Module 3 Biodiversity and Evolution Biodiversity and evolution

Module 3: Biodiversity and Evolution

Biodiversity and evolution • Evolution has generated a very wide variety of organisms. • The fact that all organisms share a common ancestry allows them to be classified. • There is increasing recognition of the need to maintain biodiversity.

Biodiversity • Biodiversity is an important indicator in the study of habitats.

Classification • Classification is an attempt to impose a hierarchy on the complex and dynamic variety of life on Earth. • Classification systems have changed and will continue to change as our knowledge of the biology of organisms develops.

Evolution • “Nothing in biology makes sense except in the light of evolution” – Theodosius Dobzhansky, 1973.

Maintaining Biodiversity • Maintaining biodiversity is important for many reasons. • Actions to maintain biodiversity must be taken at local, national and global levels.

2. 3. 1. Biodiversity Module 3: Biodiversity and Evolution

Learning Outcomes • define the terms ‘species’, ‘habitat’ and ‘biodiversity’ • explain how biodiversity may be considered at different levels; – habitat, – species – genetic

Biodiversity • The biodiversity of an area is a measure of: – Different ecosystems – Number of species – Number of individuals of each species

Biodiversity • “structural and functional variety in the living world” • Levels of biodiversity – Range of habitats in which different species live – The differences between species – Genetic variation between individuals of the same species

Species - definition • Species “a group of organisms, with similar morphological, physiological, biochemical and behavioural features, which can interbreed to produce fertile offspring, and are reproductively isolated from other species” – This often leads to disagreements and uncertainties when classifying or identifying species

Species – the two groups of criteria • Group of organisms showing similarities in – Capable of interbreeding characteristics – Capable of producing fertile offspring – Reproductively isolated from other groups • “biospecies” – – – Morphological Physiological biochemical Ecological behavioural

Habitat – definition • A habitat is the place where individuals in a species live. • Organisms show adaptations to their habitat • A full description of the habitat includes the physical and biological factors that characterise that environment

Examples of habitats • Name of the place • A description of dominant vegetation – – Coniferous forest Oak woodland Tropical rainforest Grassland • A type of environment – Freshwater pond – Rock pool on a rocky shore

The State of the planet • David Attenborough presents a series of three programmes looking at the “state of the planet” to address the concern below. • One species (humans) can so alter its environment that it can destroy whole species, and indeed whole environments. – How great is the damaged that is being caused? – Why is it that we do is so destructive? – What can we do to change?

The state of the planet Programme No. 1 • The Biodiversity on Earth – In order to understand the impact that humans are having on the environment we first need to understand the variety of life on the planet, the biodiversity. • Watch the DVD and answer the questions on the worksheet. • After watching the DVD write out your thoughts on the statement – Why conserve ecosystems?

Measuring Biodiversity

Measuring Biodiversity learning Outcomes • explain the importance of sampling in measuring the biodiversity of a habitat describe how random samples can be taken when measuring biodiversity

Measuring biodiversity • To measure biodiversity you need to find out – What species are present – The abundance of each species – The distribution of each species across the area • Compile a species list – Identification keys – Observation – Trapping of mobile animals

Measuring biodiversity • Distribution – Where the species is found • Abundance – How many of each species are present – Estimating abundance • Take a representative sample • Multiply up

Random sampling • Study a small part of the habitat • Sample sites must be selected at random – Take samples at regular intervals – Use random number tables – Select co-ordinates from a map

Number of samples • The number of samples taken will depend on – The size of the habitat – The time of year – The diversity of the habitat being studied

Recording results • Prepare a table – Space for all species – Space to record the data for each sample site

Sampling techniques • Quadrats – – Choose a suitable quadrat size Place quadrat at random Identify plants Measure their abundance • Transects – Put a tape measure across the habitat – Record all species touching the line – Can record at intervals

Sampling techniques • Belt transect – Interrupted belt transect – Continuous belt transect – Used to survey rocky shores or sand dunes Interrupted belt transect continuous belt transect

Measuring abundance • Percentage Cover – Proportion of quadrat’s area occupied by the species – Grids can help with estimates – Use a point frame within a quadrat – Include bare ground • Abundance scale – subjective – ACFOR scales • • • Abundant Common Frequent Occasional Rare • Species frequency – Proportion of quadrats with the species present

Rocky Shores Some text, photos and diagrams taken from: Marine Field Course Guide to Rocky Shores (1992) by S. J. Hawkins & H. D. Jones

Learning Outcomes • To understand that zonation occurs on a rocky shore, and the factors that control this distribution • To identify a range of organisms living on a rocky shore • To understand the importance of carrying out biological surveys • To carry out a “paper-based” transect looking at the distribution of organisms on a rocky shore • To present results as a kite diagram, and write a report of their findings.

Rocky Shore Ecology • The seashore is the boundary between land sea. • A sharp change in environmental conditions occurs between the low tide mark and the splash zone. • Most shore plants and animals have evolved from marine ancestors.

Zonation • Biomass, biodiversity and community complexity increases towards the lower shore as conditions are better for marine organisms; competition for space and food is intense. • Species occur in distinct communities or horizontal bands on the shore known as zonation.

Splash zone As you can see from these diagrams organisms show zonation. You can also see that the organisms present varies according to the exposure of the shore. Low tide

Activity • For each zone write in the degree of stress for each abiotic and biotic factor • Add on two arrows to show the direction of increasing stress caused by abiotic (red) and biotic (green) factors on the rocky shore

Factors affecting the distribution of organisms • Survival is most difficult near the top of the shore. • Biomass and biodiversity of animals and plants is low. • Those plants and animals that can survive have little competition e. g. for space, and may be abundant.

Rocky Shore Transect • On the A 4 “rocky shore” draw a belt transect using 3 cm 2 quadrats. • Calculate the abundance of each species of “plant” and “animal” in each quadrat, record your results in the table provided. • Write a report on the distribution of organisms on the rocky shore • Extension Activity – Present your results as a kite diagram for five seaweeds and five animals.

Sampling in School Grounds • Suggested activities – – – Transect in grass outside chapel Random quadrat sampling of two sites Optimum quadrat size for pinkie fields Optimum quadrat number Species frequency on pinkie fields Comparison of percentage cover and ACFOR • All students quantify the same 10 quadrats and allow for comparison

Sampling Animals • If the animals are mobile – Observation of signs left behind • Owl pellets, droppings, burrows etc – Catch or trap animals and estimate numbers from the trapped sample • Catching animals – – – Sweep netting Kick sampling Tree sampling Pitfall trap Tulgren funnel Light trap

Surveying school grounds • Suitable methods that could be used in school include – – Sweep netting in the long grass Tree sampling Pitfall trap Tulgren funnel • To allow for a comparison, each sample should be done at two sites, and some abiotic readings should be taken.

Summary of the impact of sampling • Sampling may cause damage to a habitat – Temporary disturbance – Long term disturbance • Example – Trampling – Digging for pitfall traps etc

Why do we need to study habitats? • Assess human impact • EIA – Planning process • To highlight the importance of maintaining habitats and reducing the damage

Learning Outcomes • describe how to measure species richness and species evenness in a habitat • Use Simpson's Index of diversity (D) to calculate the biodiversity of a habitat using the formula D = 1 – (∑(n/N)2) • Outline the significance of both high and low values of Simpson’s Index of Diversity (D)

Measuring Biodiversity • Species richness – Number of species present in the study area • Species evenness – Measure the abundance of individuals in each species • Increasing species richness and species evenness will increase biodiversity

Simpson’s diversity Index • Measure of biodiversity taking into account species richness and species evenness • Formula – D = 1 – [∑(n/N)2] – n = number of individuals of a particular species – N = total number of all individuals of all species

Progress Question • Use Simpson’s index to calculate the diversity of a habitat that contains the following organisms – – – 20 woodlice 5 mice 1 shrew 32 earthworms 15 grasshoppers 1 owl • Comment on the diversity of this habitat

Calculating simpson’s species n n/N (n/N)2 woodlice 20 0. 27027 0. 073046 mice 5 0. 067568 0. 004565 shrew 1 0. 013514 0. 000183 earthworm 32 0. 432432 0. 186998 grasshopper 15 0. 202703 0. 041088 owl 1 0. 013514 0. 000183 Sum 74 0. 306063

Answers to progress questions • D = 1 – 0. 306 • D = 0. 694

2. 3. 2 Classification Module 3: Biodiversity and evolution

Classification • Classification is an attempt to impose a hierarchy on the complex and dynamic variety of life on Earth. • Classification systems have changed and will continue to change as our knowledge of the biology of organisms develops.

Learning Outcomes • Define the terms classification, phylogeny and taxonomy. • Explain the relationship between classification and phylogeny. • Describe the classification of species into the taxonomic hierarchy of domain, kingdom, phylum, class, order, family, genus and species.

Definitions • Classification – The grouping of organisms into categories based on various features • Phylogeny – Study of evolutionary relationships between organisms • Taxonomy – The study of the principles of classification • Taxon – Classificatory group

Natural Classification • Concept of the species – Capable of breeding to produce fertile offspring – Have common ancestry – Have very similar genes • Hierarchy of classification – Closely related species are placed together in groups – Closely related groups are placed together in a larger group • Modern classification reflects the evolutionary distance between species

Evolutionary tree • Any two species alive today will share a common ancestor from the past • The time when the two species started to evolve separately is a branch point on the tree

Progress Questions • What is meant by the term classification? • What is meant by the term phylogeny? • What is the relationship between natural classification and phylogeny?

Answers to progress questions • What is meant by the term classification? – Classification is the sorting of living things into groups – Natural classification does this by grouping things by how closely related they are • What is meant by the term phylogeny? – The study of evolutionary relationships between organisms • What is the relationship between natural classification and phylogeny? – Natural classification groups things according to how closely related they are – This should match the evolutionary tree produced by considering how recently organisms shared a common ancestor.

Classifying living things • Carl Linnaeus – 18 th Century – – Devised a scheme of classification Organisms were put into a series of ranked categories Categories are taxonomic groups (TAXON) 5 kingdom classification

Hierarchy of classification • • Domain Kingdom Phylum Class Order Family Genus Species – This is the basic unit of classification

Taxon Description Kingdom Largest group of organisms sharing a few common features. Phylum Major subdivision of a kingdom. Class A group of related orders- subdivision of a phylum. Order A group of related families- subdivision of a class. Family A group of closely related genera- subdivision of an order. Genus A group of related species- subdivision of a family. Species A group of organisms capable of breeding and producing fertile offspring.

Hierarchy of classification Taxon Domain No. of similarities Size of group Degree of relatedness small Large Distant to common ancestor large small Recent common ancestor Kingdom Phylum Class Order Family Genus Species

Examples of Classification Taxon Tiger Human Fruit fly Domain Eukaryota Kingdom Animalia Phylum Chordata Arthropoda Class Mammalia Insecta Order Carnivora Primate Diptera Family Felidae Hominidae Drospophilidae Genus Panthera Homo Drosophila Species tigris sapiens melanogaster

Learning Outcomes • Outline the binomial system of nomenclature and the use of scientific (Latin) names for species. • Use a dichotomous key to identify a group of at least six plants, animals or micro organisms. • Outline the characteristic features of the following five kingdoms: Prokaryotae (Monera), Protoctista, Fungi, Plantae, Animalia.

Confusion over common names In North America, this animal is a moose. In Europe, this animal is an elk. In North America, this animal is an elk. In Europe, this animal is a red deer.

Binomial Classification • Universal system based on Latin names – Generic name – Specific name

Rules for using system • Name printed in Italics, or underlined if hand written • First letter of generic name in capitals • Once generic name has been used, it can be abbreviated in later text to the first letter. • If specific name not known, write sp. • If referring to all members of a genus, specific name written in plural spp.

Binomial system of nomenclature • Examples – – Homo sapiens Panthera leo Panthera tigris Lutra lutra

Identifying Living things • Dichotomous key – Asks a series of questions in pairs – You are then directed to another question or to an identification • Look at the Classification and Taxonomy fact sheet – Look at the example of a classification key as shown • Other examples – Textbook pg 207 – Revision guide pg 77

Five Kingdom Classification • • • Prokaryotae Protoctista Fungi Plantae Animalia

Prokaryotae • Oldest group of organisms on earth • Two groups originally recognised but have now been separated into two domains – Archaea – Eubacteria (includes cyanobacteria) • Distinguishing features of eubacteria (Prokaryotae) – Organisms lack nuclei organised within membranes. – No envelope-bound organelles. – No 9+2 microtubules

Protoctista • • Eukaryotic mostly unicellular Plant-like or animal-like organisms Includes – Chlorophyta (green algae) – Phaeophyta (brown algae)

Fungi • • • Eukaryotic Heterotrophic nutrition Cell walls made of chitin Usually form mycelium Carbohydrate stored as glycogen Sexual or asexual reproduction

Plantae • Features – – – Eukaryotic Multicellular Possesses chlorophyll and other pigments Autotrophic nutrition Cells walls of cellulose Carbohydrate stored as starch.

Animalia • • • Eukaryotic Multi-cellular Heterotrophic nutrition No cell walls Carbohydrate stored as glycogen Display nervous co-ordination

Learning Outcomes • Discuss the fact that classification systems were based originally on observable features but that more recent approaches draw on a wider range of evidence to clarify relationships between organisms, including molecular evidence. • Compare and contrast the five kingdom and three domain classification systems.

Modern Classification • In the 19 th and early 20 th century – classification was based on observable features – Morphology – Embryology – Anatomy • Homologous features – Evolutionary origin in the same ancestral structure • E. g. pentadactyl limb of tetrapods

New developments • The following scientific developments can now be used as a method of classifying organisms • Primary structure of proteins – Cyctochrome C is a protein used in respiration – By comparing the sequence of amino acids in the primary protein structure can determine how closely related the species are.

New developments • Scanning Electron Microscopy – Looks at morphology in greater detail • DNA sequencing – Helps classification to reflect phylogeny using nucleotide sequence data

The Three Domains • 1990 – Carl Woese – New classification system after studying ribosomal RNA – Argued that the differences in bacteria were so great they needed separating • Bacteria – Eubacteria • Archaeae – Archaebacteria – This gives three domains • Bacteria • Archaea • Eukaryotae

Why three domains? • Eubacteria are prokaryotic and fundamentally different from Archaeae and eukaryotae • Archaeae share characteristics with eukaryotae – RNA polymerase – Similar DNA replication mechanisms

Five kingdom classification

Three domain classification

2. 3. 3 Evolution Module 3: Biodiversity and Evolution

Evolution • “Nothing in biology makes sense except in the light of evolution” – Theodosius Dobzhansky, 1973.

Learning Outcomes • Define the term variation. • Discuss the fact that variation occurs within as well as between species. • Describe the differences between continuous and discontinuous variation, using examples of a range of characteristics found in plants, animals and microorganisms. • Explain both genetic and environmental causes of variation.

Variation • Variation is the differences that exist between individual organisms. – Interspecific variation (between species) • Differences that are used to assign individuals to different species – Intraspecific variation (within a species) • Individuals of the same species show variation • Variation can be inherited or influenced by the environment.

Types of variation • There are two main types of variation – Continuous variation – Discontinuous variation • There are two main causes of variation – Genetic variation – Environmental variation

Continuous variation • • Existence of a range of types between two extremes Most individuals are close to a mean value Low numbers of individuals at the extremes Both genes and the environment interact in controlling the features • Examples – Height in humans – Length of leaves on a bay tree – Length of stalk of a toad stool

Continuous variation • Use a tally chart and plot results in a histogram

Discontinuous variation • 2 or more distinct categories with no intermediate values • Examples – – Earlobes Blood groups Bacteria Flowers attached or unattached A, B, AB or o flagella or no flagella colour of petals • Genetically determined • The environment has little or no effect on discontinuous variation

Discontinuous variation

Causes of variation • Genetic Variation – Genes inherited from parents provide information used to define our characteristics • Environmental Variation – Gives differences in phenotype (appearance) but not passed on by parents to offspring – Examples • Skin colour tans with exposure to sunlight • Plant height determined by where the seed lands

Learning Outcomes • Outline the behavioural, physiological and anatomical (structural) adaptations of organisms to their environments.

Adaptations • Adaptations help organisms to cope with environmental stresses and obtain the things they need for survival. • They are features which have evolved over time and are continually subjected to selection pressures • Adaptations can be – – Structural Behavioural Physiological biochemical

A well adapted organism • List what a well adapted organism must be able to do in order to survive – E. g. find enough food / photosynthesis – Try to list 6 things

Behavioural adaptation • Any aspect of the behaviour of an organism that helps it to survive the conditions it lives in. • Example – Desert rat remains underground during the day

Physiological / biochemical adaptations • These ensure the correct functioning of all cell processes • Example – Some yeast can respire both aerobically and anaerobically depending on the availability of oxygen

Anatomical adaptations • A structure which enhances the survival of the organism • Example – Desert rats have very long loops of henle to aid the reabsorbtion of water. – Fennec fox has large ears

Pupil Activity • Watch the selection of video clips from planet earth – Make notes on the adaptations organisms show to their environments • Almost a fun game – Identify the three adaptations for the organisms shown - FUN,

Pupil Activity • Adaptations of xerophytic plants – For the list of adaptations given decide whether they are physiological, behavioural or structural adaptations. • Identifying adaptations – Look at the selection of photos – For each organism try to give an adaptations that suits the organism to its habitat.

The Saguaro Cactus

The fennec fox

Polar bear

Midge larvae

Marram Grass

Pupil Activity • Collect a copy of the worksheet on adaptations of xerophytic plants – For each adaptation given, explain how this adaptation helps the plant to survive.

Learning Outcomes • Explain the consequences of the four observations made by Darwin in proposing his theory of natural selection. • Outline how variation, adaptation and selection are major components of evolution • Define the term speciation.

Evolution and Natural Selection • Evolution – Gradual development of organisms over time • Natural Selection – Theory proposed by Darwin as a mechanism to explain how evolution occurred.

Evolution by natural selection • Darwin’s four observations – Variation exists among offspring – Offspring appear similar to parents and inherit features from them – Organisms have the ability to produce large numbers of offspring – Populations of organisms stay relatively stable over time • Darwin’s conclusions – There is a struggle to survive – Better adapted organisms survive and pass on their characteristics – Over time – changes may give rise to a new species

The theory of natural selection • • • Variation Overproduction Struggle for existence Survival of the fittest Advantageous features inherited Gradual change in the population • Write out a short explanation for each of these points.

Environmental factors • Factors that can limit population size include – – – Availability of food Predators Disease Competition for space Find a mate Physical and chemical factors • Selection pressure – An environmental factor which determines which species survive

Speciation • Speciation is the formation of a new species from a pre-existing one. • If two populations of the same species become isolated from each other • different selection pressures mean that the populations develop different adaptations • Speciation has occurred when the two populations can no longer breed together to produce fertile offspring.

Types of Speciation • Allopatric speciation – Geographical • Two populations become separated • Sympatric speciation – two species remain in the same geographical area but a reproductive barrier arises, which prevents one member of the population breeding with another

Progress Questions • State the key observations made by Charles Darwin [4 marks] • Explain the terms – Selection pressure – Selective advantage [3 marks]

Learning outcomes • Discuss the evidence supporting theory of evolution, with reference to fossil, DNA and molecular evidence.

Fossils • Fossil – Remains of organisms that are preserved in sedimentary rocks • Examples of fossils

Fossil Evidence • Fossils show certain facts – In the past species were very different than species today – Old species have died out – New species have arisen – New species often similar to old species • Questions – Why does one species die out? – Why would a similar one replace it? – Did one give rise to the other?

Brachiopods • Change gradually over time • Can be used to age rocks

Armadillo vs. Glyptodons

Fossil Evidence • One of the earliest birds • many features that are typical of the reptiles

Gaps in the fossil record • The fossil record is incomplete for many reasons – Only the hard parts of the animals become fossilised – Fossils can only form under certain conditions – After they have formed fossils could become damaged or destroyed by rock movements

More recent evidence • Biological molecules provide strong evidence for evolution – Many biological molecules are found in all organisms • All life on earth has a common ancestor – Closely related species – more similarities – Cytochrome C shows patterns of changes

Protein Evidence • The primary structure of protein molecules is determined by the sequences of bases in DNA • Vital proteins e. g. DNA and RNA polymerase are found in all living organisms

DNA evidence • Sequencing the bases in DNA allows for comparison • Comparing other primates with human DNA, shows evolutionary relationships Differences in coding sequence 1. 2% primate Chimpanzee 1. 6% Gorilla 6. 6% baboons

Progress Questions • Explain how DNA analysis and biochemistry can be used to clarify the evolutionary relationships between closely related species [5 marks] • Explain how fossils can be used as evidence for evolution [3 marks] • Explain the significance of fossils such as Archaeopteryx [2 marks]

Learning Outcome • Discuss why the evolution of pesticide resistance in insects and drug resistance in microorganisms has implications for humans

Drug resistance in micro-organisms • Using antibiotics changes the environment for the bacteria • Mutation giving resistance gives individual bacterium a selective advantage – It survives – Over time number of resistant types of bacteria increase • Some antibiotics are now ineffective

Arms Race • MRSA – Methicillin resistant Staphylococcus aureus – Developing resistance to an ever increasing range of stronger and stronger anti-biotics

Pesticide Resistance • A pesticide is a chemical designed to kill pests – Insecticide kills insects • Insecticide applies selection pressure on insect populations to develop resistance • Due to short life cycles resistance spreads quickly through the whole population

Pesticide resistance • Resistance – Breakdown of insecticide using enzymes – Modification of target receptor proteins on cell membrane • Example – Anopheles mosquito • Resistant to DDT and pyrethroids

Practice Questions • Answer questions

Learning Outcomes Evolution • • • Define the term variation. Discuss the fact that variation occurs within as well as between species. Describe the differences between continuous and discontinuous variation, using examples of a range of characteristics found in plants, animals and microorganisms. Explain both genetic and environmental causes of variation. Outline the behavioural, physiological and anatomical (structural) adaptations of organisms to their environments. . • • • Explain the consequences of the four observations made by Darwin in proposing his theory of natural selection. Define the term speciation. Discuss the evidence supporting theory of evolution, with reference to fossil, DNA and molecular evidence. Outline how variation, adaptation and selection are major components of evolution. Discuss why the evolution of pesticide resistance in insects and drug resistance in microorganisms has implications for humans

2. 3. 4 Conserving Biodiversity Module 3: Biodiversity and Evolution

Maintaining Biodiversity • Maintaining biodiversity is important for many reasons. • Actions to maintain biodiversity must be taken at local, national and global levels.

Global Problem

Endangered species

Learning Outcomes • Outline the reasons for the conservation of animal and plant species, with reference to economic, ecological, ethical and aesthetic reasons.

Definition of conservation • Management of human use of the biosphere so that it may yield the greatest sustainable benefit to present generations while maintaining it’s potential to meet the needs and aspirations of future generations. – World conservation strategy

conservation • Conservation is the protection of ecosystems, habitats and species • These means taking action to halt destruction and extinction

Conservation • Conservation involves – – Managing areas of land Taking steps to encourage new habitats Removing animals to captivity Growing plants in cultivation

Reasons for conserving species • The main reasons given for conserving species are – – Economic Ecological Ethical aesthetic

Economic reasons • Natural ecosystems provide services – Examples • • Regulation of atmosphere and climate Formation and fertilisation of soil Recycling of nutrients Growth of timber, food and fuel • Ecosystems also provide goods such as wood and fish for free.

Ecological reasons • Keystone Species – Keep ecosystems in balance • Photosynthesis – Removes CO 2 from the air and replaces oxygen

Ethical reasons • Species become extinct as a result of human action • Humans have a responsibility to maintain species, ecosystems and habitats for future generations • All organisms have a right to survive and live in the way to which they have become adapted.

Aesthetic Reasons • People enjoy – visiting wild places – Observing wildlife • The large animals are sustained by an interdependent web which includes a huge number of species • Recovery of patients • Wellbeing – physical, intellectual and emotional health

Learning Outcomes • Discuss the consequences of global climate change on the biodiversity of plants and animals, with reference to changing patterns of agriculture and spread of disease. • Explain the benefits for agriculture of maintaining the biodiversity of animal and plant species.

Genetic Diversity • Genetic diversity within species allows that species to adapt and evolve • Threats to species with a low genetic diversity include: – – Climate change Increase in levels of pollution Emergence of new diseases Arrival of pest species

Stages of human impact on genetic diversity • • • Clearing vegetation Reduce the size of natural habitats Reduce population size Reduce gene pool for species Decrease genetic variation Decrease ability of species to evolve

Modern Agriculture • Reduces the variation and genetic diversity of domesticated plants and animals, this has led to the extinction of varieties within a species. • Examples – Monoculture – Selective breeding • Estimate – one locally adapted breed of animal is lost world wide each week.

Climate change • As climate changes the species are unable to adapt due to the loss of genetic variation. • Slow migration of populations, communities and ecosystems towards the poles • Obstruction to migration include – – Major human developments Agricultural land Large bodies of water humans

The Golden Toad • • The golden toad of Costa Rica may have been driven to extinction by climate change, The toad's demise has been revealed by research into the changing populations of species in Costa Rica. The scientists concluded that rising temperatures may have been to blame. The disappearance of the toad is part of a pattern of change that is affecting not only amphibians but also reptiles and birds as well. • • • The Monte Verde golden toad is a very small toad found in the tropical forests of Monteverde, Costa Rica. It is believed to be extinct since no live specimens have been since 1989 researchers still hope that it continues to live in underground burrows.

Agriculture • Read through the list below, decide which of the changes due to global warming would benefit agriculture give reasons!! – – – – Higher CO 2 levels Higher temperature Longer growing seasons Greater evaporation of water Greater precipitation Sea level rise Increase in salinity of soil

Climate change and agriculture • Human diet is limited – Three staple foods – wheat, maize, rice – Fish stocks – cod • Crops are genetically uniform and susceptible to disease – Wild varieties hold genes which could vary the genome of our crops

Climate change and the spread of disease • Migration of insect vectors and disease – Tropical disease spread by Anopheles mosquito and the tsetse fly may become a problem in Europe • Climate change is already responsible for: – Epidemic of bird malaria in Hawaii – Viral distemper among lions in Serengeti – Black Stem Rust in wheat

Biodiversity for medicine • Potential new medicines from plants • Possible vaccines from wild micro-organisms • Study of traditional medicines

Learning Outcomes • Describe the conservation of endangered plant and animal species, both in situ and ex situ, with reference to the advantages and disadvantages of these two approaches. • Discuss the role of botanic gardens in the ex situ conservation of rare plant species or plant species extinct in the wild, with reference to seed banks.

Introduction - recap • The threats to biodiversity are caused by human activities, which are endangering species directly. • Species are now being put at risk from habitat loss, hunting, and damage by introduced species, and loss of disease resistance by pollution. • Other species are put at risk if a product from the organism becomes a status symbol or is used in folk medicine

Endangered Species • Endangered species are those that have such small numbers that they are at risk of extinction – Little genetic variability leaves them susceptible to genetic and infectious diseases • “living dead”

Conservation of endangered species • The conservation of endangered species can be: – In situ • Animals and plants are protected in their natural environment – Ex situ • Animals are cared for in zoological collections • Plants are cared for in botanical gardens

Four key aims of in situ conservation • • A natural healthy environment Sustainable use of the natural environment A secure environmental future Enjoyment of the natural environment

National Parks • In South and East Africa National parks protect the largest of the land mammals • A national park should be: – Comprehensive – Adequate – representative

Advantages reserve designation • • Conservation Protection of biodiversity Protection of cultural and natural heritage Areas maintain ecological integrity Opportunities for sustainable land uses Scientific research Meets need of indigenous people

Conflicts with designations • • Protected animals raid farmland Hunting for food Illegal harvesting of timber tourism

Examples of reserves • Phinda reserve – South Africa – Release of natural fauna • NNR in UK – protect specific species – Snake’s head fritillary Fritillaria meleagris • Marine Nature reserve – Skomer marine nature reserve, pembrokeshire

In situ conservation - UK • Designated areas in the UK – – – SSSI – sites of special scientific interest National parks AONB – areas of outstanding natural beauty NNR – National nature reserve ESA – Environmentally sensitive areas

Ex situ conservation - animals • The 3 main aims of zoos are conservation, education and research. • Captive Breeding Programmes – Rare and endangered species are bred in captivity

Captive breeding programmes • Advantages of captive breeding programmes – Fewer animals need to be caught in the wild – Reduces the chances of extinction – Reintroduction into the wild • Problems with captive breeding programmes – – – After release Too tame or too used to captivity to survive Difficulties in finding food The original threat is still there Inbreeding depression

Case Study: Nene Goose (Branta sandivicensis) • Largest native bird on Hawaii, it is a non-migratory species, which only lives on the isolated island. – C 19 – 1940 20, 000 geese 40 geese • Reason for decline - the introduction of non-native terrestrial predators, e. g. rats, dogs. • The mongoose was originally introduced to control the rat numbers, but found the geese and their eggs easier prey (biological control gone wrong again).

Case Study: Nene Goose (Branta sandivicensis) • Captive breeding programme – 1951 2 females and 1 male » sent to the wildfowl’s and wetlands trust in England. – 1971 1200 geese » in wildfowl sanctuaries around the world. 1600 geese » release back onto Hawaii • Measures were put in place to protect the geese, such as netting around nesting areas, and control of the predatory species.

Ex situ - plants • Botanical Gardens – Collect seeds from the wild – Seeds stored and germinated in protected conditions – Can increase the number of individuals of a species very quickly • KEW Gardens – 40 000 species of vascular plants – Important in maintaining biodiversity and genetic diversity in plants

Disadvantages – botanical gardens • Collection of wild seeds will cause some disturbance • Collected samples – not representative • Seeds stored may not be viable • Plants bred asexually are genetically identical

Seed Banks • E. g. millennium seed bank, West Sussex • Seeds kept in a cold store – The moisture content of seeds are reduced under low temperature and then frozen. – Some specialise in preserving varieties of crop plants – Botanist’s noah’s ark

Learning Outcomes • Discuss the importance of international cooperation in species conservation with reference to the Convention in International Trade in Endangered Species (CITES) and the Rio Convention on Biodiversity.

International Co-operation • The loss of habitat and the number of endangered species is a worldwide problem – Needs a worldwide solution

The convention of international trade in endangered species of wild flora and fauna • Consists of three Appendices protecting around 25, 000 -30, 000 species • Aim – Ensure that international trade in specimens of wildlife does not threaten their survival • CITES main aims involve the regulation and monitoring of international trade

CITES appendix 1 • Appendix I includes species threatened with extinction. • Trade in specimens of these species is permitted only in exceptional circumstances.

The convention of international trade in endangered species of wild flora and fauna • Appendix one includes species that are threatened with extinction – – – Gorillas Tigers Leopards Asiatic lion Monkey puzzle tree Cycad Araucaria araucana Cycas beddomei

CITES Appendix 1

CITES Appendix 1

CITES Appendix 1

CITES Appendix 1

CITES Appendix 1 • And finally the pitcher plant – Nepenthes rajah

CITES Appendix 2 • Appendix II includes species not necessarily threatened with extinction, • trade must be controlled in order to avoid utilization incompatible with their survival.

CITES Appendix 3 • This Appendix contains species that are protected in at least one country, which has asked other CITES Parties for assistance in controlling the trade.

Mammals • The following entire groups (orders or families) of mammals are included in CITES Appendices I or II: – all primates – all cetaceans • (whales & dolphins) – all cats • (leopard, tiger, etc) – all bears – all elephants – all rhinoceroses

Reptiles • The following entire groups (orders or families) of reptiles are included in CITES Appendices I or II: – all crocodylians • (alligators, crocodiles, caimans, etc) – all sea turtles • (Cheloniidae) – all Boidae • (boas, pythons)

invertebrates

Convention on Biological Diversity

Convention on Biological Diversity (CBD) • Signed in 1992 at the “Earth Summit” in Rio de Janeiro • Covers – Use and conservation of biodiversity – Sustainable development – co-operation between countries and states • UK government launched the Biodiveristy Action Plan in response to the convention

Learning Outcomes • Discuss the significance of environmental impact assessments (including biodiversity estimates) for local authority planning decisions.

Environmental Impact Assessment • CBD – Agenda 21 – sustainable development – Ecologists sample an area • report on the likely impact of the development on the species and their habitats – Developers and planners • Take into account the effects highlighted and seek to minimise them