Biodiversity Notes PDF

Biodiversity What is it? The biotic and abiotic diversity per unit area Biotic: Living factors, a plant, an animal, etc. Abiotic: Non-living factors, a cave, a rock, etc. 1. Habitat diversity a. Where organisms live some organisms may live in an abiotic environment such as...

Biodiversity What is it? The biotic and abiotic diversity per unit area Biotic: Living factors, a plant, an animal, etc. Abiotic: Non-living factors, a cave, a rock, etc. 1. Habitat diversity a. Where organisms live some organisms may live in an abiotic environment such as a cave and some in a biotic environment such as a plant. 2. Species diversity a. The diversity of different species in an ecosystem. 3. Genetic diversity a. The diversity of genes in one species for example almost all humans have eyes but our gene diversity means that we have different eye color. b. About human 39000 gene, plants 100s ks Natural and Human Impacts on Speciation Terminology: 1. DNA vs Chromatid vs chromosomes a. DNA = Genetic information molecule b. Chromatid = One half of a chromosome c. Chromosome = Stores the DNA 2. DNA vs gene vs allele vs genotype a. 3. Genotype vs phenotype a. An organism's genotype is the set of genes that it carries. An organism's phenotype is all of its observable characteristics. 4. DNA → mRNA → Protein → Physical traits 4 types of nitrogenous bases: Thymine Adenine Cytosine Guanine If sugar 1 holds an “A” nitrogenous base it must pair with a sugar holding a “T” nitrogenous base T must always pair with A, C must always pair with G T A C G DNA coils around protein (histone) and then around other coils to condense and condense into a chromosome. A certain length of DNA that coils for a protein = gene If a wrong pairing is made for example T with G it will result in a slightly different gene, this is called different forms/versions of a gene = allele DNA gets transcribed (copied) to make mRNA (a code) (messenger RNA) (this is because DNA can’t survive the harsh cytoplasm), once out mRNA gets translated (by the translator ribosome) into protein which is shown as a physical trait. Sources of Variation: 1. Meiosis a. Cell (2n diploid) becomes a gamete (n haploid) b. Crossover in the gametes (towards the end of the chromosomes) causes the creation of new alleles 2. Fertilization a. Fusion of male and female gametes to produce a zygote b. Both gametes carry new alleles; they fuse and create a new allele combination c. This increases variation 3. Mutation a. Change in the base of our DNA, change in N (nitrogenous bases) b. This usually happens as a copying error, and T matches with G, for example c. 1 in 10,000 mistakes are let through d. This mistakes accumulate and changes your allele 4. Exposure to mutated a. Exposure to UV light, your phone, junk food, etc tires out your body, and eventually, your body lets mistakes go through. 5. Mistakes during meiosis a. They are random and deadly but if survived might give the zygote and eventually baby a syndrome such as Down syndrome. Asexual reproduction does not result in variation (mitosis). Threats & IUCN Threats to Biodiversity: Direct Threats Overharvesting and hunting ○ Atlantic Cod Poaching ○ Bile (bears) ○ Fin (whale) ○ Sport Illegal pet trade ○ Tiger ○ Baby primates Animals are hunted for: - Food medicines - Souvenirs - Fashion - To supply the exotic pet trade Hunting up to a certain level is unlikely to be a threat Overharvesting of populations can significantly deplete numbers ○ Linked to the tragedy of the commons Poaching is illegal capturing or hunting of wildlife ○ E.g: elephant tusk ivory Illegal pet trade usually involves baby primates and exotic birds. Indirect Threats Pollution ○ Pesticides Kills bees ○ Bleaching of corals by CO2 Invasive species ○ Cane toad ○ Carp ○ Cat ○ Mosquitos ○ Zebra mussels Habitat destruction ○ Urbanisation & Agriculture Threats to tropical biomes ○ Whiting corals Invasive Alien Species: Invasive alien species are those who are introduced into ecosystems where they compete with endemic (native) species. This can lead to the extinction of the endemic species. Lionfish: - Eats 15 species of fish which were supposed to eat algea - Produces 2 million eggs per year - Native to indio-pacific, moved to US waters - Because nobody is eating the algae it will take all the oxygen and outcompete the coral - Solution: subsidy and legalization for hunting lionfish, created an artificial competitor, and marketing to encourage lionfish Grey Squirrel: - Came from North America to England - Destroy native trees and outcompete native squirrels - Solution: Trapping and poisioning the squirrel Positives: Encouraging others to combat alien invasive species through an internet trend is a good method as it gets people to do something fun while helping the environment. For example, the trend of crushing Apple Snail eggs was trending due to how satisfying it was but at the same time it was helping the environment. Getting people to fight against alien invasive species through an economic benefit works well as people get to take part in the sport while earning money on the side. For example, the government pays subsidies to people who hunt Lionfish which increased the number of Lionfish being killed. Encouraging others to hunt and eat the alien invasive species through marketing is very effective as it provides a meal and helps the environment. For example, Lionfish were marketed as a delicacy and therefore the number of them being hunted and ate increased. Negative: Transporting invasive alien species is not effective as they will always try to head back to where they had the least amount of competition. For example, Lionfish were tried to be transported back to their native indo-pacific oceans but they ended up traveling back to US waters which just resulted in a waste of money. Key Biodiversity Areas (KBAs) Most ecological hotspots are: - Tropical forests and biomes - Coastal and close to the equator  - Located in developing countries - With high numbers of endemic (native) species The main threat for ecological hotspots in developed countries are invasive species. Biodiversity hotspots are under threat from habitat destruction, which could lead to a significant loss of biological diversity, especially in tropical biomes. Research indicates that animal populations have decreased rapidly by an average of 69 percent between 1970 and 2018. Biological hotspots: places that are under threat but have suffered no extended damage, no species are extinct or threatened. KBAs: Sites that contribute significantly to the global conservation of biodiversity in terrestrial, freshwater and marine environments. KBAs are identified using taxonomic and ecological criteria and thresholds: - presence of threatened species - presence of threatened ecosystems - geographically restricted species - ecological integrity where the site remains ecologically intact, essentially unaffected by industrial human influence - biological processes where the site holds a significant proportion of a species’ population during one or more of its life stages, such as nesting, making it important for the continued survival of that species - irreplaceability where the site has very high irreplaceability for the global persistence of biodiversity Indigenous people who live in rural areas do not have access to the legal system and therefore cannot fight back against environmental or social damage being caused to them by the firms or the government. Mass Extinction Eon = A unit of time Era = A unit of time. Shorter than an eon but longer than a period Period = A unit of time. Shorter than era but longer than epoch Epoch = A unit of time. Shorter than a period but longer than an age Evidence of Anthropocene: - signals from chemical pollution are currently accumulating in geological strata, with the potential to be preserved into the far future - mixing of native and non-native species, which will be represented in the fossil record - deposits from nuclear testing - modification of terrestrial and marine sedimentary systems - minerals created solely or primarily from human activity Evolution and Speciation: What is the theory of evolution? - The cumulative changes in the genetic composition of a species. - Happens over many successive generations. - These changes give rise to species that are completely different from their common ancestor. LUCA (Last Universal Common Ancestor): - The first cell on earth - The first cell formed in the vents at the button of the ocean around 4 billion years ago which after many evolutionary changes became a human. Evolution Requirements: For evolution you almost always need the following: 1. The species over-producing 2. Competition for limited resources a. The babies with the beneficial traits will more likely survive and reproduce causing that trait to be passed down while the not beneficial trait would die out. 3. Variation within the species due to mutation a. Mutation: change in DNA or chromosomes Natural Selection & Speciation: The loss of non beneficial traits and the passing on of beneficial traits E.g: in Turtles on 2 different islands, one type has a short neck because they can survive eating grass on the floor, and the other has a long neck because their food is high up. Speciation: The formation of a new species through evolution. Reproductive Isolation = Evidence of Speciation When the two “varieties” meet and allow to socialize in nature, we can confirm that they are different species if/when: - They are unable to mate due to “no match” - They can reproduce but the offsprings are infertile Endemism: - The properties of animal or plant species adapted to a particular local habitat. - An endemic species exists only in that environment. Artificial Selection: - Selective breeding - Carried out deliberately by humans - Has been used for thousands of years to modify species, plants and animals alike. - For plants, they were usually pollinated with big plants to increase the size which led to plants such as broccoli, brussel sprouts, and cauliflower. - This artificial selection provides humans with improved crops and livestock, larger and more efficient. - Artificial selection is done for desired features such as disease resistance, improved yield, and overall just aspects that benefit humans. Natural Selection Artificial Selection No humans interferences Human interferes in breeding Naturally allow individuals to allow in Traits desired by humans are chosen different environments and go on to and the individual with these traits are reproduce allowed to mate Beneficial traits allow adaptation for Traits are not necessary “fit” for survival adaptation in wild habitat but “preferred by human” 1. Outline the factors that contribute to total biodiversity of an ecosystem The factors that contribute to total biodiversity of an ecosystem are the richness and evenness in that ecosystem. 2. Distinguish between species diversity and species richness. Species richness is that the more species the better, having a lot of different species forms interdependence and increases the ecosystem’s resilience. Evenness is whether the species are balanced or not, whether an ecosystem is not dominated by one species but filled with an even amount of species. 3. Outline what high and low values of the Simpson reciprocal index indicate about an ecosystem. The higher the Simpson reciprocal index the more ecosystems are complex in terms of richness and evenness. A high Simpson index means that an ecosystem is safer while a low means that the ecosystem is at risk of reaching the critical threshold falling into a new equilibrium. 4. Explain how diversity indices can be used to measure the impact of human activities. 5. Discuss the usefulness of providing numerical values of species diversity to understanding the nature of biological communities and the conservation of biodiversity. 6. Describe the process of natural selection, and how it leads to the generation of new species. 7. Explain how the isolation of populations leads to speciation. Conservation Strategies Why is maintaining biodiversity important? (SUMMATIVE) Ethical ○ We need to save our environment ○ Biorights, justice for nonhumans Aesthetic ○ The beauty ○ Ecotourism Ecological ○ Natural capital (food, clothing, etc) Social ○ We want to maintain the biodiversity for the indigenous Economic ○ Ecotourism, medicine from nature, etc makes money The Two Organizations for Biodiversity IGO (e.g UNEP) NGO (e.g Greenpeace) Use of media Only communicates through the media Extensive use of media, gains coverage through it, runs campaigns online, etc Speed of response It is very slow, agreements need to be Very fast but it’s not binding, they profit off of made, legislation written but once done it current issues and trends is binding Political pressures Since this is a governmental organization, decisions are affected by politics Public image Diplomatic, have to be conservative with Can be confrontational and disliked by the their allocation public due to their methods Legislation Enforce decisions via law Serve as watchdogs, shining the light on issues happening around the world Agenda Always have annual conferences and Some have long term agendas some have agendas for the future development very short term agendas Funding Funded by governments Funded by some governmental projects but mostly donations and fundraising Extent of Can cover entire continents and maybe Some NGOs have large coverage but not in geographical even the globe some restricted areas such as Afghanistan influence Conservation strategies include the following approaches: (IMPORTANT) 1. Species-based conservation Ex Situ (removing from habitat): Species being conserved outside of natural habitat (such as zoo, botanical garden, etc) Captive breeding Focuses on specific vulnerable species (usually animals) For plants, it also includes seed banks In Situ (keeping in habitat): Species are conserved within their natural habitat (usually fenced in, protected in some way) Usually will indirectly conserve the entire habitat (habitat and ecosystem) Results in preservation of many other species Ex Situ examples: CITES: Aims to prevent trades of endangered plant and animal species ○ Varied degrees of protection ○ Uses Appendix system: Appendix I = illegal trade activities Appendix II = trade is permitted under strict control to permit the process Illegal trades will result in imprisonment, fines, and seizures. Zoos: Captive breeding and reintroduction programmes Zoos must provide the animals with certain freedoms. These include the freedom: ○ From thirst ○ From thermal and physical discomfort ○ From pain, injury, and disease ○ To express normal behaviours ○ From fear and distress In Situ examples: Flagship Species You select the most appealing species to appease the public to gain funding 2. Habitat-based conservation 3. Mixed conservation 3.3.1 Conservation Strategies 3.3.1 part 3, 4, and 5 3.3.2 all