Fundamentals of Biology: Building Blocks, Challenges, and Evolution

Building Blocks of Life: Important Molecules  Water (H 2 O)  Gases (O 2, CO 2 )  Nutrients  Nitrate (NO 3 - ), nitrite (NO 2 - ), ammonia (NH 4 + )  Phosphate (PO 4 -3 )  Silica (SiO 2 )  Iron (Fe), and other trace metals

Important Molecules  Carbohydrates (C, H, O)  sugars, starches – energy  cellulose, chitin - structure  Lipids (C, H, O, some P)  fats, oils, waxes – energy, buoyancy, insulation  structural – cell membranes  hormones – messengers

Important Molecules  Proteins (C, H, O, N, some S)  amino acids  enzymes – metabolism  hormones – messengers  hemoglobin – oxygen transportation  structural – hair, nails, feathers, skin, muscle

Important Molecules  Nucleic acids (C, H, O, N, P)  nucleotides – genetic information  DNA (deoxyribonucleic acid) – chromosomes, genes  RNA (ribonucleic acid) – translate to proteins  ATP (adenosine triphosphate) – store and transfer energy

From Atoms to Ecosystems

molecules → organelles → cell (organism) molecules → cell (organism) cells → tissues → organs → organ systems → organism cells → tissues → organism

From Atoms to Ecosystems organism → population → community → ecosystem

Ecosystems and Adaptations  Adaptation:  The adjustment or changes in behavior, physiology, and structure of an organism to become more suited to an environment. (  A characteristic of an organism that makes it fit for its environment or for its particular way of life. (McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.)

Challenges of Life in the Ocean  Organisms deal with challenges that are unique to marine environment  Must maintain suitable conditions inside their body, regardless of the external conditions - Homeostasis

Challenges of Life in the Ocean - Temperature  Dictates where organisms live  Affects how organisms metabolize  Physiologically adapted to live within a certain temperature range USFWS NOAA

Challenges of Life in the Ocean - Temperature

Challenges of Life in the Ocean - Temperature  Ectotherms  “Cold-blooded”, metabolic heat lost  Cannot regulate internal temperature, so same temperature as environment (poikilotherms)  Most marine animals (invertebrates, most fish, most reptiles) NOAA

Challenges of Life in the Ocean - Temperature  Endotherms  “Warm-blooded”, metabolic heat retained (fat, feathers for insulation)  Can regulate internal temperature, regardless of external environment (homeotherms)  Mammals, birds

Challenges of Life in the Ocean - Temperature  Endotherms  Some large fish and turtles are endotherms, but not homeotherms  Metabolic heat retained, so warmer than surroundings, but internal temperature is relative, not set

Challenges of Life in the Ocean - Salinity  Diffusion – molecules move from high concentrations to low until equal  Cell membranes are selectively permeable to different substances  Osmosis – passive diffusion of water across membranes  Active transport – expend energy to work against diffusion

Challenges of Life in the Ocean - Salinity Osmoconformers – do not regulate

Challenges of Life in the Ocean - Salinity Osmoregulators

Challenges of Life in the Ocean - Salinity Osmoregulators Hawksbill turtles have glands (near eyes) to excrete excess salt

Evolution  The gradual change in the genetic makeup of species and populations  The diversity of organisms today is the result of billions of years of evolution

Evolution  Theory of evolution – not a hypothesis, but a widely accepted scientific concept  Evidence exists from the past (fossils)  Evolution observed within our lifetime (bacteria, plants, worms, insects)

Evolution  Adaptation and natural selection – individuals best adapted to their environment survive and produce offspring  Changes and challenges – adapt or become extinct

Phylogenetics  Reconstructs evolution by grouping organisms by their relatedness  Fossil record (incomplete)  Body structure  Reproduction and behavior  Embryology and larval development  Genetics (DNA, RNA)

Phylogenetics using ribosomal RNA sequence Carl Woese

Phylogenetics

Classification of Organisms Kingdom

sub-, super-, infra-categories, too: - subclass Placentalia (placentals) - suborder Odontoceti (toothed whales) Classification of Organisms

 Species – binomial nomenclature (Linnaeus) Genus species  Use instead of common names to avoid confusion: “Dolphin”  Coryphaena hippurus – Mahi mahi fish  Tursiops truncatus – Flipper

Classification of Organisms  Species – “populations of organisms that have common characteristics and can successfully breed with each other” Acropora palmataAcropora cervicornis

Classification of Organisms  One species or three? Montastraea annularisMontastraea faveolataMontastraea franksi