I've been teaching Koreans for awhile now, and have observed a lot about their culture. They live on a peninsula, surrounded by the ocean on three sides, so as you'd expect, their culture is in many ways a maritime culture. You can see this in their diet, which is heavily reliant on seafood. Yet anthropologists believe Koreans originally came from north-central Asia (somewhere north of Mongolia). There are certain linguistic similarities to Mongolian and other Central Asian languages. Although they left Central Asia thousands of years ago, there are still traces of their origins in modern Korean culture. For example, in their diet. Koreans love to barbeque meat, which is a trait of Central Asian people, and of plains people generally. Also, in smaller villages, the sport of wrestling is popular, as it is among Mongolian and Turkic people of Central Asia. Koreans' preference for sitting and lying on mats on the floor may also be a holdover from their nomadic past, when they lived in tents. Drums are important in traditional Korean music, and they are worn on the chest (like in a marching band). This also points toward their Central Asian background (many plains cultures use drums).
Some social groups adapt quickly when they migrate into a new environment. The Cajuns of southern Louisiana, for instance, have developed a culture suited to their bayou environment in a relatively short period of time. The Cajun/Acadian culture is very different from the culture of France, where their ancestors came from, or even Nova Scotia, where they first settled in North America.
Other groups are slower to adapt, and even after many centuries the original environment in which their culture was born is still evident. Look at the British, for example. Living on an island, one would expect to find a maritime culture. While Scottish and English are famous sailors, seafood has never been a mainstay of the British diet. Sure, fish and chips may be a famous dish in England-- but the English have to batter and deep fry fish before they consider it palatable. Japanese and other maritime peoples eat fish raw, or cooked with little seasoning. Beef, not fish, is the preferred source of protein in Britain, and has been since deer became scarce. This is because the Celtic, Saxon, Norman and other peoples who migrated to Britain were not maritime people. They were woodland people, with a woodland diet, from the mainland.
There are 6 geographic cultural groups, by my estimate.
1. Plains Cultures. People who live on steppe or prairie. These cultures are nomadic or semi-nomadic originally. They are hunters, not agriculturalists, so meat is a big part of their diet. Much of their culture references the most important animal to plains nomads: the horse.
2. Northern Woodland Culture. The culture of much of Europe. Agriculture and animal-rearing are important.
3. Tropical. The cultures of Southeast Asia, India, and Central Africa.
4. Arid/Semi-arid. The cultures of Arabia, North Africa and the American Southwest (Hopi, Navajo, etc.)
5. Maritime. There are two types of maritime culture: sailors and fisherman.