1 / 22

Evidence for Evolution

Evidence for Evolution. Fossils and Geologic Time Similarities in Anatomy Similarities in Development Molecular Similarities. I. Fossils and Geologic Time. Fossils are hard parts or traces of organisms in soil that has become rock. Examples of geologic strata (layers).

oki
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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Evidence for Evolution • Fossils and Geologic Time • Similarities in Anatomy • Similarities in Development • Molecular Similarities

  2. I. Fossils and Geologic Time Fossils are hard parts or traces of organisms in soil that has become rock.

  3. Examples of geologic strata (layers)

  4. Strata visible at Sideling Hill(Interstate 68 near Hancock, MD) Changes over time due to earth movement

  5. Age of the fossil = age of strata it is in

  6. Some elements used in dating rocks: Isotope Stable element Half life Half of this… turns into this…. in this amount of time…. Uranium-238Lead-2064.5 billion yearsPotassium-40Argon-401.25 billion yearsUranium-235Lead-2070.70 billion years Dating a fossil based on the age of volcanic rock

  7. Different fossil types are found in different strata Trilobites are found in the same strata, all over the world.

  8. Fossils show species change over time • Example – horse ancestors

  9. Evidence for Evolution I. Fossils and Geologic Time • Age of the fossil = age of strata it is in • Different fossil types are found in different strata • Fossils show species change over time • Example – horse ancestors II. Similarities in Anatomy III. Similarities in Development IV. Molecular Similarities

  10. II. Similarities in Anatomy • Homologous structures are inherited from a • common ancestor • Example: Fish fin, fossil amphibian foot

  11. Homologous structures are inherited from a • common ancestor • Example: Mammal forelimbs

  12. Analogous structures:similar function but develop from different ancestors. • Example: butterfly wings, bird wings

  13. II. Similarities in Anatomy • Homologous structures • Analogous structures • Vestigial (non-functional) traits • Example: Eyes of cave salamander, cave fish Blind cave fish (Mexican tetra) Blind cave salamander

  14. Evidence for Evolution I. Fossils and Geologic Time • Age of the fossil = age of strata it is in • Different fossil types are found in different strata • Fossils show species change over time • Example – horse ancestors II. Similarities in Anatomy • Homologous structures are inherited from a common ancestor • Example: Fish fin, fossil amphibian foot • Example: Mammal forelimbs • Analogous structures: similar function but develop from different ancestors. • Example: butterfly wings, bird wings • Vestigial (non-functional) traits • Example: Eyes of cave salamander, cave fish III. Similarities in Development IV. Molecular Similarities

  15. III. Similarities in Development Cat embryo Human embryo (32 days) Dolphin embryo (24 days) f = forelimb bud, h = early hindlimb bud

  16. III. Similarities in Development • Examples: tails, gill pouches, hind limbs

  17. An atavism is a trait that can be traced to a common ancestor but that usually disappears during development in the modern species, such as a tail in a human.

  18. Evidence for Evolution I. Fossils and Geologic Time • Age of the fossil = age of strata it is in • Different fossil types are found in different strata • Fossils show species change over time • Example – horse ancestors II. Similarities in Anatomy • Homologous structures are inherited from a common ancestor • Example: Fish fin, fossil amphibian foot • Example: Mammal forelimbs • Analogous structures: similar function but develop from different ancestors. • Example: butterfly wings, bird wings • Vestigial (non-functional) traits • Example: Eyes of cave salamander, cave fish III. Similarities in Development • Examples: tails, gill pouches, hind limbs IV. Molecular Similarities

  19. IV. Molecular Similarities • Gel electrophoresis

  20. Genome similarities – comparing total DNA sequences Researchers used a sample of blood from this chimpanzee to compare chimps' genetic code with that of humans (about 3 billion base pairs). The scientists found that the two species share 96 percent of the same DNA.

  21. Nucleotide differences in genes coding for proteins (such as hemoglobin, Cytochrome c) Example of an evolutionary tree based on molecular similarities (how many nucleotides are different in the Cytochrome C gene)

  22. Evidence for Evolution I. Fossils and Geologic Time • Age of the fossil = age of strata it is in • Different fossil types are found in different strata • Fossils show species change over time • Example – horse ancestors II. Similarities in Anatomy • Homologous structures are inherited from a common ancestor • Example: Fish fin, fossil amphibian foot • Example: Mammal forelimbs • Analogous structures: similar function but develop from different ancestors. • Example: butterfly wings, bird wings • Vestigial (non-functional) traits • Example: Eyes of cave salamander, cave fish III. Similarities in Development • Examples: tails, gill pouches, hind limbs IV. Molecular Similarities • Gel electrophoresis • Genome similarities – comparing total DNA sequences • Nucleotide differences in genes coding for proteins (such as hemoglobin, Cytochrome c)

More Related