Body Size: The physical measurements of a body.Body Constitution: The physical characteristics of the body, including the mode of performance of functions, the activity of metabolic processes, the manner and degree of reactions to stimuli, and power of resistance to the attack of pathogenic organisms.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Dinosaurs: General name for two extinct orders of reptiles from the Mesozoic era: Saurischia and Ornithischia.Body Surface Area: The two dimensional measure of the outer layer of the body.Body Weights and Measures: Measurements of the height, weight, length, area, etc., of the human and animal body or its parts.Body Image: Individuals' concept of their own bodies.Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.Body Height: The distance from the sole to the crown of the head with body standing on a flat surface and fully extended.LizardsClutch Size: The number of offspring produced at one birth by an oviparous or ovoviviparous animal.Body Mass Index: An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)Iguanas: Large herbivorous tropical American lizards.Mammals: Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Predatory Behavior: Instinctual behavior pattern in which food is obtained by killing and consuming other species.Sex Characteristics: Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.Feeding Behavior: Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.Food Chain: The sequence of transfers of matter and energy from organism to organism in the form of FOOD. Food chains intertwine locally into a food web because most organisms consume more than one type of animal or plant. PLANTS, which convert SOLAR ENERGY to food by PHOTOSYNTHESIS, are the primary food source. In a predator chain, a plant-eating animal is eaten by a larger animal. In a parasite chain, a smaller organism consumes part of a larger host and may itself be parasitized by smaller organisms. In a saprophytic chain, microorganisms live on dead organic matter.Ecosystem: A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)Basal Metabolism: Heat production, or its measurement, of an organism at the lowest level of cell chemistry in an inactive, awake, fasting state. It may be determined directly by means of a calorimeter or indirectly by calculating the heat production from an analysis of the end products of oxidation within the organism or from the amount of oxygen utilized.Birds: Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.Paleontology: The study of early forms of life through fossil remains.WingLarva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Extinction, Biological: The ceasing of existence of a species or taxonomic groups of organisms.Body Composition: The relative amounts of various components in the body, such as percentage of body fat.Anthropometry: The technique that deals with the measurement of the size, weight, and proportions of the human or other primate body.Sexual Behavior, Animal: Sexual activities of animals.Obesity: A status with BODY WEIGHT that is grossly above the acceptable or desirable weight, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).Energy Metabolism: The chemical reactions involved in the production and utilization of various forms of energy in cells.Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Smegmamorpha: Group of fish under the superorder Acanthopterygii, separate from the PERCIFORMES, which includes swamp eels, mullets, sticklebacks, seahorses, spiny eels, rainbowfishes, and KILLIFISHES. The name is derived from the six taxa which comprise the group. (From, 8/4/2000)Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Flight, Animal: The use of wings or wing-like appendages to remain aloft and move through the air.Beetles: INSECTS of the order Coleoptera, containing over 350,000 species in 150 families. They possess hard bodies and their mouthparts are adapted for chewing.Carnivora: An order of MAMMALS, usually flesh eaters with appropriate dentition. Suborders include the terrestrial carnivores Fissipedia, and the aquatic carnivores PINNIPEDIA.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Birth Weight: The mass or quantity of heaviness of an individual at BIRTH. It is expressed by units of pounds or kilograms.Reptiles: Cold-blooded, air-breathing VERTEBRATES belonging to the class Reptilia, usually covered with external scales or bony plates.Beauty: Characteristics or attributes of persons or things which elicit pleasurable feelings.Invertebrates: Animals that have no spinal column.Population Density: Number of individuals in a population relative to space.Longevity: The normal length of time of an organism's life.Geography: The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)Strepsirhini: A suborder of PRIMATES consisting of the following five families: CHEIROGALEIDAE; Daubentoniidae; Indriidae; LEMURIDAE; and LORISIDAE.Territoriality: Behavior in defense of an area against another individual or individuals primarily of the same species.Ecology: The branch of science concerned with the interrelationship of organisms and their ENVIRONMENT, especially as manifested by natural cycles and rhythms, community development and structure, interactions between different kinds of organisms, geographic distributions, and population alterations. (Webster's, 3d ed)Competitive Behavior: The direct struggle between individuals for environmental necessities or for a common goal.HornsMating Preference, Animal: The selection or choice of sexual partner in animals. Often this reproductive preference is based on traits in the potential mate, such as coloration, size, or behavioral boldness. If the chosen ones are genetically different from the rejected ones, then NATURAL SELECTION is occurring.Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Organ Size: The measurement of an organ in volume, mass, or heaviness.Regression Analysis: Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.Animal Distribution: A process by which animals in various forms and stages of development are physically distributed through time and space.Perciformes: The most diversified of all fish orders and the largest vertebrate order. It includes many of the commonly known fish such as porgies, croakers, sunfishes, dolphin fish, mackerels, TUNA, etc.Locomotion: Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.Integumentary System: The outer covering of the body composed of the SKIN and the skin appendages, which are the HAIR, the NAILS; and the SEBACEOUS GLANDS and the SWEAT GLANDS and their ducts.Growth: Gradual increase in the number, the size, and the complexity of cells of an individual. Growth generally results in increase in ORGAN WEIGHT; BODY WEIGHT; and BODY HEIGHT.Beak: In some animals, the jaws together with their horny covering. The beak usually refers to the bill of birds in which the whole varies greatly in form according of the food and habits of the bird. While the beak refers most commonly to birds, the anatomical counterpart is found also in the turtle, squid, and octopus. (From Webster, 3d ed & Storer, et al., General Zoology, 6th ed, p491, 755)Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Personal Satisfaction: The individual's experience of a sense of fulfillment of a need or want and the quality or state of being satisfied.