Complex sentence: According to a genetic study by Embrapa, corn cultivation was introduced in South America from Mexico, in two great waves: the first, 5000 years ago, spread through the Andes; the second, about 2000 years ago, through the lowlands of South America.
Split into simpler sentences: According to a genetic study by Embrapa, corn cultivation was introduced in South America from Mexico, in two great waves: the first, more than 6000 years ago, spread through the Andes. The second wave, about 2000 years ago, through the lowlands of South America.