Unit 3 (Kognity Only) Flashcards
1
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Biodiversity
A
The degree of variation of all life on earth, both within and between species and habitants
2
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The three components of biodiversity
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Species, habitat, and genetic diversity
3
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Biodiversity is not constant….
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It changes over space or time
4
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Different areas of the world have
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An inherently higher biodiversity than other
5
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Tropical rainforest biome
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The most diverse terrestrial ecosystem
6
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Hot and cold deserts are
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The most sparse biomes for biodiversity
7
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Tropical rainforest biomes have approx.
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1,500 flowering plant species, 700 tree species, and 400 bird species
8
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The Sahara desert biome has approx.
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500 species of plants, 90 bird species, and more than 100 reptile species
9
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Tropical coral reefs have….
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A large variety of life due to the warm water and plenty of sunlight conditions
10
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The oceanic abyssal zone….
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Has very low diversity due to the cold/dark conditions at 4,000-6,000 metres deep
11
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Biodiversity is essential for….
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The earth to function effectively
12
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In order to conserve biodiversity….
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We must both understand and quantify it (we are losing species and habitats at an alarming rate
13
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The highest biodiversity is found
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Around the equator and the tropics
14
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The lowest biodiversity is found
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Towards the north and south poles
15
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Terrestrial
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On or relating to the earth
16
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Areas with higher biodiversity have….
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Fewer limiting factors
17
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What will create a higher level of primary productivity and abundant plant growth?
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Equitable climate, plentiful precipitation, high isolation, suitable temperatures
18
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More vegetation increases
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The number of habitats, food, water, and animal shelter to decrease competition and increase the amount of species variety within a particular area
19
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Areas with a better climate and fewer limiting functions….
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Will have a higher biodiversity
20
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Regions in the same climatic zone….
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Can have very different levels of biodiversity
21
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Factors of biodiversity:
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Climate, age of the area, environmental stability, range of habitats
22
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Age of an area (biodiversity)
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Older areas tend to have higher biodiversity since they have had a longer time span allowing organisms to diversify more and mor
23
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Environmental stability (Biodiversity)
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Environmental disturbances such as volcanic eruptions, earthquakes, and floods, and/or climatic disturbances such as glaciations or drought - may destroy large numbers of species causing less time for colonisation and species adaption
24
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Range of habitats (Biodiversity)
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A wide range of habitats will allow the organisms to move into new habitats and ecological niches evolving and driving speciation
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Range of habitats are due to:
Greater vertical extent of the vegetation, altitudinal variation, latitudinal ranges, variation in rock and soil types
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Greater vertical extent of vegetation
Forests versus grasslands, because forests are layers they offer a wider range of habitats
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Altitudinal variation
Any area with a mountain range will have a range of climates associated with the different heights and so different organisms in each zone
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Latitudinal ranges
Areas that extend across the latitudes will have the same sort of variation as seen in mountain ranges
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Variation in rock and soil types:
Changes in the abiotic environment will cause changes in the biotic environment so increasing biodiversity
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Human survival is dependent on
Biodiversity and living things
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People become detached from nature....
Because of urbanisation
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Conservationists find that action is easier....
If people believe inaction will cost themselves in some way
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Human benefits of biodiversity
Financial benefits, natural capital provides goods that can be extracted, processed, and sold such as timber, agricultural food crops, medicines, pharmaceutical drugs, and clothes. Also numerous research and educational opportunities for humans since we only know few things about some biomes (tropical rainforests), If we damage the environment it will effect our lives creating a domino effect
34
Humans biodiversity positive feedback loop
Insecticides to kill pesticides, residue drains into water bodies and is taken in by fish, the poison becomes more and more concentrated until it gets to humans
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Non human biodiversity advantages
Biodiversity maintains genetic diversity being important to the continuation of evolution, natural areas allow humans to get away from city life, global ecosystems provide invaluable services including the balance of atmospheric gases, clean air, the water cycle, climate regulation, soil formation and protection, pollution breakdown and absorption
36
Reasons to put prices on nature:
Gives an actual value that people can understand. People know how much material things cost so they have a point of comparison. Putting a high price on something may make people realise its value and his understand its importance
37
Reasons not to put prices on nature:
Once you place a price, the item can be "sold" which may encourage governments in some areas to sell land to the "highest bidder." There may be a bias towards protecting areas that are worth more, and ignoring other areas seen to be less beneficial
38
Scientists agree there are about
10 million species on the earth - previous estimates have ranged between 10-100 million
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Three-quarters of known species
Are on land
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The percentage of land species that have been recorded
14%
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Percentage of the plant and animal species that are in tropical rainforest
50%-90%
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Percentage of species that are invertebrates
More than half
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Species diversity
Number of different species in a given area taking into account the richness and evenness of the species
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The two factors to consider when measuring diversity
Richness and evenness
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Richness
Measure of the number of different species in one area more species means richer environment
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Limitations with the measurement of richness
No account is taken of how common or rare a species is. It may also be inaccurate as species need to reproduce to maintain their presence in the ecosystem
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Evenness
The relative abundance of species.
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Positives of measuring evenness
It take into account the abundance or scarcity of each species and eliminates problems of just analysing species richness
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Relative species abundance
How common or rare a species is in relative to other species in a defined location
50
Relative abundance
The percent composition of an organism of a particular kind relative to the total number of organisms in the area
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The more rich and even a habitat / location is
The more diverse
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Simpson's diversity index formula
D = N (N - 1) / Σ n ( n - 1)
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N in Simpson's diversity index
Total number of organisms of all species found
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n in Simpson's diversity index
The number of individuals of a particular species
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Sample calculation SDI (D = N (N - 1) / Σ n ( n - 1))
150(149) / 50(49) + 50(49) + 50(49) + 50(49)
D = 22,350 / 2450 + 2450 + 2450
D = 22,350 / 7,350
D = 3.04
56
What does Simpson's diversity index show
The higher value of D the higher the diversity of the area - it puts a mathematical value on the diversity of a community so we can compare them over time and space and the state of an ecosystem over time - this could also helo with future development plans such as new projects close to natural areas
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Limitations of Simpsons diversity index
It is realistic to compare a rainforest with grassland but it can be useful to compare communities that should have a similar diversity, eg: 2 tropical grasslands
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Reasons for a low diversity
Close to a source of pollution, agricultural spraying of herbicides, subject to harvesting some of the species, closer to human habitation and so subject to degradation
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Changes of diversity can be documented in a
Millenium ecosystem assessment
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Species diversity in any ecosystem is....
The culmination of millions of years of evolution which occurs in association with other living organisms in the same area.
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Ecosystem in balance
Species interact with each other and the abiotic environment, and perform various functions within the system. So loss of just one species affects many others causing the system to go out of balance
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Insects (bees), Mammals (bats), and birds pollinate:
90% of all plats
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Humans rely on many species for....
Modern pharmaceuticals derived from plants *aspirin, penicillin, painkillers) and those in the developing world need plants for medication
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Habitat diversity
The range of different habitats in an area (also known as ecosystem diversity)
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Habitat is the....
Abiotic and biotic environment that a species lives in
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Habitat diversity
The range of places were plants and animals can live
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Terrestrial Biomes
In terrestrial biomes, abiotic environments are the most important for plants - the plants act as habitat for animals
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Determining factors of what species and plants can grow in an area
Temperature range, soil type, precipitation, and light
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A variety of vegetation communities in an areas means....
A larger habitat range for animals - type of vegetation is also important in this
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Vegetation
Plants considered collectively, especially those found in a particular area or habitat
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Woodland vegetation
Has many layers and thus creates a multi storied apartment block for animals
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Grassland vegetation
Provides only one layer of accomodation with less diversity
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High habitat diversity gives....
Different areas for populations of species to spread into, separation prompts greater gene pool various. A wide range of spaces for animals to adapt and/or move inn to for high species diversity
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High genetic diversity increases....
Species adaptability and can lead to speciation and thus to higher species diversity
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High species diversity creates....
A higher habitat diversity
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Marine habitats are different to terrestrial onces since....
They are transient and changeable and it is not only vegetation which provides animal habitats
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Suitability of habitats in marine environments....
Depends on abiotic factors themselves rather than the plants that are determined by the abiotic factors
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Abiotic factos include
Dissolved gases, land run-off, marine topography, nutrients, ocean gyres and currents, pH, salinity, sunlight, temperature (linked to latitude, ocean currents, and hydrothermal vents), and turbulence
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Genetic diversity
The variation of genes within the genetic pool of a population of a species; it is the means by which a population can adapt to change
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If there is a high level of genetic diversity....
There is a higher probability that some individuals within the population possess the genes that are best suited to any changes in the environment
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A smaller population of organisms....
Is likely to have a smaller gene pool, lower genetic diversity, and less adaptability
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Within a species there are....
Individuals and populations
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Every individual has....
A slightly different genetic make up from every other member of the species
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Individuals within a population will be....
More similar to each other than individuals from another population
85
Genetic diversity example":
Domestic cats - they belong to the same species and can interbreed but there is a huge variation between different breeds
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Genetic diversity in wild animal populations....
Is crucial for their survival
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Animals that are widespread and found in many different areas....
Have a higher chance of survival since each population will have different genetic makeup with different strengths and adapt abilities, and if one population is wiped out by disaster, other population will go unaffected and the species will carry on
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One of the most widespread species of the planet
Vulpes - The red fox - is had the adaptability to urban environments
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One of the most narrowspread species of the planet
Lemurs which are only downs in Madagascar - if they are wiped out, their chance of recovery is only in zoos. They have a small population, low genetic diversity and in-breeding may weaken them
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Why is genetic diversity important?
There is a better chance that some species will remain resilient and survive environmental change caused by disease, climate change, and pollution, low genetic diversity causes inbreeding to make genetic population make-up more uniform, so population disabilities will compone more common, Extinction is frequently preceded by a drop in genetic diversity, Once lost genetic diversity is almost impossible to regain, genes code our food, medicine, biofuels. If something we let on (eg: wheat) is struck by disease then genetic diversity increases the chances of us finding alternatives that are disease free
91
Two responses that life can make to the Earth's changes
Adapt and diversity, go extinct
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Go extinct
If the change is too rapid, evolution is often too slow to keep pace and some organisms will become extinct - 5 such events have occurred in the history of the earth named the mass extinction
93
Adapt and diversity
If the change is slow and progressive, life can adapt to the new conditions and biodiversity increases
94
The different approaches taken to the conservation of biodiversity
Policies, legislation, designation of protected areas, education programmes, promotion of sustainable activities such as ecotourism, habitat restoration programmes, species breeding programmes
95
MEDCs
Can afford to spend more money on biodiversity conservation - they have more technological tools and have world leading institutes on conservation
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A large amount of diversity is located in....
Biological hotspots in LEDCs
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To address inequity
Various conservation groups have formed to help share resources and expertise
98
Resources available to help with conservation....
Vary from place to place
99
The conservation of a threatened species in a remote part of the world
May be considered of little value for some people
100
Humans are dependent on biofiversity....
Both indirectly and indirectly
101
Reasons given for biodiversity conservation depend on EVS
an ecocentric view would argue that it is our moral duty to conserve biodiversity and that every species has biorights, the right to exist. Deep ecologists adopt a holistic world view, valuing how biodiversity is interconnected and believe that the spiritual and aesthetic value is important to human well-being. At the other extreme of the scale, Cornucopians with a technocentric view would argue that exploitation and loss of biodiversity is acceptable and that human ingenuity will help replace any lost resources. Environmental managers with an anthropocentric view would consider the ecological environment, economic and social aspects with the aim of achieving sustainable development.
102
Utilitarian value
Where there is an economic value associated with the use of resources
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Non-utilitarian values
when use does not have any economic value
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Utilitarian values include:
Direct use: (Consumptive use, such as goods that are harvested food, timber, medicines. Non-consumptive for aesthetic, recreational and educational use.) Ecological services: carbon sink, production of oxygen, water filtration, waste assimilation, nutrient recycling, flood control. (Value estimated to be US$16-54 trillion per year.) Option value - potential value in the future, for instance from discoveries of new medicines. Bequest value - passing benefits to future generations.
105
Non-utilitarian values
Intrinsic value: the right of a species to exist (biorights), an ethical based reason (supported by deep ecologist) Existence value: knowing the species exist. (any of us may never visit the Amazon rainforest but we gain satisfaction from knowing it exists.)
106
The Millenium Ecosystem Assessment linked biodiversity to human well being and categorised biodiverse values into:
Provision value: food, freshwater, wood, fuel
Regulating value: climate change, flood regulation, water purification
Supporting value: nutrient cycling, soil formation, primary production
Cultural value: aesthetic, spiritual, educational and recreational uses
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Intrinsic value
Belonging naturally, essentially
108
For conservation initiatives to be effective they need to:
Involve action at the local level that leads to change, Be supported by policies, legislation and resources (such as training, advice and finance).
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International agreements are sometimes vital eg:
Biodiversity does not respect human created national borders. Many species (animals, birds, fish) migrate from one area to another. Human activities have impacts on biodiversity beyond borders such as the demand for exotic pets that drives international trade and cause species loss (global demand for primates such as baby chimpanzees has contributed to a reduction of their wild populations in parts of Africa)
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Decisions to conserve biodiversity
Can be made at international or national level before being implemented locally
111
Non governmental organisations and inter-governmental organisations
Campaign and work towards conserving biodiversity
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NGOs
Non-profit, voluntary organisations usually funded by charitable donations and membership fees. They vary from being focused on one specific problem in one location (for example, Brainforest is protecting rainforest in Gabon) to working at an international level focusing on a range of related concerns such as WWF, or Greenpeace
113
The emergence of NGOs began....
In the 1960s when there were clear signs of damage humans are doing to the environment
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Intergovernmental organisations
Consist of members from different countries. They are funded by its members, (United Nations)
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United Nations
Founded in 1945 and currently consists of 193 members and has specialised agencies that are independent international organisations with their own specific aims, such as: The United Nations Environment Programme (UNEP), Food and Agricultural Organizations (FAO), Intergovernmental Panel on Climate Change (IPCC)
116
Collaboration between nations with biodiversity:
Conventions increasingly promote collaboration between nations to help conserve biodiversity. Examples from Convention on Biological Diversity (CBD) include: Consortium of Scientific Partners, South-south cooperation, Triangular cooperation
117
Consortium of scientific partners
To help achieve targets within the CBD strategic plan, a consortium of scientific partners was set up in 2006. This originally consisted of six leading scientific institutions to share their expertise and experience to develop education and training opportunities in LEDCs. More than 20 scientific institutes from across the world have now become partners
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South-south cooperation
The CBD strategic plan for 2011-2020 includes the need of south-south and triangular cooperation. ‘South’, refers to LEDCs and ‘north’ are MEDCs
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Triangular cooperation
Collaboration between two or more LEDCs and a third party which could be a MEDCs or organisation with the appropriate knowledge and resources.
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CBD strategic plan recognises that LEDCs....
through traditional north-south countries, have built up considerable knowledge, experience and expertise on biodiversity conservation. Hence these countries are now in a position to help other LEDCs, though exchange of knowledge, technology and resources.
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Flagship species
Species which are used as the symbol of conservation. “They are typically charismatic and large animals” If a flagship species is protected, this would be beneficial to the whole ecosystem
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Action taken to improve survival of flagship species
Will also benefit the whole ecosystem
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Umbrella species
Large species in size, which means that they require large habitats. By protecting this habitat, other habitats for other species are protected as well. AN example of an umbrella species is the Giant Panda, which is also a flagship species
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Keystone Species
Species that interact through the food web with other species in the community. If one is lost, this could lead to the phasing out of other species. “Conserving a keystone species helps to protect the integrity of the community.”
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In-situ conversation
Protection of species in their habitat
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Ex-situ conservation
improve the probability of survival of the species by taking them out of their habitat and breeding them in captivity; with the intention of re-introducing them back into the wild in the future.
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Ex-situ conservation can be...
A long and expensive process in which organisms are taken out of their natural habitat in order to be conserved. The application of ex-situ conservation to plants and animals is discussed below.
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Advantages of ex-situ conservation
Increase numbers and decrease risk of extinction. Opportunity to learn more about the species biology and behaviour. Use of zoos, aquariums and botanical gardens to educate public about the species and gain financial and political support. Genetic pool can be enhanced (including use of reproductive technology eg artificial insemination). Provides a temporary safe place to live while habitats are being restored.
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Disadvantages of ex-situ conservation
Require resources including finances to undertake ex-situ conservation. Does not address causes of habitat loss. Genetic pool may be small, not representative of original populations and could result in inbreeding problems. They may not be able to survive in the wild if re-introduced. Need to develop hunting skills and migratory patterns which are difficult to learn in captivity.
Captivity can be detrimental to their health and also lead to aggressive behaviour. They may be susceptible to disease when concentrated in a small area. Breeding in captivity can be difficult for some species e.g. the giant panda. There are ethical concerns about keeping animals in captivity.
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CITES
Convention on International Trade in Endangered Species of Wild Fauna and Flora - 1973 (Ratified by more than 180 nations.
Aims to ensure that international trade does not threaten survival of the species. It has three lists of controlled fauna and flora)
131
CITES Appendices
Appendix I contains species threatened with extinction and trade is only allowed under exceptional circumstances. Appendix II contains species at potential risk from international trade; a permit is required for all trade in these species. Appendix III contains species protected in one or more countries; they are not under global threat but are of concern in the countries which have nominated them for protection. Trade in appendix III species is regulated by use of permits and national laws.
132
The convention on biological diversity
1992, Focus on the conservation of biodiversity, sustainable development and use, to share fairly and equitably the benefits of genetic resources, “Ratified by over 160 nations”
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Strengths of CITES
Restricts trade which threatens species becoming extinct.
Encourages education about endangered species. Increases awareness of endangered species and changes perception about their use e.g. as pets or ornaments. Can stimulate funding into research and conservation activities.
134
Weaknesses of CITES
Participation is only voluntary. Focuses on preservation of species - not sustainable use. If people are allowed to benefit from the wildlife (through tourism revenue or trade of natural income), they have an incentive to protect them. Focuses on species conservation, whereas the main threat to biodiversity is habitat loss.
Effective enforcement can be difficult. Trade is often driven underground (illegal/black market). Many countries with limited resources have other national priorities.
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In-situ conservation method
To prevent a species becoming extinct, the reasons for species loss need to be addressed. For example, if poaching is the main threat, it is necessary to stop the poachers. In some situations where the habitat has been degraded or lost, habitat restoration could be required which can be a difficult and lengthy process.
136
Ex-situ plant conservation
Samples of plant species under threat may be removed from their habitat and placed in botanical gardens or herbariums. Organisations involved with ex-situ plant conservation are able to maintain genetic stock and are involved with biodiversity conservation programmes. Scientists are able to conduct research to extend our knowledge and understanding about these plants.
137
Ex-situ animal conservation
This usually involves removal of the species from their natural habitat and placing them into captivity (e.g. zoo or aquarium) as part of a breeding programme to increase numbers. In some cases reproductive technology can be used to achieve greater success rates. The aim is to reintroduce the species back into the wild where they can help repopulate the area. Often species loss has occurred as a consequence of habitat degradation or loss. Therefore, habitat restoration and protection must occur prior to re-introducing the animals back. The animals are unlikely to survive if the original threats are not eradicated.
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Protected area
a clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long term conservation of nature with associated ecosystem services and cultural values.
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Reasons for protecting an area:
Level of biodiversity (e.g. by protecting biological hotspots a diverse range of species can also be protected) Presence of endemic species, Rarity of habitat type, Geological features, Aesthetic value often referred to as natural beauty, Amenity, Cultural and religious, Educational, Scientific value
140
Protected areas are vital in conserving biodiversity
It is now also recognised the important functions ecosystems perform in the stability of our environment.
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What is edge effect?
Dramatic change in the composition of the vegetation at the boundary, (EGL where an area is fenced and cleared around the reserve creating an ‘abrupt edge’.) This clearance of land at the forest edge increases sunlight to the lower forest levels, increases temperature, lowers humidity and can result in an increase of air movement. These changes in abiotic factors can adversely affect the habitat conditions and threaten some species. Also the risk from predation and hunting by humans can increase near the edge.
142
To avoid edge effect....
To avoid the dramatic change in abiotic conditions at the edge of a reserve, a gradual change in vegetation away from the reserve is more favourable than an abrupt change.
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Three distinct zones in designing protected areas
Core area, Buffer, and transition zone
144
Core area
Pristine natural environment under protection
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Buffer zone
found between the core area and transition zone. To minimise any harm in this area, use is limited e.g. for scientific research, training and education. This area acts as a barrier to protect the core area from human activities in the transition zone.
146
Transition zone
where there is sustainable use of natural resources. This area can be affected by human activities outside the transition zone such as intensive farming.
147
Value of reserves
Reserves can be connected using wildlife corridors which are areas of habitats that are retained or created for animals to move through.
148
Linking reserves advantages
It can allow migration between reserves and reduce isolation of the population. Immigration from other reserves can increase the gene pool in the reserve. It can allow for seasonal migration.
149
Linking reserves disadvantages
Increase spread of disease from one reserve to another. Increase threat from invasive species. Increase threat from predators and hunters.
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Proximity to human influence
Activities within nearby human settlements may adversely affect behaviour of some species within the reserve. This can vary from noise disturbances, light pollution at night to atmospheric and aquatic pollution of a shared watershed. If reserves are near to human settlements, large animals may venture out of the reserve and raid crops and even attack people. Hence the proximity of reserves to urban areas needs to be carefully considered in the planning stages, with consideration of a buffer zone.
151
Difficulties of creating a protected area:
Expensive, from buying and managing, often resulted in removal of people and communities so people have been left homeless and without any livelihood. Heritage and culture of a community may be inextricably linked to the ecosystems they have been removed from. Plans for protected areas should not increase the hardship of local people but consider them as partners, often with extensive knowledge about the ecosystem. Conservation strategies that utilise the knowledge and services of local communities are now more popular.
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A successful protected area includes:
Community support and involvement, Adequate funding,
understanding through research, Education to promote sustainable use of resources, Effective management enhancing or maintain habitats and species (management plan), Legislation and effective enforcement, such as park rangers, Legal status as protected areas to provide support for conservation efforts, eg:National Parks, Variety of biodiversity
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Small or large reserve?
Varies for individual species. Large species require large areas, small plants and insects can have smaller areas. Some species may be able to attain all their requirements for a viable population by moving between the smaller reserves. Several small reserves will be a greater edge effect than having one large reserve.
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The size of an ideal reserve:
Larger reserves can support more ecosystems, habitats and species. Large or migratory animal species need bigger areas to provide adequate resources to support a viable population. Small reserves are fragments of larger ecosystems and need to be carefully managed. EG: migratory species' movement between reserves may need to be planned by examining past migratory routes to create suitable routes between reserves.
155
Human presence, development and population growth can adversely affect habitats by:
Conversion of land to urban use containing high levels of buildings and roads. Removal for use for agriculture purposes.
Fragmentation through transport routes such as roads and railways.
Degradation through over-exploitation of natural resources such as timber. Degradation through pollution which can have effects both locally and further away from the source, such as gaseous emissions from use of fossil fuels can lead to localised photochemical smog, regional acid rain and at a global level contribute to climate change.
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Impacts of habitat loss or degradation
Can lead to a decline in species numbers and biodiversity. With so many species at potential threat, it can be difficult to decide which species to focus our limited resources and time on. The conservation status of a species is determined in an attempt to decide where to place our conservation efforts.
157
Rainforest biomes cover
6% of land surface
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Biological hotspot conservation
At least 1,500 vascular plants as endemics — (a high percentage of plant life found nowhere else on the planet.) A hotspot, in other words, is irreplaceable. 30% or less of its original natural vegetation. In other words, it must be threatened.
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Who invented biological hotspots?
1988, British environmentalist Norman Myers, before responsibility went to conservation international
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Biological hotspot world facts:
There are 34-35 global biodiversity hotspots, mostly located in the tropical rainforest. They occupy only 2.3% of Earth’s land area, contain approximately 50% of the earth’s endemic plant species and 42% of all terrestrial vertebrates (birds, mammals, reptiles and amphibians).
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How are biological hotspots identified?
They are focused in areas where it can protect the highest numbers of species
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Rainforest biome biodiversity facts:
contain more than half the world’s plant and animal species. High level of primary production to support an array of species. World's oldest biomes and have developed into climax communities with high levels of biodiversity.
163
Nutrient cycles within the rainforest....
Tend to be short. Nutrient levels in the soil are low as nutrients are easily leached out by the continual rain. Nutrients are mostly held within the biomass especially the root mats. Therefore, removal of trees can cause nutrient levels within the ecosystem to decline rapidly.
164
Goods and services provided by the tropical rainforest
Resources for humans include food, timber and medicines. Services include the absorption of carbon dioxide (carbon sink), production of oxygen, soil stability and filtration of water.
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Other values of tropical rainforests
Intrinsic, cultural, spiritual, religious, aesthetical, education and scientific value.
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Vertical rainforest layers
Emergent, canopy, understory, forest floor / ground layer. - each layer has different environmental conditions with its own community of species
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Emergent layer
Which is the highest layer and consists of trees that extend beyond the general canopy
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Canopy level
Fairly dense and significantly reduces light penetrating further into the forest
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Understory layer
Below the canopy layer consisting of cherub plants and tree saplings
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The forest floor / ground layer
Receives less than 2% of the light, green plants are limited in number. Humidity is high due to limited air movement and high evaporation rates
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IUCN Red list
Provides information and analysis on the status, trends and threats to species to inform and catalyse action for biodiversity conservation
172
Criteria for determining conservation status
Population size reduction, Geographical range, Number of locations, extent of habitat fragmentation, habitat quality, probability of extinction
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Population size / number if mature individuals
The number of mature individuals of a species. Counted as those able to reproduce. With a smaller population, opportunity to breed is lower and hence increasing the risk of extinction. Inbreeding is also more likely to occur in a small population increasing the probability of offspring suffering from genetic abnormalities.
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Population size reduction
The loss of individuals within the population is calculated for a period of 10 years or three generations of the species. The greater the rate of decline in population size, the higher the risk that the species will become extinct.
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Geographical range: extent of occurrence
The extent of occurrence is the boundary that can be drawn around the sites the species occupies. Hence the extent of occurrence includes the area of occupancy and may also contain habitats within the boundary not used by the species.
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Geographical range: area of occupancy
AO - where the species can normally be found. Hence the extent of occurrence includes the area of occupancy and may also contain habitats within the boundary not used by the species.
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Number of locations
With the variety of threats to species and habitats discussed in the previous section, the number of locations a species is found in may decline. This problems is often most acute on islands and other areas with endemic species.
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Extent of habitat fragmentation
Occurs through human activities such as urban development and roads. Depending on the level of fragmentation sub-populations may become isolated and not have the critical numbers of mature individuals to successfully breed.
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Quality of habitat
Organisms are dependent on their habitat for food and water. Hence it contributes to the survival and success of a species. If there is decline in the habitat, for instance from logging activities there may be a decline in available food.
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Probability of extinction
This is the predicted likelihood of all the populations of the species in the wild dying out in the future.
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Species characteristics which contribute to whether it is more vulnerable to extinction:
The degree of specialisation, their trophic level
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The degree of specialisation
EG: Species with a very restricted diet. This includes pandas who are reliant on bamboo and therefore are more vulnerable than species that depend on a wider range of foods.
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Trophic levels
Organisms high up in a food chain may be exposed to higher levels of pollutants due to the process of bio-magnification and bio-accumulation.
184
Endemic
A disease throughout the region, but maybe in other locations - Malaria, DDT
a species throughout the region but not found anywhere else - Species
185
Compositional layers (materials or layers the earth is made of)
Crust, mantle, core
186
Two types of layers within the earth
Mechanical layers, and chemical/compositional layers
187
Mechanical layers
Lithosphere, asthenosphere, mesosphere, outer core, inner core
188
Convergent boundaries
plates move towards each other - When two plates collide, one will dive under the other (heavier one), this creates subduction zone, This creates pressure and creates a dike, so magma comes up through the crust, This could create a volcano, Sometimes it will be folded, and create mountains, the peaks continue to grow every year
Movement is usually gradual, sometime dramatic above land, Can result in earthquakes
189
Transform boundaries
move past each other, Creates a fault in land, Can cause an earthquake, Fault line pressure builds up??
190
Divergent boundaries
Plates spread apart from each other, Lava will come up and solidify where the gaps are, Space can create a crack (great rift valley), Seafloor spreading, the ocean being pulled apart
191
Human influencing impacts on biodiversity
Population growth, over-exploitation of resources, habitat fragmentation/degradation/loss, invasive species, pollution, climate change
192
Humans threaten species....
Directly through hunting or harvesting or indirectly through activities leading to destruction or degradation of habitat or action contributing to climate change.
193
The rate at which biodiversity is being threatened....
has increased since the industrial revolution and is considered to be linked to human population growth.
194
Population growth
The human population has increased exponentially since the industrial revolution when death rates decreased as a consequence of developments in science and technology, leading to improvements in sanitation, healthcare, nutrition and agriculture.
195
With growth in human population
there is increasing demand on natural resources which has led to over-exploitation of species, habitat degradation, human introduction of alien species and pollution of the environment, all contributing to species extinction.
196
Invasive species
Humans move species around the world for their use, such as crop plants and animals. Some species have been moved unintentionally, such as stowaways within crops or in ballast waters of ships moving cargo around the world. Some species have adapted to the new conditions and have gone on to breed successfully. Problems have arisen when they degrade the habitat or out-compete local species for resources such as food.
197
Islands are very vulnerable to
Invasive species. Local species, often also endemic lack the ability to adapt to hunting by humans or to the introduction of a new predator (such as cats and dogs). Prior to colonisation, Mauritius had more endemic species than it does today.
198
Climate change impact
Human activity increases greenhouse gases such as carbon dioxide, methane and chlorofluorocarbons in the atmosphere. This causes an increase in global temperature, change in precipitation patterns and extreme weather patterns. As a consequence, species unable to adapt to or unable to migrate to more suitable conditions may die out.
199
The international panel on climate change
suggested that up to 30% of plants and animals are at risk from extinction as a consequence of climate change. Prediction of which areas may gain or lose plant species are illustrate in the figure below.
200
Atmospheric Pollution
can occur from use of cars or production of electricity and can lead to a change in some localised groups of species, such as lichen. Some species are intolerant to air pollution and therefore they will decline in number.
201
Burning of fossil fuels
leads to emissions of sulphur dioxide and nitrogen oxides that are the precursors of acid rain. Acid rain has devastated large areas of forest, for instance in Sweden and Germany, changing the conditions in lake systems and reducing overall biodiversity.
202
Pollution
Aquatic habitats are being polluted through discharges of waste water including sewage and industrial effluent together with urban drainage and farm run-off. These inputs can degrade the habitat and decrease species diversity.
203
Disposal of waste on land....
Fly tipping can contaminate the ground and degrade the habitat. The use and disposal of non-biodegradable material such as plastics has exacerbated this problem. Dumping of waste at sea can also cause problems from animals becoming tangled in waste or from ingestion of material that block their digestive system.
204
Over-exploitation of resources
Renewable resources such as animals, fish and plants need to be managed sustainably to secure a continued supply. They need time to re-generate, otherwise, numbers will fall below a threshold level from which they cannot recover. The population will become exhausted and collapse. Therefore, hunting or over-harvesting for food, timber, medicines, skins and furs can led to species loss.
205
Colonisation example
There are many historical examples of when humans have colonized an area (such as Easter Island), and the growth in population has exceeded the carrying capacity of the area and exhausted the local environment leading to loss and extinction of species.
206
Habitat fragmentation, degradation and loss (Forest)
Forests have often been exploited for construction material, firewood, food and medicines. Land cleared to use for settlements, industrial development, grazing and growing crops.
207
Habitat fragmentation, degradation and loss (technology)
Technological developments in the 1950s intensified farming. Areas such as wetlands previously unsuitable for arable farming could now be drained resulting in habitat loss. Subsequent agriculture run-off rich in nitrates and phosphates from fertilizers, pesticides and organic matter (from slurry and silage) led to pollution and degradation of aquatic habitats.
208
Mechanisation
With mechanisation, larger areas of land could be farmed and yields could be further improved with the use of fertilizers and pesticides.
209
Soil erosion
frequently high in these cleared areas and soil fertility declines rapidly. In some cases "slash and burn" techniques are used to clear forest areas, where fire may become out of control and penetrate deep into the forest. Both the reduction in forest habitats and fire threatens many species.
210
Subsidence farming
Here an increase demand for food by a growing population has sometimes led to loss of soil fertility where the land becomes exhausted and is no longer able to support the crops. Therefore, people have often resorted to clearing forest areas to use for agriculture
211
Ecological impacts of mining
Fragmentation of habitats through development of roads to transport the mined goods and for movement of the workforce and other materials. Mining often involves clearance of forest leading to soil erosion and siltation of rivers. Groundwater and surface waters can become contaminated with pollutants such as metals (acid mine drainage). Dust and particulates released into the air can also contaminate and reduce air quality. The physical disturbance and noise in the area can adversely effect some species, which could also reduce successful breeding rates.
212
Charles Darwin and Alfred Wallace's ideas
If you take any two creatures on earth and trace their ancestry back far enough you will find a common ancestor.
213
Evolution
the change in the genetic composition and therefore the heritable traits of a population over successive generations and it can impact individuals and whole species. Evolution is descent with modification.
214
Causes of evolution
The initial cause of evolution is the process of genetic variation, which is then passed on to the next generation because it gives an individual some kind of survival advantage. It is caused by a number of interlinking factors the most important being mutations and natural selection.
215
Mutations
A mutation is a change in the and can be a single change or multiple changes. Evolution is usually the result of an accumulation of several mutations. Mutations are totally random and may or may not manifest themselves in the individual. They may be beneficial, harmful or neutral but are unconscious. Genes do not mutate to consciously change the individual. Mutations can have small and large-scale impacts. They can cause albinism or make bacteria resistant to antibiotics
216
Natural selection
The gene variation has survival advantages.
217
Artificial selection
clearest pieces of evidence for evolution is our own success in artificial selection. Humans have taken species and “evolved” them for characteristics that suit our purposes. Wild grasses have given us all our major cereal crops (such as wheat, rye, rice, barley), human domestication of the wolf has created a plethora of pet dogs.
218
Convergent evolution
Where similar structures have evolved independently in different organisms without the presence of a common ancestor, have both evolved the same buoyancy control but they are unrelated.
219
Vestigial Structures
These are parts of an animal that no longer serve any purpose but they serve as reminders of what the organism evolved from.
220
Fossil record
shows the changes in organisms over time as the organisms’ structure can be compared to past and present species thus allowing the construction of a tree of life.
221
Biogeographical Distribtion
a single species would spread into various niches, adapt to different conditions and evolve into a new species. This is also an example of divergent evolution - prompted Darwin and Wallace's theory
222
Speciation
the formation of a new species through biological processes. - creates more species which therefore increases biodiversity
223
Evolution drives...
Speciation, but isolation has to encourage changes in part of the population
224
Geographic isolation
Populations are physically separated and can no longer interbreed
225
Temporal isolation
Populations live their lives at different times of the day and so do not meet to breed.
226
Behavioural isolation
They have different mating rituals.
227
Natural selection
The gradual evolutionary change that results from genetic variation in each generation. The various heritable traits will endow individuals with different rates of reproductive success, which then become more or less common in a population. Traits that increase the survivability of individuals will become more common as their bearers will pass them on to their offspring, and vice versa.
228
Four basic ideas of the theory of evolution
firstly that species change over time and space, secondly that all organisms share a common ancestor, thirdly that change is gradual and finally that it is driven by natural selection.
229
Mechanism of natural selection
Within a population of one species, there is genetic diversity, called variation. The offspring of fitter individuals may inherit genes that give them that advantage. Due to natural variation, some individuals will be fitter than others and therefore have a comparative advantage. Fitter individuals are more likely to survive long enough to reproduce than less fit individuals
230
Variation
Species show Genetic diversity / variation. If they do not, survivability of the species is in question. This variation may be in the physical or behavioural attributes, such as size, fur colour, eye colour and mating calls
231
The rate at which biodiversity is being threatened....
has increased since the industrial revolution and is considered to be linked to human population growth.
232
Population growth
The human population has increased exponentially since the industrial revolution when death rates decreased as a consequence of developments in science and technology, leading to improvements in sanitation, healthcare, nutrition and agriculture.
233
With growth in human population
there is increasing demand on natural resources which has led to over-exploitation of species, habitat degradation, human introduction of alien species and pollution of the environment, all contributing to species extinction.
234
Invasive species
Humans move species around the world for their use, such as crop plants and animals. Some species have been moved unintentionally, such as stowaways within crops or in ballast waters of ships moving cargo around the world. Some species have adapted to the new conditions and have gone on to breed successfully. Problems have arisen when they degrade the habitat or out-compete local species for resources such as food.
235
Islands are very vulnerable to
Invasive species. Local species, often also endemic lack the ability to adapt to hunting by humans or to the introduction of a new predator (such as cats and dogs). Prior to colonisation, Mauritius had more endemic species than it does today.
236
Climate change impact
Human activity increases greenhouse gases such as carbon dioxide, methane and chlorofluorocarbons in the atmosphere. This causes an increase in global temperature, change in precipitation patterns and extreme weather patterns. As a consequence, species unable to adapt to or unable to migrate to more suitable conditions may die out.
237
The international panel on climate change
suggested that up to 30% of plants and animals are at risk from extinction as a consequence of climate change. Prediction of which areas may gain or lose plant species are illustrate in the figure below.
238
Atmospheric Pollution
can occur from use of cars or production of electricity and can lead to a change in some localised groups of species, such as lichen. Some species are intolerant to air pollution and therefore they will decline in number.
239
Burning of fossil fuels
leads to emissions of sulphur dioxide and nitrogen oxides that are the precursors of acid rain. Acid rain has devastated large areas of forest, for instance in Sweden and Germany, changing the conditions in lake systems and reducing overall biodiversity.
240
Pollution
Aquatic habitats are being polluted through discharges of waste water including sewage and industrial effluent together with urban drainage and farm run-off. These inputs can degrade the habitat and decrease species diversity.
241
Disposal of waste on land....
Fly tipping can contaminate the ground and degrade the habitat. The use and disposal of non-biodegradable material such as plastics has exacerbated this problem. Dumping of waste at sea can also cause problems from animals becoming tangled in waste or from ingestion of material that block their digestive system.
242
Over-exploitation of resources
Renewable resources such as animals, fish and plants need to be managed sustainably to secure a continued supply. They need time to re-generate, otherwise, numbers will fall below a threshold level from which they cannot recover. The population will become exhausted and collapse. Therefore, hunting or over-harvesting for food, timber, medicines, skins and furs can led to species loss.
243
Colonisation example
There are many historical examples of when humans have colonized an area (such as Easter Island), and the growth in population has exceeded the carrying capacity of the area and exhausted the local environment leading to loss and extinction of species.
244
Habitat fragmentation, degradation and loss (Forest)
Forests have often been exploited for construction material, firewood, food and medicines. Land cleared to use for settlements, industrial development, grazing and growing crops.
245
Habitat fragmentation, degradation and loss (technology)
Technological developments in the 1950s intensified farming. Areas such as wetlands previously unsuitable for arable farming could now be drained resulting in habitat loss. Subsequent agriculture run-off rich in nitrates and phosphates from fertilizers, pesticides and organic matter (from slurry and silage) led to pollution and degradation of aquatic habitats.
246
Mechanisation
With mechanisation, larger areas of land could be farmed and yields could be further improved with the use of fertilizers and pesticides.
247
Soil erosion
frequently high in these cleared areas and soil fertility declines rapidly. In some cases "slash and burn" techniques are used to clear forest areas, where fire may become out of control and penetrate deep into the forest. Both the reduction in forest habitats and fire threatens many species.
248
Subsidence farming
Here an increase demand for food by a growing population has sometimes led to loss of soil fertility where the land becomes exhausted and is no longer able to support the crops. Therefore, people have often resorted to clearing forest areas to use for agriculture
249
Ecological impacts of mining
Fragmentation of habitats through development of roads to transport the mined goods and for movement of the workforce and other materials. Mining often involves clearance of forest leading to soil erosion and siltation of rivers. Groundwater and surface waters can become contaminated with pollutants such as metals (acid mine drainage). Dust and particulates released into the air can also contaminate and reduce air quality. The physical disturbance and noise in the area can adversely effect some species, which could also reduce successful breeding rates.
250
Charles Darwin and Alfred Wallace's ideas
If you take any two creatures on earth and trace their ancestry back far enough you will find a common ancestor.
251
Evolution
the change in the genetic composition and therefore the heritable traits of a population over successive generations and it can impact individuals and whole species. Evolution is descent with modification.
252
Causes of evolution
The initial cause of evolution is the process of genetic variation, which is then passed on to the next generation because it gives an individual some kind of survival advantage. It is caused by a number of interlinking factors the most important being mutations and natural selection.
253
Mutations
A mutation is a change in the and can be a single change or multiple changes. Evolution is usually the result of an accumulation of several mutations. Mutations are totally random and may or may not manifest themselves in the individual. They may be beneficial, harmful or neutral but are unconscious. Genes do not mutate to consciously change the individual. Mutations can have small and large-scale impacts. They can cause albinism or make bacteria resistant to antibiotics
254
Natural selection
The gene variation has survival advantages.
255
Artificial selection
clearest pieces of evidence for evolution is our own success in artificial selection. Humans have taken species and “evolved” them for characteristics that suit our purposes. Wild grasses have given us all our major cereal crops (such as wheat, rye, rice, barley), human domestication of the wolf has created a plethora of pet dogs.
256
Convergent evolution
Where similar structures have evolved independently in different organisms without the presence of a common ancestor, have both evolved the same buoyancy control but they are unrelated.
257
Vestigial Structures
These are parts of an animal that no longer serve any purpose but they serve as reminders of what the organism evolved from.
258
Fossil record
shows the changes in organisms over time as the organisms’ structure can be compared to past and present species thus allowing the construction of a tree of life.
259
Biogeographical Distribtion
a single species would spread into various niches, adapt to different conditions and evolve into a new species. This is also an example of divergent evolution - prompted Darwin and Wallace's theory
260
Speciation
the formation of a new species through biological processes. - creates more species which therefore increases biodiversity
261
Evolution drives...
Speciation, but isolation has to encourage changes in part of the population
262
Geographic isolation
Populations are physically separated and can no longer interbreed
263
Temporal isolation
Populations live their lives at different times of the day and so do not meet to breed.
264
Behavioural isolation
They have different mating rituals.
265
Natural selection
The gradual evolutionary change that results from genetic variation in each generation. The various heritable traits will endow individuals with different rates of reproductive success, which then become more or less common in a population. Traits that increase the survivability of individuals will become more common as their bearers will pass them on to their offspring, and vice versa.
266
Four basic ideas of the theory of evolution
firstly that species change over time and space, secondly that all organisms share a common ancestor, thirdly that change is gradual and finally that it is driven by natural selection.
267
Mechanism of natural selection
Within a population of one species, there is genetic diversity, called variation. The offspring of fitter individuals may inherit genes that give them that advantage. Due to natural variation, some individuals will be fitter than others and therefore have a comparative advantage. Fitter individuals are more likely to survive long enough to reproduce than less fit individuals
268
Variation
Species show Genetic diversity / variation. If they do not, survivability of the species is in question. This variation may be in the physical or behavioural attributes, such as size, fur colour, eye colour and mating calls. Some of these variations will benefit individuals in the struggle for resources and certain individuals will survive longer and leave more offspring, thus the occurrence of those beneficial traits will become more frequent.
269
Volcanic activity
Creates new habitats and niches both on land and in the oceans. Any new land created by volcanic eruptions is subject to succession as species colonise the area. If volcanic eruptions are in the oceans they create new islands and seamounts.
270
Mass Extinction
is a sudden global decrease in the number of species over a relatively short period of time.
271
Background or normal extinction
the standard rate at which species go extinct.
272
Survival of the fittest:
The most important aspects of natural selection: survival and reproductive success. What constitutes fitness is variable through time and space; biggest, strongest and fastest may not always be the best for survival. Fitness is comparative not absolute.
273
Inheritance
For a variation to be inherited it must be heritable – because the variation in individuals is caused by differences in genes (inheritance units), And give an advantage in the competition for resources.
274
Comparative advantage
Many organisms are r-strategists, and produce more offspring than can be supported in the habitat. This causes competition for resources - individuals with the “best” characteristics will out-compete their contemporaries and are more likely to survive to reproductive age. This is a comparative, not an absolute advantage.
275
Traits that increase survive biliary of individuals
Are more common as their bearers will pass them on to their offspring and vice versa by natural selection
276
Who developed the theory of evolution?
Darwin, developed his theory by natural selection based on empirical evidence
277
Four underpinning ideas of evolution
Species change overtime and space, all organisms share a common ancestor, change is gradual, change is driven by natural selection
278
Darwin's means by which changes can take place in natural selection
Within a population of 1 species there is genetic diversity (variation), the offspring of fitter individuals may inherit genes that give them that advantage, due to natural variation, some individuals will be fitter and therefore have a comparative advantage, fitter I civilians are more likely to survive long enough and reproduce (in comparison to others)
279
Variation
If species so not show a wide range of genetic diversity or variation, survivability is questioned. Variation may be physical or behavioural such as size, fur colour, eye colour, and calls
280
Some variations will....
Benefit individuals in the stiffly for resources, some individuals survive longer and leave more offspring, so these beneficial traits become more frequent
