evolution continued evidence other concepts n.
Skip this Video
Loading SlideShow in 5 Seconds..
Evolution Continued: Evidence & Other Concepts PowerPoint Presentation
Download Presentation
Evolution Continued: Evidence & Other Concepts

Loading in 2 Seconds...

play fullscreen
1 / 24

Evolution Continued: Evidence & Other Concepts - PowerPoint PPT Presentation

  • Uploaded on

Evolution Continued: Evidence & Other Concepts.

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

Evolution Continued: Evidence & Other Concepts

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
evolution continued evidence other concepts

Evolution Continued: Evidence & Other Concepts

Paleontologists have long thought that Archaeopteryx fossils, including this one discovered in Germany, placed the dinosaur at the base of the bird evolutionary tree; evidence suggests the beast may have been a birdlike dinosaur.CREDIT: Humboldt Museum fürNaturkunde Berlin


Summary color is orange; vocabulary is underlined.

  • Hyperlinks are in green; they will take to you videos and animations.

Unit #12

Evolution Continued



Today, most of the evidence for evolution is grouped into these main categories:

    • Fossil Record
    • Biogeography
    • Homologies
      • Anatomy
      • Embryology
      • Molecular
    • Observable Events


The Evidence of Evolution Use the information on the following slides to complete your “Matching Notes” student sheet.
1 fossil record watch fossils as evidence for evolution textbook reference pg 399 400

Most fossils are found in layered sedimentary rock

  • Older fossils = lowest layers
  • Comparing fossils from different layers shows:
    • Life on Earth has changed
    • Increased biodiversity
1 - FOSSIL RECORDWatch “Fossils As Evidence for Evolution” Textbook Reference pg. 399-400
fossils cont

Paleontology – study of fossils

  • Types of Fossils:
    • Remains: EX bone, tooth, or shell
    • Traces: EX burrow, footprint, or imprint

Dinosaur fossil searcher Ray Stanford discovered a large fossil of a Nodosaur just a few feet from this spot.


Fossils Cont.


2 biogeography watch biogeography as evidence for evolution



Beaver andMuskrat



Coypu andCapybara

  • Biogeography: the geographic distribution of organisms
    • organisms living widely apart (even different continents),may be similar because they share a common ancestor
2 – BiogeographyWatch “Biogeography As Evidence for Evolution”
3 - Homologies: AnatomyWatch “Anatomical Development and Homologies as Evidence for Evolution” Textbook Reference pg. 400-402
anatomy cont

Homologous structures: w/ similar structure, but different function show an evolutionary relationship

    • EX limbs of vertebrates (turtle, alligator vs. mammal)


Anatomy Cont.
anatomy cont1

Show an organism’s evolutionary past

  • Ancestral species would have similar structures that are still functioning
    • EX human tailbone, appendix, whale femur/pelvis
  • Vestigial structures: reduced in size, are nonfunctioning remnants of similar structures in ancestral species


Anatomy Cont.
4 homologies developmental embryology textbook reference pg 402

Embryos of different species may appear similar in early stages of development

    • Can show developmental relationships


4 - Homologies: Developmental (Embryology) Textbook Reference pg. 402
4 homologies developmental homeobox hox genes

Hox genes:found in animals, determine the pattern of the body during development

    • Control transcriptionfactors
    • Can show genetic relationships
4 - Homologies: Developmental (Homeobox/Hox Genes)
5 homologies biochemistry

The genetic code [GCAT] is the same in all organisms

    • Triplets (or codons) of DNA bases code for specific amino acids to build proteins


5 – Homologies: Biochemistry

Textbook Reference pg. 402-403

biochemistry cont

Sequenceof amino acids in a particular protein is compared between organisms

    • AA Sequencing is probably the strongestevidence for relationships among organisms
  • Cladogram: diagram that shows the evolutionary relationship among a group of organisms.


Biochemistry Cont.
observable events

Some changes in species have been observed and studied inrecent times

  • Observable events show that evolution is an ongoing process
Observable Events
speciation textbook reference pg 409

Species: a group of organisms that breed with one another and produce fertile offspring

    • Speciation: the formation of a new species as a result of evolutionary change caused by certain isolating mechanisms
    • Isolating Mechanism Animation
Speciation Textbook Reference pg. 409


isolating mechanism reproductive isolation textbook reference pg 410

Two populations become reproductively isolated from each other

    • Members cannot interbreed because of genetic material is too different

Spotted owl subspecies living in different geographic locations show some genetic and morphological differences.

Isolating Mechanism: Reproductive IsolationTextbook Reference pg. 410
isolating mechanism behavioral isolation

Photo Credit, Mike Eggett

  • Two populations are capable of interbreeding, but have differences in courtship rituals, etc that involve behavior.
    • EX two different species of cricket that would be indistinguishable unless you heard their mating songs, a noticeably different pitch 
Isolating Mechanism: Behavioral Isolation
isolating mechanism geographic isolation

Two populations are separated by geographic barriers

    • EX rivers, mountains, or bodies of water


Isolating Mechanism: Geographic Isolation
isolation mechanism temporal isolation

Two species reproduce at different times.

Photo Credit, Christian Ziegler

Populations may mate or flower at different seasons or different times of day. Three tropical orchid species of the genus Dendrobium each flower for a single day; the flowers open at dawn and wither by nightfall. 


Isolation Mechanism: Temporal Isolation
genetic equilibrium

Do a population’s genes (or gene pool) change over time? Yes!

    • % of an allele in a gene pool= allelic frequency
    • Genetic equilibrium: frequency of alleles remains the same
      • A population in equilibrium is NOT evolving
      • Influenced by
        • environment, mutations
        • Genetic drift
Genetic Equilibrium
types of evolution divergent evolution

Adaptive radiation: type of divergent evolution; ancestral species evolve into an array of species to fit diverse habitats

    • EX Galápagos Finches


Types of Evolution: Divergent Evolution

Textbook Reference pg. 412-13

true or false the shark and the dolphin are closely related
True or False? The shark and the dolphin are closely related?


types of evolution convergent evolution

Convergent evolution: when unrelated species occupy similar environments, evolving similar traits, but are NOT closely related

    • Convergent evolution results in analogous structures
    • EX Bat wing vs. butterfly wing


Types of Evolution: Convergent Evolution