Evidence for evolution
This presentation is the property of its rightful owner.
Sponsored Links
1 / 45

Evidence for Evolution PowerPoint PPT Presentation


  • 62 Views
  • Uploaded on
  • Presentation posted in: General

Evidence for Evolution. A slide extravaganza…. Types of evidence…. 1. Evidence from the fossil record (dead things). Fossil formation. Bones and shells undergo mineral replacement and are turned into rock

Download Presentation

Evidence for Evolution

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


Evidence for Evolution

A slide extravaganza…


Types of evidence…

  • 1. Evidence from the fossil record (dead things)


Fossil formation

  • Bones and shells undergo mineral replacement and are turned into rock

  • Soft material either disappears, or leaves an impression in the earth (that turns to rock)


A selection of fossils…


Fossils show transitions

The Archaeopterix -- between reptile and bird


Scallops


From early to modern horse


(Living things show transitions too)


Coelacanths - “the living fossil”


Types of evidence…

  • 1. Evidence from the fossil record


Types of evidence…

  • 1. Evidence from the fossil record

  • 2. Comparative Anatomy


A. Homologous Structures

Homo - logy

Homologous structures have the same underlying forms


Wing anatomy comparison

And compared to our arm…


Arm anatomy comparison


B. Analogous Structures

Ana - logy

Analogous structures have a similar outward appearance (but different underlying forms)


Convergent evolution Distantly related organisms evolve similar external features

Divergent evolution

A common ancestor gives rise to organisms that evolve for different environments

Types of evolution


Homologous structures

Analogous structures

Convergent evolutionDistantly related organisms evolve similar external features

Divergent evolution

A common ancestor gives rise to organisms that become more different with time.

Which goes with which? ….


Homologous structures

Analogous structures

Convergent evolutionDistantly related organisms evolve similar external features

Divergent evolution

A common ancestor gives rise to organisms that become more different with time.

Which goes with which?


C. Vestigial Structures

Vestige - a left-over/ remnant

Vestigial structures are evolutionary “leftovers” from an earlier ancestor


The “dew” claw of a wild cat


The human appendix

Fetal Human

Rabbit

Adult Human


Membranes in our eyes


Hip bones in whales

(Look at that “hand” too!)


Types of evidence…

  • 1. Evidence from the fossil record

  • 2. Comparative Anatomy


Types of evidence…

  • 1. Evidence from the fossil record

  • 2. Comparative Anatomy

  • 3. Comparative Embryology


Human embryo at 5 weeks


Embryos…

…can you guess which one is human?


Embryos…

…how about now?


And now…

Were you right?


Types of evidence…

  • 1. Evidence from the fossil record

  • 2. Comparative Anatomy

  • 3. Comparative Embryology


Types of evidence…

  • 1. Evidence from the fossil record

  • 2. Comparative Anatomy

  • 3. Comparative Embryology

  • 4. Molecular Evidence


Comparing DNA…


Determining relationships

DNA similarity between species is used to determine how closely related they are.

This is in turn used to construct possible evolutionary trees.


How closely related are these fellows?

Mystery critter! (I’m not telling)

Brown Bear

…got your guess?

Giant Panda


An Evolutionary Tree

This tree was constructed by looking at % similarity of DNA among “bears”

…so why is he called a red panda?


Types of evidence…

  • 1. Evidence from the fossil record

  • 2. Comparative Anatomy

  • 3. Comparative Embryology

  • 4. Molecular Evidence


Types of evidence…

  • 1. Evidence from the fossil record

  • 2. Comparative Anatomy

  • 3. Comparative Embryology

  • 4. Molecular Evidence

  • 5. Behavior


Behavioral similarities

  • Duck and other bird mating dances

  • How primates carry their young

  • Fish swimming motions and salamander walks

  • And on and on and on….


Types of evidence…

  • 1. Evidence from the fossil record

  • 2. Comparative Anatomy

  • 3. Comparative Embryology

  • 4. Molecular Evidence

  • 5. Behavior


Types of evidence…

  • 1. Evidence from the Fossil Record

  • 2. Comparative Anatomy

  • 3. Comparative Embryology

  • 4. Molecular Evidence

  • 5. Behavior

  • 6. Direct observation

    • also known as microevolution


Artificial selection

Remember us?


And look at us!


And Natural Selection

Hawaiian Rock Wallabies!


The Beak of the Finch

  • Biologists Peter and Rosemary Grant documented natural selection occurring in populations of finches on the Galapagos islands over a period of only 20 years! This generation to generation changes in the frequency of certain traits is called microevolution.


  • Login