BSC2010-evolution-7-2024
Page 1: Overview of Taxa
Taxonomic Domains: Metazoa, Archaea, Bacteria
Major Clades: Excavata, Amoebozoa, SAR, Archaeplastida, Fungi
Course Information: BSC 2010, Fall 2024
Page 4: Outline of Key Topics
Phylogenetics: Describing relationships among species
Fossil data
Morphological data
Molecular data
Radiocarbon dating is a technique used to determine the age of organic materials by measuring the decay of carbon-14 isotopes, providing crucial insights into the timeline of evolutionary events.
Reconstructing Phylogenetic Trees:
Principle of parsimony
Classification: Taxonomy
Binomial nomenclature
Hierarchical classification system
Page 5: Constructing the Tree of Life
Means of Determining Evolutionary Relationships:
The fossil record
Morphological data
Molecular data
Page 6: The Fossil Record
Definition: Preserved parts or impressions of organisms from the past
Usually hard parts (bones, teeth, etc.)
Typically found in sedimentary rocks
Importance:
Provide insights into species diversity, speciation, and extinction
Fossil record is biased and incomplete:
Few organisms become fossils, difficult preservation, soft tissue rarely preserved
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Page 8: Dating Rocks and Fossils
Methods of Dating:
Relative ages can be determined by sedimentary strata
Absolute ages assessed through radiometric dating
Example: Radiocarbon dating
Concepts:
"Parent" isotope decays to "daughter" isotope at a constant rate
Each isotope has a known half-life
Page 9: Accumulation of Isotopes Over Time
Illustrative graph showing decay of isotopes over multiple half-lives
Page 10: Morphological Data
Comparative Analysis of Traits:
Homologies (similar due to shared ancestry) vs. analogous traits (homoplasy)
Challenges in identifying true evolutionary relationships
Use of fossil records and geographic patterns
Example: Comparison of placental and marsupial anteaters
Page 11: Plant Classification
Based on sexual parts
Page 12: Molecular Data
DNA Sequence Comparison:
More similar sequences suggest closer evolutionary relations
Molecular data may sometimes disagree with morphological and fossil evidence
Page 13: Hawaiian Silverswords
Example of molecular data in phylogenetics
Page 14: Depiction of Phylogenetics
Phylogenetic Trees:
Visual representations of evolutionary relationships
Formed based on differences in traits/DNA among species
Morphological, functional, and molecular traits
Page 15: Applications of Phylogenetics
Understanding Relationships Among Taxa:
Biogeography patterns
Trait evolution patterns
Practical Applications:
Conservation (e.g., test products like wood and meat)
Agriculture (analyze cultivars)
Forensics (DNA fingerprinting)
Medicine (e.g., tracking anthrax strains)
Page 16: Example Species
Species List with Taxonomic Information:
Canis lupus, Panthera pardus, Taxidea taxus, Lutra lutra, Canis latrans
Order: Carnivora
Families: Felidae, Mustelidae, Canidae
Page 17: Sister Taxa in Phylogenetics
Representation of Ancestral Lineage:
Taxon A through F
Visualization of common ancestors and branches (nodes)
Page 18: Ancestral vs. Derived Traits
Definitions:
Shared ancestral character: originated from the ancestor of the taxon
Shared derived character: unique evolutionary novelties in a clade
Page 19: Example of Shared Ancestral Character
Visualization of shared ancestral traits among species
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Page 21: Shared Derived Character
Visibility of specific given traits in species' evolution.
Page 22: Derived Character Analysis
Focus on the evolution of specific traits (e.g., prehensile control in tails)
Page 23: Distinguishing Character Types
Method for Systematists: Analyze shared derived vs. shared ancestral characters
Unique identification in phylogenetic studies
Page 24: Assessment of Characters in Systematics
Character Table and Phylogenetic Tree Representation:
Visual aid for understanding character evolution across taxa
Page 25: Principle of Parsimony
Key Principle:
Simplest hypothesis explains the evolutionary tree
Chooses the tree with the least number of shared derived characters
Avoids the use of analogous characters
Page 26: Application of Parsimony Method
Example of evaluating phylogenetic relationships with shared derived traits.
Page 27: Issues in Phylogenetics
Concerns:
Data scarcity
Disagreements with fossil evidence
Horizontal gene transfer and trait reversals
Page 28: Systematics and Classification
Definitions:
Systematics: study of classification and evolutionary relationships
Taxonomy vs. Phylogenetics
Page 29: Taxonomy Defined
Historical Context:
Initiated by Carl Linnaeus in the 1700s
Uses morphological similarity: anatomy, fossils, behavior
Introduction of binomial nomenclature and hierarchical systems
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Page 31: Guidelines for Binomial Nomenclature
Standards:
Genus name capitalized, species name lowercase
Italicized or underlined for emphasis
Page 32: Hierarchical Classification System
Structure:
Kingdom > Phylum > Class > Order > Family > Genus > Species
Page 33: Example of Hierarchical Classification
Human Classification:
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Genus: Homo
Species: H. sapiens
Page 34: Life Forms Classification Overview
Classification categories include Eukaryota, Bacteria, Archaea, etc.
Page 35: Three Domains of Life
Overview of major groups: Eukaryotes, Bacteria, and Archaea
Visual representation of life’s common ancestor and how it branches into different taxa.