How to make a flying human

Question

We are in a future where genetics has advanced to a point where arbitrary modifications can be done to living beings. Now a geneticist wants to make a flying human. That is, he wants to modify a human so that his arms turn into wings (but still with hands at the end, so doing all things humans usually do is possible), and so that the human could actually fly using those wings. But apart of the wings, the modifications should be as conservative as possible; that is, it should be the minimum change necessary to make the human fly, and it should affect the normal human abilities as little as possible. In particular, he should still look as human as possible. If possible, he should have the ability to go directly from running to flying.

My question is: What minimal changes would have to be made to the human body to enable flying?

Answer 1

The largest bird ever to fly were the Teratorns (a type of Condor), the largest of which, Argentavis magnificens, had a wingspan of 6 to 8 metres, and weighed 70kg.

Source: http://library.sandiegozoo.org/factsheets/_extinct/teratorn/teratorn.htm

The average weight of an adult human is 62kg, which is actually less than that of the Teratorn.

So, a lightweight human in theory could fly. Clearly you would modify the humans not to store large amounts of fat, and for a thinner frame. Bird bones are not actually lighter than human bones as they are denser and stiffer despite being hollow. You would somehow need to remove the weight of the wings and other adaptions from the rest of the body to keep the weight constant as you add flight capability.

Other adaptations made in birds that would most likely be needed in your humans are:

• A deep, solid breastbone (sternum) to which the wing muscles can be anchored.
• Get rid of un-needed bones. For example fewer fingers, thinner skulls, etc.
• Keep reproductive organs tiny most of the time, have a breeding season.
• Much larger more efficient lungs (continuous flow)
• A more powerful heart and increased blood flow to the wing muscles

Source: http://web.stanford.edu/group/stanfordbirds/text/essays/Adaptations.html

The most visible change needed though would be the six meter wingspan. Each arm would need to be 3 meters long. In other words the arm would extend from their shoulder and the elbow would nearly reach the floor, and then the forearm would extend back up the same distance to place their hand by their shoulder. Even folded up this would be a massive deal, and would greatly limit them in their daily lives.

The wrist may well need to be elongated as well to give the wings 3 points of articulation, which would mean the first two bones would not need to be so long but the hand becomes even less flexible and useful.

While they would have no problem reaching top shelves they would have to be constantly folding their arms and find most areas designed for normal humans incredibly claustrophobic. All furniture and living areas would need to be designed especially for their use or be uncomfortable. In particular they would struggle to reach or do anything close to them, preferring to actually be a distance from anything they are working with.

So in conclusion, your flying humans would have enormously over-long arms and clumsy few-fingered hands. They would have large massively muscled and protruding chests and thin fragile skulls.

But they would fly.