Evolution Lecture 1 Name________Date ________ Chapter 22~ Descent with Modification: A Darwinian View of Life

C.H.A.M.P.S. Behavioral expectations C. – conversation level – 0 while others are instructing or contributing; 1 while directed to collaborate; 1 when working independently, only as needed for assignment. H – what to do if you need help – whisper question to neighbor if not interrupting instruction; raise hand, but don’t interrupt teacher’s instructions or sentence. Wait for permission/right time to speak.

C.H.A.M.P.S. Behavioral expectations A. – Activity - 1 – note-taking, interactive instruction, questions to activate prior knowledge and check for understanding. M – movement – stay in seat unless it is your time to help the teacher in some way, such as passing out materials.

C.H.A.M.P.S. behavioral expectations P – Participation behaviors – listening, sitting up, writing, speaking when called on to answer or ask a relevant question. S – criteria for success– write down main ideas and new vocabulary; answer questions in complete sentences.

Focused Learning Targets I will be able to distinguish between different scientist’s contributions to the theory of evolution. I will be able to evaluate how examples and observations in nature show evidence of evolution, and which kind of evidence they represent. I will know that I can do these thinking tasks when I complete the mastery task for ‘evidence of evolution’ with 80-100% proficiency.

Evolution Evolution: the change over time of the genetic composition of populations Natural selection: populations of organisms can change over the generations if individuals having certain heritable traits leave more offspring than others (differential reproductive success) Evolutionary adaptations: a prevalence of inherited characteristics that enhance organisms’ survival and reproduction November 24, 1859

Origin of species CFU: 1.What is evolution? Evolution is the change over time of the genetic composition of populations. 2.What is Natural Selection? Natural selection is the mechanism, or the way that populations of organisms change over the generations, if individuals having certain heritable traits leave more offspring than others (differential reproductive success) 3.What is evolutionary adaptation?

Activating Prior Knowledge 4. How many of the previous scientists do you remember from 9th grade? Could you list what you remember? Examples: Linnaeus: taxonomy Hutton: gradualism Lamarck: evolution Malthus: populations Cuvier: paleontology Lyell: uniformitarianism Darwin: evolution Mendel: inheritance Wallace: evolution

Evolutionary history Linnaeus: taxonomy Hutton: gradualism Lamarck: evolution Malthus: populations Cuvier: paleontology Lyell: uniformitarianism Darwin: evolution Mendel: inheritance Wallace: evolution

Check for understanding 6. Did only one scientist contribute to our understanding of evolution? Why do you think this happened? Many scientists built their knowledge on top of others’ research to develop what we accept as true, today. 7. What do you think taxonomy is? Look up the answer if you do not know. Taxonomy is the branch of science concerned with classification, especially of organisms; systematics.

Descent with Modification, I 5 observations: 1- Exponential fertility 2- Stable population size 3- Limited resources 4- Individuals vary 5- Heritable variation

Check for understanding: 8. what is exponential fertility? 9. If scientists observed this a very long time ago, could you also think of an example of this, today? 10. What organisms might have exponential fertility? 11. What does it mean to have heritable variety? See next slide for answers

Answers to #8-#11: 8. Exponential fertility is when a population shows exponential birth rates. 9. An example of exponential fertility today is when bacteria multiply or when animals with short gestation periods and large brood sizes reproduce, such as rabbits. 10. Organisms that might show exponential fertility are insects, spiders, bacteria, rodents and many small mammals, most fish and some species of turtles. 11. To have heritable variety is to have a population with many differences or a diversity of phenotypes: traits that are inherited and passed to the next generation.

Descent with Modification, II 3 Inferences: 1- Struggle for existence 2- Non-random survival 3- Natural selection (differential success in reproduction)

Check for understanding 12. An inference is a logical conclusion or decision based on an observation or observations. Explain how a scientist might come to these three inferences, based on the five observations? Based on these observations, there is a pattern which would lead one to think of a mechanism or system which both controls population size and favors some traits over others for survival in the context of that ecosystem..

Evolution evidence: Biogeography Geographical distribution of species Examples: Islands vs. Mainland Australia Continents

Activate prior knowledge 13. What do you know about the strange creatures of the Galapagos Islands? These are the creatures which inspired some of Darwin’s most important conclusions. 14. How might creatures be different on islands verses a mainland? Why? Creatures on islands may have been isolated from mating with species members in a nearby ecosystem, and therefore adapt specifically to their habitat. Therefore, evolutionary traits that are selected for survival and reproduction may be quite different from other places.

Evolution evidence: The Fossil Record Succession of forms over time Transitional links Vertebrate descent

Check for understanding 15. What does the word succession mean? Succession (general definition) means: (a.) The act of following in order or sequence. (b.) A following of things, events, people, or ranks after another in sequence of time, as in a succession of disasters. 16. What does succession of forms mean? Succession of forms means that there was a progression of forms in organisms, over time, which looked like a logical sequence of change in the organism.

Check for understanding continued. 17. what does the word transitional mean? ‘Transitional’ means ‘in the midst of change.’ 18. What are transitional links, when one speaks of evolution, do you think? Google this if necessary. ‘Transitional links’, in the context of evolution means organisms which provide a connection between two pathways of form progression, over time. For example, the species or kind of dinosaur with the bodily structure which later evolved into birds of today.

Check for understanding continued 19. What is a vertebrate? A vertebrate is any organism with a backbone. The backbone usually also houses a central nervous system spinal cord running within it. 20. What does the word descent mean? ‘Descent’ means ‘passed down’ by inheritance to subsequent generations. 21. What does the phrase vertebrate descent mean, then, do you think? Google this if necessary. This means the evolutionary pattern or pathway by which vertebrate organisms pass on traits to subsequent generations.

Evolution evidence: Comparative Anatomy Homologous structures (homology) Descent from a common ancestor Vestigial organs Ex: whale/snake hindlimbs; wings on flightless birds

Homology 22. What do you think homologous structures are? Homologous structures are bodily parts and structures which are common to different species. These may serve as proof that different organisms evolved from a similar point Hint: the wings of pterosaurs (1), bats (2) and birds (3) are analogous as wings, but homologous as forelimbs.

Check for understanding cont. 23. 23. What are vestigial organs, in your own words? Vestigial organs are body parts that no longer hold as much importance for a creature’s survival in our environment, and because of this, have gradually been phased out and left to atrophy in size.

Vestigial structures official definition from biologists leftovers Reduced in size over time vestigial refers to an organ or part (for example, the human appendix) which is greatly reduced from the original ancestral form and is no longer functional or is of reduced or altered function. Vestigial structures provide a clue to the evolutionary history of a species because they are remnants of structures found in the ancestral species.

Evolution evidence: Comparative Embryology Pharyngeal pouches, ‘tails’ as embryos

Evolution evidence: Molecular Biology Similarities in DNA, proteins, genes, and gene products Common genetic code

Check for understanding 24. What were the different arguments and evidence used to argue for Darwin’s theory of natural selection and evolution? A. B. C.

Final words…... “Absence of evidence is not evidence of absence.”

Check for understanding? How do you think humans have evolved? Give an example and explain how a specific animal species may have evolved? Picture cartoons are an option.