Unit+4+-+Conservation+and+biodiversity

=__**TOPIC 4**__=


 * 4.1.1 Define the terms //biodiversity//, //genetic diversity//, //species diversity// and //habitat diversity// **** . **

Blue book page 99-100
 * Pdf ESS Book: page 174 of 290 **

BIODIVERSITY: GENETIC DIVERSITY: SPECIES DIVERSITY: HABITAT DIVERSITY:


 * Link to 2.3.5 Simpson’s biodiversity index (pdf ESS book: page 34 of 290) **


 * 4.1.2 Outline the mechanism of natural selection as a possible driving force for speciation. **

Blue book page 100

Speciation occurs as a result of the isolation (geographical or reproductive) of populations. The concept of fitness should be understood.

i) What is Geographical isolation, and give an example of when it has occurred? ii) What is Reproductive isolation, what causes reproductive isolation?

The history of the development of the modern theory of evolution is not expected, nor is a detailed knowledge of genetics (including allele frequency).

//Theory of Evolution most closely associated with Sir Charles Darwin – The Origin of Species. Explains how the large variety of life developed on Earth. Works on the following key premises:// - //We get our characteristics from our parents.// - //No two individuals are the same.// - //Those better able to survive will reproduce.// - //Survivor’s characteristics are passed on to their offspring.// //This process is known as **NATURAL SELECTION**. Several factors act to support this theory:// - //Fossil record (older less complex).// - //Artificial selection works (humans have made changes in a very short time).// - //Life has been on Earth for a long time (4500 million years)// - //DNA Record (we share a common ancestor).// - //Mutations occur all the time.// The peppered moth, //Biston betularia,// lives in most parts of Britain. It flies by night and spends the days resting on tree trunks. It has speckled wings, which camouflage in beautifully on lichen-covered tree trunks. This gives it protection against insect eating birds. In the 19th century (the 1800s) big coal-burning industries grew up in the North of England. The air became polluted and the lichens were killed. The trees were often blackened with soot. In 1849, an unusual peppered moth was spotted near Manhester. It was almost black. By 1900, 98% of the peppered moths living near Manchester were black. Today most moths are speckled again.
 * __ Example of natural selection __**

1) Is this an example of speciation? 2) Suggest what occurred to make moth become black 3) What was the selective advantage that the black moth had
 * QUESTIONS from the example of the peppered moth: **


 * 4.1.3 State that isolation can lead to different species being produced that are unable to interbreed to yield fertile offspring. **


 * Pdf ESS book: page178 of 290 **

Blue book page 100-101


 * Biology 8th Edition by Campbell and Reece.pdf (page537 of 1465) has some wonderful examples of barriers to reproduction **

Isolation of populations, behavioural differences that preclude reproduction and the inability to produce fertile offspring (leading to speciation) should all be examined, with examples.

1) give an example of an isolated population which developed into a new species 2) give an example of a species which arose out of behavioural differences which preclude reproduction

Isolation leads to a variation in populations. May even change so much they cannot interbreed effectively. Why? //Isolation can lead to some species being unable to reproduce with it other to produce viable offspring. This situation results in the creation of a new species. This isolation can occur due to several factors:// //Geographical – actual physical barriers between organisms// //e. g. Tree kangaroos v land kangaroos. Tree in S.E. Asia and land in Australia. Separated when Gondwanaland split.// //Temporal – breed at different times so do not mix// //e.g. California Field Crickets. Closely related but breed at different times of the day so no mixing of gametes// //Ecological – breed in different habitats// //e.g. Lady Birds in Japan very similar. Live on and eat different plants. Therefore, they breed on these plants too// //Behavioral – species have different mating rituals// //e.g. Fruit Flies have a specific dance with which to breed. Similar flies do not and hence will not breed.// //Mechanical – structural differences in the breeding mechanism stops gamete transfer. (NOT COMMON)// //e.g. Species of fruit fly that if they breed will cause injury or death.// //Gametic – gametes have specific ways of combining genetic material// //e.g. Male Abalone gametes have a chemical that dissolves into the female gamete to allow fertilization but only of the same species.// //Hybrid – offspring cannot reproduce due to genetic incompatibility. This can produce embryos that die or sterile offspring.// //e.g. Goats and sheep embryos die. Donkey and horse produce mule, which is sterile.//
 * __ Notes: __**

Note Figure 5.7 page 103.


 * 4.1.4 Explain how plate activity has influenced evolution and biodiversity. **


 * Pdf ESS book: P180 of 290 **

Blue book page 102 Note Figure 5.7 page 103. Biology 8th Edition by Campbell and Reece: page 556 of 1465 – ‘concept 25.4’

The consequences of plate tectonics on speciation should be understood (that is, the separation of gene pools, formation of physical barriers and land bridges) together with the implications these consequences have for evolution. The role of plate activity in generating new and diverse habitats, thus promoting biodiversity, should also be considered. Detailed understanding of the mechanism of plate tectonics is not required.

http://www.youtube.com/watch?v=Dj8K0O3ehps

What is Gondwanaland? What is a marsupial and what makes them special? How is biodiversity increased by plate tectonics?

// Web page on Earth’s structure. // [|//http://www.bnsc.gov.uk/assets/channels/education/ae/Earth_interior.gif//]
 * //__Plate Tectonics__//**

//The Earth is not a solid mass. In fact most of the Earth is liquid. The crust floats on the surface of the upper most liquid layer – the Mantle. The crust is not solid – it has many cracks. These cracks and the movement of the mantle gives rise to many of the geological features we see today.//

Web page on plates. []

//Plates have moved over the millions of years of the Earth’s development – Continental Drift. This has lead to the isolation of some species that has made them evolve completely differently.//

// Web page on Continental Drift // [|//http://www.nature.nps.gov/geology/usgsnps/animate/PLATES_3.MPG//] [|//http://www.ucmp.berkeley.edu/geology/tecall1_4.mov//]


 * 4.1.5 Explain the relationships among ecosystem stability, diversity, succession and habitat. **

Note factors p 105 and 106 (Krakatoa p273) Biology 8th Edition by Campbell and Reece: page 1259 of 1465 – ‘Ecological succession’
 * Pdf ESS book: page 182 of 290 **

Consider how:
 * Diversity changes through succession
 * Greater habitat diversity leads to greater species and genetic diversity
 * A complex ecosystem, with its varitey of nutrient and energy pathways, provides stability.
 * Human activities modify succession, for example, logging, grazing, burning
 * Human activities often simplify ecosystems, rendering them unstable, for example, North America wheat farming versus tall grass prairie
 * An ecosystem’s capacity to survive change may depend on diversity, resilience and inertia

1) Give an example of how an ecosystems’s capacity to survive change depends on diversity, resilience and inertia 2) Why is virgin tropical rainforest considered a stable ecosystem? 3) Summarise the stages of succession for a known ecosystem? 4) What is the difference between a primary and secondary succession? Which of these is generated by human activities? Give three examples of how human activities can modify succession?

__Maintaining Diversity__ Biodiversity will tend to be maintained if:
 * More complex ecosystems – more complex systems are more resilient as they do not rely on one type of organism.
 * Stage of Succession – more mature ecosystems tend to be more diverse. However, climax communities may reduce diversity slightly.
 * Limiting Factors – reduction in limiting factors
 * Inertia – ecosystems tend to resist change due to resilience (ability to recover) and stability (tendency to maintain equilibrium).
 * __ Consider how: (1-6) __**


 * 1. How Diversity changes through succession? **


 * 2. Greater habitat diversity leads to greater species and genetic diversity. **


 * 3. A complex community with a variety of energy pathways leads to stability **


 * 4. Human activities influence succession (mining, logging, dams etc.) **


 * 5. Human activity simplifies ecosystems rendering them unstable **


 * 6. An ecosystem capacity to survive may depend on its diversity, resilience and inertia **


 * __ 4.2 EVALUATING BIODIVERSITY & VULNERABILITY __**

BLUE BOOK: P 91, Chapter 5: Biodervisity p91 Ebook: Chapter 4

4.2.1 Identify factors that lead to loss of diversity.

4.2.2 Discuss the perceived vulnerability of tropical rainforests and their relative value in contributing to global biodiversity.

4.2.3 Discuss current estimates of numbers of species and past and present rates of species extinction.

Examine the fossil record for evidence of mass extinctions in the past, and compare and contrast the possible causes of these to present-day extinctions. The time frame of these periods of extinction should be considered.

[]

4.2.4 Describe and explain the factors that may make species more or less prone to extinction.

The following factors (among others) will affect the risk of extinction: numbers, degree of specialization, distribution, reproductive potential and behaviour, and trophic level.

4.2.5 Outline the factors used to determine a species’ Red List conservation status.

[|**http://www.iucnredlist.org/**]

4.2.6 Describe the case histories of three different species: one that has become extinct, another that is critically endangered, and a third species whose conservation status has been improved by intervention.

4.2.7 Describe the case history of a natural area of biological significance that is threatened by human activities.

Students should know the ecological, socio- political and economic pressures that caused or are causing the degradation of the chosen area, and the consequent threat to biodiversity.

// 4.3.1 State the arguments for preserving species and habitats. //

// 4.3.2 Compare and contrast the role and activities of intergovernmental and non-governmental organizations in preserving and restoring ecosystems and biodiversity. //

// 4.3.3 State and explain the criteria used to design protected areas. //

// http://www.unesco.org/mabdb/br/brdir/asia/Chinamap.htm // []

// 4.3.4 Evaluate the success of a named protected area. //

// 4.3.5 Discuss and evaluate the strengths and weaknesses of the species- based approach to conservation. //