So, what is the meaning of human existence? I suggest that it is the epic of the species, begun in biological evolution and prehistory, passed into recorded history, and urgently now, day by day, faster and faster into the indefinite future, it is also what we will choose to become.From Section I "The Reason We Exist":
In ordinary usage the word “meaning” implies intention, intention implies design, and design implies a designer. Any entity, any process, or definition of any word itself is put into play as a result of an intended consequence in the mind of the designer. This is the heart of the philosophical worldview of organized religions, and in particular their creation stories. Humanity, it assumes, exists for a purpose. Individuals have a purpose in being on Earth. Both humanity and individuals have meaning.
There is a second, broader way the word “meaning” is used and a very different worldview implied. It is that the accidents of history, not the intentions of a designer, are the source of meaning. There is no advance design, but instead overlapping networks of physical cause and effect. The unfolding of history is obedient only to the general laws of the Universe. Each event is random yet alters the probability of later events. During organic evolution, for example, the origin of one adaptation by natural selection makes the origin of certain other adaptations more likely. This concept of meaning, insofar as it illuminates humanity and the rest of life, is the worldview of science.
We are about to abandon natural selection , the process that created us, in order to direct our own evolution by volitional selection— the process of redesigning our biology and human nature as we wish them to be.
Humanity, I argue, arose entirely on its own through an accumulated series of events during evolution. We are not predestined to reach any goal, nor are we answerable to any power but our own. Only wisdom based on self-understanding, not piety, will save us.
...the grand master is multilevel selection . This formulation recognizes two levels at which natural selection operates: individual selection based on competition and cooperation among members of the same group, and group selection, which arises from competition and cooperation between groups. Group selection can occur through violent conflict or by competition between groups in the finding and harvesting of new resources.
Probably ... during the habiline period, a conflict ensued between individual-level selection, with individuals competing with other individuals in the same group, on the one side, and group-level selection , with competition among groups, on the other. The latter force promoted altruism and cooperation among all the group members. It led to innate group-wide morality and a sense of conscience and honor. The competition between the two forces can be succinctly expressed as follows: Within groups selfish individuals beat altruistic individuals, but groups of altruists beat groups of selfish individuals. Or, risking oversimplification, individual selection promoted sin, while group selection promoted virtue.
So it came to pass that humans are forever conflicted by their prehistory of multilevel selection. They are suspended in unstable and constantly changing positions between the two extreme forces that created us. We are unlikely to yield completely to either force as the ideal solution to our social and political turmoil. To give in completely to the instinctual urgings born from individual selection would be to dissolve society. At the opposite extreme, to surrender to the urgings from group selection would turn us into angelic robots— the outsized equivalents of ants.