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Biodiversity
Bio= life
Diversity =Different forms
...
The life
form can be algae, very big plant, trees, etc
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When you look around, you see a lot of living forms
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No one knows how many different species of living organisms are there on Earth
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More than 1
...
Around a
quarter of a million flowering plant species and thousands of other plants are not
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Some
biologists think that there may be as many as 100 million species on Earth
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One tree in a tropical rainforest can contain as many as 1,200 species of beetle
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There is much interaction
biodiversity, it was fundamental to sustainable life on earth and we have at last recognised
how much human activity affects biodiversity
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Human activities include making buildings like
factories, housing, release artificial satellites etc
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Worked out quarries can form new lakes
and wet lands that are valuable for
wildlife
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An
understanding of biodiversity can help us to hopefully limit
changes that we do and even to reverse it
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How to measure biodiversity?
It is not possible to count it one by one
...
Ecology is the study of the interaction between living
and non-living things
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All organisms have their
own requirements
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Humans belong to single species
...
e
...
: dogs are a species, but there are different branches
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But if this species was to breed with another species, the offspring is
very likely to be infertile
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Sometimes the problems are minor
but gradually it will affect the organism
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Each species have a
particular requirement in their habitat
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g
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Population: a group of animals/organisms of the same species living in the same place at
the same time, and are able to interbreed together
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Ecosystem: the cell sustains system
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The living things, in order to live, take support of the non-living organisms
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g
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But an aquarium, it is an artificial aquatic ecosystem
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It is cell sustained
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Species richness: the number of different species in the area you are studying
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For example, if you did 50 quadrats, and in 22 of them you found daisies, you can calculate
the frequency
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This will give the frequency for daisies in that area
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This can be used to find
the species density
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You simply count the number of individuals of that species in each quadrat and total
all the results, and then divide by the total area of the quadrat
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The area of the quadrat is 0
...
Total area
5x0
...
5msqaured
...
For example, say
there were 4 daisies
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25m^2 –> giving the species density
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Many plants and animals, counting individuals in a quadrat is not an option
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In cases like this, you can estimate the percentage cover of the species
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Then you can approximately
decide what percentage of the area inside the quadrat is occupied by each species
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Eg: there may be bare grounds in the quadrats and the
numbers may come up to less than 100%
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That
is a point quadrat
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Small mammals such as mice can be caught in a Longworth trap (one
Simon used)
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Net can be also be used to catch aquatic organisms
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The technique of this would vary according to the size of the body of water
or whether it is still or moving
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First as many individuals are caught, and marked in a way that will not
affect its future chance if survival
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The marked are counted, returned to habitat and left to mix with
the rest of the population
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Other assumptions are that the marked individuals are more likely to die than the unmarked
ones, and that there will not be any birth or immigrations between sampling which would
add extra unmarked individuals to the population
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Number caught in 1st x number caught in second / number caught in 2nd that are
marked
Species evenness: when we have the data on the kind of species in two habitats, and
approximate number of their populations we can compare their species evenness
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Species evenness is greatest when the population sizes of the different species are most
similar
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Simpson’s Index of Diversity
When you have collected information about the numbers of species and their density in the
area you are studying, you can use your results to calculate the value for biodiversity in that
area
...
(check
book for equation)
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n- Total number of organism of a particular species
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Values of D ranges from 0- 1
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As long as you can recognise them as different species, you don’t need to find their
official names
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We shouldn’t damage the organisms
that live there
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Whilst preparing the quadrats, counting etc, we may
damage some plants or animals
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We should try not to trample on plants in a field or animals on a rocky shore as
it could have an impact
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If you take organism from a pond, or a tree to count and identity them, you must replace
them in their original habitat as quickly as possible
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Nevertheless, sampling is bound to have an impact on the habitat
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It is difficult to put forward a case for conserving a habitat if you do not know
what lives in it
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Classification


The process of dividing and arranging plants and animals into groups, depending
upon similarities
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This was the main
reason behind Carolos Linnaeus’ work of classification on living organisms in the 18th
Century
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Eg: in the botanical gardens, the name of the trees can be tagged
on there
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Carolos Linnaeus built on previous attempts of classification and grouped plants and
animals according to their visible features and putting those with similar appearances and
structure into the same group
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So they used visible
features
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Linnaeus introduced the simple binomial system of naming them by giving
them two names (binomial (to names) nomenclature (for identification))
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Different areas, for
the same plant you use different names
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Most scientists still use it, and it is known
as Taxonomy (the classification)
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In biological classification, the Taxa form a hierarchy
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Eg: the structure of shoe flower and lady’s finger are the same
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However they belong to two different species
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Domain is just
eukaryote and prokaryote
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Species concept
Sometimes different species can interbreed, eg: lion and tiger, so we get liger or tigon is
there
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Then we have horses and donkeys, you get mule (male donkey) and hinny (male horse)
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The definition is good for organisms that are alive today but it doesn’t help us very much to
decide whether two fossil ammonites belong to the same or different species or whether
two kinds of birds for which we only have skeleton or feathers in a museum were able to
breed together
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If one species can evolve into another, then we have to expect to find some
groups of organisms were it is difficult to decide if we are dealing with one
species or two
...
the difficulty is that blackberries produce asexually, but occasionally they do
produce sexually then there are slight variations in their offspring
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Unsure if they are the same
or different species??!?

Phylogeny – study of evolutionary relationships
In modern ways, we can use embryonic relationship
...
As a result of evolution we can say all organisms came about from one common
ancestor
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So without the changes in the organism, it wouldn’t survive
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If it is useful, then that
particular organism can produce more their offspring
...
So next time you need a higher
dose
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Also mosquito repellent, they can evolve, or they won’t survive
...
But it is just too slow to notice it
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One group will be very tall, rich and facial structure will be different, as they won’t

be using their lower jaw for chewing
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The other group will be dwarfs, they
are poor, they use their jaw, etc …
Eg: Darwin’s finches
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But in
different conditions, so where one condition where they have access to grains, so to take the grains,
they needed sharp beaks
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Then he moves to another area where there are fruits
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Then when
he moved to another area, the birds have long beaks, so in that area, small insects and worms are
present in holes, tree trunks or soil
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So depending upon
the habitat, the birds have different adaptations, especially the beak structure
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It is
not easy to determine the relationship between the different species of the living organisms
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Palaeontology is the study of fossils or study different organs… there will be similarities between all
the species
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Eg: bird and insects have
wings, the function is same but the structure is different? Or the other way? But it shows they are
evolved from a common ancestor
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Eg: if any organism has
hair, where the end (?) attach to the placenta, and that feeds it young on milk, is classified as
Mammalia (class)
...
This then shows that all mammals have
arisen from a common ancestor that lived millions of years ago
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It seems that they must be closely related to other mammals and also
they are placed in that class as everything else is the same characteristics
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The belief is that monotremes are a side branch of the mammalian family
tree, which took its own individual line of evolution quite soon after the mammals first evolved
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They include the spiny ant eater, giant ant eater
and aardvark (diff ant eaters)…
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Strong front claws for grasping,
small heads and long tongues for reaching into ant’s nests and no teeth
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Pangolins are said to be related to the carnivore aardvarks
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Giant anteaters branched off from
the main mammalian family tree a long time ago
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Here
observable similarities are there as a result of convergent evolution (evolution can be convergent
or divergent)
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Different species have different base sequences in various
regions of the DNA
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In modern phylogenetic taxonomy studies take place looking at similarities and differences between
key regions of the DNA in different species
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Some evolve quickly, some there is no
change, like bacteria
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Some believe that we are evolved from the
monkeys
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They both have a common ancestor and from this ancestor, the two
groups that split are monkeys and humans
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Fossil remains have
found on several human like organisms that are now extinct
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And some of the extinct organisms are placed in Homo, Neanderthal, erectus,
heidelbergensis etc
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Recently discovered that Homo floresiensis have many
characteristics with humans, but it is still in dispute
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The fossils of past humans are very fragmentary
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We have managed to extract DNA
from fossils in 1997? DNA from some fossil Neanderthal was sequenced to see if they can see any
similarities between the normal, modern humans and Neanderthals
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But relationship to the modern great apes to us:
They are all placed in different genera to us, eg gorilla have the genera gorilla, chimps, belongs to
pan, and orangutans to pongo
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Hence why they are placed in three genera
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Between humans there are only very small differences in DNA
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Non-coding DNA doesn’t appear to be used for making proteins, it doesn’t pick the
proteins, so it is easy for bases to change and mutate without having any effect on the organism
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Goodman found we share more than 99% of our coding DNA with Chimps

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