Common Ancestry

* Enduring understanding 1.B: Organisms are linked by lines of descent from common ancestry.

- Essential knowledge 1.B.1: Organisms share many conserved core processes and features that evolved and are widely distributed among organisms today.

• a. Structural and functional evidence supports the relatedness of all domains. Evidence of student learning is a demonstrated understanding of each of the following:
  • 1. DNA & RNA are carriers of genetic information through transcription, translation and replication.
  • 2. Major features of the genetic code are shared by all modern living systems.
  • 3. Metabolic pathways are conserved across all currently recognized domains.
• b. Structural evidence supports the relatedness of all eukaryotes.
  • Learning Objectives:
    • LO 1.14: The student is able to pose sientific questions that correctly identify essential properties of shared, core life processes that provide insights into the history of life on Earth.
    • LO 1.15: The student is able to describe specific examples of conserved core biological processes and features shared by all domains or within one domain of life, and how these shared, conserved core processes and features support the concept of common ancestry for all organisms.
    • LO 1.16: The student is able to justify the scientific claim that organisms share many conserved core processes and features that evolved and are widely distributed among organisms today.

- Essential knowledge1.B.2: Phylogenetic trees and cladograms are graphical representations (models) of evolutionary history that can be tested.

• a. Phylogenetic trees and cladograms can represent traits that are either derived or lost due to evolution.
• b. Phylogenetic trees and cladograms illustrate speciation that has occurred, in that relatedness of any two groups on the tree is how by how recently two groups had a common ancestor.
• c. Phylogenetic trees and cladograms can be constructed from morphological similarities of living or fossil species, and from DNA and protein sequence similarities, by employing computer programs that have sophisticated ways of measuring and representing relatedness among organisms.
• d. Phylogenetic trees and cladograms are dynamic (i.e. phylogenetic trees and cladograms are constantly being revised), based on the biological data used, new mathematical and computational ideas, and current and emerging knowledge.
  • Learning Objectives:
    • LO 1.17: The student is able to pose scientific questions about a group of organisms whose relatedness is described by a phylogenetic tree or cladogram in order to (1) identify shared characteristics, (2) make inferences about the evolutionary history of the group, and (3) identify character data that could extend or improve the phylogenetic tree.
    • LO 1.18: The student is able to evaluate evidence provided by a data set in conjunction with a phylogenetic tree or a simple cladogram to determine evolutionary history and speciation.
    • LO 1.19: The student is able to create a phylogenetic tree or simple cladogram that correctly represents evolutionary history and speciation from a provided data set.