Speciation Quotes

If evolution almost always occurs by rapid speciation in small, peripheral isolates, then what should the fossil record look like? We are not likely to detect the event of speciation itself. It happens too fast, in too small a group, isolated too far from the ancestral range.

The history of life is more adequately represented by a picture of 'punctuated equilibria' than by the notion of phyletic gradualism. The history of evolution is not one of stately unfolding, but a story of homeostatic equilibria, disturbed only 'rarely' (i.e. rather often in the fullness of time) by rapid and episodic events of speciation.

anyone who writes about "Darwin's theory of evolutionin the singular, without segregating the theories of gradual evolution, common descent, speciation, and the mechanism of natural selection, will be quite unable to discuss the subject competently.

Evolution is the fundamental idea in all of life science, in all of biology. The key to our being here now is time, 4.54 billion (Earth) years of time. Nuclear fission wasn't discovered until long after Charles Darwin and Alfred Russell Wallace published their original books and papers, for example. Our ability to measure atomic masses wasn't developed until long after their deaths. These features of nature enabled us to reckon the age of the Earth and compare it with speciation rates here.

The theory of punctuated equilibrium, proposed by Niles Eldredge and myself, is not, as so often misunderstood, a radical claim for truly sudden change, but a recognition that ordinary processes of speciation, properly conceived as glacially slow by the standard of our own life-span, do not resolve into geological time as long sequences of insensibly graded intermediates (the traditional, or gradualistic, view), but as geologically "sudden" origins at single bedding planes.

Cultural speciation had been crippling to human moral and spiritual growth. It had hindered freedom of thought, limited our thinking, imprisoned us in the cultures into which we had been born. . . . These cultural mind prisons. . . . Cultural speciation was clearly a barrier to world peace. So long as we continued to attach more importance to our own narrow group membership than to the ‘global village’ we would propagate prejudice and ignorance.

The issue, as correctly emphasized by Carl Sagan, is the probability of the evolution of high intelligence and an electronic civilization on an inhabited world. Once we have life (and almost surely it will be very different from life on Earth), what is the probability of its developing a lineage with high intelligence? On Earth, among millions of lineages of organisms and perhaps 50 billion speciation events, only one led to high intelligence; this makes me believe in its utter improbability.

On Earth, among millions of lineages or organisms and perhaps 50 billion speciation events, only one led to high intelligence ; this makes me believe its utter improbablity.

Speciation does not necessarily promote evolutionary change; rather, speciation 'gathers in' and guards evolutionary change by locking and stabilization for sufficient geological time within a Darwinian individual of the appropriate scale. If a change in a local population does not gain such protection, it becomes-to borrow Dawkins's metaphor at a macroevolutionary scale-a transient duststorm in the desert of time, a passing cloud without borders, integrity, or even the capacity to act as a unit of selection, in the panorama of life's phylogeny.

Although random mutations influenced the course of evolution, their influence was mainly by loss, alteration, and refinement... Never, however, did that one mutation make a wing, a fruit, a woody stem, or a claw appear. Mutations, in summary, tend to induce sickness, death, or deficiencies. No evidence in the vast literature of heredity changes shows unambiguous evidence that random mutation itself, even with geographical isolation of populations, leads to speciation.

Ordinary speciation remains fully adequate to explain the causes and phenomenology of punctuation.

The biggest bursts of speciation that we know about in the history of the earth are soon after great cataclysms, like the extinction of the dinosaurs, which create new opportunities, and all sorts of new forms spring up... So, quite often, the reasons for creativity depend on accidents or disasters that prevent the normal habits being carried out.