The researchers studied how a gene called Hd1 affects when rice plants flower. They looked at different types of rice from China and found that changes in Hd1 are linked to when the plants bloom in short days. By analyzing the DNA of rice plants, they discovered that Hd1 evolved differently in different types of rice, suggesting that rice was domesticated from various wild rice groups. They also found that wild rice with specific Hd1 changes only grows in Southern China, hinting that this region might be where rice was first domesticated. This research helps us understand how rice plants were changed over time to adapt to different light conditions and when they flower.