spatial distribution marine organisms are either pelagic (found in the water column) or benthic...
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Spatial DistributionSpatial DistributionSpatial DistributionSpatial Distribution
•Marine organisms are either pelagic (found in Marine organisms are either pelagic (found in the water column) or benthic (living on, in, or the water column) or benthic (living on, in, or near the seafloor). Benthic organisms often near the seafloor). Benthic organisms often move on the sea bottom (epifaunal) or through move on the sea bottom (epifaunal) or through the sediment beneath its surface (infaunal).the sediment beneath its surface (infaunal).– Pelagic species found in the water column are Pelagic species found in the water column are
either swimmers (nekton) or drifters (plankton). either swimmers (nekton) or drifters (plankton). Planktonic drifters are termed phytoplankton if Planktonic drifters are termed phytoplankton if they are photosynthetic or zooplankton if they are they are photosynthetic or zooplankton if they are heterotrophic consumers.heterotrophic consumers.
Spatial DistributionSpatial DistributionSpatial DistributionSpatial Distribution
•Fig. 2.1 A spatial classification of marine organisms. Fig. 2.1 A spatial classification of marine organisms.
Evolutionary RelationshipsEvolutionary Relationshipsand Taxonomic and Taxonomic ClassificationClassification•Evolutionary AdaptationsEvolutionary Adaptations– Natural selection, the mechanism that drives Natural selection, the mechanism that drives
evolutionary adaptation, predicts that, on evolutionary adaptation, predicts that, on average, only those individuals that are best average, only those individuals that are best adapted to current local conditions will survive adapted to current local conditions will survive and reproduce, thus donating their genetically and reproduce, thus donating their genetically heritable traits to their offspring.heritable traits to their offspring.
Evolutionary RelationshipsEvolutionary Relationshipsand Taxonomic and Taxonomic ClassificationClassification
Evolutionary RelationshipsEvolutionary Relationshipsand Taxonomic and Taxonomic ClassificationClassification
Fig. 2.3 The basic components of sexual reproduction. The chromosome arrangement of each cell is shown to the right.
Evolutionary RelationshipsEvolutionary Relationshipsand Taxonomic Classificationand Taxonomic ClassificationEvolutionary RelationshipsEvolutionary Relationshipsand Taxonomic Classificationand Taxonomic Classification
• Evolutionary Evolutionary AdaptationsAdaptations
Evolutionary RelationshipsEvolutionary Relationshipsand Taxonomic Classificationand Taxonomic ClassificationEvolutionary RelationshipsEvolutionary Relationshipsand Taxonomic Classificationand Taxonomic Classification• Taxonomy and ClassificationTaxonomy and Classification
– All species that have ever existed on All species that have ever existed on Earth are classified in a taxonomic system Earth are classified in a taxonomic system based on their phylogenetic based on their phylogenetic interrelationships. These systems are interrelationships. These systems are often expressed as branching figures, or often expressed as branching figures, or cladograms, that diagrammatically cladograms, that diagrammatically represent current hypotheses concerning represent current hypotheses concerning evolutionary history.evolutionary history.
Evolutionary Relationships Evolutionary Relationships and Taxonomic Classificationand Taxonomic ClassificationEvolutionary Relationships Evolutionary Relationships and Taxonomic Classificationand Taxonomic Classification
•Fig. 2.5 A cladogram illustrating the relationships between Sirenians and elephants and their Fig. 2.5 A cladogram illustrating the relationships between Sirenians and elephants and their
close relatives based on differences in mitochondrial DNA.close relatives based on differences in mitochondrial DNA.
Evolutionary RelationshipsEvolutionary Relationshipsand Taxonomic and Taxonomic ClassificationClassification
Evolutionary RelationshipsEvolutionary Relationshipsand Taxonomic and Taxonomic ClassificationClassification
• Taxonomy and ClassificationTaxonomy and Classification– Today we follow a system of naming Today we follow a system of naming
species that is a modification of species that is a modification of nomenclature first formulated by Linneaus nomenclature first formulated by Linneaus more than two centuries ago. This system more than two centuries ago. This system recognizes five fundamentally different recognizes five fundamentally different types of living creatures, or kingdoms: types of living creatures, or kingdoms: Monera, Protista, Fungi, Plantae, and Monera, Protista, Fungi, Plantae, and Animalia.Animalia.
Evolutionary RelationshipsEvolutionary Relationshipsand Taxonomic Classificationand Taxonomic ClassificationEvolutionary RelationshipsEvolutionary Relationshipsand Taxonomic Classificationand Taxonomic Classification
• Fig. 2.7 A phylogenetic tree illustrates the evolutionary Fig. 2.7 A phylogenetic tree illustrates the evolutionary relationships of the major groups of marine organisms.relationships of the major groups of marine organisms.
Trophic RelationshipsTrophic RelationshipsTrophic RelationshipsTrophic Relationships
• Harvesting EnergyHarvesting Energy– All organisms must acquire energy and All organisms must acquire energy and
matter to survive, and two sources of each matter to survive, and two sources of each are known to be used by living creatures.are known to be used by living creatures.
– Organisms capable of creating their own Organisms capable of creating their own organic compounds from inorganic molecules organic compounds from inorganic molecules are autotrophic; those species that must are autotrophic; those species that must ingest preformed organics are termed ingest preformed organics are termed heterotrophic.heterotrophic.
Trophic RelationshipsTrophic RelationshipsTrophic RelationshipsTrophic Relationships
•Fig. 2.12 Energy flow in a marine ecosystem.Fig. 2.12 Energy flow in a marine ecosystem.
Food Chains and Food Web
Trophic RelationshipsTrophic RelationshipsTrophic RelationshipsTrophic Relationships
• Food Chains and Food WebsFood Chains and Food Webs– Both energy and matter flow through Both energy and matter flow through
ecosystems, typically in extremely ecosystems, typically in extremely complex patterns in the sea termed food complex patterns in the sea termed food webs.webs.
Trophic Trophic RelationshipsRelationshipsTrophic Trophic RelationshipsRelationships
•Fig. 2.14 A marine food web, Fig. 2.14 A marine food web, illustrating the major trophic illustrating the major trophic relationships that lead to an adult relationships that lead to an adult herring. herring. Adapted from Hardy 1924.Adapted from Hardy 1924.
The General Nature of Marine The General Nature of Marine LifeLifeThe General Nature of Marine The General Nature of Marine LifeLife
• Unlike terrestrial creatures, marine Unlike terrestrial creatures, marine organisms exist in a dense, circulating, organisms exist in a dense, circulating, salty medium that constantly salty medium that constantly repositions them along with their food, repositions them along with their food, waste products, and offspring.waste products, and offspring.
The General Nature of Marine LifeThe General Nature of Marine LifeThe General Nature of Marine LifeThe General Nature of Marine Life
• Fig. 2.15 Major biotic components of a marine ecosystem with their interconnecting paths Fig. 2.15 Major biotic components of a marine ecosystem with their interconnecting paths of energy and nutrient exchange. of energy and nutrient exchange. Adapted from Russell-Hunter 1970. Adapted from Russell-Hunter 1970.
The General Nature of The General Nature of Marine LifeMarine LifeThe General Nature of The General Nature of Marine LifeMarine Life
• Most photosynthetic species in the sea Most photosynthetic species in the sea are microscopic organisms that exist in are microscopic organisms that exist in concentrations that are thousands of concentrations that are thousands of times more dilute than that observed in times more dilute than that observed in a healthy lawn. Hence consumers that a healthy lawn. Hence consumers that feed on microscopic particulate matter feed on microscopic particulate matter are much more common in the sea than are much more common in the sea than on land.on land.