Transcript Welcome to Advanced Higher Biology

Advanced Higher Unit 2Organisms and Evolution
Field techniques for biologists
Field techniques introduction
• This section of the course and your Project will
be based around environmental biology.
• To begin- Why would biologists study an
ecosystem?
THINK, PAIR AND SHARE
• Think and discuss a partner for 1 minute.
• Share your ideas with the rest of the class.
Ideas?
• To monitor susceptible or endangered species.
• To assess the effects of pollution, intensive
farming, habitat destruction and other human
influences on populations.
• To assess the effects of hunting and fishing on
wild populations.
• To monitor levels of food species (eg fish) and
species used as raw materials for humans.
• To monitor abundance and biodiversity.
• Find new species.
Field techniques
• Many factors can be measured within an ecosystem, so;
• What do we need to measure?
• Living organisms-plants, animals (biotic)
• pH, temperature, wind speed, moisture, light intensity,
pollution (abiotic)
• How are they measured?
• Sampling!
Field techniques
• So why sample?
• How many pink flowers are in the field?
• Without counting them all you’ll never know.
Field techniques
• Sampling will allow you to know what kind of plants and
animals are in a particular habitat without having to
count every single one.
• Your sampling strategy therefore has to be efficient and
cover enough area to give a good representation of your
habitat.
• Include both abiotic and biotic factors so you can
determine any relationships, differences in areas or
changes over time.
Sampling techniques
• How do we sample?
• Biotic (living) factors•
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Quadrats- grasslands/lichens,
Capture techniques eg pitfall traps,
Sweep nets,
Camera traps,
Scat sampling,
Kick sampling,
Tree beating.
Quadrats
Pitfall traps
Tree beating
Scat
sampling
Sweep netting
Kick sampling
Sampling techniques
• Abiotic (non-living) factors• soil samples, pH meters, moisture meters,
thermometers, anemometers, oxygen probes,
humidity, water velocity.
• All samples that are taken have to be
appropriate to the aim of your investigation.
Examples of equipment used to measure light
intensity, wind speed, oxygen concentration,
humidity and temperature
Sampling techniques- example
Sampling plants:
• Numbers (abundance) of plants per unit area
• % cover of plants
• Height of plants
• Leaf size / stem height / internode length
• Yield of seeds/fruits over time
• Species diversity
What equipment is needed for this?
• Quadrat (what size?)
• Ruler / metre stick
• Plant ID key
Sampling techniques-example
Sampling animals
• Numbers (abundance) of animals (how easy is
this?)
• Species diversity
• What equipment is needed for this?
• Animal ID key
• Method to collect / trap animals?
• Techniques include pitfall traps, tree beating,
sweep nets, leaf litter scraping
Getting your samples
A) Health and Safety
(a) Health and Safety what
you need to know
• Fieldwork may involve a wider range of
hazards compared with working in the
laboratory.
• Hazards and risks associated with
terrain, weather conditions and isolation
must be assessed.
Hazards and ethics
• Fieldwork, unlike lab work, means that
you are observing not controlling the
environment so there may be a wider
range of hazards compared with working
in the laboratory.
• There are some essential considerations
regarding hazards and risks.
Health and safety
• What are some of the risks associate with
fieldwork?
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Terrain
Weather conditions
Exposure
Isolation
• How can we minimise these risks?
• Risk assessment
• Take precautions
• Work in a safe, sensible manner
Risk assessment
• Risk assessments should be carried out before any
fieldwork so you are aware of the hazards and how to
minimise them.
• You have to consider the likelihood of the hazard
occurring (low, medium, high), how you can control it and
the likelihood of it occurring after your control
mechanism.
• All hazards should be low after control mechanism,
otherwise it is not safe to work.
Risk assessment
• Activity- work with your partner and try to
complete the risk assessment sheet for the
following scenario.
• You are looking to investigate pollution in the
White Cart. You’ll be working in the river,
around a sewage outflow pipe. You’ll be taking
water samples and doing kick sampling.
• What are the risks and how do you minimise
them?
Risk assessment
Activity:________________________
Hazard
Likelihood
of
occurrence
Severity
Location:_____________________________
Control mechanism
Likelihood of
occurrence after
control
Risk assessment
Activity:________________________
Hazard
Drowning
Exposure to
cold
Infections from
pollution
Location:_____________________________
Likelihood
of
occurrence
Medium
Severity
Control mechanism
High
Low
Medium
Medium
Medium
Always work within view of
others. Wear suitable footwear
to avoid slipping. Never work in
water deeper than half a
wellington boot
Wear suitable warm clothes.
Change clothes if wet.
Wear rubber gloves at all times.
Wash hands thoroughly once
finished. Do not consume food
and drink while working in river.
Likelihood of
occurrence after
control
Low
Low
Low
(a) Health and Safety what
you need to know
• Fieldwork may involve a wider range of
hazards compared with working in the
laboratory.
• Hazards and risks associated with
terrain, weather conditions and isolation
must be assessed.
b) Sampling of wild organisms
what you need to know
• Sampling should be carried out in a manner that minimises
impact on wild species and habitats.
• Consideration must be given to rare and vulnerable species and
habitats, which are protected by legislation.
• The chosen technique such as point count, transect or remote
detection must be appropriate to the species being sampled.
• Quadrats of suitable size and shape are used for sessile and
slow-moving organisms; capture techniques for mobile species.
• Elusive species can be sampled directly using camera traps or an
indirect method such as scat sampling.
• Sampling should be carried out in a
manner that minimises impact on wild
species hand habitats.
• Consideration must be given to rare and
vulnerable species and habitats, which
are protected by legislation.
Quadrats
• Quadrats of suitable size and shape are
used for sessile and slow-moving
organisms.
Transects
• Capture techniques are used for mobile
species.
• These include– Pitfall traps
– Nets
– Remote detection-Camera traps and Scat
sampling (for elusive species)
Activity
• Write your own notes on the following
sampling techniques using your pupil notes:
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Point count
Transect
Quadrats
Camera traps
Scat sampling
b) Sampling of wild organisms
what you need to know
• Sampling should be carried out in a manner that minimises
impact on wild species and habitats.
• Consideration must be given to rare and vulnerable species and
habitats, which are protected by legislation.
• The chosen technique such as point count, transect or remote
detection must be appropriate to the species being sampled.
• Quadrats of suitable size and shape are used for sessile and
slow-moving organisms; capture techniques for mobile species.
• Elusive species can be sampled directly using camera traps or an
indirect method such as scat sampling.
c) Identifying your
samples
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c) Identifying your samples
what you need to know
Identification of a sample can be made using classification guides,
biological keys or analysis of DNA or protein.
Familiarity with taxonomic groupings allows predictions and inferences
to be made between the biology of an organism and better-known
(model) organisms.
Genetic evidence reveals relatedness obscured by divergent or
convergent evolution.
Life is classified into three domains, the archaea, bacteria and
eukaryota.
The plant kingdom has major divisions such as mosses, liverworts, ferns,
conifers and flowering plants.
The animal kingdom is divided into phyla, which include the Chordata
Arthropoda, Nematoda, Platyhelminthes and Mollusca.
c) Identifying your samples
what you need to know
• Model organisms from within all taxonomic groups are
used to obtain information that can be applied to
species that are more difficult to study directly.
• Model organisms that have been very important in the
advancement of modern biology include the bacterium
E. coli; the flowering plant Arabidopsis thaliana; the
nematode C. elegans; the arthropod Drosophila
melanogaster and mice, rats and zebrafish which are
chordates.
• The classification of life according to relatedness is
central to biological understanding.
Identification and Taxonomy
• During your investigation you’ll be sampling areas and
identifying various organisms.
• Identification can be done using classification guides,
biological keys or DNA/protein analysis.
• How we classify organisms comes from Taxonomy- the
branch of science concerned with the classification of
organisms.
• How do we classify organisms?
• What are taxonomic groups?
Classification of life
Identification
• In the field, identification of a sample can be
made using classification guides and biological
keys, or observations and data that can be
used with these and later recorded.
• Lab techniques can also be used in
identification. Analysis of DNA or protein can
be used. This can be particularly useful where
visual identification is not clear and
differences are at a cellular level.
Model organisms
• Familiarity with taxonomic groupings allows
predictions and inferences to be made
between the biology of an organism and
better-known (model) organisms.
• Model organisms are those that scientists
already know a lot about and have been
studying for many years.
• Organisms such as E. Coli, drosophila, yeast,
maize, mice and zebrafish are all good
examples of model organisms from
different taxonomic groups.
• Sometimes, organisms may appear more or less related
than they actually are due to convergent and divergent
evolution respectively.
• Genetic evidence is often used to dispel myths regarding
relatedness.
• It was recently used to show that red pandas are more
closely related to racoons rather than the former
theory, which suggested greater relatedness to the
giant panda.
The closest living relative to
the elephant- the hyrax
Divergent evolution
• Organisms evolve and share a common ancestor.
Convergent evolution
• Convergent evolution is the
process whereby organisms not
closely related (not
monophyletic), independently
evolve similar traits as a result
of having to adapt to similar
environments or ecological
niches.
Taxonomy
• Taxonomy means classification.
• In Biology this means the name we
give to a species.
• Taking the tiger as an example:
Taxonomy
• Life
can be classified into 3
domains- archaea, bacteria
and eukaryota
•Archaea- prokaryotic, often
thought of as bacteria but
distinct evolution from
bacteria.
•Bacteria- prokaryotic
contains many common
examples- e.coli
•Eukaryota- eukaryotes,
plant and animal kingdom
under this domain
The three domains of life
Taxonomy
• The
plant kingdom has major
divisions including mosses,
liverworts, ferns, conifers
and flowering plants.
•The animal kingdom has phyla
including
•Chordata (sea squirts
/vertebrates)
•Arthropoda (jointed
invertebrates)
•Nematoda (round worms)
•Platyhelminths (flat worms)
•Mollusca
Taxonomy- example
•Some classifications contain
sub-orders or sub- families
depending on the organism and
detail of classification.
•Human taxonomy•Eukaryota
•Animalia
•Chordata
•Mammalia
•Primates
•(Haplorhini)
•Hominidae
•Homo
•H. sapiens
Taxonomy-example
•E.coli•Domain: Bacteria
•Phylum: Proteobacteria
•Class:
Gammaproteobacteria
•Family:
Enterobacteriaceae
•Genus: Escherichia
•Species: E. coli
Taxonomy-example
• White Daffodil
•Kingdom: Plantae
•Phylum: Angiosperms
•Class: Monocots
•Order: Asparagales
•Family: Amaryllidaceae
•Subfamily:
Amaryllidoideae
•Genus: Narcissus
•Species: N. poeticus
Taxonomy
•The related nature
shown by taxonomic
groups, allows scientists
to study model
organisms.
•It’s easier to test
drugs/diets/genetic
diseases in mice than
humans!
Activity 1
Use your notes and the Scholar Study Guides
to describe all of the divisions of the plant and
animal kingdom.
Activity 2
Activity 2
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c) Identifying your samples
what you need to know
Identification of a sample can be made using classification guides,
biological keys or analysis of DNA or protein.
Familiarity with taxonomic groupings allows predictions and inferences
to be made between the biology of an organism and better-known
(model) organisms.
Genetic evidence reveals relatedness obscured by divergent or
convergent evolution.
Life is classified into three domains, the archaea, bacteria and
eukaryota.
The plant kingdom has major divisions such as mosses, liverworts, ferns,
conifers and flowering plants.
The animal kingdom is divided into phyla, which include the Chordata
Arthropoda, Nematoda, Platyhelminthes and Mollusca.
c) Identifying your samples
what you need to know
• Model organisms from within all taxonomic groups are
used to obtain information that can be applied to
species that are more difficult to study directly.
• Model organisms that have been very important in the
advancement of modern biology include the bacterium
E. coli; the flowering plant Arabidopsis thaliana; the
nematode C. elegans; the arthropod Drosophila
melanogaster and mice, rats and zebrafish which are
chordates.
• The classification of life according to relatedness is
central to biological understanding.
d) Monitoring
Populations
d) Monitoring Populations what
you need to know
• Presence, absence or abundance of indicator species can give
information of environmental qualities, such as presence of pollutant.
• Mark and recapture is a method for estimating population size. A
sample of the population is captured and marked (M) and released.
After an interval of time, a second sample is captured (C). If some of
the individuals in this second sample are recaptures (R) then the total
population N = (MC)/R, assuming that all individuals have an equal
chance of capture and that there is no immigration or emigration.
• Methods of marking include banding, tagging, surgical implantation,
painting and hair clipping.
• The method of marking and subsequent observation must minimise the
impact on the study species.
• Classification of vegetation types is based on indicator species within
the community structure.
• Monitoring populations; their presence,
absence or abundance can be used to give
information of environmental qualities, such
as presence of pollutant.
• Understanding the tolerances of a particular
species means you can use them as indicators
for the environment and for the community.
• e.g. Lichens and air quality (in particular SO2
pollution).
Mark and capture activity
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‘Capture’ a sample from the box.
Mark them using a felt-tip pen.
Return the sample and ‘capture’ another sample.
Record the number of recaptures and use the equation
to get a total population size.
• N= (MC)/R
• How accurate is it?
• Does the sample size need to be the same each time?
Monitoring Populations
• Mark and recapture is a method for estimating population size.
• A sample of the population is captured and marked (M) and released.
A second sample is captured (C). If some of the individuals in this
second sample are recaptures (R) then the total population
N = (MC)/R.
• The method of marking and subsequent observation must minimise the
impact on the study species.
• Methods of marking include banding,
tagging, surgical implantation, painting
and hair clipping.
Banding
• Often metal, bands with an individual
identifier are attached to the animal where
it will not impede their movement.
• If it will not be possible or appropriate to
physically recapture different colours of
bands or sequences of colour bands can be
used for remote identification (e.g. through
binoculars)
• Often used on birds, attached to the leg.
• e.g. penguin chicks are tagged early to
track their colony.
Tagging
• Tags will vary according to the species you are
tracking. The tag is used for remote tracking e.g.
radio transmitters.
• The tag has to be securely attached, but also not
interfere with the animals normal behaviour.
• e.g. transmitters attached to turtle shells.
Surgical Implantation
• Tags can be implanted to prevent them interfering
with the animal. For example, external tags on fish
make a large difference to their streamlining
• Since the animal undergoes a surgical procedure
there are implications for their welfare and for the
expertise required.
• e.g. tracking striped bass.
Painting
• Non-toxic, biodegradable paints must be used. Care
must also be taken that the paint does not blog skin
surfaces for heat regulation, secretion or respiration.
• It is also important to consider the impact of scent
and colour marking on animals.
• e.g. hedgehogs in Guernsey.
Hair Clipping
• A clearly identifiable section of hair removed can be
used as very effective method of identification.
• Care has to be taken regarding; size of clipping,
distress to animal, social signals with animals.
• e.g. tracking mice in field studies
• (HINT: COMMON EXAM QUESTION)
Some assumptions in this method
include;
-all individuals have an equal chance
of capture
- no immigration or emigration in
time interval between 1st and 2nd
sample
• In a survey to estimate a monarch butterfly
population in Strathclyde Park, the following data
were obtained.
• Number of monarch butterflies first captured,
marked and released = 540
• Number of marked monarch butterflies in second
capture = 60
• Number of unmarked monarch butterflies in second
capture = 180
• Calculate the estimated population of monarch
butterflies in Strathclyde Park.
d) Monitoring Populations what
you need to know
• Presence, absence or abundance of indicator species can give
information of environmental qualities, such as presence of pollutant.
• Mark and recapture is a method for estimating population size. A
sample of the population is captured and marked (M) and released.
After an interval of time, a second sample is captured (C). If some of
the individuals in this second sample are recaptures (R) then the total
population N = (MC)/R, assuming that all individuals have an equal
chance of capture and that there is no immigration or emigration.
• Methods of marking include banding, tagging, surgical implantation,
painting and hair clipping.
• The method of marking and subsequent observation must minimise the
impact on the study species.
• Classification of vegetation types is based on indicator species within
the community structure.
e) Measuring and recording
animal behaviour
e) Measuring and recording animal
behaviour what you need to know
• An ethogram of the behaviours shown by a
species in a wild context allows the
construction of time budgets.
• Measurements such as latency, frequency and
duration.
• The importance of avoiding
anthropomorphism.
Measuring and Recording Animal
Behaviour
• When sampling a populations size,
abundance or diversity within an ecosystem,
the behaviours of animals may also be
recorded.
• Ethograms are a catalogue or inventory of
behaviours or actions exhibited by an
animal.
• These are particularly important when
dealing with the welfare of animals eg in
captivity or while being observed in their
territory.
• A detailed list with clear defined
descriptions can be produced
(qualitative vs quantitative!)
• e.g. a hamster in a cage
Avoiding anthropomorphism
• Anthropomorphism is a
particular problem when
studying animal behaviour. It
is important to treat
information in a scientific
manner and not attribute
human characteristics to nonhuman species.
• Remaining objective in behaviour studies is
helped by using measurable, clearly defined
definitions.
• Latency – the time between a stimulus and
response
• Frequency – how often a particular behaviour
occurs
• Duration – the length of time a particular
instance of a behaviour lasts.
Time budgets
• All of these can be used to produce a clear
picture of how a particular species behaves.
• The time budget is the time allocated to
particular behaviours in a given time frame.
• Comparisons of animals in the wild and animals
in other contexts e.g. zoos can highlight
changes from the normal time budget.
e) Measuring and recording animal
behaviour what you need to know
• An ethogram of the behaviours shown by a
species in a wild context allows the
construction of time budgets.
• Measurements such as latency, frequency and
duration.
• The importance of avoiding
anthropomorphism.
Past Paper Questions
CfE AH Specimen Paper
• Section 1: Q25
• Section 2: Q10
Think, pair, share
• In pairs:-think back and answer the following:1.
2.
3.
4.
5.
6.
7.
8.
Why do we monitor populations of plants/animals?
How do we monitor these populations?
Name two ways we can sample plant and animal species.
What is the abundance and diversity of an organism.
Explain the process of random, systematic and stratified sampling.
What do we use to identify organisms?
What are dependent, independent and confounding variables?
Describe how you completed one of the practicals; including
equipment, variables and techniques used.