note that, while these activities are (often) illegal, they are still things that people want to do and the mafia/gangs are basically providing a goods/services to their customers. As they see it, they’re just businessmen. They’re out to make money, not commit random violence.

That said, these guys do commit lots of violence, including murder, blackmail and extortion. Even violent crime can be its own niche, if it pays well enough.

(Ironically, police crackdown on ethnic Sicilian control in NYC coincided with a massive increase in crime–did the mafia, by controlling a particular territory, keep out competing bands of criminals?)

On a more pleasant note, society is now rich enough that many people can make a living as professional sports stars, marry other professional sports stars, and have children who go on to also be professional sports stars. It’s not quite at the level of “a caste of professional athletes genetically optimized for particular sports,” but if this kept up for a few hundred years, it could be.

Similarly, over in Nepal, “Sherpa” isn’t just a job, it’s an ethnic group. Sherpas, due to their high elevation adaptation, have an advantage over the rest of us when it comes to scaling Mt. Everest, and I hear the global mountain-climbing industry pays them well for their services. A Sherpa who can successfully scale Mt. Everest many times, make lots of money, and raise lots of children in an otherwise impoverished nation is thus a successful Sherpa–and contributing to the group’s further genetic and cultural specialization in the “climbing Mt. Everest” niche.

India, of course, is the ultimate case of ethnic groups specializing into specific jobs–it’d be interesting to see what adaptations different groups have acquired over the years.

I also wonder if the caste system is an effective way to minimize competition between groups in a multi-ethnic society, or if it leads to more resentment and instability in the long run.

Zoroastrian (Parsi) DNA

Farvahar. Persepolis, Iran.

Zoroastrianism is one of the world’s oldest surviving religions and possibly its first monotheistic one. It emerged in now-Iran about 3,000 years ago, but following the Arab (Islamic) conquest of Persia, many Zoroastrians migrated to India, where they became known as the Parsi (from the word for “Persian.”) To be clear, where this post refers to “Parsis” it means the specific Zoroastrian community in India, and where it refers to “Iranian Zoroastrians” it means the Zoroastrians currently living in Iran.

Although Zoroastrianism was once the official state religion of Persia, today only about 190,000 believers remain (according to Wikipedia,) and their numbers are declining.

If you’re thinking that a diasporic community of monotheists sounds familiar, you’re in good company. According to Wikipedia:

Portuguese physician Garcia de Orta observed in 1563 that “there are merchants … in the kingdom of Cambaia … known as Esparcis. We Portuguese call them Jews, but they are not so. They are Gentios.”

Another parallel: Ashkenazi Jews and Parsis are both reported to be very smart. Famous Parsis include Queen Guitarist Freddy Mercury, nuclear physicist Homi J. Bhabha, and our Harvard-employed friend, Homi K. Bhabha.

Lopez et al have recently carried out a very interesting study of Zoroastrian DNA, The Genetic Legacy of Zoroastrianism in Iran and India: Insights into Population Structure, Gene Flow, and Selection:

Historical records indicate that migrants from Persia brought Zoroastrianism to India, but there is debate over the timing of these migrations. Here we present genome-wide autosomal, Y chromosome, and mitochondrial DNA data from Iranian and Indian Zoroastrians and neighboring modern-day Indian and Iranian populations and conduct a comprehensive genome-wide genetic analysis in these groups. … we find that Zoroastrians in Iran and India have increased genetic homogeneity relative to other sampled groups in their respective countries, consistent with their current practices of endogamy. Despite this, we infer that Indian Zoroastrians (Parsis) intermixed with local groups sometime after their arrival in India, dating this mixture to 690–1390 CE and providing strong evidence that Iranian Zoroastrian ancestry was maintained primarily through the male line.

Note that all diasporic–that is, migrant–groups appear to be heavily male. Women tend to stay put while men move and take new wives in their new homelands.

By making use of the rich information in DNA from ancient human remains, we also highlight admixture in the ancestors of Iranian Zoroastrians dated to 570 BCE–746 CE, older than admixture seen in any other sampled Iranian group, consistent with a long-standing isolation of Zoroastrians from outside groups. …

Admixture with whom? (Let’s just read the paper and see if it answers the question):

Furthermore, a recent study using genome-wide autosomal DNA found that haplotype patterns in Iranian Zoroastrians matched more than other modern Iranian groups to a high-coverage early Neolithic farmer genome from Iran

A study of four restriction fragment length polymorphisms (RFLPs) suggested a closer genetic affinity of Parsis to Southern Europeans than to non-Parsis from Bombay. Furthermore, NRY haplotype analysis and patterns of variation at the HLA locus in the Parsis of Pakistan support a predominately Iranian origin. …

In (1) and (2), we detected admixture in the Parsis dated to 27 (range: 17–38) and 32 (19–44) generations ago, respectively, in each case between one predominantly Indian-like source and one predominantly Iranian-like source. This large contribution from an Iranian-like source (∼64%–76%) is not seen in any of our other 7 Indian clusters, though we detect admixture in each of these 7 groups from wide-ranging sources related to modern day individuals from Bangladesh, Cambodia, Europe, Pakistan, or of Jewish heritage (Figures 2 and S7, Tables S5–S7). For Iranian Zoroastrians, we detect admixture only under analysis (2), occurring 66 (42–89) generations ago between a source best genetically explained as a mixture of modern-day Croatian and Cypriot samples, and a second source matching to the Neolithic Iranian farmer WC1. … The two Iranian Zoroastrians that had been excluded as outliers exhibited admixture patterns more similar to the Lebanese, Turkish Jews, or Iranian Bandari individuals than to Zoroastrians (Table S8).

Parsi Wedding, 1905

If I assume a generation is about 25 years long, 27 generations was about 675 years ago; 32 was about 800 years ago. (Though given the wide range on these dates, perhaps we should estimate between 425 and 1,100 years ago.) This sounds consistent with Parsis taking local wives after they arrived in India between the 8th and 10th century CE (after the Arab conquest of Perisa.) Also consistently, this admixture isn’t found in Iranian Zoroastrians.

The Iranians’ admixture occurred about 1,050 and 2,225 years ago, which is an awfully broad time range. Could Croatian or Cypriot migrants have arrived due to the Greek/Roma/ Byzantine Empires? Were they incorporated into the Persian Empire as a result of its territorial conquests or the Arab conquest? Or were they just long-distance merchants who happened to wander into the area?

The Fire Temple of Baku

The authors found that Parsi priests had “the lowest gene diversity values of all population samples studied for both Y and mtDNA,” though they didn’t have enough Iranian Zoroastrian priest samples to compare them to Parsi priests. (I bet this is similar to what you’d find if you sampled Orthodox rabbis.)

Finally, in the genetic selection and diseases section, the authors write:

In the case of the Iranian Zoroastrians, … some of the most significant SNPs… are located upstream of gene SLC39A10 … with an important role in humoral immunity61 or in CALB2 … which plays a major role in the cerebellar physiology.62

With regard to the positive selection tests on Parsis versus India Hindu/Gujarati groups, the most significant SNPs were embedded in WWOX … associated with neurological disorders like early epilepsy … and in a region in chromosome 20 … (see Table S11 for a complete list). …

Genetic isolation and endogamous practices can be associated with higher frequencies of disease prevalence. For example, there are reports claiming a high recurrence of diseases such as diabetes among the Iranian Zoroastrians, and Parkinson, colon cancer, or the deficiency of G6PD, an enzyme that triggers the sudden reduction of red blood cells, among the Parsis.

However, the authors warn that these results are weak (these are rare conditions in an already small population) and cannot not be depended upon.