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A pilot ladder is a highly specialized form of rope ladder, typically used on board cargo vessels [1] for the purposes of embarking and disembarking pilots. The design and construction of the ladders is tightly specified [2] by international regulation under the SOLAS regime. Pilot ladders and other boarding arrangements must be carefully ...
In biology, taxonomic rank (which some authors prefer to call nomenclatural rank [1] because ranking is part of nomenclature rather than taxonomy proper, according to some definitions of these terms) is the relative or absolute level of a group of organisms (a taxon) in a hierarchy that reflects evolutionary relationships.
Evolutionary progress as a tree of life. Ernst Haeckel, 1866 Lamarck's two-factor theory involves 1) a complexifying force that drives animal body plans towards higher levels (orthogenesis) creating a ladder of phyla, and 2) an adaptive force that causes animals with a given body plan to adapt to circumstances (use and disuse, inheritance of acquired characteristics), creating a diversity of ...
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms.It is intended as introductory material for novices; for more specific and technical definitions from sub-disciplines and related fields, see Glossary of cell biology, Glossary of genetics, Glossary of evolutionary biology, Glossary of ecology ...
A pilot ladder has specific regulations on step size, spacing and the use of spreaders. It is the use of spreaders (long treads that extend well past the vertical ropes) in a pilot ladder that distinguishes it from a Jacob's ladder. When not being used, the ladder is stowed away, usually rolled up, rather than left hanging.
The idea of a tree of life arose from ancient notions of a ladder-like progression from lower into higher forms of life (such as in the Great Chain of Being).Early representations of "branching" phylogenetic trees include a "paleontological chart" showing the geological relationships among plants and animals in the book Elementary Geology, by Edward Hitchcock (first edition: 1840).
Some examples of contingency affecting evolutionary outcomes have been identified. In the E. coli long-term evolution experiment , out of the 12 populations, only one evolved the highly beneficial trait of growing on citrate , which further experimental replays using frozen ancestral bacteria showed required particular 'potentiating' mutations ...
For example, a molecule can be viewed as a grouping of elements, and an atom can be further divided into subatomic particles (these levels are outside the scope of biological organisation). Each level can also be broken down into its own hierarchy, and specific types of these biological objects can have their own hierarchical scheme.