I think that 1) would be easier to prove than 2). Perhaps by analysing historical instances it might be possible to refine this hypothesis?

I think you are right about ‘good’ and ‘bad’ invasions. The Mongol invasion of Iran was definitely bad but the Roman and Norman invasions of Britain seem to have done more good than harm. But how can we judge? I remember a friend commenting that the Spanish invasion of South America is generally regarded as a wicked crime and a disaster – but the civilization they destroyed was cruel, blood-thirsty and a planetry blight.

It has been thought that Indigenous Australian came to ‘Sahul’ (the single Pleistocene landmass encompassing Australia, New Guinea, and Tasmania)via New Guinea 50,000 years ago. [ http://sahultime.monash.edu.au/explore.html ] It is now believed that they diversified genetically from the other group of people inhabiting the earth 80,000 years ago.

Yet the evidence of Dreaming sites seems to suggest that indigenous peoples were in Australia the seas were higher than they are currently, which if the Sahul timeline is correct, must be some time prior to 100,000 years. So…

The Turkish invasion of Iran is very complex for someone not familiar with the shifting territories and dynasties of central asia and the middle east. But under Toghril Beg’s successor it seems Iran enjoyed a cultural and scientific renaissance. And yes the French province of Normandy takes its name from the first norman (Norse man) invasion of France in the eighth century ending the Frankish Carolingian Empire. The invading vikings burnt the Abbey of Fontenelle, and the monks also lost archives and libraries in the invasion.

So, invasions can lead to both a increase and a loss of knowledge. I wonder does that mean some invasions are advantageous and others disadvantageous for humanity?

I have not been to Spain for a while and your story is attracting me to the idea!
Europe’s population is becoming very mixed very quickly (as is Australia’s) and the experience of adjusting to other language and cultures is taking place everywhere. From an evolutionary point of view it is likely to produce ‘hybrid vigour’ and to decrease the incidence of inherited diseases.
I am not sure how biologists define a species but do know that many animal species are becoming extinct http://en.wikipedia.org/wiki/List_of_extinct_mammals. It is hard to know what line humans should take on this issue. I am horrified by the current rate of extinction and, like many people of my age, would rather the world stayed as it was than continued to change – except of course for its many bad aspects which most certainly need to change.
A curious aspect of the Turkish invasion of Iran (and most invasions of China) is that the invaders became ultra-enthusiastic adopters of the cultures of the countries they conquered – as indeed happened with the Norman invasion of France.

Thank you for all the facts. In Europe there have been so many population flows that the idea of ‘indigenous’ is hardly a useful term – at least not in comparison with Australia.
Perhaps we should widen the discussion further and think about what was long thought to be the extinction of Neanderthal man. Genetics indicates that inter-breeding took place but on the whole it seems that, as in the evolution of all species, a more evolved species led to the extinction of less evolved species, because stronger bodies and stronger brains create a competitive advantage. Setting morality to one side, it is within the bounds of possibility that this is what is happening to the indigenous people of Australia and to less-skilled people in developed countries.

Not all of the cultures listed are undisputedly indigenous cultures.

A few facts:
(1) Granada was an Ibero-Celtic settlement which the Greeks were first to colonize.
(2) Legend attributes the founding of the city of Barcelona to the Greek hero Hercules, however the name has Iberian origins.
(3) The Roman campaign to conquer Briton was gradual and all subsequent invasions and rules were fairly sporadic until the Norman conquest in 1066.
(4) The Norman invasion of Ireland was at the request of Dermot MacMurrough (Diarmait Mac Murchada), the ousted King of Leinster, who sought their help in regaining his kingdom.
(5) The city of Constantinople was renamed Istanbul.
(6) The Qing Empire was forced to cede Manchuria north of the Amur to Russia under the Treaty of Aigun.
(7) Evidence for a prior Dravidian culture is said to be evidenced by the large urban ruins of what has been called the “Indus valley culture”.

It seems some arrivals have more or less hallmarks of a military campaign and are carried out with greater or lesser assent of the legitimate ruler. Long campaigns to prevent foreign invasions seem to leave material evidence of seacoast(ie. St Bruno’s Fort in Lisbon) or boundary fortifications (ie. Hadrians Wall).

Thank you for the extended story! I am really getting a feel for what it would have been like to have been a resident of (1) Granada when the Moors arrived (2) Barcelona when Castillian became the official language (3) Britannia when the Romans, Anglo-Saxons, Danes or Normans arrived (4) Ireland when the English arrived (5) Constantinople, as the great capital of Greek civilization, when it fell to the Turks in 1453 (6) Beijing when it fell to the Manchurians in 1644 (7) India when the Aryans arrived. Wouldn’t you say that each of these was an example of indigenous people being militarily, culturally, and often linguistically, overcome by foreigners?

Although relative minority status may affect the degree of recognition their culture is accorded. The moari are 11-12% of New Zealand’s total population.
[ http://www.tourism.net.nz/new-zealand/about-new-zealand/maori-culture.html ]

In the examples you give Jewish and Christian Turks make up less than 0.2% of the population, Palestinians in Israel are approximately 20% of the population and the Flemish comprise a majority at 60% of Belgium’s population.

To illustrate that minority status is not the critical factor consider yourself as a minority in Spain:

The Alvarez family may have invited you to stay with them after meeting you at a restuarant in Barcelonia while you were on vacation. If they gave you a room in their home, taught you to speak Spanish, included you in their evening ritual of grilling Catalan sausage, drinking Sanguia and dancing Flamenco in the evenings and Jose gave you guitar and violin lessons, you would probably be feeling quite friendly towards your Spanish hosts.

If Santiago introduced you to the delights of breeding Spanish flowers (in particular pomegranates, carnations and blue bells) and paid you in Euro for being a judge at the Festival of Flowers, strange as you might feel in dress of the vaqueros you would probably agree to don national costume for the event.

When Maria’s wedding was held after she graduated from Bau you would probably also be delighted that she chose La Sagrada Familia for the ceremony. (And even more astonished when her novio asked you to be padrino de boda.) But afterall you reason, you had watched Maria grow up from age five! (They are also thinking of calling their first boy Tomas after you).

The Alvez parents are now over sixty seven and considering retiring to Costa de la Luz and ask if you would like to rent the house?

Thank you for the analogy. It helps me understand the situation while also reminding me of (1) the treatment of Jewish and Christian minorities in Turkey, since the 1930s (2) the treatment of the the Palestinians in Israel since 1948 (3) the treatment of the other minorities in many other countries – in fact the Flemish population of Brussels is not without grudges. Some minorities yield to the oppression and ‘go under’. Other minorities seem to resist the oppression and, in some respects, flourish. I do not think one can regard the unemployed as a minority in quite this sense but there are many ‘laws for the rich’ which weigh against them. For example, in the UK there are planning laws which prevent poor people from buying land at agricultural prices and using it to build dwellings and start businesses. (I support these laws but regret their consequences).