Human beings are ultimately nothing but carriers-passageways- for genes. They ride us into the ground like racehorses from generation to generation. Genes don't think about what constitutes good or evil. They don't care whether we are happy or unhappy. We're just means to an end for them. The only thing they think about is what is most efficient for them.
The quote from Haruki Murakami's "1Q84" suggests that humans primarily serve as vessels for the continuation of genes. It highlights the idea that our existence and experiences are secondary to the biological imperatives of our genetic material. This perspective emphasizes the notion that we may be exploited by our genes, much like racehorses being used for racing purposes, with the sole aim of ensuring their survival and propagation through generations.