Radiometric dating blind test
Then, even if circumstances change such that it no longer provides any survival or reproductive advantage, the behavior will still tend to be exhibited -- unless it becomes positively disadvantageous in the new environment.
adaptive radiation: The diversification, over evolutionary time, of a species or group of species into several different species or subspecies that are typically adapted to different ecological niches (for example, Darwin's finches).
The diameter of the aperture determines the intensity of light admitted. archeology: The study of human history and prehistory through the excavation of sites and the analysis of physical remains, such as graves, tools, pottery, and other artifacts.
The pupil of a human eye is a self-adjusting aperture. archetype: The original form or body plan from which a group of organisms develops.
Exceptions are those coded for by the RNA of certain viruses, such as HIV.
These all develop through an embryo that is enclosed within a membrane called an amnion.
The amnion surrounds the embryo with a watery substance, and is probably an adaptation for breeding on land.
acquired trait: A phenotypic characteristic, acquired during growth and development, that is not genetically based and therefore cannot be passed on to the next generation (for example, the large muscles of a weightlifter).
adaptation: Any heritable characteristic of an organism that improves its ability to survive and reproduce in its environment.