Vertebrate Zoology Chapters 1 & 2 PDF

Vertebrate Zoology Introduction Chapters 1 & 2  What is Zoology?  Cell Theory – All living things are made of cells Genetic Unity – DNA contains the hereditary The information for all living things Commonality The more closely related 2 organis...

Vertebrate Zoology Introduction Chapters 1 & 2  What is Zoology?  Cell Theory – All living things are made of cells Genetic Unity – DNA contains the hereditary The information for all living things Commonality The more closely related 2 organisms are, the more similar their DNA of All Living Source of genetic and physical diversity through mutations Things Organisms share a common genetic history (i.e. evolution) Evolution is the unifying theory of biology Evidences for evolution: Biodiversity, Fossil Record, Comparative Embryology, DNA, Biogeography, Comparative Anatomy Organisms must adapt to existing conditions or face extinction Classification of Species Mnemonic Device: Dashing King Phillip Came Over For Good Soup  A method for determining evolutionary relationships Phylogeny – Diagram that shows the Phylogenetic branching events of a species or group Systematics of related species during evolution Systematics – Uses fossils, molecular and genetic data to infer evolutionary relationships and classify organisms Figure 26.4 Order Family Genus Species Panthera Felidae Panthera pardus (leopard) Taxidea Carnivora Taxidea Mustelidae taxus (American badger) Lutra Lutra lutra (European otter) Canis latrans Canidae Canis (coyote) Canis lupus (gray wolf) © 2017 Pearson Education, Inc.  Sister Taxa – Branch Point – Groups that Represents the share an divergence of immediate two species common Phylogeny ancestor Vocabulary Rooted Tree – Includes a Basal Taxon – Diverges early in the history of a branch to group and represent the originates near last common that common ancestor of all ancestor of the taxa in the tree group  Phenotypic and genetic similarities due to shared ancestry are called homologies Morphological Organisms with similar morphologies or and Molecular DNA sequences are likely to be more closely related than organisms with Homologies different structures or sequences Synapomorphy - A characteristic present in an ancestral species and shared exclusively (in more or less modified form) by its evolutionary descendants. Homologous vs. Analogous When constructing a phylogeny, systematists need to distinguish whether a similarity is the result of homology or analogy Homology is similarity due to shared ancestry Analogy is similarity due to convergent evolution Convergent evolution occurs when similar environmental pressures and natural selection produce similar (analogous) adaptations in organisms from different evolutionary lineages Cladistics Cladistics groups organisms by common descent Clade - group of species that includes an ancestral species and all its descendants Clades can be nested in larger clades, but not all groupings of organisms qualify as clades Monophyletic – A clade that consists of the ancestor species and all its descendants Paraphyletic – A clade that consists of an ancestral species and some, but not all, of the descendants Polyphyletic – A clade that consists of various species with different ancestors  A shared ancestral character (symplesiomorphy) is a character that originated in a distant ancestor of the taxon A shared derived character (synapomorphy) is an evolutionary novelty unique to a particular clade (ancestor and descendants) An outgroup is a species or group of species that is closely related to the ingroup, the various species being studied The outgroup is a group that has diverged before the ingroup Systematists compare each ingroup species with the outgroup to differentiate between shared derived and shared ancestral characteristics How are Shared Ancestral and Derived Characters Different? Significance: Indicates Example: Backbone in Shared Ancestral Definition: A trait that is traits inherited from vertebrates. It’s present shared by two or more distant ancestors, not Character taxa and their earliest in all vertebrates and necessarily useful for (Symplesiomorphy) their earliest common common ancestor. defining clades within a ancestor. group. Example: Feathers in Definition: A trait that is birds. Feathers are shared Shared Derived shared by two or more Significance: Indicates by all modern birds and taxa and their most traits that evolved more Character recent common ancestor, their most recent recently and are useful (Synapomorphy) common ancestor, but but not by more distant for defining clades. not by their earlier ancestors. ancestors. How are Cladistics and Phylogenies Different? Output: Produces cladograms, which are Focus: Organizing organisms Method: Uses a specific diagrams showing Cladistics based on common ancestry method to group species relationships based on and shared characteristics. into clades. shared traits and common ancestors. Output: Produces Method: Can use various Focus: The evolutionary phylogenetic trees, which data sources history and relationships show the inferred Phylogenies among species or groups of (morphological, genetic, evolutionary relationships, etc.) to infer evolutionary species. taking into account the time relationships. and branching patterns. Phylogenies represent the Cladistics is a specific broader concept of method to classify evolutionary relationships Key Difference: organisms based on and history, which can be common ancestry and illustrated with various shared characteristics. types of trees and methods. Animal Characteristics (Invertebrates & Vertebrates) Eukaryotic Multicellular Heterotrophic Internal digestion Epithelial and connective tissue Muscle and nervous tissue Diversity of Extant Vertebrates  5 Chordate Characteristics 1. A dorsal, hollow nerve cord - develops into the brain and spine in vertebrates 2. A notochord - develops into the vertebrae in vertebrates 3. Pharyngeal slits - openings in the pharynx (neck region) that develop into gill arches in bony fish and into the jaw and inner ear in terrestrial animals 4. Endostyle - an organ in the pharynx that helps with filter feeding; synthesizes thyroxine 5. A post-anal tail Figure 2.1 A simplified phylogeny of the animal kingdom (Metazoa)  Cephalochordata Extant which includes lancelets (aka Nonvertebrate amphioxus) Chordates Urochordata which includes sea squirts (aka tunicates) Cephalochordata Invertebrate (nonvertebrate) chordate No backbone Retain all 5 chordate characteristics as adults Filter-feeders V-shaped myomeres for propulsion Lancelet or amphioxus Urochordata Invertebrate (nonvertebrate) chordate No backbone Have chordate characteristics as larvae but only retain pharyngeal slits (basket) as adult Covering or tunic is made from cellulose Sessile adults  Vertebrates get their name from their vertebrae Vertebrae are the bones that make up the spinal column Vertebrae replace the notochord What Encircle the nerve cord Distinguishes Cranium made of bone, cartilage, or fibrous materials and surrounds the brain a Vertebrate? Head that is distinctive and contains sensory organs and a tripartite brain (fore-, mid-, and hindbrain) Anterior pituitary that produces and regulates hormones Mineralized tissues that create rigid support structures Figure 2.4 Generalized chordate structure compared with generalized vertebrate structure Nonvertebrate Chordate Primitive Vertebrate  Table 2.1 Comparison of features of nonvertebrate chordates and vertebrates * * * * * *  Bodies form from 3 germ layers (tissue layers) Ectoderm – The outermost layer, forms the epidermis, lining of most anterior & posterior parts of digestive tract, and most of nervous system Mesoderm – The middle layer, forms muscles, skeleton, connective tissues, circulatory system, and urogenital system Vertebrate Endoderm – The innermost layer, forms rest of the Body digestive tract lining, including the liver and pancreas, most respiratory surfaces, taste buds, thyroid, Development parathyroid, and thymus glands Development of Tripartite Brain Forebrain – olfactory and visual sensory structures; integrative and associative area Midbrain – incoming information from hearing and touch organs; outgoing motor responses Hindbrain – controls involuntary motor activities including respiration and circulation  Expression Progression Duplication of Hox Genes Hox genes regulate the expression of developmental genes Occur in clusters that are arranged in the same linear sequence as the structures they control along the anterior-posterior axis of the body All animals have Hox genes, but vertebrates have as many as 13 clusters due to duplication events Neural Crest Development Only occurs in vertebrates Can be considered 4th germinal layer Migratory and multipotency (differentiates into many cell types) Forms adrenal glands, melanocytes, secretory cells of gut, and smooth muscle tissue lining aorta  Adult Tissue Types Epithelial tissues – sheets of tightly connected cells that form boundaries between inside and outside of body and compartments within Muscle tissues – contain actin and myosin causing muscle cells to contract and exert force Neural tissues – includes neurons and glial cells Connective tissues – provide structural support, protection, and strength; includes bone, cartilage, adipose tissues (fat), blood, tendons, and ligaments Axial Musculature Axial muscles are used for locomotion  The Alimentary System Vertebrates eat bite-sized pieces of food instead of filter-feeding particles Have a stomach and intestines divided into 2 regions Basic The Cardiovascular System Vertebrate Closed circulatory systems Systems The Excretory System Kidneys – functional unit is nephron The Reproductive System Gonads become paired instead of singular  Chemosensation – taste and smell Basic Vision – vertebrates have similar eye structure with lens, iris, muscles, and retina where the photoreceptors are located Vertebrate Electroreception – ability to detect electrical impulses of Systems - other organisms; only works in water; some extant fishes produce electrical discharges The Mechanoreception – hair cells in lateral line system detect movement of water on the body Sensory Balance and orientation – vestibular apparatus detects an animal’s position in space System Tetrapod hearing – cochlea and vestibular apparatus receive the sound There are 7 1 2 Classes of 3 Vertebrates 4 Agnatha are jawless fish 5 Cartilaginous and bony fish evolved jaws Amphibians evolved 4 legs 6 Reptiles, birds, and mammals evolved an amnion Birds evolved feathers 7 Mammals evolved hair  “On Being the Right Size” An endoskeleton allows vertebrates to grow to large sizes Internal Made of bone or cartilage Endoskeleton can be divided into 4 parts Braincase Vertebrae Bones – axial and appendicular Gill arches (in fish and some amphibians)