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 für Naturkunde Berlin Evolution Continued: Evidence & Other Concepts

On the following slides, the orange sections identify the main points; Underlined words = vocabulary! Hyperlinks are in green. http://1.bp.blogspot.com/-zkeALNoUN-A/T_Kt0nx-8-I/AAAAAAAAAWo/udwwi2Zs5UI/s1600/Evolution__Biologia_UEPB_by_resenhista.jpg

Today, most of the evidence for evolution is grouped into these main categories: Fossil Record Biogeography Homologies Anatomy Embryology Molecular Observable Events http://en.wikipedia.org/wiki/File:Equine_evolution.jpg The Evidence of Evolution Use the information on the following slides to complete your “Matching Notes” student sheet.

Evidence Concept Map

1 - FOSSIL RECORD Watch “Fossils As Evidence for Evolution” 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 RECORD Watch “Fossils As Evidence for Evolution”

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. Tracy A. Woodward / THE WASHINGTON POST Fossils Cont. http://www.washingtonpost.com/rf/image_606w/2010-2019/WashingtonPost/2012/08/17/Local/Images/NASADino6_1345234800.jpg

2 – Biogeography Watch “Biogeography As Evidence for Evolution” Biogeography: the geographic distribution of organisms organisms living widely apart (even different continents), may be similar because they share a common ancestor Beaver Muskrat Beaver and Muskrat Coypu Capybara Coypu and Capybara 2 – Biogeography Watch “Biogeography As Evidence for Evolution”

3 - Homologies: Anatomy Watch “Anatomical Development and Homologies as Evidence for Evolution”

Homologous structures: w/ similar structure, but different function show an evolutionary relationship EX limbs of vertebrates (turtle, alligator vs. mammal) http://4.bp.blogspot.com/-0rVjJQ9_gsQ/TtoEjKxfZ1I/AAAAAAAAA2Y/5XV9AmEwOlE/s1600/Pentadactyl.JPG Anatomy Cont.

Vestigial structures: reduced in size, are nonfunctioning remnants of similar structures in ancestral species Show an organism’s evolutionary past Ancestral species would have similar structures that are still functioning EX human tailbone, appendix, whale femur/pelvis http://www.kirksville.k12.mo.us/khs/teacher_web/alternative/whale-vestigial-structure.jpg Anatomy Cont.

Can you spot the vestigial limbs? (Photo Credit: Marc Mythos)

4 - Homologies: Developmental (Embryology) Embryos of different species may appear similar in early stages of development Can show developmental relationships http://www.evolutionnews.org/Mader_2010.jpg http://www.pbs.org/wgbh/nova/evolution/guess-embryo.html 4 - Homologies: Developmental (Embryology)

4 - Homologies: Developmental (Homeobox/Hox Genes) Hox genes: found in animals, determine the pattern of the body during development Control transcription factors Can show genetic relationships 4 - Homologies: Developmental (Homeobox/Hox Genes)

5 – Homologies: Biochemistry http://www.nobelprize.org/nobel_prizes/medicine/laureates/1993/illpres/protmol-aminoacid-v4.gif 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

Sequence of amino acids in a particular protein is compared between organisms AA Sequencing is probably the strongest evidence for relationships among organisms Cladogram: diagram that shows the evolutionary relationship among a group of organisms. http://www.bio.miami.edu/dana/pix/hemoglobincomparison.jpg Biochemistry Cont.

Some changes in species have been observed and studied in recent times Observable events show that evolution is an ongoing process P. & R. Grant’s Study of Beak Size Shift in Darwin’s Finches H. Kettlewell’s Study of Peppered Moth Color Shifts Observable Events

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 http://evolution.berkeley.edu/evosite/evo101/VBDefiningSpeciation.shtml

Isolating Mechanism: Reproductive Isolation Two populations become reproductively isolated from each other Members cannot interbreed so the genetic material becomes too different Spotted owl subspecies living in different geographic locations show some genetic and morphological differences. Isolating Mechanism: Reproductive Isolation

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  Video Cricket songs http://www.pbs.org/wgbh/evolution/library/05/2/swf_pop/l_052_01.html Isolating Mechanism: Behavioral Isolation

Isolating Mechanism: Geographic Isolation http://biology-forums.com/gallery/33_14_07_11_6_00_25.jpeg 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.  Britannica Isolation Mechanism: Temporal Isolation

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 Video 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 Video http://media-1.web.britannica.com/eb-media/11/54911-004-B661673C.jpg Types of Evolution: Divergent Evolution

True or False? The shark and the dolphin are closely related? http://matthewbonnan.files.wordpress.com/2012/06/convergent-evolution.jpg

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 http://bio3vo.files.wordpress.com/2011/04/analogous-structures.jpg Types of Evolution: Convergent Evolution