Ecology Notes Part 1. Abiotic NONliving components in an ecosystem. Ecosystem

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1 Ecology Notes Part 1 Ecology the study of the relationship between organisms and their environment Ecosystem an organism s surroundings consisting of both living and nonliving things and how that organism interacts with it all Abiotic NONliving components in an ecosystem Natural Disasters Floods Fires Tornados Rocks, Soil Water Atmosphere gases Weather Precipitation Wind sun 1

2 4/11/14 Biotic living factors in an ecosystem Habitat an organism s specific location where they reside within the environment Other organisms such as: Animals Plants Decomposers Fungi Protist Bacteria Organism s Niche specific way of living for each organism A niche includes where they live, diet (prey), defense mechanism (how protect from predators), reproduction, etc Each organism has unique niche but can overlap with other niches. 2

3 Different Niches Different environments Different habitats Different mating Different diets Different defenses All result in species becoming DIFFERENT! Community all interacting organisms (in differing species) in an environment Population # of organisms of the SAME species, living within a certain area at a particular time. Populations grow when birth rate exceeds the death rate. Populations can t grow forever. Limiting Factors anything that keeps a population from growing indefinitely/forever 3

4 Organisms produce more offspring than can survive which creates competition. What would be a Limiting Factor for these baby birds? Limiting Factors Shelter, Resources, Mating (reproduction), Territory (dominance) Graphing a population over time will produce S shape (sigmoid curve) Why do you think this happens? Carrying Capacity The maximum number a population can hold successfully. Limiting factors set this limit Each population has their own unique carrying capacity based on what the ecosystem can hold. 4

5 Graph won t always be perfect. Why? Competition Species Interactions the use of the same limited resource by two or more organisms/species Scarcity (not enough) of resources (abiotic or biotic) will result in organisms competing. If the niches of two organisms overlap Predator/Prey relationship (competitive relationship) Predator captures, kills, and eats the prey Regulators of population size Survival depends on ability to capture food Spider web, sharp teeth, quickness, camouflage Prey Survival depends on ability to avoid being captured and eaten 5

6 90 Hares and Lynx Populations Hares (x1000) Lynx(x1000) 80 Number of pelts in thousands Year Ecology Notes Part 2 Species Interactions Symbiosis Cooperative relationship Close interactions between organisms Symbiotic relationship Endosymbiosis Ectosymbiosis Symbiosis 6

7 Both species benefit Mutualism** Pollinators and the plants they pollinate The birds and mammals eat the fruit or berries they spread the seeds for the plants. Parasitism** One organism benefits, one is harmed Endoparasites - (inside) Parasite feed on the host, may not kill the host right away Wasps Ectoparasites (outside) 7

8 Commensalism** One species benefits while the other species is not affected Cucumber & Pearlfish Boxing crab and anemones Whales and barnacles barnacles get a ride and protection Symbiotic Relationships** MUTUALISM + / + PARASITISM + / - COMMENSALISM + / EVOLUTION** The change of inheritable characteristics in populations through successive generations. Change over LONG periods of time Evidence of Evolution** Structures of Organisms DNA Sequences Fossils Bones, imprints 8

9 Comparative Anatomy The study of similar structures in different organisms Homologous Structures** similar structure Shared common ancestor Comparative Anatomy Vestigial Structures** organs or parts that appear to have no known function Tail Bone and Appendix in humans Leg bones in python Comparative DNA** DNA à RNA à PROTEIN the more similar the proteins-amino acids, then the more closely related 9

10 Charles Darwin Believed organism with superior traits will live and pass those traits on to their offspring while the others die out. Giraffes with long necks out-reproduced the short necks. Short necks slowly become extinct. Darwin s Finches Each species of finch lives on a different island which have different environments. Certain beaks are an advantage - based on the food on that island. NATURAL SELECTION ** Charles Darwin Survival of the fittest All organisms want is to survive & reproduce so they can pass on their better traits. Natural Selection Made Easy 10

11 Adaptations** Inherited trait that improves the chances of survival and reproduction of an organism in their environment. main.org/asset/ lsps07_int_nowh erehide/ Defense Mechanisms** Camouflage 11

12 Defense Mechanisms** Mimicry Organisms will acquire similar characteristics to other species to help protect themselves Defense Mechanisms** Poison Ivy Poisonous Snakes Saying -- If red touches yellow, you re a dead fellow. If red touches black, you re okay, Jack! Thorns 12