Modern evolutionary classification notes ch 18 2
Download
1 / 14

Modern Evolutionary Classification Notes- Ch. 18.2 - PowerPoint PPT Presentation


  • 463 Views
  • Uploaded on

Modern Evolutionary Classification Notes- Ch. 18.2. Evolutionary Classification. Modern classification is based on evolutionary theory Phylogeny – study of how orgs are related to each other (their evo relationships)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Modern Evolutionary Classification Notes- Ch. 18.2' - wilmet


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Evolutionary classification
Evolutionary Classification

  • Modern classification is based on evolutionary theory

  • Phylogeny – study of how orgs are related to each other (their evo relationships)

  • Evolutionary Classification – grouping organisms based on their evolutionary history


Homologous structures
Homologous Structures

  • One way to discover relationships is by comparing anatomical structures (body organs and parts).

  • Parts that are alike in basic structure and origin in several organisms but are not used for the same reason are called homologous structures.

  • Ex. All above have the same bones and number, used differently- evidence points to common ancestor.


Cladograms
Cladograms

  • Certain features shared by different group of organisms are known as “derived characters.”

  • Derived characters – characteristics that are in recent parts of lineage but not in older members

  • Used to make cladograms (aka phylogenetic tree)

  • The more derived characteristics two organisms share, the closer their evolutionary relationship


Sample Evolutionary Tree

Small difference

Common Ancestor

Largest difference

Moderate difference

Smallest difference

Relative Time


Traditional Classification Vs Cladogram

Section 18-2

Appendages

Conical Shells

Crustaceans

Gastropod

Crab

Crab

Limpet

Limpet

Barnacle

Barnacle

Molted exoskeleton

Segmentation

Tiny free-swimming larva

TRADITIONAL CLASSIFICATION

CLADOGRAM

Go to Section:


Traditional Classification Vs Cladogram

Section 18-2

Appendages

Conical Shells

Crustaceans

Gastropod

Crab

Crab

Limpet

Limpet

Barnacle

Barnacle

Molted exoskeleton

Segmentation

Tiny free-swimming larva

TRADITIONAL CLASSIFICATION

CLADOGRAM

Go to Section:


Dna rna
DNA & RNA

  • All living things have it

  • Compare organisms by genes

  • More similar = more recent common ancestor


Molecular clocks
Molecular Clocks

  • Estimates amount of time since species diverged

  • Uses mutations as markers

  • Compare similarities and differences in genes


Quick lab
Quick Lab

  • Identify the organisms in the table that is the least closely related to the others.

  • Construct a cladogram of these animals. Do NOT copy the table.

  • Analysis questions on next slide.


3 analysis questions
3. Analysis Questions

  • What trait separates the least closely related organism from the other animals?

  • List the animals in your cladogram in order of distance from the least closely related organism.

  • Explain if your cladogramindicates that lizards and humans share a more recent common ancestor than either does with an earthworm.

  • Where would you insert a frog if you added it to the cladogram? Explain your answer.


Extra practice
Extra Practice

1. Construct a cladogram for the info above.

2. Three previously unknown vertebrates have been discovered in a rainforest in South America.

a. “rat-like creature”

b. “iguana-like creature”

c. “goldfish-like creature”

Place these animals on your cladogram and justify your placement.


ad