Sapiens: Chapter 20 Summary & Analysis

Harari thinks about the future of Homo sapiens. He thinks our species has long tinkered with nature—our ancestors, for example, realized that they could breed fat hens with slow cocks and yield fat, slow offspring that were easier to catch. Today, scientists in laboratories are engineering living beings. Brazilian artist Eduardo Kac even paid a laboratory to breed him a fluorescent rabbit. The lab did it by implanting fluorescent jellyfish DNA into a rabbit embryo. Harari thinks about three types of biological engineering: biological enhancement (such as mixing DNA), cyborgs (adding inorganic parts to organic beings), and artificial intelligence (inorganic life).

Biological engineering is quite common in human societies. Humans even used to castrate young men so they’d have soprano singing voices. Nowadays, however, scientists can do a lot more. They even engineered a mouse with a human ear growing on its back. Harari worries about governments who might try to genetically engineer superior beings that can subjugate the rest of humanity. He also worries about animals being mistreated in laboratory experiments. Geneticists are even trying to extract Neanderthal DNA from the human genome and resurrect the Neanderthals. Harari wonders why they want to do this. He also worries about geneticists tinkering with human DNA so much that they turn Homo sapiens into something else entirely. 

Cyborgs are living creatures whose bodies are enhanced with artificial technology. For example, DARPA (a U.S. military research agency) is currently funding research into insects embedded with computer chips, so that they can fly behind enemy lines and transmit information back to the US government. Harari ponders cyborg technology like hearing aid implants and thought-controlled detachable bionic limbs. Scientists are also working on a way for brains and computers to directly interface. He imagines people linking their brains up through interfaces that let them experience other people’s memories. Harari suggests that such changes would be so radical, it’s hard to anticipate how they might affect humanity. 

Harari thinks about machine learning and artificial intelligence next. He imagines remarkable machines that can play chess or invest in the stock market far better than humans can. Then he imagines technology that allows people to upload their brains to a hard drive. He wonders if the digital brain would have thoughts and feelings too. Harari thinks it’s foolish to overlook the possibility of intelligent, inorganic beings being part of the world in the future.

Harari worries about the “breakneck speed” of developments in bioengineering, cyborg technology, and artificial intelligence. He worries about employers asking prospective candidates to send their DNA samples instead of their CVs, and whether this would lead to genetic profiling. He also worries about companies fiddling with bioengineering and creating entire new species of animals for profit. He worries about advances in medicine that create a “superhuman elite” who might subjugate the rest of humanity. He wonders if Homo sapiens are on the precipice of a new dawn—an age of machines that will take over the world and eclipse our status at the top of the food chain.  

Harari knows that a lot of what he says is speculation, and he doesn’t want to alarm his readers. But he does wonder about what the future will look like with new beings in it that surpass Sapiens. He wonders what political and ethical systems such beings would adopt. Most scientists say they’re doing research to cure disease or save lives. Harari worries about this, and he thinks that the rest of humanity should try and influence the direction that scientists take, before it’s too late.