If you like orange juice on the side with your breakfast, you should be thanking climate change for that. Without it, your morning refreshment would’ve been a lot more expensive.
Images courtesy: Reuters
According to new research, sudden changes in the climate between 6 to 8 million years ago caused citrus trees to migrate out of the Himalayas and to the rest of the world.
To study this phenomenon, scientists mapped the genomes of 58 different kinds of citrus fruits. They found that citrus trees today are descendants of 10 older species that used to reside in the southeast foothills of the Himalayas, including parts of Assam, northern Myanmar, and western Yunnan.
It’s already known that the Himalayas are constantly growing, at about 1 centimetre a year. That was happening 8 million years ago too. As a result, when the mountain range eventually got high enough, the monsoons on its slopes got weaker and drier, forcing the citrus to spread further throughout southeast Asia, where they then gradually adapted to the newer biomes.
Despite how common they are now, until this point it was unclear just where citrus trees originated. This study doesn’t just show their history, says co-author Daniel Rokhsar from UC Berkeley, but also gives geneticists a road map to create new varieties of the trees through gene modification.
In fact, the citrus fruits we know today are evolved forms of ancient trees. Oranges, the bitter rind of which can be used to make marmalade, is a mix of ancient wild mandarins and wild pomelo. And scientists still aren’t sure whether that combination happened naturally or because of the efforts of farmers.
When scientists manage to parse all this data, they could potentially create varieties of citrus we’ve never seen before; perhaps lemons that can grow to the size of your fist, or oranges protected by a hard shell. The possibilities are limitless.