 Once something is lost, it is very hard or impossible to re-evolve. So Leilimus are this group of lizards that include over 250 species. They are found in the southern half of South America, but most of them are found on the Andes mountain. The key for them to adapt to the high mountains of the Andes, which are really cold, is to evolve repeated times, life-bearing. One of the most groundbreaking results is that we found that these lizards originated in cold high mountain areas, but then dispersed into warm lowland areas and re-evolved egg laying. We have found evidence that these lizards might be breaking dollars long, which states that structures once lost cannot be regained. The evolutionary history of these lizards is very strongly linked to the Andes mountains. As the Andes have uplifted in the last 20 million years, which is very young in geological timescale, we have found that these lizards have diversified at exactly the same rate that the Andes have uplifted. Thanks to this study, we have found how important it is to understand the biological diversity in the light of geological diversity and the complexity of a landscape.