5.4: an introduction to the theory of evolution. what do we need to know about evolution (weds)?...
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5.4: An introduction to the Theory of Evolution
What do we need to know about Evolution (Weds)?
5.4.1: Define Evolution
5.4.2 Outline the evidence for evolution (X4)
5.4.3: State that populations tend to produce more offspring than the environment can support
5.4.4. Explain that one of the consequences of potential ovrpopulation is a struggle for survival
What do we need to know about Evolution (Thurs)?
5.4.5. State that the members of a species show variation
5.4.6. State how sexual reproduction promotes variation in a species
Explain HOW natural selection leads to evolution
Explain two example o evolution in response to environmental change
Objectives for todayMeet Charles Darwin and his world-changing
‘theory’….
5.4.1: Define Evolution
5.4.2: Outline the evidence for evolution provided by the fossil record, selective breeding of domesticated animals and homologous structures
‘Isn’t Evolution “just” a theory?’
Darwin’s Theory of Evolution
"the single best idea anybody ever had” (Daniel Dennet, Philosopher)
“a big idea, arguably the most powerful idea ever “ (Richard Dawkins, Philosopher)
“Its publication (The Origin if Species) changed the world”
5.4.1: Define Evolution
Synonyms for EvolutionCharles Darwin used ‘Descent with modification’
‘Survival of the fittest’
‘Theory of Natural selection’
Richard Dawkins’ Theory of Evolution
‘Given sufficient time, the non –random survival of hereditary
entities (which will occasionally miscopy) will generate complexity, diversity, beauty and an illusion of
design so persuasive that it is almost impossible to distinguish
from deliberate intelligent design’
Hypothesis vs. TheoryWhat’s the difference?.....
http://www.youtube.com/watch?v=85diEXbJBIk&feature=youtu.be
(6 minutes)
Let’s begin by meeting Charles Darwin…
http://www.youtube.com/watch?v=vmphlbRhLu8&feature=youtu.be
(6.40 mins)
Evolution in a nutshell: The Tree of Life
Wellcome Tree of Life
http://www.wellcometreeoflife.org/
Homework:
Charles Darwin Now that you have
background on Charles Darwin read the short packet and answer the questions.
Natural Selection: The survival and reproduction of individuals with favorable heritable traits.
Empirical Evidence: the record of one's direct observations or experiences
Friday1. The Evidence for Evolution
2. How does natural selection actually work?
Examples of natural selection in action: antibiotic resistance, rodenticide resistance, pesticide resistance…
Opponents to The Theory of Evolution: The Blind Watchmaker
oh yeah, it's David Attenborough again...
Evidence for Evolution1. The Fossil Record
2. Artifical Selection – breeding of plants and domestic animals
3. Geographical Distribution
4. Homologous Structures
Evidence for Evolution 1: The Fossil Record
The Fossil Record Palaeontologists uncover
fossilised remains in sedimentary rock deposits and use the information to create timelines
Organic matter trapped in sand/ silt/fossils
Compressed over time
Dated by isotopic carbon (50,000 years), potassium40 (1.28 Billion years), 238 Uranium
Oldest fossils are at the bottom, youngest at the top
Fossil Evidence for Evolution
http://www.pbs.org/wgbh/evolution/sex/mating/index.html
Evidence for Evolution 2: Homologous structures
Homologous traits have similar embryological origins and development
Indicative of common acnestry: what Darwin called ‘Unity of Type’
Indicative of adaptive radiation
Pentadactyl limb
Human appendix
Whale pelvic and thigh bone
Homologous structures: Pentadactyl Limb
Homologous structures: Whale Pelvic bone
Homologous structures: Human appendix
Evidence for evolution 3: Artificial Selection
Evidence for evolution: Artificial selection
Evidence for evolution: Geographical Distribution
Before humans arrived, Australia had > 100 types of marsupials, but no placental mammals
Hawai’I and New Zealand had unique biotic environments – plants, insects, birds but no placental mammals
Evidence for Evolution: Observable Changes
Development of new species is RAPID in species with a short reproductive cycle: bacteria, viruses, parasites, moths etc etc etc
Week 5: October 2 - 5TEST on populations and evolution: Friday or
Monday?
The Mechanism of Evolution: Natural
Selection
Hummingbirds and natural Selection
How does natural selection work?
1. Too many offspring
2. Natural genetic variation
3. Struggle for survival
4. Differential survival and reproduction
Too many offspringResults in competition for available resources –
food, shelter, mates, water, sunlight
Natural Variation: Prokaryotes
Bacteria and other primitive organisms reproduce asexually
May change their genetic make-up by means of mutation
May change their genetic makeup by means of plasmid transfer
Natural Variation: Eukaryotes
Mutation
Mutations can result in advantageous or disadvantageous changes
In each generation, only a few genes mutate, and most mutations produce effects that are neither good or harmful
Sexual Reproduction
A much more powerful source of combination, since thousands of genes are mixed and copied
MEIOSIS CROSSING OVER in
prophase 1 Random assortment of
chromosomes in metaphase 1
RANDOM FERTILISATION
http://i-biology.net/ibdpbio/05-ecology-and-evolution/evolution/
Slide 14 – 27
http://www.pbs.org/wgbh/evolution/library/01/2/quicktime/l_012_02.html
Peppered Moth simulationPeppered moth simulation
Your evolution Assignments: for Thursday
On the syllabus for 5.4.8, it says "Explain two examples of evolution in response to environmental change; one must be antibiotic resistance in bacteria. “
Your job is to find information on another example of evolution in response to environmental change. You should be prepared to share with the class a brief summary that includes: what organism was affected, what caused the change, and what the change was.
!
Group 1: Antibiotic Resistance in Bacteria
Group 1 will look at develop of antibiotic resistance against tuberculosis
Resources:
http://www.sumanasinc.com/scienceinfocus/sif_antibiotics.html
http://www.who.int/topics/tuberculosis/en/
http://www.euro.who.int/en/what-we-do/health-topics/communicable-diseases/tuberculosis
http://www.guardian.co.uk/world/2012/mar/25/drug-resistant-strains-of-tb
http://www.cdc.gov/tb/
Group 2: Pesticide Resistance
Group 2 will look at development of pesticide resistance in rodents
Resources:
http://www.mhhe.com/biosci/esp/2001_gbio/folder_structure/ev/m2/s1/evm2s1_6.htm
http://www.pbs.org/wgbh/evolution/library/10/1/l_101_02.html
http://evolution.berkeley.edu/evolibrary/article/agriculture_04
Group 3: Development of resistance in Malaria parasites
Group 3 will look at development of drug resistance in Malaria parasites (and also look at evolutionary strategies being used to combat malaria!)
http://www.bbc.co.uk/news/health-17628172
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)60484-X/abstract
http://online.wsj.com/article/SB10001424052702303815404577335703043691304.html
http://www.who.int/drugresistance/malaria/en/
http://www.who.int/drugresistance/publications/WHO_CDS_CSR_DRS_2001_4/en/index.html
http://www.scientificamerican.com/article.cfm?id=malaria-resistant-mosquitoes-lab-bred-first-time
Group 4: Peppered MothsGroup 4 will look at the evolution of the
peppered moth in industrial UK (industrial melanism, quite controversial!)
http://www.techapps.net/interactives/pepperMoths.swf
http://www.christs.cam.ac.uk/darwin200/pages/index.php?page_id=g5
http://www.youtube.com/watch?v=LyRA807djLc
http://www.bbc.co.uk/radio4/science/thematerialworld_20071011.shtml