Read the passage carefully and answer the following questions:
For traditional Darwinian natural selection to work, the entities in question must display some property or ability that can be inherited, and that results in their having more offspring than the competition. For instance, the first creatures with vision, however fuzzy, were presumably better at avoiding predators and finding mates than the sightless members of their population, and had more surviving progeny for that reason. In technical terms, then, selected entities must exist in populations showing heritable variation in fitness, greater fitness resulting in these entities’ differential reproduction.
Even if inherited properties are the result of undirected or ‘random’ mutation, repeating the selection process over generations will incrementally improve on them. This produces complex adaptations such as the vertebrate eye, with its highly sophisticated function. Lightsensitive areas acquired lenses for focusing and means for distinguishing colours step by advantageous step, ultimately producing modern eyes that are clearly for seeing. So even without an overall purpose, evolution, through selection, creates something that behaves as if it has a goal.
Back in 1979, when Lovelock’s first popular book, Gaia: A New Look at Life on Earth, came out, the wider field of evolutionary biology was becoming a very reductionist discipline. Richard Dawkins’s The Selfish Gene had been published three years earlier, and it promoted a hardcore gene-centrism insisting that we look at genes as the fundamental units of selection - that is, the thing upon which natural selection operates. His claim was that genes were the reproducing entities par excellence, because they are the only things that always replicate and produce enduring lineages. Replication here means making fairly exact one-to-one copies, as genes (and asexual organisms such as bacteria) do. Reproduction, though, is a more inclusive and forgiving term - it’s what we humans and other sexual species do, when we make offspring that resemble both parents, but each only imperfectly. Still, this sloppy process exhibits heritable variation in fitness, and so supports evolution by natural selection.
In recent decades, many theorists have come to understand that there can be reproducing or even replicating entities evolving by natural selection at several levels of the biological hierarchy - not just in the domains of replicating genes and bacteria, or even sexual creatures such as ourselves. They have come to embrace something called multilevel selection theory: the idea that life can be represented as a hierarchy of entities nested together in larger entities, like Russian dolls. As the philosopher of science Peter Godfrey-Smith puts it, ‘genes, cells, social groups and species can all, in principle, enter into change of this kind’.
But to qualify as a thing on which natural selection can operate - a unit of selection - ‘they must be connected by parent-offspring relations; they must have the capacity to reproduce,’ Godfrey-Smith continues. It’s the requirement for reproduction and leaving parent-offspring lineages (lines of descent) we need to focus on here, because they remain essential in traditional formulations. Without reproduction, fitness is undefined, and heritability seems to make no sense. And without lines of descent, at some level, how can we even conceive of natural selection?
Q. “So even without an overall purpose, evolution, through selection, creates something that behaves as if it has a goal” Which of the following best captures the essence of this statement?