Evidence to Support Evolution Honors ninth grade science
Warm up… 1. Use the diagram and explain the process of natural selection.
Examples of Natural Selection: Sickle cell Anemia Peppered Moth
Pace of Evolution GRADUALISM: Evolution occurs slowly Many transitions occur PUNCTUATED EQUILIBRIUM: Evolution occurs in quick bursts Many periods of no change
Evidence to Support Evolution
1. Fossils Trace of a dead organism Organisms buried in moist area Minerals in bone are replaced Soft tissues don’t often fossilize Age determined by radiometric dating
2. Comparative Embryology Vertebrates are similar in early developmental stages Differences accumulate during development Development instructions are added to instructions inherited from ancestors.
2. Comparative Embryology
3. Transitional Forms Intermediates between old and new species Ex: modern horse descended from dog-sized animal with multiple toes
Transitional Forms Fish to Amphibians
Transitional Forms Reptiles to Birds
Transitional Forms Land Mammals to Aquatic Mammals
4. Homologous Structures Structures with a common ancestry Modified versions of structures from other organisms Ex: bones in appendages
4. Homologous Structures
5. Vestigial Structures No present function Remnants of an organism’s past; previously served a function Ex: human appendix-may once have been used for digestion Ex: whale’s pelvis-not needed for swimming, is needed for walking
5. Vestigial Structures
NOW… SciChat
Warm up… What are some things that could be pieces of evidence that would support the idea that evolution has happened?
6. DNA and Proteins DNA makes proteins Evolutionary history is held in the DNA sequence If species change, their DNA changes Closely related organisms share DNA similarities Ex: humans and chimps share 98% DNA
6. DNA and Proteins Human-Human=99.5% similar Human-Chimpanzee=98% similar Human-Cat=90% similar Human-Cow=80% similar Human-Mouse=75% similar (90% analogous regions) Human-Chicken=60% similar Human-Fruit Fly=60% similar
Warm up… Did any individual Peppered moth change its color during its lifetime? Why? (or why not?) Explain the change from light colored to dark colored moths. 36:15
Now… Quick Check-15 minutes-you know it or you don’t Peppered Moth Graph This MUST be finished TODAY Graded TODAY and returned for the questions TOMORROW Work time
Warm up… What is the difference between an independent variable and a dependent variable? Explain the steps of Natural Selection. How does antibiotic resistance show natural selection?
Check yours… X Transitional Vestigial DNA Fossils Embryology Homologous Transitional Vestigial Embryology DNA Fossils Gill Slits… X Forelimbs… DNA… Archaeopteryx… Whale pelvis… Common ancestor… Modern horse…
Check yours… 2. UNDERLINE each of these terms or ideas (not the descriptions) Overproduction Inherited variation Struggle to survive Successful reproduction Adaptation of the species 3. Underline your example Underline each piece of natural selection you used to defend it
Transitional Forms Activity Turn to pages 112-113 in the GREEN textbook. Read about the transitional forms of the whale. In your notes, describe what scientists think the ancient ancestor the modern whale was like.
NOW… Watch the Sickle Cell Anemia Video Read the Sickle Cell Anemia Article Use the information to complete the FRONT of the Natural Selection Examples sheet
Warm up… Watch the Peppered Moth video Complete the BACK of the Natural Selection Examples sheet you received yesterday (We will do antibiotic resistance in another class period)
Examples of Natural Selection: Sickle cell Anemia Peppered Moth
Which is NOT homologous & Why? A Human Lizard Octopus B Bird Whale Grasshopper Lizard Human