Meat grown in a laboratory from cultured cells is turning that vision is a reality. Several start-ups are developing lab-grown beef, pork, poultry and seafood—among them Mosa Meat, Memphis Meats, SuperMeat and Finless Foods. And the field is attracting millions in funding. In 2017, for instance, Memphis Meats took in $17 million from sources that included Bill Gates and agricultural company Cargill, according to a report from Scientific American.

If widely adopted, lab-grown meat, also called clean meat, could eliminate much of the cruel, unethical treatment of animals that are raised for food. It could also reduce the considerable environmental costs of meat production; resources would be needed only to generate and sustain cultured cells, not an entire organism from birth.

The meat is made by first taking a muscle sample from an animal, Scientific American reported. Technicians collect stem cells from the tissue, multiply them dramatically and allow them to differentiate into primitive fibers that then bulk up to form muscle tissue. Mosa Meat says that one tissue sample from a cow can yield enough muscle tissue to make 80,000 quarter-pounders.

According to a post in The Guardian, most meat people eat in 2040 will not come from animals, citing a report that predicts 60% will be either grown in vats or replaced by plant-based products that look and taste like meat.

The report by the global consultancy AT Kearney, based on expert interviews, highlights the heavy environmental impacts of conventional meat production and the concerns people have about the welfare of animals under industrial farming.