Comparing relative dating and radiometric dating
The term can also be applied to larger groups of organisms, as in "the adaptive radiation of mammals." adaptive strategies: A mode of coping with competition or environmental conditions on an evolutionary time scale.
Species adapt when succeeding generations emphasize beneficial characteristics.
Allometric relations can be studied during the growth of a single organism, between different organisms within a species, or between organisms in different species. amino acid: The unit molecular building block of proteins, which are chains of amino acids in a certain sequence.
allopatric speciation: Speciation that occurs when two or more populations of a species are geographically isolated from one another sufficiently that they do not interbreed. There are 20 main amino acids in the proteins of living things, and the properties of a protein are determined by its particular amino acid sequence.
In a diploid cell there are usually two alleles of any one gene (one from each parent).
Within a population there may be many different alleles of a gene; each has a unique nucleotide sequence.
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.
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).
They have moist scaleless skin which is used to supplement the lungs in gas exchange.
The eggs are soft and vulnerable to drying, therefore reproduction commonly occurs in water.
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.Peaks on the landscape correspond to genotypic frequencies at which the average fitness is high, valleys to genotypic frequencies at which the average fitness is low. adaptive logic: A behavior has adaptive logic if it tends to increase the number of offspring that an individual contributes to the next and following generations.