Phylogenetic abilities/behaviors (as opposed to ontogenetic abilities)

Those abilities and behaviors that are typical of the species.  For example, walking is a phylogenetic ability of humans. Ontogenetic abilities are those supported by the culture.  An example would be a specific dance step (e.g., a polka) that is unique to the individual or culture, but not seen in all humans.  See Ontogenetic skills, …

Phyletic gradualism and punctuated equilibrium

New species originate in a small, isolated peripheryof ancestor’s geographical range (allopatric speciation) See Biological evolution, Constraint, Founder effect (or principle), Genetic drift (or random walk), Jacob-Monod operon model, Macroevolution (or horizontal evolution) and microevolution (or vertical evolution), Modern synthesis, Mutation (biology), Palaeontology, Phyletic, Phylogeny, Regulator genes (or regulatory), Speciation, Species, Structural genes, Theory of …

Phototaxis

Reflexive locomotion toward (‘positive’) or away (‘negative’) fromlight in phototropic organisms (e.g., phototropic eukaryotes and prokaryotes) along a light gradientor vector.  In such organisms, photoaxisis mediated by a pair of very simple eyes or eyespots involving type I sensory rhodopsin photoreceptors.  See Cones and rods, Eurkaryote cell (or organism), Prokaryote cell (or organism)

Phospholipids

Also called phosphatides, they are compounds of various phosphorous-containing lipids that are composed of a glycerol molecule bonded to two fatty acid molecules, and a phosphate group with a nitrogen-containing component.  The phospholipids lecithins and sphingomyelin facilitate the maturation of the fetal lungs before birth.  Those belonging to cell membranes form a two-molecule thick sheet …

Phosphate

A salt or ester of phosphoric acid.  While commonly associated with fertilisers, they are involved in many biochemical processes, often as part of complex molecules, such as adenosine triphosphate.  An ester is a compound formed by the reaction of an acid with an alcohol and also includes the fats and oils that are esters of …

Phonology

A term that refers to the structure of speech sounds in a language, and also to the study of speech sounds, a multifaceted enterprise.  The importance of phonology for the development of  reading is that children’s awareness of the phonology of their own language (phonological awareness) has a considerable impact on the progress that they …