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

Other methods for dating fossils

Dating Methods

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