Darwin's original thesis, and the viewpoint supported by evolutionary gradualists, is that species change continuously but slowly and in small increments.
达尔文最初的论点以及进化渐进主义者所支持的观点是,物种的变化是持续的,但非常缓慢,增量也很小。
Surveyors marched inland from the coast for thousands of miles, stopping at increments of as little as a few feet to measure their elevation, and marking each increment with two poles.