4.1 Biodiversity in ecosystems
4.1.1 Define the terms biodiversity, genetic diversity, species diversity and habitat diversity.
In the biodiversity chapter following topics are explained,
Total world biodiversity – In this section there is information about the comparison of total amount of species and total estimated species, some graphs are used for accurate explanation.
The table 5.2 shows the six mass extinctions
The biggest one (6th) was 251 million years ago in the geological period of Permian-Triassic 95% of all species and 54% of all species were died by the extinction and the second biggest is happening right now the estimate of losses is unknown yet. Difference between these two extinctions is that 251 million years ago the extinction was caused by natural abiotic factors such as climate and nowadays this extinction is caused by human biotic factors.
In the TO DO section there is a Hotspot table shown, where are different hotspots (continents, areas, countries) and plant species endemic plant species and endemics as a percentage of world total.
On the page 99 there is information about types of diversity species diversity, genetic divesirty, species diversity genetic diversity and habitat diversity.
Hotspots – In Geology Hotspots have high biodiversity but also high number of endemic species. High number of endemic species puts those species in danger and that’s why places like that are called hotspots.
Biodiversity - The variety of different organisms and species in a given ecosystem.
Endemic Species - Species in that live only in a specific area
Keystone Species – Species which are more important for the ecosystem. If you remove them, the negative effect on the environment will be much more than in case of removal other species. Mostly they are either predators or engineering species.
Genetic diversity - This is genetic diversity between and within the same species. This helps to predict life essential predictions and adaptations.
Species diversity - Species diversity is a measure of the diversity within an ecological community that incorporates both species richness (the number of species in a community) and the evenness of species' abundances. Species diversity is one component of the concept of biodiversity.
Habitat diversity – Variety of different types of habitat (place where animals live) and ways in which species live or survive. Can be connected to overall diversity.
Total world biodiversity – In this section there is information about the comparison of total amount of species and total estimated species, some graphs are used for accurate explanation.
The table 5.2 shows the six mass extinctions
The biggest one (6th) was 251 million years ago in the geological period of Permian-Triassic 95% of all species and 54% of all species were died by the extinction and the second biggest is happening right now the estimate of losses is unknown yet. Difference between these two extinctions is that 251 million years ago the extinction was caused by natural abiotic factors such as climate and nowadays this extinction is caused by human biotic factors.
In the TO DO section there is a Hotspot table shown, where are different hotspots (continents, areas, countries) and plant species endemic plant species and endemics as a percentage of world total.
On the page 99 there is information about types of diversity species diversity, genetic divesirty, species diversity genetic diversity and habitat diversity.
Hotspots – In Geology Hotspots have high biodiversity but also high number of endemic species. High number of endemic species puts those species in danger and that’s why places like that are called hotspots.
Biodiversity - The variety of different organisms and species in a given ecosystem.
Endemic Species - Species in that live only in a specific area
Keystone Species – Species which are more important for the ecosystem. If you remove them, the negative effect on the environment will be much more than in case of removal other species. Mostly they are either predators or engineering species.
Genetic diversity - This is genetic diversity between and within the same species. This helps to predict life essential predictions and adaptations.
Species diversity - Species diversity is a measure of the diversity within an ecological community that incorporates both species richness (the number of species in a community) and the evenness of species' abundances. Species diversity is one component of the concept of biodiversity.
Habitat diversity – Variety of different types of habitat (place where animals live) and ways in which species live or survive. Can be connected to overall diversity.
4.1.2 Outline the mechanism of natural selection as a possible driving force for speciation.
Speciation occurs as a result of the isolation (geographical or reproductive) of populations. The concept of fitness should be understood. The history of the development of the modern theory of evolution is not expected, nor is a detailed knowledge of genetics (including allele frequency).
Modern Science is based on Charles Darwin’s theories which are mainly outlined in his book “The origin of species.” Species are mainly formed by gradual change over a long time. Scientifically this is called speciation.
Main Factors in forming are: Structure of DNA, Environment and adaptations.
There are two main selection ways by which different populations are organized and species are differentiated over a period of time. These are Artificial Selection and Natural Selection
Natural selection - The process whereby organisms better adapted to their environment tend to survive and produce more offspring. During the process there is no human intervention. For example: a giraffe with a slightly longer neck than the other giraffes may be able to reach tree leave that are out of reach of the others and so get more food. This gives that giraffe and advantage. These small differences mean that some individuals will be more successful and likely to survive and to pass their genes on to the next generations. Over time population gradually changes.
Artificial Selection – This process is balanced by human and makes the populations fit human needs. For example: Farmer has dogs, with the purpose of protecting his farm. His need is a big strong dog, so he looks at the puppies and feeds the biggest one, maybe even kills the rest. Now the big dog will pass his genes onto the next generations and eventually all of them will be big.
These slight advantages especially re-shape the specie population during harsh climatic conditions. Over many Generations, if a population is separated from others, the difference may increase to such an extent that, in case of populations be reunited, they will be unable to interbreed or produce a fertile offspring. This is called Isolation. Isolation can also happen in populations that can mix freely between each other.
Modern Science is based on Charles Darwin’s theories which are mainly outlined in his book “The origin of species.” Species are mainly formed by gradual change over a long time. Scientifically this is called speciation.
Main Factors in forming are: Structure of DNA, Environment and adaptations.
There are two main selection ways by which different populations are organized and species are differentiated over a period of time. These are Artificial Selection and Natural Selection
Natural selection - The process whereby organisms better adapted to their environment tend to survive and produce more offspring. During the process there is no human intervention. For example: a giraffe with a slightly longer neck than the other giraffes may be able to reach tree leave that are out of reach of the others and so get more food. This gives that giraffe and advantage. These small differences mean that some individuals will be more successful and likely to survive and to pass their genes on to the next generations. Over time population gradually changes.
Artificial Selection – This process is balanced by human and makes the populations fit human needs. For example: Farmer has dogs, with the purpose of protecting his farm. His need is a big strong dog, so he looks at the puppies and feeds the biggest one, maybe even kills the rest. Now the big dog will pass his genes onto the next generations and eventually all of them will be big.
These slight advantages especially re-shape the specie population during harsh climatic conditions. Over many Generations, if a population is separated from others, the difference may increase to such an extent that, in case of populations be reunited, they will be unable to interbreed or produce a fertile offspring. This is called Isolation. Isolation can also happen in populations that can mix freely between each other.
4.1.3 State that isolation can lead to different species being produced that are unable to interbreed to yield fertile offspring.
Isolation of populations, behavioural differences that preclude reproduction and the inability to produce fertile offspring (leading to speciation) should all be examined, with examples.
4.1.4 Explain how plate activity has influenced evolution and biodiversity.
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.
Another important factor that has affected succession processes for millions of years is tectonic plate activity that causes continental drift. Energy and heat inside the earths crust cause plates to move and change position. For millions of years earth has changed the shape and continents have moved apart from each other creating many natural hazards and environmental changes. Continental drift has caused isolation between species. Continental drift eventually creates new species but also can decrease overall biodiversity for a short period of time.
Another important factor that has affected succession processes for millions of years is tectonic plate activity that causes continental drift. Energy and heat inside the earths crust cause plates to move and change position. For millions of years earth has changed the shape and continents have moved apart from each other creating many natural hazards and environmental changes. Continental drift has caused isolation between species. Continental drift eventually creates new species but also can decrease overall biodiversity for a short period of time.
Similarity between species on different continents is explained by the theory which proves that millions of years go all continents were united and didn’t have water between them. Continent was called Pangea.
4.1.5 Explain the relationships among ecosystem stability, diversity, succession and habitat.
Diversity changes through successionGreater habitat diversity lead to greater species and genetic diversity
A complex ecosystem with its variety of nutrient and energy pathways, provides stability
Human activities often simplify ecosystems, rendering them unstable, for example, North American wheat farms versus tall grass prarie. An ecosystems capacity to survive change may depend on diversity, resilience and inertia
A complex ecosystem with its variety of nutrient and energy pathways, provides stability
Human activities often simplify ecosystems, rendering them unstable, for example, North American wheat farms versus tall grass prarie. An ecosystems capacity to survive change may depend on diversity, resilience and inertia