BIO

• Systematics


  The study of the diversity of life forms and the evolutionary relationships of organisms
• Systematists


  • Use data from fossils to molecules to genes to infer evolutionary relationships and reconstruct the Tree of Life
• Cladogram


  Shows evolutionary relationships of organisms, can help trace the evolutionary history of a species or a group of species, called its phylogeny
• Phylogenetic tree


  An extensive and more detailed cladogram showing evolutionary relationships of all organisms
• Phylogenetic trees can be used to test hypothesis on evolution
• Phylogenetic trees can give more information about possible characteristics of extinct species based on its supposed lineage
• Phylogenetic trees can help in classification
• Tree of Life


  A model and a phylogenetic tree that shows the evolutionary relationships of all organisms, backed up by evidences from fossil, behavioral, molecular, and morphological data
• Homology


  The similarity in physical structures, anatomy or genes due to shared ancestry between species or groups
• Molecular homology


  Measuring the degree of similarities in DNA to reveal mutations and infer evolutionary relationships
• Developmental biology


  Observing the stages of a species' development, from an embryo up to maturity, can provide evidence of evolution and infer phylogeny
• Biogeography


  The geographic distribution or dispersal of species influenced by events like continental drift, can give inferences about how one species led to another
• TUV NORD
• ISO 9001
• Grade 11/12 - Biology 2
• Section 3: Systematics Based on Evolutionary Relationships
• Tree of Life and Systematics
• Biogeography


  Distribution and evolutionary relationships
• The geographic distribution or biogeography of species is influenced by events such as dispersal and continental drift. Such information can give inferences about how one species led to another.
• Fossil evidence


  • Lystrosaurus
  • Cynognathus
  • Mesosaurus
  • Glossopteris
• Molecular clocks


  Time of evolutionary change
• Some regions of the DNA change at a consistent rate while others are unpredictable. A molecular clock is the time for evolutionary changes to occur, shown by the length of branches in a tree.
• Models using molecular clocks

  • Intracellular Models
  • Multicellular Models
  • Human Disease Models
• Longer branches meant higher mutation rates and fast evolution
• Evidences used to infer evolutionary relationships
• Online Video Watching: LS4A - Evidence of Common Ancestry and Diversity, Bozeman Science, July 10, 2013
• Recitation: Explain how each evidence of evolution can be used to infer relationships and to construct a phylogenetic tree
• Evidences of evolution


  • Fossil evidence
  • Homology
  • Developmental biology (Embryology)
  • Biogeography
  • DNA, RNA, and proteins
• Applications of phylogenetics


  How useful are phylogenetic trees?
• A sister taxon, or closest relative, of an organism or group, is a possible "reservoir" of beneficial genes useful in breeding or in genetic engineering.
• Phylogenetic trees can show species relatedness or identity using molecular data to help in impact assessment and policy-making.
• A phylogenetic tree derived from accumulated data and fossil records can support some hypothesis about evolutionary lineages, like how birds descended from dinosaurs, among others.
• Important terms


  • Taxonomy
  • Classification
  • Description
  • Hierarchy
  • Identification
  • Nomenclature
  • Systematics
  • Phylogeny
  • Character
  • Analogous character
  • Homologous character
  • Character state
  • Clade
  • cladogram
• Systematics is the study of biodiversity and the relationship of species and groups of species.
• Phylogenetic trees are more detailed cladograms showing the most possible phylogeny of a species.
• Evidences of evolution can be used to infer evolutionary relationships.
• The Tree of Life is a model including all species and widely-accepted evolutionary relationships.
• References/Bibliography


  • CHED. 2016. "Lesson 14: Systematics Based on Evolutionary Relationships: Tree of Life and Systematics."
  • Freeman, S., K. Quillin, L. Allison, M. Black, G. Podgorski, E. Taylor, and J. Carmichael. 2017. Biological Science 6th ed.
  • Simpson M.G. 2006 Plant Systematics.
  • Urry, L., Cain, M., Wasserman, S. Minorsky, P., & J. Reece. 2017. Campbell Biology, 11th ed.
• DepED MATATAG
• DEPARTMENT OF EDUCATION