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.