Speciation Quotes
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.
Stephen Jay Gould
Evolution is all about processes that almost never happen. Every birth in every lineage is a potential speciation event, but speciation almost never happens, not once in a million births. Mutation in DNA almost never happens - not once in a trillion copings - but evolution depends on it. Take the set of infrequent accidents - things that almost never happen - and sort them into the happy accidents, the neutral accidents, and the fatal accidents; amplify the effects of the happy accidents - which happens automatically when you have replication and competition - and you get evolution.
Daniel Dennett
After the many hundreds of generations that Australian, East Asian, African, European and indigenous American populations of Homo sapians developed in isolation from each other, in different environments, there ought to be divergence aplenty, though nowhere near to speciation. And so there is. That is why a roomful of Australian aborigines looks nothing like a roomful of Hungarians, and neither looks anything like a roomful of Quechua-speaking South American indigenes.
John Derbyshire
In this crucial sense, the theory of punctuated equilibrium adopts a very conservative position. The theory asserts no novel claim about modes or mechanisms of speciation; punctuated equilibrium merely takes a standard microevolutionary model and elucidates its expected expression when properly scaled into geological time.
Stephen Jay Gould
Finally, the claim that we equated punctuated equilibrium with saltation makes no sense within the logical structure of our theory - so, unless we are fools, how could we ever have asserted such a proposition? Our theory holds, as a defining statement, that ordinary allopatric speciation, unfolding gradually at microevolutionary scales, translates to punctuation in geological time.
Stephen Jay Gould
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.
Lynn Margulis
