進化という科学的真理が反対しようもないほど確証されるもので、実質的に論駁できない。

、。

The scientific truth of evolution is so thoroughly confirmed as to be beyond any possibility of dispute, and essentially irrefutable.

Literal

Evolution [called-という] scientific truth [subject-が] oppose-[no-way-to-ようもない] [to-the-extent-ほど] is-confirmed thing [is-で], substantially cannot-refute.

Academic prose at full formality. Three dense grammar points: (1) ~という科学的真理 defines evolution as 'the scientific truth called X,' using という to equate a name with a concept. (2) 反対しようもない combines the volitional 反対しよう with the suffix ~ようもない ('no way to / no means of'), yielding 'there is no way to oppose it' — a fixed pattern expressing the absolute impossibility of an action. (3) The ほど ('to the extent that') then scales that impossibility into a degree phrase: 'confirmed to such a degree that there is no way to oppose it.' The sentence closes with 論駁できない (論駁 = 'refutation,' a Sino-Japanese word at the upper end of academic vocabulary).