Unit 3 Biodiversity SLIDESMANIA A World Rich in Biodiversity Biodiversity, short for Biological Diversity is: SLIDESMANIA � The variety of organisms in a given area � The genetic variation within a population � The variety of species in a community � The variety of communities in an SLIDESMANIA.C � A World Rich in Biodiversity � Certain areas of the planet, such as tropical rainforest, contain an extraordinary variety of species � Humans need to understand and preserve SLIDESMANIA SLIDESMANIA.C biodiversity for our own survival SLIDESMANIA The study of biodiversity starts with the unfinished task of cataloging all the species that exist on earth The number of species known to science is about 1.7 million, most of which are insects Actual number of species on Earth is unknown Scientists accept an estimate of greater than 10 million for the total number of species. SLIDESMANIA.C Unknown Diversity Unknown Diversity SLIDESMANIA SLIDESMANIA.C New species are considered known when they are collected and described scientifically Unknown species exist in remote wilderness, deep oceans, and even cities Some types of species are harder to study and receive less attention than large, familiar species Levels of Diversity SLIDESMANIA Biodiversity can be studied and described at three levels species diversity ecosystem diversity genetic diversity Species diversity refers to all the differences between populations of species, as well as between different species. Ecosystem diversity refers to the variety of habitats, communities, and ecological processes within and between ecosystems Levels of Diversity Genetic diversity refers to all the different genes contained within all members of a population A gene is a segment of DNA that is in a chromosome and that codes for a specific hereditary trait. SLIDESMANIA Benefits of Biodiversity SLIDESMANIA Biodiversity can affect the stability of ecosystems and the sustainability of populations We depend on healthy ecosystems to ensure a healthy biosphere that has balanced cycles of energy and nutrients Species are part of these cycles SLIDESMANIA SLIDESMANIA.C Species are Connected to Ecosystems � � SLIDESMANIA � When scientists study any species closely, they find that it plays an important role in an ecosystem Every species is probably either dependent on or depended upon by at least one other species in ways that are not always obvious When one species disappears from an ecosystem, a strong in a food web is � � Some species are clearly critical to the functioning of an ecosystem A keystone species is a species that is critical to the functioning of the ecosystem in which it lives because it affects the survival and abundance of many other species in its community. SLIDESMANIA ○ Example: sea otter, wolves of Yellowstone SLIDESMANIA.C Keystone Species: Help determine what kind of other species and how many other species live in a community, thereby shaping the entire community SLIDESMANIA Keystone Species in Georgia - Oysters � Oysters - enhancing water quality by filtering up to 1.5 gallons of water per hour � Oyster reefs stabilize shorelines, protecting them from the erosive forces of tidal currents, winddriven waves, and boat wakes � Reefs provide habitat for birds, mammals, crustaceans, and fish. SLIDESMANIA and… Gopher tortoise SLIDESMANIA � Gopher tortoise, designated Georgia's State Reptile in 1989 – the only native tortoise in the entire southeast � build burrows to lay their eggs and hide from predators; some going 45 feet deep � Over 360 other animals are known to use these burrows, alongside or after the tortoise abandons it � species known to use burrows are foxes, frogs, snakes, armadillos, burrowing owls Indicator Species � A species or group of species chosen as an indicator of, or proxy for, the state of an ecosystem or of a certain process within that ecosystem. ○ Examples include crayfish as indicators of freshwater quality; SLIDESMANIA ● peregrine falcons as an indicator of pesticide loads; ○ or native plants as indicators for the SLIDESMANIA.C ○ corals as indicators of marine processes such as siltation, seawater rise and sea temperature fluctuation; Indicator species in Georgia � Blind salamander � salamander’s habitat is aquifers. ○ It lives in the groundwater we rely on for drinking. SLIDESMANIA ○ Declines or disappearances of blind salamanders � River Otter � the otter is a carnivore contaminants that occur in the environment may concentrate in the otter over time in a process known as biomagnification. Native Species � native plants are those that are "naturally occurring, either presently or historically, in any ecosystem of the United States � Others define native species as: ○ Native species are species that have been established in the food web in a specific habitat/biome for a long period of time. SLIDESMANIA ○ those that grow naturally in a particular region without direct or indirect human intervention ○ plants that were present in a particular area prior to European settlement of that area Before the development of the nursery industry, native plants were the only choice for landscape plantings. Early settlers transplanted dogwood, redbud, oakleaf hydrangea and other plants with appealing qualities from the woods into their landscapes. Harvesting native plants from the wild for landscape purposes is illegal in some areas. SLIDESMANIA SLIDESMANIA.C Plants Native to Georgia Black-eyed Susan Dogwood Tree Oakleaf Hydrangea SLIDESMANIA Redbud Animals Native to Georgia � Another term used to define “native” species is the term “endemic” to Georgia � Examples of animals that are native to Georgia are � black bear, fox squirrel, flying squirrel, various bat species, mink, West Indian manatee, woodchuck, white-tailed deer, � bottlenose dolphin, muskrats, beavers, otters, squirrels, rabbits, and raccoons, � many reptiles like alligators, rattlesnakes, snapping turtles and eastern king � over 200 species of birds SLIDESMANIA � A species that is from another SLIDESMANIA ecosystem and does not have an established niche in the new ecosystem. � This species takes over the role of an organism in the native ecosystem. � Harmful to the ecosystem. � Invasive species typically reproduce quickly, have few/no predators, Invasive Species These species are called "generalists“ (can eat a variety of foods and thrive in a range of habitats). Invasive species in Georgia English Ivy Joro Spider Gypsy Moth Kudzu Golden Bamboo SLIDESMANIA Endangered Species � a species of animal or plant that is seriously at risk of extinction. � Threatened - any species that is likely to become an endangered species within the foreseeable future � Examples: ○ Sea Turtle SLIDESMANIA ○ Smooth coneflower ■ Green pitcher plant SLIDESMANIA.C ○ Salamander Why are these Georgia Species Endangered? Smooth coneflower Green pitcher plant SLIDESMANIA � Plant collecting, fire suppression, residential & industrial development, highway construction and improvement, and certain types of roadside and powerline right-of- � Collection for commercial sale; fire suppression; and increased residential, agricultural, and silvicultural development Leatherback Sea Turtle � Incidental capture in fishing gear (bycatch), � Hunting of turtles, � Collection of eggs for human consumption SLIDESMANIA Blind Salamander � Habitat loss � Invasive species like pigs are a growing threat to many species, � Global declines in insect abundance may also be greatly affecting them � Water pollution Species and Population Survival The level of genetic diversity within SLIDESMANIA populations is a critical factor in species survival Genetic variation increases the changes that some members of the population may survive environmental pressures or changes Small and isolated populations are less likely to survive such pressures Species and Population WhenSurvival a population shrinks, its genetic SLIDESMANIA diversity decreases as though it is passing through a bottleneck Even if such a population is able to increase again, there will be inbreeding within a smaller variety of genes The members of the population may then become more likely to inherit genetic diseases Taxonomic � With the large diversity of living organisms, Naming a system was devised to organize them based on their interrelatedness Domain Kingdom Phylum Class Order Family Genus Species SLIDESMANIA Photo by Dimitry B on Unsplash Human Classification Taxon Reason Domain Eukarya Cells have nuclei and organelles (eukaryote). Kingdom Animalia Multicellular. Unable to produce own food (heterotrophic). Phylum Chordata Have a nerve cord along the back. Class Mammalia Warm-blooded, gives birth to live young, has hair. Order Primates Forward-facing eyes, enlarged brains, vertical posture. Family Hominidae Capacity for language, culture, empathy. SLIDESMANIA o The final two taxa, genus and species, are used to define the species’ scientific name. o Homo sapiens o Italicized or underlined o Genus capitalized, species lower case • The scientific naming system is important, as many species have multiple common names. Use binomial nomenclature to identify organisms • Cougar, catamount, painter, panther, ghost cat, puma, shadow cat, mountain lion, deer tiger, devil cat, sneak cat, plain lion, fire cat, mountain screamer, Florida panther, silver lion… SLIDESMANIA SLIDESMANIA.C • The cougar holds the Guinness world record for number of common names, with 40 in English alone! • Two animals with many classification levels in common are considered very closely related – they diverged recently. • Wolves and dogs share the same domain, kingdom, phylum, class, order and family. Canis familiaris Domesticated dog SLIDESMANIA Canis lupus lupus European Wolf SLIDESMANIA o Habitat – Particular type of environment where an organism can survive o Habitats have a range of factors that influence the community that lives there – temperature, precipitation, etc. o Critical factor: factor that plays the greatest role in determining the range of an organism’s habitat. o Critical factors have a “Goldilocks Effect”, meaning there can be too much or too little of it SLIDESMANIA.C Who Lives Where? o Optimal range – When the right level of an environmental factor is present, population levels will be growing or at their peak. o At the zone of physiologic stress, levels of the factor are too high or too low. The population barely survives. o At the zone of intolerance, the population dies out. SLIDESMANIA Adaptations The range of tolerance for a species is largely defined by the presence of adaptations. Adaptation: adjustment or changes in behavior, physiology, and structure of an organism to become more likely to survive in a particular environment. SLIDESMANIA Physical adaptations are structural differences in coloration, body shape, musculature, etc. Adaptations Behavioral adaptations: adaptations that involve behavior Examples: Bower Birds build “fancy” nests to attract mates Some birds dance to attract mates Many animals migrate to find food or shelter Moonwalking bird SLIDESMANIA Adaptations Physiologic adaptations: includes an organism’s body’s response to stimulus Examples: Sweating too cool down Leaves changing colors in Autumn Pupils dilating in response to light SLIDESMANIA Evolution � Evolution – a change in the characteristics of a population from one generation to the next generation � Two Mechanisms that may lead to the evolution of a population � Natural Selection � Artificial Selection Natural Selection: the environment or “nature” selects which traits are successful and will be passed on to the next generation Organisms possessing unsuccessful traits do not survive to pass traits to offspring SLIDESMANIA Coevolution Coevolution: when organisms that live in close relationships influence each other’s evolution Example: Ants and Acacia Trees in Africa SLIDESMANIA Behavior of ants encouraged Acacia Trees to develop certain traits Ants protect the trees from herbivores and disease Trees with the following traits favoring the ants are healthier and more likely to survive Thorns with large hollow base Sweet nectar Tree characteristics encourage ants’ to continue living and feeding on the trees It is believed thatAnts this exchange Protect Acacia Tree led to development of special characteristics Artificial Selection humans for characteristics desirable to them. * Humans select the traits that are passed on to the next generation SLIDESMANIA.C • The selective breeding of organisms by SLIDESMANIA SLIDESMANIA.C SLIDESMANIA Population Growth Patterns o As their ecosystem and community change, populations of organisms undergo different growth patterns. o The most common growth pattern is called logistic growth, which takes the shape of an “S” o Logistic growth starts off fast, but gradually slows down as the population encounters environmental resistance. o Environmental resistance can come in two forms: o Density-dependent factors, such as disease, or competition for resources which affect dense populations more SLIDESMANIA o Density-independent factors such as natural disaster or climate change, which similarly affect o The growth-limiting factors will cause the population’s growth to slow and eventually stabilize. o The point at which a population size stabilizes is the carrying capacity, or the maximum population size that can be sustained by the ecosystem o Exponential Population Growth: when a population has a constant growth rate and is not limited by resources, or diseases. SLIDESMANIA o Exponential growth, which takes the shape of a “J”, does not experience growth-limiting factors. o The population will continue to grow, eventually exceeding the carrying capacity. is called an overshoot o WhenoaThis population overshoots the carrying capacity, it experiences a dieback, where the population falls back to carrying capacity SLIDESMANIA o Exponential growth is unusual, and does not typically occur under normal circumstances Community Interactions SLIDESMANIA One of the most basic interactions is predator-prey, where one organism hunts and consumes the other SLIDESMANIA.C How quickly populations grow and the maximum size they attain are often the result of interactions with other populations of organisms o Competition, where organisms and populations compete for resources, is another common interaction. o Water, food, territory, mates. o When the competition occurs within members of the same species, it is called intraspecific. o When the competition occurs between different species, it is called interspecific. SLIDESMANIA Symbiosis � Symbiosis: close interaction between two or more different organisms � The closest relationships of all are symbiosis. These involve a lot of close contact between two species. ○ When the relationship benefits both organisms, it is called mutualism. (sea anemone and clownfish) ○ When one organism benefits while the other is unaffected, it is called commensalism. (bison and cowbirds, whale and barnacles) SLIDESMANIA ○ When one organism benefits while the other is harmed, it is called parasitism. (flea on a dog, tick on an animal Threats to Biodiversity H P I O P Pollution Overexploitation Habitat Loss Invasive Species Population growth (human) SLIDESMANIA Biodiversity = the number and variety of organisms in an area (remember!!!) We can describe the major threats to biodiversity using the acronym H.I.P.P.O. Habitat Loss SLIDESMANIA Main causes of habitat loss: Deforestation Agriculture Land development Roads, subdivisions, shopping malls… Water development: Building dams Invasive species = organisms that are not native to an ecosystem and whose introduction causes or is likely to cause harm *Problems with invasive species *No natural population controls, such as predators or competition *Populations grow rapidly and can outcompete native populations for resources SLIDESMANIA.C Invasive Species SLIDESMANIA Kudzu SLIDESMANIA.C Invasive Species around home SLIDESMANIA Pollution Pollution = an undesirable change in the natural environment that is caused by the introduction of substances that are harmful to living organisms ○ Pollution can cause imbalances of environmental factors that can end up being deadly for many organisms � Problems from pollution ○ Acid Rain ■ Changes the natural pH of the environment SLIDESMANIA ● Eutrophication ○ Causes ‘dead zones’ in aquatic environments Since 1800’s the human population has been growing exponentially This increases the demand for resources which increases the disruption of ecosystems SLIDESMANIA.C Population Growth (Human) SLIDESMANIA Overharvesting Overexploitation = to excessively catch, collect, or hunt something to the point in which the population is too low to sustain itself in the wild ■ SLIDESMANIA Examples: Overfishing, Overhunting, Overharvesting
