Scientists cracked the human genome years ago, but for the first time are considering synthesizing one from scratch. According to a report from the New York Times, a recent letter presented at a closed-door meeting of scientists at Harvard University reveals the details of the ambitious plan.

The idea of a completely synthetic human genome has understandably raised a number of questions, and even a few ethical concerns. Among other reasons, the ability to synthesize all of the DNA contained in a human chromosome could one day lead to walking, talking humans with no biological parents.

The Harvard presenters asked attendees not to reveal the subject matter or make posts on social media during the meeting. Organizers said that the proposed project could revolutionize our understanding of human genetics and redefine the scope of possibilities in the genetic engineering field.

Critics of the idea raised points that have been discussed for some time now. Would the ability to synthesize a human genome lead to people engineered to have desired traits, like good looks, higher intelligence or physical strength?

A letter written by Stanford bioengineer Drew Endy and Northwestern University bioethicist Laurie Zoloth voiced these concerns regarding the project. “Would it be O.K., for example, to sequence and then synthesize Einstein’s genome? If so how many Einstein genomes should be made and installed in cells, and who would get to make them?”

Currently, it’s relatively difficult to synthesize a genome. Scientists can create DNA strands that consist of roughly 200 base pairs; a single gene can consist of hundreds or thousands of base pairs. Limitations to the technologies are quickly eroding, however, and scientists say it won’t be long before synthesizing the billions of letters needed for a human genome becomes feasible.

The project has not yet received funding, but could one day lead to a drastically different paradigm about what’s possible in the world of genetics.

The letter can be found here.