1 Apply Concepts To an evolutionary taxonomist, what determines whether two species are in the same genius - PowerPoint PPT Presentation

Loading...

PPT – 1 Apply Concepts To an evolutionary taxonomist, what determines whether two species are in the same genius PowerPoint presentation | free to download - id: 7d82fe-YjhhM



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

1 Apply Concepts To an evolutionary taxonomist, what determines whether two species are in the same genius

Description:

Title: Ch 18 Classification Author: Dan Last modified by: Your User Name Created Date: 7/19/2010 6:48:25 PM Document presentation format: On-screen Show (4:3) – PowerPoint PPT presentation

Number of Views:40
Avg rating:3.0/5.0
Slides: 19
Provided by: Dan1165
Learn more at: http://hlww.demo.ties.k12.mn.us
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: 1 Apply Concepts To an evolutionary taxonomist, what determines whether two species are in the same genius


1
  • 1 Apply Concepts To an evolutionary taxonomist,
    what determines whether two species are in the
    same genius
  • 2 Explain What is a derived character
  • 3 Review How do taxonomist use the DNA sequences
    of species to determine how closely two species
    are related
  • Relate Cause and Effect Explain why the
    classification of American vultures has changed

2
Ch 18 Classification
  • 18.2 Modern Evolutionary Classification

3
Evolutionary Classification
  • Phylogenetic systematics
  • Group species into larger categories that reflect
    lines of evolutionary descent
  • Not overall similarities and differences
  • Phylogeny
  • Study of how living and extinct organisms are
    related to one another.

4
  • Clade
  • Group of species that includes a single common
    ancestor and all descendants of that ancestor
  • Monophyletic group
  • Must only include all species that are descended
    from a common ancestor
  • Cladogram
  • Links groups of organisms by showing how
    evolutionary lines, or lineages, branched off
    from common ancestors.

5
Building Cladograms
  • Node
  • Represents the last point the new lineages shared
    a common ancestor
  • Speciation event.

6
  • Cladograms branching patterns indicate degrees
    of relatedness among organism.

7
  • Lineages 3 and 4 share a common ancestor more
    recently with each other than they do with
    lineage 2
  • Lineages 3 and 4 are more closely related to each
    other than they are with lineage 2.

8
  • This represents current hypotheses about
    evolutionary relationships among vertebrates.

9
Derived Character
  • Trait that arose in the most recent common
    ancestor and was passed along to its descendants.

10
  • Four limbs is a derived character for the clade
    tetrapoda
  • Hair is a derived character for the clade
    Mammalia.

11
Reading Cladograms
  • Simplified phylogeny of the cat family.

12
  • Lowest node represents the last common ancestor
    of all four-limbed animals.

13
  • Forks show the order in which various groups
    branched off over the course of evolution.

14
  • Trait of four limbs, for example, appeared before
    the trait of hair in the history of the cats
    lineage.

15
  • Some clades match up with traditional taxonomic
    groups
  • Mammalia
  • Some dont
  • Reptilia.

16
(No Transcript)
17
  • Two clades do include the birds
  • Clade Aves and clade Reptilia
  • Birds are reptiles.

18
DNA in Classification
  • The more derived genetic characters two species
    share
  • More recently they shared a common ancestor
  • More closely they are related in evolutionary
    terms.
About PowerShow.com