chồng chéo cơ chế cơ bản đã được chứng minh là có liên quan ngay cả trong cùng một thí nghiệm. Một trọng tâm của lập luận của chúng tôi là nó là khả năng để tạo ra các Pars rằng sự tiến hóa đã lưu giữ. Các cơ chế khác nhau do đó được khuếch đại, theo loài và tình hình đã dẫn đến cải cách hành chính. | 120 The biology of predictive adaptive responses overlapping underlying mechanisms have been shown to be involved even within the same experiment. A focus of our argument is that it is the capacity to induce PARs that evolution has preserved. Various mechanisms have therefore been amplified according to both the species and the situation that led to the PAR. This has the implication that scientists should not spend time debating the relative merits of one experimental model or another - an activity that it is easy to fall into and of course one that the peer-review system for appraising grant applications and papers for publication readily tends itself to . Common phenotypes and common pathways Common phenotypes do not imply common pathways in evolution or in biological process. For example there are many ways in which pathological hypertension can develop - a tumour of the adrenal gland producing too much aldosterone a fluidretaining hormone diseases of the kidney affecting another hormone called renin persistent stress acting on the autonomic nervous system some brain tumours insulin resistance and obesity as well as the common form of hypertension that involves changes in vascular reactivity. Evolutionary biology can provide many examples where quite different routes to a final phenotype have evolved separately. The most well-known example is the eye which has evolved several times independently in different cladistic lines of speciation. The insect eye and the mammalian eye have quite different evolutionary histories. Obviously a visually responsive organ is a highly desirable survival characteristic and thus the visually aware phenotype has had a real evolutionary advantage. Hence there is a common phenotype possessing an eye but there are many pathways to achieving This phenomenon is called convergent evolution. Another example is colour vision which has been adopted by a range of species from insects to birds and mammals but the photoreceptor mechanisms
