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1Presented by Sarah Piccorelli Evolution & Natural Selection AND The Six Kingdoms of Life & Biological CommunitiesPresented by Sarah Piccorelli
2Evolution Evolution is a process. Here are some things you might need to know about evolution…Evolution is a process.Dictionary definition: growth to maturity and development of an individual living thingSpecies are thought to have descended from earlier species.
3Natural SelectionNow that you have some background knowledge on evolution, we’ll move our focus to natural selection…From one generation to the next, inherited traits that enabled species to survive in a given environment were preserved. Unfavorable traits were eliminated.Charles Darwin is an important name to remember when you think of natural selection.
4Results of Natural Selection But… What does that really mean??From generation to generation, as the world around you changes, you change with it. In turn, you, as a class (or group of similar species living together), survive longer.Adaptation: evolutionary modification of an individual that improves that individual’s chances of survival and reproductive success in its environment…
5Charles Darwin & Natural Selection The environment plays a crucial role in Darwin’s theory.He proposed the idea of evolution by natural selection back in the 19th century and it’s still accepted today.His theory of evolution by natural selection consists of four observations about the natural world.
6Four Observations About the Natural World You might want to take notes if you haven’t already started doing so…(hint. hint.)High reproductive capacityHeritable variationLimits on population growth, or a struggle for existenceDifferential reproductive success
7High Reproductive Capacity & Heritable Variation Each species will produce more offspring than will reach maturity.Natural populations have the reproductive potential to increase their numbers continuously over time.The individuals in a population exhibit variation.Each individual has a unique combination of traits, such as size, color, and ability to tolerate harsh environments.
8Struggle for Existence & Differential Reproductive Success Only so much food, water, light, and growing space are available to a population, and organisms compete with one another for the limited resources available to them.Not all of the offspring will survive to reproductive age because there are more individuals than the environment can supportMore factors of limited population growth? Predators and diseases.The individuals that possess the most favorable combination of characteristics are most likely to survive, reproduce, and pass their traits to the next generation.Reproduction is the key to natural selection, in that the best adapted individuals reproduce most successfully.New species are created when enough changes accumulate within geographically separated populations.
9Kingdoms of LifeArchaea – they live in oxygen-deficient enviornments and are adapted to harsh conditionsBacteria – the thousands of remaining kinds of prokaryotesEukarya – classified as eukaryotes, organisms with eukaryotic cells
10The Six KingdomsAnimaliaPlantaeFungiProtistaArchaeaBacteria
11Biological Communities Vast assemblages of organisms are classified into communities.Community means an association of different populations of organisms that live and interact in the same place at the same time.Many organisms in a community are interdependent.
12InterdependencySpecies compete with one another for food, water, living space, and other resources.Some organisms kill and eat other organisms.Some species form intimate associations with one another, whereas other species seem only distantly connected.
13More About Communities… In a community you’re either a producer, a consumer, or a decomposer.Communities vary greatly in size, lack precise boundaries, and are rarely completely isolated.They interact with and influence other communities around them, even if how they do so isn’t always apparent right away.(example: A forest is a community, but so is a rotting log in that same forest.)
14Continued…Organisms exist in an abiotic (nonliving) environment that is as essential to their existence as is their biotic (living) environment.A biological community and its abiotic environment comprise an ecosystem.
15Summary Result of natural selection: adaptation Your notes should look like:Evolution: Species are thought to have descended from earlier species.Natural Selection: From one generation to the next, inherited traits that enabled species to survive in a given environment were preserved. Unfavorable traits were eliminated.Result of natural selection: adaptationSix Kingdoms : Animalia, plantae, fungi, protista, archaea, and bacteriaCommunity is a an association of different populations of organisms that live and interact in the same place at the same time.Many organisms in a community are interdependent.
16Community Interactions in an Oak Forest & Ecological Niches Matt Maruzzi
17Community Interactions in an Oak Forest Relationship between acorns, mice, deer, gypsy moths, and ticks“Bumper” crop of acorns occur every 3-4 yearsBumper crop- Particularly productive harvest yielded for a particular crop
18Bumper crop of acorns allows the white- footed mouse population to thrive Mice also feed on gypsy moth pupae, which causes the trees in the forest to be healthier.Healthier trees attract more deerMore deer and mice causes there to be more ticksTicks result in an increase in Lyme disease
20The Ecological NicheEcological Niche- Organism’s role in the ecosystemOrganisms in an ecosystem are believed to have an ecological nicheEcological niche of an organism may be bigger than it actually isFundamental niche- Potential/ idealized ecological niche of an organismRealized niche- Lifestyle the organism actually pursues and resources it actually uses
21Green & Brown Anoles Green anole native to Florida Brown anoles introduced to Florida from Cuba outcompete green anolesGreen anole’s niche is restrictedBrown anole’s niche is increased
22Competition All organisms interact with one another! Three Main Types of Interactions:-Symbiosis-Predation-Competition
23Competition occurs when two or more individuals attempt to use essential common resources such as food, water, shelter living space or sunlightCompetition occurs amongst individuals:-within a certain population Intraspecific competition-between spaces Interspecific competition
24Competition is not always straightforward, direct interaction!Flowering plants that live in pine forests may compete with conifers for soil nutrients and moisture.Flowers supply nectar as a source of food for insects.The reduced number of needle easting insects means less impact on the conifersVs.Some of these insects also prey on needle eating insects
25Competitive Exclusion Similar species have fundamental niches that overlap.Competitive Exclusion- the notion that no two species can indefinitely occupy the same ecological niche.Interspecific competition eventually excludes one of two species from its environmental niche.Species can compete for necessary resources without aggressive interactions, but two species of absolutely identical niches cannot coexist.Coexistence between species like this is only possible if the overlap is reduced.
26Russian Biologist G. F. Gause conducted several experiments in which he concluded that certain conditions favored certain species. Either way, of two similar species in a mixed culture, one will eventually triumph over the other in a mixed environment.Both P. aurelia and P.caudatum populations develop and thrive at a certain point in their own single-species environment.Gause studied the interactions between two different species of the unicellular protist, Paramecium.
27When both species are grown in a mixed environment, the P When both species are grown in a mixed environment, the P. aurelia pushes the the P.caudatum to extinction, proving the concept of competitive exclusion.
28Resource Partitioning Because competition depletes limited resources and can cause extinction of some species, natural selection favors those species that avoid or reduce competition.Resource Partitioning- the reduction in competition for environmental resources that occurs among coexisting species as a result of each species’ niche differing from those of other in one or more waysIn Central and South American rainforests, fruit-eating species such as birds, primates, and bats have overlapping niches. They collectively avoid competition through resource partitioning. Examples include: timing of feeding, nest sites, location of feeding etc.
29SymbiosisSymbiosis is a close relationship between two different species.Each member of the symbiosis process is called a symbiont.In symbiosis each symbiont may or may not benefit from the relationship.Consists of Commesalism, Paratism, and Mutalism.
30CoevolutionCoevolution is the interdependent evolution of two interacting species.Symbiosis is the result of coevolution.An example of coevolutionary symbiosis is flowering a plant then have insects and other types of pollinators spread the existence of the plant.
31MutualismMutualism is a symbiotic relationship in which both species are benefitted.This is the most common example of symbiosis.An example of mutalism is when a flower is planted and pollinator comes along to feed off the pollen. The pollinator gets a source of food and the plant is spread through the process.
32Flowers in Symbiosis Flowers are a big part in Symbiosis. Flowering plants has actually evolved to attract pollinators which creates symbiosis.This helps to increase symbiosis and benefits both the pollinators and the plant.
33Mycorrhizae!!!!!Mycorrhizae (fungi), shows the mutualistic relationship between the roots of plants and fungi.Mycorrhizae is a popular example of mutualism.The fungi absorbs essential nutrients and minerals and provides them to the plant. In return the plant provides it with food made through photosynthesis.
35Commensalisms and Parasitism What is commensalisms?What is parasitism?By: Kimberly HolsborgAPES per.3/435
36CommensalismCommensalism: An association between two different species in which one benefits and the other is unaffected.In ecology, commensalism is a class of relationship between two organisms where one organism benefits without affecting the other.
37CommensalismExample:The relationship between two kinds of insects: silverfish and army ants.Silverfish tend to move along in permanent association with marching columns of army ants and share there surplus of food with their raids. The army ants derive no benefit or harm from the silverfish.
38An example of commensalism: cattle egrets foraging in fields among cattle or other livestock. As cattle, horses and other livestock graze on the field, they cause movements that stir up various insects. As the insects are stirred up, the cattle egrets following the livestock catch and feed upon them. The egrets benefit from this relationship because the livestock have helped them find their meals, while the livestock are typically unaffected by it.
39Commensalism Example: The relationship between a tropical tree and many epiphytes:(Epiphytes- smaller plants including mosses, orchids, bromeliads, and ferns that live attached to the bark of trees.)
40The epiphytes anchors itself to the tree but does not obtain nutrients or water directly from the tree. Its location on the tree allows it to obtain an adequate amount of light, water (from rainfall), and required nutrients and minerals (washed out of trees from rainfall). As a result, the epiphytes benefits from the association, leaving the tree unaffected.
41Other examples:The most common example is the clownfish and the sea anemone. The clownfish shelters among the tentacles of the sea anemone, and the sea anemone is not affected.
42Continued…. Barnacles: - live on whales and get to be transported to different areas of the ocean to feed. The whales are not affected.-Barnacles are highly sedentary crustaceans that must attach themselves permanently to a hard substrate, such as the shells of mollusks or whales or anything else on which they can gain a foothold. When they attach to the shell of a scallop, for instance, barnacles benefit by having a place to stay, leaving the scallop presumably unaffected.
43A titan triggerfish creates feeding opportunities for smaller fish by moving large rocks too big for them to shift themselves.This shows the symbiotic relationship commensalism, the bird gets food from the back of the cow but the cow is not affected
44What is Parasitism?A symbiotic relationship in which one organism benefits and the other is adversely affected.
45Facts about Parasitism In parasitism one organism, the parasite obtains nourishment from another organism, the host.Rarely will a parasite kill its host, but it may weaken the host.Parasite can live outside the host, on their body or within the host.Parasitism is a successful lifestyle, for the parasite… More than 100 parasites can be found living in or on the human species.
46Other interesting Facts Many parasites do not cause disease, but…When a parasite does cause disease or sometimes death to their host its knows as a pathogen.Unlike predators, parasites increase their fitness by exploiting hosts for resources necessary for their survival, e.g. food, water, heat, habitat, and transmission.
47Parasites are classified based on their interactions with their hosts… Parasites that live on the surface of the host are called ectoparasites:Examples: mites, ticks, head lice, mosquitoesThis shows parasitism. The tick gets the blood it needs to survive, but the dog is harmed by the tick transmitting disease into its blood.
48Those that live inside the host are called Endoparasites which include: parasitic worms: tape worms, flatworms, flukesbacterium: crown gall disease (enters through wounds)Most humans become infected with the beef tapeworm by eating undercooked beef infested with tapeworms.The tapeworm attaches to the wall of intestines where it rapidly grows by absorbing nutrients. (no symptoms, other then weight loss)
49The mosquito takes blood from human and may inject disease which may harm the human. The mosquito gets food, but the human may become sick. (Malaria) Shistosoma mansoni endoparasite that lives in human blood vessels.
50Mistletoe PlantsMistletoe plants grow on a wide range of host trees, and commonly reduce their growth but can kill them with heavy infestation.
51Crown Gall DiseaseThe bacterium is parasitic: It infects its plant host by entering through an open wound, inserts a small segment of its genetic code into the plant's genome, devours energy made by the plant, and forms knobby brown lesions on the plant stem.
52Lets play a game ! What did you learn? Any questions?
63Plant Defenses Adaptation's that help protect them from being eaten SpinesThornsTough, leathery leavesThick wax on leavesThese discourage animals from grazing
64Plant DefensesProduces protective chemicals that are inedible even toxic to herbivoresIngredients can be:Marijuana, Opium poppy, tobacco, peyote cactusFor example: Nicotinefound in tobacco is sotoxic to insects, that it isused in some commercialInsecticides.
65Milkweeds Produce alkaloids and cardiac glycosides Poisonous to all animals except a small group of insects.Predators also learned avoid these insects
66Defensive adaptations of Animals Underground burrowsWoodchucks, WoodpeckersMechanical DefensesQuills of porcupine, Shell of a turtleAnimals Living in GroupsHoneybees, PigeonsWarning colorationPoison arrow frog, Striped skunkCryptic Coloration (camouflaged)Caterpillars, blend in with twigsSeahorse blend in with coral
70Does the Extinction of species threaten the normal functioning and stability of ecosystems? By Amanda Denizard
71Species richness, Ecosystem services, and community stability Ecologists and conservationists have been debating whether the extinction of species threatens the everyday functions and stability of ecosystems.Ecosystems supply human societies with tons of environmental benefitsEcosystems with a larger amount of species richness have a higher quality of ecosystem services than ones with lower species richness
72(this includes clean air, water, and fertile soil) Ecosystem service: Important environmental benefits that ecosystems provide to humans.(this includes clean air, water, and fertile soil)Some ecosystems that are more commonly known are forests, grassland and fresh water systems.
73Community stability: the absence of change. Community stability is the the result of resistance and resilience.Resistance: the ability of a community to withstand environmental disturbances, natural or human.Resilience: The ability of a community to recover quickly to its former state following the disturbance.
74Lake Victoria: the worlds Second largest freshwater lake In East Africa.Home to about 400 different speices of cichlids(sik’ lids), small colorful fishes.These fishes thrive throughout the lake ecosystem on algae and provide protein to the diets of 30 million humans living in the area.
75Compared to 50 years ago more than half of the cichlids and other native fishes are extinct today. As a result, the the algal population increased rapidly. When the algae die their decomposition uses up the dissolved oxygen in the water.
76A major contributor to the destruction of Lake Victoria is the Nile Perch. Human Caused factors are also to blame for the disappearance of the cichlids.(pollution, overfishing, sediment pollution, ect .)Biologists are currently trying to find a fishing level that will be sustainable but also maintain speices richness of native species.
78Community Development A community develops gradually, through a sequence of species.Succession: process of community development over time, usually described in terms of the changes in species composition of the plants growing in an areaClimax community: stable and persistent communityMature climax community are not in a state of permanent stability but rather a state of continual disturbance, as a community changes in species composition and abundance while appearing to stay uniform
79Primary SuccessionEcological succession that begins in an environment that has not been previously inhabited.Pioneer community: the initial community that develops during primary succession (ex. Lichens)Lichens → mosses → grasses → shrubs → trees
80Primary Succession on Sand Dunes Henry Cowles developed the concept of succession in the 1880s.He studied succession on sand dunes around the shores of Lake Michigan.The shrinking lake exposed new sand dunes that displayed a series of stages in the colonization of land.grasses → shrubs → poplars → pine trees → oak trees
81Secondary SuccessionEcological succession that takes place after some disturbance destroys the existing vegetarians; soil is already presentDuring summer 1998, wildfires burned about 1/3 of Yellowstone National Park, and this natural disaster provided a chance for biologists to study secondary succession.Less than a year later, trout lily and other herbs covered the ground, and ten years after the fires, a young forest dominated the area.
82Old Field SuccessionBiologist have studied secondary succession on abandoned farmland extensively.The first year after cultivation stops, crabgrass dominates the field.The second year, horseweed is the dominant species.During the third year, other weeds (broomsedge, ragweed, aster) establish themselves.In 5 to 15 years, the dominant plants are pines, and throughout the next century or so, depending on the environmental changes produced by these plants, pines give way to hardwoods such as oaks.