Peter Caradonna, for whom I work, once gave a lecture that started with a question: Who here is indigenous? One or two people of the 50 person crowd raised their hands. If we aren't indigenous that what are we? The same dictionary.com entry noted above included antonyms of indigenous as "foreign, alien". So if we are not indigenous are we then foreign? Where I live, in the United States, many people would take offense to that, so maybe we need to reevaluate how we interpret indigenous.
If you were to ask an American to give an example of indigenous people the most common answer would be American Indians. Ask them to name some characteristic traits of these indigenous people and you are likely to get answers that include a deep appreciation for the earth, respect for tradition, and awareness of their heritage. Nobel traits regardless of your origin. Traits that that some may say are lacking in our current society.
Prior to the industrial revolution much architecture around the world would have fit my description of indigenous simply due to the fact that it wasn't economical to bring in exotic materials for buildings. Additionally, the import of new and unfamiliar materials would often require the import of the skilled labor necessary to have it installed. With the rise of technology and transportation it became more economical to bring in non-regional materials. Advances in technology also saw the emergence of more standardized building materials symbolizing a loss of the connection to local materials. Following this standardization of materials came the standardization of aesthetic personified by the International Style of architecture.
The acceptance, and promotion by many leading architect of the time, of a singular International Style can be seen as the turning point away from the elements of indigenous architecture that made it valuable to its occupants and culture. People love to travel because it exposes them to something new. We visit different places to eat their food, listen to their music, see their architecture, experience their culture. Increased globalization is increasing homogenization, I've traveled to different states and seen the same style housing, the same strip malls, the same food, I had to search out the things that made it unique.
There is currently very little regional variation as far as building materials are concerned, the local lumber yard in New York and Arizona stock the same items, therefore the skill set of the labor force differs very little based on location. This isn't necessarily a bad thing, it is a part of the culture of our time, an ever shrinking world with ever growing technology. Another element of indigenous architecture that has largely been lost is its relationship to local conditions, specifically climate and culture. While some try to mimic the styles of the past it is often done without regard to why it was done in the past, which was usually a direct response to specific local conditions whether it be materials, climate, or use. Even if the reasoning is understood, indigenous architecture isn't about copying the past, it's about addressing the specific needs of the place in which it exists.
Modern, or contemporary, indigenous architecture can take the form of the favelas of Brazil or the High Line in New York. It is about its time and place so it is ever changing. If we think of ourselves as indigenous, we're all indigenous to somewhere, we can think of our architecture as indigenous and create an architecture of our time and place to serve our needs. I'm not a sociologist but maybe if we reconsidered our indigenousness we would approach things differently and feel more of an ownership to the place we are indigenous to. With ownership comes pride, which demands thoughtfulness, which will result in art, architecture, culture that is more unique and appropriate to its time and place.