Classification, biodiversity, evolution Flashcards
(107 cards)
1
Q
What is the binomial system, phylogeny and classification
A
BINOMIAL SYSTEM
-system that uses the genus name and species to avoid confusion when naming organisms
PHYLOGENY
-study of evolutionary relationships
CLASSIFICATION
-process of placing living things into groups
2
Q
Why do we classify living things
A
-for our convenience
-to make study of living things manageable
-easier to identify organisms
-helps us see relationships between species
3
Q
List the 8 taxonomic levels in classification
A
DOMAIN- domain is the highest taxonomic rank
-there are three domains, Archaea, Eubacteria and Eukaryote
KINGDOM- traditionally 5 main kingdoms; plantae, animalia, fungi and proctista are all eukaryotes which possess a nucleus
-all single celled organisms that do not possess a nucleus are grouped into kingdom prokaryote
PHYLUM- major subdivision of the kingdom
-a phylum contains all groups of organisms that have same body plan - e.g. possession of a backbone
CLASS- group of organisms that all possess the same general traits -e.g. same number of legs
ORDER- subdivision of class using additional information about the organism e.g. class mammal divided into meat eating (carnivore) or vegetation eating animals (herbivora)
FAMILY- group of closely related genera e.g. within order carnivora we might recognise the dog family and cat family
GENUS- group of closely related species
SPECIES- basic unit of classification
-all members of species show some variation but essentially same
4
Q
Describe classifying species
A
-at higher levels of ranked system, differences between the organisms can be very great
-therefore quite easy to place a species into its domain, kingdom or phylum
-within phylum, species must be placed in a class
-this becomes more difficult as differences between classes in one phylum may not be very great
-as you descend to lower taxonomic groups it becomes increasing difficult to separate closely related species and to place a species accurately
-a more and more detailed description of the species is required
5
Q
What is the binomial naming system
A
-binomial means 2 names
-binomial system of naming organisms; the genus name and the species name are used
-thus humans become Homo sapies
-the genus name always given a capital whilst the species given a lowercase
6
Q
Who devised the binomial system
A
-made up by Carl Linnaeus
-before this a common name was used however it doesn’t work well because:
-some organism may have completely different common name in different parts of one country
-different common names used in different countries
-translation of languages or dialects may give different names
-same common name may be used for different species in other parts of the world
-Linnaeus used Latin as universal language
-this means whenever a species is named, its given a universal name
-every scientist in every country uses same name, avoiding confusion
7
Q
Features of classification
A
1) observable features
2) better, more detailed evidence e.g. microscopes
3) best, DNA/RNA/ proteins
8
Q
Define autotroph, photoautotroph, chemoautotroph and heterotroph
A
AUTOTROPH- organism that can make its on organic molecules from simple inorganic molecules
PHOTOAUTOTROPH- use light energy as food to make food
CHEMOAUTOTROPH- use chemicals to make food
HETEROTROPH- organism that requires ready made source of organic molecules
9
Q
Describe animalia
A
-eukaryotic, multicellular
-heterotrophic
-usually able to move around
-nervous and hormonal system
-blastocyst- typical in embryonic development
10
Q
Describe plantae
A
-autotrophic- use photosynthesis
-growth restricted to meristems
-have cells surrounded by cellulose cell wall
-multicellular, eukaryotic
-contain chlorophyll
11
Q
Describe fungi
A
-are eukaryotic
-have cell walls made of chitin
-saprotrophic- cause decay of organic matter
-can exist as single cells called yeast or they may have mycelium consists of hyphae
-unicellular or multicellular
12
Q
Describe protoctista
A
-are eukaryotic
-mostly single celled (amoeba, paramecium) but can be multicellular e.g. algae
-mostly free living
-show wide variety of forms
-show various plant like or animal like features
-have autotrophic or heterotrophic nutrition- some photosynthesise, some ingest prey, some feed using extracellular enzymes and some are parasites
13
Q
Describe prokaryote
A
-have no nucleus
-have loop of DNA that is not arranged in linear chromosomes
-have naked DNA not wound around histone proteins
-no membrane bound organelles
-have smaller ribosomes than in other groups
-have cells smaller than those of eukaryotes
-may be free living or parasitic
14
Q
Why has evidence for classification evolved
A
-using observables features has created a largely successful classification of living things
-however since organisms adapt to their environment its possible 2 unrelated species could adapt similar ways and therefore look similar- convergent evolution
-these two species might be classified in same taxonomic group according to their observable features
-most recent research uses wider range of techniques and produced even more detailed evidence for classification
15
Q
Biological molecules in classification
A
-evidence from biological molecules can help determine how closely related one species is to another
-certain larger biological molecules can help determine how they not identical in every species
-these are molecules involved in most fundamental characteristics of life, such as respiration and protein synthesis
-if we assume earliest living things had identical versions of these molecules then differences seen today as a result of evolution
-two organisms with similar molecules will be closely related as they have not evolved separately for long
-two organisms with very different versions of molecule are less closely related as they have evolved separately for longer
-differences between these molecules in different species reflect evolutionary relationships
-such evidence has largely backed up the evolutionary relationships that have already been worked out
-however, we can use it to clarify or correct relationships we are unsure about
16
Q
BIOLOGICAL MOLECULES: cytochrome c
A
-a protein called cytochrome c is used in process of respiration
-all living organisms that respire must have cytochrome c but its not identical in all species
-also can be done for haemoglobin as universal and can be analysed for differences in amino acids
-proteins are large molecules made from chain of amino acids
-the amino acids in cytochrome c can be identified
-if we compare sequences of amino acids in samples of cytochrome c from two different species we can draw conclusions:
-if sequences are same, two species closely related
-if sequences are different, two species are not so closely related
-the more differences found between sequences less closely related the two species
17
Q
BIOLOGICAL MOLECULES: DNA
A
-reflect evolutionary relationships
-another biological molecule found in all living organisms is DNA
-DNA provides genetic code- instructions producing proteins
-the code is same for all organisms- universal
-this means that particular sequence of DNA codes for same sequence of amino acids in bacterium as in any other organism
-changes to sequences of bases in DNA are called mutations
-mutations occur at random causing amino acid sequence change
-comparison of DNA sequences provides another way to classify species
-the more similar the sequence in a part of DNA the more closely related the two species
-if there are many differences, the species have evolved separately for a long time and they can be considered as less closely related
-this is probably most accurate way to demonstrate how closely related one species is to another
18
Q
Describe three domain classification
A
-1990 Carl Woese suggested new classification system
-he based his ideas on detailed study of ribosomal RNA gene
-he divided kingdom Prokaryote into two groups: Eubacteria and Achaebacteria
-this division is based on fact bacteria are fundamentally different from Archaea and eukaryote
19
Q
Structural differences of bacteria
A
-different cell membrane structure
-flagella with different internal structure
-different enzymes for synthesising RNA- RNA polymerase
-no proteins bound to their genetic material
-different mechanisms for DNA replication and synthesising RNA
20
Q
Describe the features archaea share with eukaryotes
A
-similar enzymes for synthesising RNA e.g. RNA polymerase
-similar mechanisms for DNA replication and synthesising RNA
-production of some proteins that bind to their DNA
21
Q
How did Woese devise the three domain system
A
-RNA and DNA are part of basic mechanism that translates genes into visible characteristics
-Woese argued that these differences between bacteria and archaea are fundamental
-he suggested that the two are more different from each other than the archaea and eukaryote
-therefore an accurate classification system must reflect this difference
-Woese three domain system of classification is now widely accepted by most biologists
22
Q
Artificial classification
A
-some classification done for convenience
-for example in biology a wildflower guide often has all plants with yellow flowers on one page and all blue on another
-this is known as artificial classification
-based on only a few characteristics
-does not reflect any evolutionary relationships
-provides limited information
-is stable
23
Q
Natural classification
A
-biological classification involves detailed study of individuals in a species
-individual members of a species will show variation
-for example all varieties of dog are of the same species
-underneath obvious visible differences all dogs very similar - we consider them to be closely related
-two closely related species will be placed in a group together- a genus
-closely related genera will be placed together in a larger group- a family
-these ranked groups create a hierarchy known as natural classification
-uses many characteristics
-reflects evolutionary relationships
-provides lots of useful information
-may change with advancing knowledge
-natural classification that reflects real relationships between groups could be very useful
-for example if we want to find out more about endangered species we may not want to risk harming any of few remaining members of species
-however if we know of another very similar species that is not endangered, we can carry out research on second species to provide applicable information to endangered species
24
Q
What is phylogeny
A
-any two species living today have had common ancestor
-the time at which the two species started to evolve separately is a branch point on the tree
-the more recent the common ancestor the more closely related the two species are
-phylogeny is the study of evolutionary relationships between species
-it involves studying how closely different species are related
-it should be noted common ancestors do not survive today
-we cannot say that we evolved from apes, gorillas or modern day fish
-we evolved from ancestor that lived at some time in past
-it happens that the gorilla also evolved from the same ancestor
25
Define monophyletic group, phenetic concept, phylogenetic concept and species
MONOPHYLETIC GROUP -consists of ancestral species and all its descendants
SPECIES- group of individuals that actually or potentially interbreed - biological concept, however is issue of ring species
PHENETIC CONCEPT- set of organisms that are phenotypically similar
PHYLOGENETIC CONCEPT- may be determined by DNA
26
Who was Charles Darwin
-a naturalist who spent much of life observing and studying living organisms
-theory of evolution was not his idea
-the idea one species might evolve from another over time was not new but Darwin proposed mechanism for this process
-it cause certain amount upheaval in victorian britain as countered religious beliefs
-proposed natural selection- term used to explain how features of environment apple selective force of reproduction of individuals in a population
27
Research of Charles Darwin
-Darwins ideas began developing during 5yr trip around world in ship called HMS beagle
-visited galapagos islands where discovered unusual species
-many species similar to those on south american mainland
-there was clear variation between members of same species found on different islands
-also noted what appeared to be wide variety of bird species were actually closely related finches
-Darwin concluded that one species had arrived on islands from mainland and then evolved to form different species
28
Who was Alfred Wallace
-another naturalist who independently came to same conclusion as Darwin
-Wallace had made collections in both Amazon and south east Asia
-their first publications were joint papers on subject of evolution by natural selection
-soon followed by Darwins book the origin of species
29
What observations did Darwin make
1) offspring generally appear similar to parents
2) no two individuals are identical
3) organisms have ability to produce large numbers of offspring
4) populations in nature tend to remain fairly stable in size
30
How are Darwins conclusions summarised
-there is struggle to survive
-better adapted individuals survive and pass on their characteristics
-over time number of changes may give rise to new species
31
EVOLUTION EVIDENCE: fossil evidence
-in past world was inhabited by species that were different from those present today
-old species have died out and new species have arised
-new species that have appeared are often similar to older ones found in same place
-Darwin began to understand that fossil species gave rise to more modern species and he felt this must be because more modern species had variations that were better adapted to environment
-also found that many fossil species were much larger than modern but otherwise appeared very similar
-for example some modern species of armadillo grow to only 15cm long whilst glyptodont was many times this size
-one most complete fossil records for evolution is hors
-the similarity of fossil sequences of horse provide evidence that one species arose from a previous one
32
EVOLUTION EVIDENCE: biological molecules
-recent study of biological molecule provides very strong evidence for evolution
-the fact certain molecules are found throughout living world is evidence in itself
-if one species give rise to another, both are likely to have same biological molecules
-this suggests the all species arose from one original ancestor
-two closely related species will have separated only relatively recently- their biological molecules are likely to be identical or very similar
-in species that took separate evolutionary paths a long time ago their biological molecules are likely to differ more
-evidence from molecules such as cytochrome c and other proteins show this pattern of changes
-genes can be compared by sequencing bases in DNA
-the greater number of similarities between gene sequences the more closely related species and more recent their evolution
-also shows that more distantly related species the more differences in the DNA
33
Steps to natural selection
1)overproduction
2) competition
3) variation, better adapted
4) due to genetic variation in alleles, through mutation/ meiosis
5) selection pressures in environment determine which will survive
6) live longer- survival of fittest
7) other die younger
8) reproduce more; more offspring
9) alleles passed to offspring
10) offspring have more appropriate characteristics
11) many generations
12) beneficial alleles increase in frequency= evolution
34
Define speciation
formation of new species from an existing one
35
Differences between individuals
-presence of difference between individuals is called variation
-no two individuals are exactly alike, however similar may look
-identical twins start as one cell that divides and separates into two
-each two cells develops into a separate person
-whilst 2 original cells had same genetic information, subsequent replication of DNA and cell divisions may have introduced changes to DNA
-also slight environmental differences in womb or after birth can mean that the individuals show physical differences
36
Variation within species
-like any other species, humans show variation
-if you think of almost any characteristic there will differences between members of population- for example eye colour, hair colour, nose shape
-these differences known as intraspecific variation
-greater the genetic diversity of species, greater intraspecific variation
37
Variation between species
-variation that occurs between species usually obvious
-this variation usually used to separate members of one species from another
-variation between species is called interspecific variation
38
Continuous variation
-continuous variation is where there are two extremes and a full range of intermediate values between them
-most individuals close to mean value
-number of individuals at extremes is low
-continuous variation is often regulated more than one genes and can be influenced by the environment in which an organism lives
-examples of continuous variation include: height in humans, length of leaves, number of flagella on bacterium
-this type of variation usually quantifiable and best to plot data using histogram
39
Discontinuous variation
-discontinuous variation is where there are two or more distinct/ discrete categories with no intermediate values
-the members of a species may be evenly distributed between the different forms or there may be more of one type than the other
-discontinuous data usually regulated by a single gene and is not influenced by environment in which organism lives
-examples of discontinuous variation includes: gender, human blood groups
-discontinuous data can be shown on bar chart
40
VARIATION CAUSES: inherited or genetic variation
-the genes we inherit from our parents provide information that is used to define all our characteristics
-the combination of alleles that we inherit is not the same as that in any other living thing
-we may share many alleles with other members of out species and we share genes with members of other species
-however there is never a complete match
-human cells contain approximately 20,000 genes
-many of these have more than one allele
-the chances of any two individuals having exactly same combination of alleles is remote
-so the combination of characteristics that each of us possess is unique
41
VARIATION CAUSES: environmental variation
-many characteristics can be affected by environment
-for example an overfed pet will be obese
-a persons skin will become tan/darker with careful exposure to sun
-a hawthorn tree usually grows upright to height on 6m but if nibbled by animals/ cut by farmer it will become bushy
-in this case, environment affected the way it grows
-if hawthorn grows in rock crevice with very little soil or water it may grow to only 150cm
42
VARIATION CAUSES: combined effects
-environmental variation and genetic variation are not isolated
-in past century humans have become taller as result of better diet
-however good diet may be you are unlikely to grow very tall if rest of family is short- this is because height you can reach is limited by genes
-not all our genes are active at any one time
-for example when we reach puberty many changes occur in our body because different genes become active
-changes in the environment can also directly affect which genes are active
43
Describe simpsons biodiversity index
HIGH
-more diverse
-small change to habitat may affect only one species
-habitat is stable
-able to withstand change
LOW
-low diversity
-habitat is dominated by a few species
-small change could damage whole habitat
-e.g. disease, humans
-unable to withstand change
-habitat unstable
44
What is adaptation
-all members of species slightly different- they show variation
-any variation that helps organism survive is an adaptation- the organism is adapted to their environment
-adaptations help organisms cope with environment stresses and obtain things needed to survive
-well adapted organisms will be able to:
-find enough food or photosynthesis well
-gather enough nutrients
-defend itself from predators and diseases
-survive physical conditions of its environment such as changes in temperature, light, water
-respond to changes in the environment
-have sufficient energy to allow successful reproduction
-adaptations can be anatomical, behavioural or physiological
45
Define anatomical, behavioural and physiological adaptations
ANATOMICAL- structural features
BEHAVIOURAL- ways behaviour modifies for survival
PHYSIOLOGICAL -affect the way that processes work
46
Anatomical adaptations of marram grass
-marram grass is a xerophyte as it lives on sand dunes where there is little water available
-long roots- enables plant to reach water deep underground
-roots spread over wide area- enables marram to absorb lot of water when its available
-also helps stabilise sand dunes
-curled leaves- reduces surface area exposed to wind
-traps air inside lower epidermis so moisture can build up in enclosed space
-lower epidermis covered in hairs- reduces air movement so water vapour remained close to lower epidermis
-lower epidermis folded to create pits in which stomata positioned- water vapour builds up in pits, further reducing water loss
-low density of stomata- fewer stomata=less water vapour lost
-leaf covered thick waxy cuticle- reduces evaporation of water from cells
47
Physiological/ biochemical adaptations of marram grass
-ability to roll its leaf is due to the action of specialised hinge cells in lower epidermis
-these cells lost water when water is scarce and lose turgidity- meanings leaf rolled more tightly
-when water available, hinge cells turgid to open leaf and allow carbon dioxide access for photosynthesis
-guard cells work in similar way to open and close stomata
-non turgid cells close stomata/ viceversa
-marram grass not salt tolerant but maintains cell water potential that it lower than the other plants
-this enables it to survive salty conditions found beside sea
-leaves contain many lignified cells that provide support when turgidity is lost-keeps leaf upright when water is not available
48
Describe behavioural adaptations
-a behavioural adaptation is an aspect of the behaviour of an organism of helping it to survive the conditions it lives in
-for example when you touch an earthworm it quickly retracts and withdraws into it burrow
-the earthworm has no eyes so it cannot tell you are not a bird about to it eat it
-its rapid withdrawals is a behavioural adaptation to avoid being eaten
-many plants respond to their environment
-for example marram grass responds to shortage of water by rolling the leaf more tightly closing the stomata
-both changes help reduce transpiration
-also when covered by sand, marram grass will grow more quickly to reach sunlight
49
Convergent evolution
-since adaptations are selected by environment its quite possible for two unrelated species living in similar habitats to evolve similar adaptations
-where those species adopt a similar lifestyle they may evolve to look very similar
-a mole is a burrowing mammal that feeds on small animals in soil
-marsupial moles live in australia and are part of group mammals that have been evolving separately from placental mammals for up to 100 million years
-despite this separate evolution and being unrelated, marsupial moles and placental moles share a number of characteristics and look similar
-cylindrical body
-small eyes
-strong front legs
-large claws
-short fur
-short tail
-nose with tough skin for protection
-this is known as convergent evolution
50
Natural selection
-an individual that has a characteristic which helps it survive in its environment is more likely to survive long enough to reproduce
-the process of evolution works by selecting individuals with particular adaptations to survive and reproduce
-these adaptations are therefore passed to next generation
-over long period of time- possibly over very man generations- more and more individuals in population will have that adaptive characteristic- adaptation has been selected
51
How does natural selection work
1) mutation creates alternative versions of a gene (alleles)
2) this creates genetic variation between individuals of a species (intraspecific variation)
3) once variety exists environment can select, When resources scarce environment will select those variations that give an advantage. This is selection pressure
4) individuals with advantageous characteristics will survive and reproduce
5) therefore they pass on their advantageous characteristics (inheritance)
6) the next generation will have higher proportion of individuals with successful characteristics. Over time, group of organisms becomes well adapted to its environment (adaptation)
-variation must occur before evolution can take place
-it is genetic variation that is important for evolution
-variation due to environmental factors will not be passed on to offspring
52
Evolution - pesticide resistance in insects
-some insects are pests-they eat our food crops or cause damage to them
-also act as vectors which transmit pathogens
-humans have devised ways to kill insects; some will always survive
-pesticides are chemicals designed to kill pests
-insecticides specifically kill insects
-an insecticide applies very strong selection pressure
-if an individual insect is susceptible it will die
-if it has some form of resistance it may survive- this will allow them to reproduce and pass on resistant characteristics
-resistance quickly spreads through whole population
53
When was pesticide resistance documented
-resistance to pesticides first documented in 1914 when scale insects were found to be resistance to inorganic insecticides
-as we have introduced new classes of insecticides such as cyclodienes, carbamates, formamidines, organophosphates and pyrethroids cases of resistance have been documented within 20yrs
-resistance can arise within as little as 2yrs
54
Issues of pesticide resistance
-when insects become resistance to pesticides it can lead to the pesticide accumulating in food chain
-if insects are resistant they survive application of these chemicals
-the insects may then be eaten by their predators
-the insects may then be eaten by their predators
-the predators receive a larger dose of the insecticide and its quite possble for insecticide to move all up food chain
-in this way, humans may receive large doses of insecticides
-because increasing resistance and DDT accumulates in food chain, it has been banned in many areas
55
Microorganism evolution
-use of antibiotics is a very powerful selection pressure on bacteria
-when you take antibiotics most of bacteria are killed
-but there may be one of a few that are resistant
-they are rarely completely unaffected by antibiotic but more resistant than most
-so many people stop taking the antibiotics before they have finished the prescribed course
-this allows resistant bacteria to survive and reproduce to create resistant strain of bacteria
-overuse and incorrect use of antibiotics has led to stains of bacteria that are resistant to virtually all the antibiotics in use
-some doctors now prescribe multiple antibiotics
-this greatly reduces the chances that some bacteria will survive
56
Antibiotic resistance
-some bacteria have gained a particularly wide range of resistance
-superbug MRSA stands for meticillin-resistant Staphlyococcus aureus
-the bacterium has developed resistance to an ever increasing range of stronger and stronger drug
-medical researchers are struggling to develop new and effective drugs but the bacterial populations rapidly become resistant to them
-need to conserve biodiversity and find new antibiotics
57
Natural selection pressures
-availability of food
-predators- camouflage/ behaviours
-disease
-physical and chemical factors- e.g. temperature
58
Biodiversity
-biodiversity is a measure of all different plant, animal, fungus, and other microorganisms species worldwide, the genes they contain and ecosystems which they form part of
-biodiversity is about structure and functional variety in living world
-we consider it at a number of levels
59
Habitat biodiversity
-a habitat is the place where individuals in a species live
-the range of habitats in which different species live is known as the habitat biodiversity
-common habitats found in UK include sand dunes, woodland, meadows and streams
-carefully manicured lawns, ponds, dark corners between buildings or a small patch of trees are all different habitats
-each habitat occupied by range of organisms
60
Species biodiversity
-a species consists of individual organisms that are very similar in appearance, anatomy, physiology, biochemistry and genetics
-as a result, individuals in a species can interbreed freely to produce fertile offspring
-the range of organisms found in habitat contributes to species biodiversity
-however, its not simple matter of counting number of different species- two habitats may have an equal number of different species but they may not be equally diverse
-species richness- number of species
-species evenness- proportions of different species
61
Genetic biodiversity
-genetic biodiversity is the variation between individuals belonging to same species
-this is variation found within any species that ensures we do not all look identical
62
Random sampling
-sample sites inside habitat randomly selected
-this can be achieved by using randomly generated numbers as coordinates
-ensures data not bias by selectively sampling
-may not cover all areas of a habitat equally
-species with low presence may be missed, leading to underestimate of biodiversity
63
Opportunistic sampling
-when researcher makes sampling decisions based on prior knowledge or during process of collecting data
-researcher may deliberately sample an area they know contains a particular species
-easier and quicker than random sampling
-data may be biased and overestimate biodiversity
64
Stratified sampling
-dividing habitat into areas which appear different and sampling each area separately
-ensures all different areas of a habitat are sampled and species not underrepresented
-possibility may lead to overrepresentation of some areas in sample
65
Systematic sampling
-samples taken at fixed intervals across a habitat
-for example line and belt transects
-useful to show clear gradient in some environmental factor
-only species on line or within belt can be recorded
-other species may be missed, leading to underestimate of biodiversity
66
Sampling animals by observation
-many animals are not easy to spot and more difficult to count
-larger animals can detect presence of humans before we see them and hide
-small animals will also hide and often move too quickly to accurately count
-therefore obtaining quantitative data on animals is difficult
-you can note presence of many larger animals through careful observation- looking for signs they left behind
-for example many animals leave footprints or identifiable droplets
-ecologists often rely on these signs to estimate population sixes
-recent advances allow scientists to use DNA sequences to distinguish droppings from different individuals
67
Catching invertebrates
-technique of sweep netting involves walking through habitat with stout net, identify contents on white sheet, careful that animals do not crawl or fly away; type of sampling good for low vegetation thats not woody
-collecting from trees using sweep net unlikely to work well- better to spear white sheet under branch and knock the branch with stick; vibrations dislodge small animals which drop onto sheet
-pitfall trap set up in soil to catch small animals, trap should be sheltered so rain does not flood it
-tullgreen funnel is small animal catching device, should have leaf litter in funnel and animals fall through mesh screen to be collected in jar beneath the funnel
-light trap collect flying insects at night, UV light attracts the insects
68
Trapping small animals
-small animals can be caught and population estimates calculated
-techniques used will depend on habitat and type of animal being caught
-care should be taken not to harm animals and may need a license to trap some animals
-small mammals can be trapped using longworth trap
-human trap that causes no harm, uses mark and recapture technique
-capture a sample of animals and mark each in a way that causes no harm
-number marked = C1
-release marked and leave traps for another time period
-number captured on second occasion is C2
-number already marked on second occasion is C3
-total population= (C1 X C2)/ C3
69
Sampling plants process
-sampling is done to get a representative sample of biodiversity
-preparation: clothing/ footwear appropriate, apparatus, dichotomus key, consider environmental impacts (carry out EIA environmental impact assessment)
1) preliminary visit- map, species list, patterns
2) plan sampling strategy- random, stratified, systematic
3) conduct sampling- identify species through key
4) process data- averages, %, totals, mean percentage cover, statistics
5) present findings- graph, conclusion, biodiversity index
-quadrat or point frame quadrat
-line transect or belt transect
-ACFOR- abundant, common, occasional, frequent, rare
70
How to calculate proportion of polymorphic gene loci
number of polymorphic gene loci/ number of loci
71
WHAT AFFECTS BIODIVERSITY: human population growth
-several thousands years ago, humans lived as hunter gatherers
-however as human population grows and we demand more food and consumer goods, we have greater and greater effect on other species
-we have learned to use environment to our advantage
-we alter ecosystems to provide ourself with food
-we destroy and fragment habitats
-we overexploit earths resources
-we pollute atmosphere
-as a result of our activities we often harm other species either directly or indirectly and this can lead to extinction
72
WHAT AFFECTS BIODIVERSITY: agriculture
-agriculture has huge effect on biodiversity of natural habitats
-as we clear natural vegetation we reduce size of habitats and population size of any wild species living in those habitats
-this reduces genetic diversity of species as their population is reduced
-this means that the species has less capacity to adapt to changing conditions through evolution
-it may also leave isolated and fragmented populations that are too small to survive
73
WHAT AFFECTS BIODIVERSITY: monoculture agriculture
-modern agriculture relies upon monoculture and selective breeding to increase efficiency
-a monoculture is a crop consisting of one strain of the species- it has limited genetic diversity
-this makes the product easier to harvesy
-the oil palm which is grown for palm oil is a good example; 85% of palm oil is produced in indonesia and malaysia
-rainforests with huge natural biodiversity are cut down at 150 hectares an hour
-these are replaced by single strain of one species
74
WHAT AFFECTS BIODIVERISTY: selective breeding
-selective breeding also reduces genetic diversity because farmers select particular traits such as rapid growth of high protein content
-concentrating on these characteristics means that other characteristics may be ignored altogether
-again the genetic diversity of species declines
-selecting for specific breeds of domesticated plants and animals means that other breeds become rare and may die out
-again loss of these varieties reduces genetic diversity of species- process known as genetic erosion
75
WHAT AFFECTS BIODIVERSITY: climate change
-human activities appear to be altering the climate
-species that have lost their genetic diversity show less variation between individuals
-as climate changes they are less able to adapt to changes in temperature and rainfall in area where they live
-the only alternative will be for them to move and follow the climate pattern to which they are most suited
-this will mean a slow migration of populations, communities and whole ecosystems towards the poles- plants currently growing in southern europe may soon grow in northern europe
-however there are obstructions to migration- major human developments, agricultural land, large bodies
-domesticated plants and animals are particularly at risk
-we have selectively bred our crops and animals to provide best yield in specific conditions which means they have little variation
-as result, unlikely to be able to survive changing conditions and vulnerable to disease
-efficiency of agriculture will decline and less food will be available
76
WHAT AFFECTS BIODIVERSITY: extinction
-extinction occurs when the last living member of a species dies
-since humans started to spread widely over the earth about 100,000 years ago, the rate of extinction has risen dramatically
-some scientists believe that increasing human activity caused the extinction of animals such as giant sloth
-these animals were hunted for food
-it is certain that:
-1/3 worlds primate species now face extinction
-some scientists believe up to half species alive today could be extinct by year 2100
-current rate of extinction is 100-1000 times normal background rate
-current rate of extinction is at least as fast in any other extinction event
-many scientists believe we are at start of great mass extinction event
-there have been 5 other mass extinction event in past - e.g. dinosaurs
-this extinction event is being caused by human activity rather than by natural climate change or by a natural disaster
77
REASONS MAINTAIN BIODIVERSITY: interdependence of organisms
-natural ecosystems are complex; the have developed over millions of years as species have evolved to live and depend on each other
-all organisms in a habitat are linked together in a food chain/ web
-the range of relationships between organisms includes predator-prey intra and interspecies competition and parasitic or mutualistic relationships
-when one species is affected by human activity and numbers decline then this will affect other species
-habitats with higher species diversity tend to be more stable as they can withstand a certain amount of change
-however in a simple habitat with lower species diversity the loss in numbers of one species may affect the entire ecosystem
-some species have disproportionate effect on their environment relative to their abundance
-the decline of such keystone species will have a dramatic or even catastrophic effect on the habitat
-keystone species may be predator that limit the population of herbivores so that the vegetation is not overgrazed
78
Examples of keystone species
-many plants are also keystone species
-a plant that is dominant in the habitat has many effects upon the other species in the habitat e.g. sugar maple tree
-tree has deep roots which can access water deep and transfer it to shallower regions that are dry making it available for others
-foliage keeps soil cool and moist from covering canopy
-shade prevents excess undergrowth which allows other species to take root and grow
-sap is sweet and provides food for a variety of insects
-another example of keystone species is beaver
-there may be relatively small populations of beaver but dams they build have huge effects on habitats
79
MAINTAIN BIODIVERSITY: genetic resource
-allowing biodiversity to decline means genetic diversity also declines
-this means we could lose some natural solutions to our problems
-wild animals and plants may hold answers to problems held by climate change
-populations of wild plants growing in an area have had thousands of years to evolve
-they have adapted to overcome problems presented by environment
-they may also have adapted to pests and diseases found in area
-by careful selection and breeding from wild strains we may be able to breed new crop varieties that can cope with new conditions due to climate change
-genetic engineering to produce transgenic species could also be used to good effect
-the number of potential new medicines and vaccines to be found in native plants, animals is unknown
-plants have evolved wider range of molecules that combat diseases
-any of these molecules could be of value in developing new pharmaceutical products
-it is important to maintain genetic diversity of wild species because of potential that exists
80
Economic reasons to maintain biodiversity
-in 1997 international team of economists and environmental scientists attempted to quantify the economic value of ecosystems
-they looked at ways natural ecosystems perform processes that are of value to humans
-regulation of atmosphere and climate
-purification and retention of fresh water
-formation and fertilisation of soil
-recycling on nutrients
-detoxification of recycling wastes
-crop pollination
-growth of timber, food and fuel
-discovery of molecules with potentials as medicines
-all of these factors impact food production
-one of most immediate effects that loss of biodiversity has is depletion of soil
-soil that is subject to monoculture becomes less and less fertile and as a result agricultural yields declines
-this is because crop takes minerals out of soil and when crop is harvested these minerals are removed from ecosystem
-when monoculture grown, the plants always take same minerals and effect is observed more quickly
-effects of soil depletion seen in huge dust storms in America in 1930s
-
81
Aesthetics reasons to maintain biodiversity
-we experience feelings of joy and wellbeing when observing variations in nature
-clear that natural systems are very important for our wellbeing, physical intellectual and emotional health
-however there are more basic reasons to maintain aesthetic value created by biodiversity
-landscapes are formed by action of climatic factors on land
-but the living biosphere also has its effect on landscape
-diverse tropical forests protect soil from climatic factors such as rainfall which could erode and wash away exposed soil
-woodland or forest acts as reservoir when it rains
-trees take up water and organic matter in soil holds water
-means runoff and drainage are reduced
-the water that collects in forested hills will slowly drain away and supply water downstream for some time after rain stopped
-reducing biodiversity exposes soil and changes landscape
-deforestation has been lined to severe flooding in many areas
-protection of the soil is reduced when trees are removed and replaced by buildings or agriculture
-rainfall drains more quickly and there is more runoff- this means that flooding is more likely
-in an extreme case the rainfall will erode the soil and wash downstream
-soil is deposited where the water flow is reduced and further reduces drainage- increases chances of flooding
-region where flooding is regional, means water is no longer stored in hills and when rain stops, flooding quickly followed by drought
82
Conservation in situ
-conservation is not passive process involves active management
-aim is to maintain biodiversity by enabling endangered species to survive
-conservation in situ means to conserve species in natural habitat
-involves attempting to minimise human impact on natural environment
83
In situ legislation
-possible to pass legislation to stop activities such as hunting, logging and clearing land for development or agriculture
-legislation is particular to different countries- can be difficult to persuade countries that legislation is necessary and some difficult to enforce
84
In situ: wildlife reserves
-wildlife reserves are designated areas established for conservation of habitats and species
-large reserves are important part of conservation efforts in many parts of world
-land management agreements on private land and farm sites also used for conservation
-principles for choosing wildlife reserve includes:
1) comprehensiveness- how many species represented in area
2) adequacy- is area large enough to provide for long term survival of all species
3) representativeness- full range of biodiversity
- conservation should not mean excluding all human activity
-reserve should meet needs to indigenous people- may use land for religions or traditional hunting
85
Why may wildlife reserves cause conflict
-when they are set up without the consideration of other people
-protected animals coming out of reserve to raid crops
-people continuing to poach protected animals
-illegal harvesting of timber and other plant products
-tourists feeding protected animals or leaving litter
86
Wildlife reserves in UK
-national parks- areas of protected countryside, everyone can visit
-national nature reserve (NNR) - set up to protect sensitive features of environment and enable research and education
-sites of special scientific interest (SSSI)- wildlife and geological sites including large wetlands, meadows
-local nature reserves (LNR) - often run by country wildlife trusts
-marine conservation zones- around UK coasts
-areas important to conserve biodiversity of nationally rare, threatened and representative habitat and species
87
Advantages of in situ conservation
-plants, animals conserved in natural habitat
-permanently protects biodiversity and representative samples of ecosystems
-permanently protects significant elements of natural and culture heritage
-allows management of areas to ensure ecological integrity maintained
-many provide opportunities for ecologically sustainable land uses including traditional outdoor heritage activities
-facilitates scientific research
-may be possible to improve and restore ecological integrity of an area
88
Disadvantages of in situ conservation
-endangered habitats may be fragmented and each small area may not be large enough to ensure survival
-population may already have lost much of its genetic diversity
-conditions that caused habitats or species to become endangered may still be present
-area can act as honeypot to poaches or ecotourists inadvertently cause disturbance
89
Repopulation
-where biodiversity has been lost it is possible to rebuild it
-there are many examples of sites where recreated wildlife habitats have been made to work
-In UK numbers of bitterns and otters are increasing in new reed beds
-also conifer crops are being cleared for wildlife habitat recovery and large areas of grazing land are being helped to revert to traditional meadow grassland
90
Ex situ conservation: zoos
-wildlife parks play an important role in conservation
-many focus on captive breeding; breeding endangered species and conducting research that is beneficial
-modern reproductive technologies such as freezing eggs, sperm and embryos can preserve large amounts of genetic material
-artificial insemination, in vitro fertilisation and embryo transfer are techniques are also being used with wild animals
-reproductive physiology is quite species specific and further research into each endangered species is needed to ensure techniques used effectively
-some zoos may carry out research on domestic species or common wild species very similar to target species- this means endangered species are spared from experiments but will benefit in long term
91
Define ex situ conservation
-conserving endangered species by activities that take place outside its normal habitat
92
Advantages of ex situ conservation
-organisms are protected from predation and poaching
-health of individuals can be monitored and medical assistance given
-populations can be divided so if disaster strikes, another will survive
-genetic diversity of population can be measured
-selective breeding can increase genetic diversity
-modern reproductive technology increase endangered species numbers
-research into reproductive physiology, lifestyle and ecology of endangered species is made easier
-conservation sites can be used as attractions to raise funds for further conservation effots
-conservation sites can be used for education
93
Disadvantages of ex situ conservation
-captive population likely to have limited genetic diversity
-animals may be exposed to wide range of different diseases
-organisms are living outside their natural habitat
-may not behave as normal and reproduction may be difficult
-correct environmental conditions for survival may be difficult to achieve
-may be expensive to maintain environmental suitable conditions
-even if reproduction successful, animals have to survive reintroduction to wild where need to find food and survive predation
-when reintroduced may be difficult to accept from existing wild species
94
Ex site: botanic gardens
-as part of life cycle, most plants naturally have dormant stage- the seed
-as seeds produced in large numbers they can be collected from wild without causing too much disturbance to ecosystem or damaging wild population
-seeds can be stored in huge numbers without occupying too much space
-plants can be bred asexually
-botanic gardens can increase numbers of individuals very quickly though techniques such as tissue culture- provides ample supply for research or for reintroduction to wild
-captive bred individuals can be replanted in wild
95
Problems of botanic gardens
-funding botanic garden can be difficult- public perception of plants not same as animals, fewer people willing to sponsor plant
-collecting wild seeds will cause disturbance
-collected samples may not have representative level genetic diversity
-seeds collected from one area may be genetically different from another area therefore may not survive elsewhere
-seeds stored for any length of time may not be viable
-plants bred asexually will be genetically identical- reducing genetic diversity
-conclusions from research based on small sample may not be valid for whole species
96
Ex situ: seed banks
-a seed bank is a collection of seed samples- e.g. kew millenium
-its aim is store representative sample of seeds from every known species of plant
-these will include examples of rarest, most useful and most threatened pecies
-seed banks contain seeds that remain viable for decades and possibly hundreds of years
-however seeds are not simply being stored- some of them are being used to provide range of benefits to humanity
-benefits include providing seeds for food crops and building materials for rural communities and disease resistant crops for agriculture
-seeds can also be used for habitat reclamation and repopulation of endangered habitats
-collections held in milennium seed bank and knowledge derived from them provide almost infinite options for conservation and use
97
Storage of seeds
-in order to prolong viability, seeds stored in very dry or freezing conditions- seeds resistant to dessication and level of moisture in each seed has direct effect on storage
-for every 1% decrease in seed moisture level, life span doubles
-for every 5 degree reduction in temperature, life span also doubles
-seeds stored for decades deteriorate- there is little use in storing seeds that die and will not be able to germinate
-essential to test the seeds at regular intervals to check viability
-scientists at milennium seed bank carry out experiments to discover the most effect methods of storage
98
Why do species and habitats need protecting
-loss of habitat and increasing number of endangered species is a worldwide problem
-it can be tackled at local level efforts however may be insignificant if other countries do not contribute
-therefore needs worldwide solution- international cooperation
99
CITES
-conservation on international trade in endangered species of wild flora and fauna is an international agreement between majority of governments in the world
-it was first agreed 1973 and overall aim is to ensure international trade in specimens of wildlife does not threaten their survival
100
Aims of CITES
-regulate and monitor international trade in selected species
-ensure trade wild plants for commercial purposes prohibited
-ensure trade in artificially propagated plants allowed, subject to permit
-ensure some slightly less endangered wild species may be traded subject to permit as agreed between exporting and importing countries
-international trade policies can be very hard to enforce
-where there is a demand for a product, there will be attempts to supply it
-smuggling of live plants, animals and their products is a constant problem
101
Rio conservation on biological diversity
-signed by 150 government leaders at 1992 Rio earth summit
-convention dedicated to promoted sustainable development
-recognises that biological diversity is more than just plants and animals its also about need to secure sources of food, medicines, fresh air and water in which to live
102
Aims of rio convention
-conservation of biological diversity
-sustainable use of its components
-appropriate shared access to its genetic resources
-appropriate shared access to its genetic resources
-appropriate sharing and transfer of scientific knowledge and technology
-fair and equitable sharing of benefits arising from use of genetic resources
-convention encourages cooperation between countries
-encourages each partner to develop national strategy for conservation and sustainable use of biological diversity
-more specifically states partner states must adopt ex situ conservation facilities mainly to complement in situ measures
103
Roles of zoos, botanic gardens and seed banks
-international cooperation involves sharing of research, genetic information and technology
-ex situ conservation facilities in different member states provide support for each other and share technologies and genetic material
-breeding programmes in zoos are strengthened by importing animals from parks or zoos in other counties
-different zoos specialise in breeding of different animals
-they will hold studbooks for that species for world zoo community
-time, expense and distress to rare animals can be reduced by importing genetic material
-research and technology is shared between member states to help improve chances of success
-reintroduction of animals bred in zoos will fail unless cooperation from other countries
-similarly plant breeding programmes can be enhanced by sharing stored specimens
104
Local conservation schemes
-conservation schemes are not limited to international agreements- many governments make agreements with local land owners
-they are designed to enhance biodiversity and conservation of land
105
Countryside stewardship scheme
-was introduced in england in 1991 and applied to land that was not considered to be an environmentally sensitive area
-payments were made to farmers and other land managers in order to enhance and conserve english landscapes
106
Aims of countryside steward scheme
-improve natural beauty and diversity of countryside
-enhance, restore and recreate targeted landscapes
-improve opportunities for public access
-this scheme was replaced by environmental stewardship scheme 2005
-it provides funding to farmers and other land managers in england to deliver effective environmental management on their land
107
How to conserve, enhance and promote countryside
-looking after wildlife species and their habitats
-ensuring land is well managed and retains traditional character
-protecting historic features and natural resources
-ensuring traditional livestock and crops are conserved
-providing opportunities for people to visit and learn about countryside
