ecosytems and biolgical diveristy

• Boitic factors are factors that infulence an organsims behavouir and its interaction with the environment and they inculde the living factors for example temperature, light, pH, oxygen, nutrients
• Abiotic factors are non-living factors such as water, air, soil, climate etc.
• An ecosystem is all the living things (organism) in a particular area interacting with each other and their physical surroundings
• The range of differnt inhertianl triats with species is called gentic diversity
• Biodiversity is the variety of life on earth at every level from genes to entire habitats
• a community is a group of organisms that live in the same area and interact with each other of the same species
• An adapation is a charactisc that an organism has inherited and that makes suited survive in its envoriment
• Niche is the role played by a species within it's environment
• Natural selection comes into play when organsims in an envoriment are subjected to selection pressuares
• A habitat is where an organism lives, feeds and breeds
• interspecfic competion is competion betwen different organsims for the same sourced of food
• intraspecific competition is competition between individuals of the same species for limited resources
• Predator- prey relations are communisam, mutalism, and parasitism
• Parasitism is one partner benefits at the expense of another
• Commensalism is one partner benefits but not harmed by the other
• competion exculasion princple is when two organsims compete for a niche at the same time but the less favoured loses
• The less favoured species leaves to find a new niche or they share the resources, this is called resource partiting
• • Physicalgoical adapatdtions refer to fundamnetal changes in an organsims internal procces or systems that enhance its ability to survive and reproduce in an particular envoriment.
• behavioural adaptations are actions taken by organisms to increase their chances of survival and reproduction
• structural adapations are the physical features of an organism that help it to survive in its environment for example e.g. a penguin has blubber to protect itself from freezing temperatures
• evoulation is the change in aliving organsim over a long peroid of time
• natural selection is the process by which individuals with advantageous traits have higher chance of surviving and passing on those genes to offspring
• "survival of the fittest" refers to the least suited species to die out or reproduce less frequently. Better suited species reprdouce more frequently and unfaourfable genes are removed
• Charles darwin and alferd wallace were the first to propose the theory of evolution by natural selection
• theory of evolution states that all living things share common ancestry, they evolved through descent with modification
• While darwin was travelling on the voyage he collected thousands of specicmans inculding geoolgical and fossil evidance, he also studied the behaviour of animals
• darwin's finch experiment showed how birds with longer beaks could crack seeds easier than birds with shorter beaks
• Darwins finches had different beak sizes and shapes depending on their diet
• The theroy of evoulation by natural selction states that more are born survive and of those that ar born there is varation
• Darwin put his theory of evoulation foward in 1859
• Variations must be heritable so it can pass down to future generations
• The process of evolution by natural selection is known as Darwinian Evolution
• heritability - some variations are passed onto offspring, others aren't
• Organisms best suited to the selection pressuares will tend to be more abudant because they have a better chance of survival
• effects of selection presuuare

  changes in pouplation sizes may effect other species living in the ecosystem too for example the poluation of preys will decarse if the predator becomes more abundant and icreases if the predator becomes more abudant
• Selection pressuers makes some charactistic favouarble and others unfavourable, driving the evoulation of the species towards the favourable characteristic and may inculde how the organism looks, moves, and behaves
• changes in boitic factors or abotic factors can be advantegous or unfavourable for an organsim therfore changes create selection pressuares
• populaton size is the number of organisms of the same species in an ecosystem
• population distrubation is where a species is spread throught an envoriment
• Boitic selction pressuares on cane toads:

  very few native predators in austriala has acted as a favourable selction pressuare for the cane toad allowing it to avoid consumpation, survive to reproduce, and icrease population size

  Few Austrialn disesase can kill cane toads allowiong them to avoid contarcting disease and again survive to repordouce and increasing their poulation size