ADAPTATION

	ADAPTATION- ANY HERITABLE 
	BEHAVIORAL, MORPHOLOGICAL OR 
	PHYSIOLOGICAL TRAIT THAT MAINTAINS OR 
	INCREASES THE FITNESS OF AN ORGANISM 
	UNDER A GIVEN SET OF ENVIRONMENTAL 
	CONDITIONS

		HERITABLE - CAPABLE OF BEING PASSED 
		FROM ONE GENERATION TO THE NEXT, I.E., 
		GENETIC (BASED IN THE COMPLEX OF 
		GENES)

		FITNESS - A MEASURE OF THE 
		CONTRIBUTION MADE BY AN INDIVIDUAL 
		TO THE GENETIC CONSTITUTION OF THE 
		NEXT, AND SUBSEQUENT, GENERATIONS OF 
		A POPULATION OF ORGANISMS

			NATURAL SELECTION - ACTS TO 
			FAVOR INDIVIDUALS THAT POSSESS 
			HERITABLE FEATURES THAT INCREASE 
			FITNESS

				NATURAL SELECTION ACTS ON THE 
				OUTWARD EXPRESSION (PHENOTYPE) 
				OF THE UNDERLYING GENETIC 
				CONSTITUTION (GENOTYPE) OF AN
				INDIVIDUAL

					PHENOTYPES ARE THE TRAITS OF 
					AN ORGANISM THAT SHAPE 
					(ALLOW) ITS INTERACTIONS 
					WITH THE ENVIRONMENT IN 
					WHICH IT LIVES

						LOCAL POPULATIONS OF A 
						SPECIES THAT HAVE 
						ADAPTED TO LOCAL 
						ENVIRONMENTAL 
						CONDITIONS ARE CALLED 
						ECOTYPES
							MICROENVIRONMENTS 
							WITHIN LOCAL HABITATS 
							MAY BE ASSOCIATED 
							WITH VARIATIONS IN 
							PHENOTYPE - THIS TYPE 
							OF VARIATION IS 
							TERMED PHENOTYPIC 
							PLASTICITY 

	TOLERANCE

		BECAUSE OF LIMITATIONS IMPOSED BY THE 
		ADAPTATIONS OF AN ORGANISM IT CAN 
		OCCUR (AND FUNCTION) ONLY BETWEEN 
		CERTAIN UPPER AND LOWER LIMITS OF 
		ENVIRONMENTAL CONDITIONS (RANGE OF 
		TOLERANCE)

			THE LAW OF TOLERANCE (SUBSUMES 
			THE EARLIER "LAW OF THE MINIMUM"
			AND "LAW OF LIMITING FACTORS") 
			EMPHASIZES THE ORGANISMÕS RESPONSE 
			TO VARIOUS INTENSITIES OR 
			CONCENTRATIONS OF ENVIRONMENTAL 
			CONDITIONS

			AND, MAY BE IDEALISTICALLY 
			ILLUSTRATED AS A BELL-SHAPED 
			CURVE WITH ZONES OF INTOLERANCE,
			SURVIVAL, GROWTH AND MAXIMUM 
			FITNESS

		WITHIN THE ADAPTIVE LIMITS OF AN 
		ORGANISM, IT MAY BE ABLE TO INCREASE 
		OR DECREASE THE ZONE OF TOLERANCE -
		ACCLIMATIZATION

			E.G., INCREASE IN OXYGEN CAPACITY OF 
			HUMAN BLOOD AT HIGH ALTITUDES

			AND, SWITCH TO DIFFERENT ENZYMES 
			BY FISH AS TEMPERATURE CHANGES 
			SEASONALLY
	HOMEOSTASIS

		HOMEOSTASIS - THE MAINTENANCE OF A 
		NEARLY CONSTANT UNIFORM ENVIRONMENT 
		IN A CHANGING EXTERNAL ENVIRONMENT

			THE COSTS (IN TERMS OF ENERGY) FOR 
			THE PHYSIOLOGICAL AND/OR 
			BEHAVIORAL RESPONSES NECESSARY TO 
			MAINTAIN HOMEOSTATIC LEVELS OF 
			SOME INTERNAL CONDITIONS MAY BE 
			GREAT

				SO, SOME SPECIES CONFORM TO THE 
				EXTERNAL ENVIRONMENT OVER 
				SOME RANGE OF CONDITIONS

					E.G., POIKILOTHERMS ALLOW 
					BODY TEMPERATURE TO 
					FLUCTUATE

			BUT, THE COSTS OF NOT MAINTAINING 
			HOMEOSTASIS MAY BE EVEN GREATER 
			(DEATH)

				SO, MANY SPECIES REGULATE 
				INTERNAL CONDITIONS

					E.G., HOMEOTHERMS MAINTAIN 
					BODY TEMPERATURE OVER A 
					FAIRLY WIDE RANGE OF 
					EXTERNAL TEMPERATURES

						THE MAINTENANCE OF 
						HOMEOTHERMY MAY BE 
						COMPLEX

							E.G., HOMEOSTATIC 
							CONTROL OF HUMAN 
							BODY TEMPERATURE

			NO INDIVIDUAL IS AN ABSOLUTE 
			REGULATOR OR CONFORMER IN THAT:

				INTERNAL CONDITIONS CANNOT BE 
				HELD EXACTLY CONSTANT FOR LONG

				NOT ALL INTERNAL CONDITIONS 
				NEED BE REGULATED/CAN BE 
				ALLOWED TO CONFORM