Ecology! the study of the relationship between organisms and their environment

Ecology Notes

Ecology! the study of the relationship between organisms and their environment

An ecosystem is an organism s surroundings consisting of both living and nonliving things.

Abiotic NONliving components in an ecosystem u Natural Disasters u Floods u Fires u Tornados u Rocks, Soil u Water u Atmosphere u Gases u Weather u Precipitation u Wind u Sun

Biotic LIVING factors in an ecosystem u Other organisms such as: u Animals u Plants u Decomposers u Fungi u Protist u Bacteria

Habitat an organism s specific location where they reside within the environment

specific way of living for each organism A niche includes habitat diet defense mechanisms reproduction etc. Organism s Niche Each organism has unique niche but can overlap with other organism s niches.

Different Niches Different environments Different habitats Different mating Different diets Different defenses All result in species becoming DIFFERENT!

Community all interacting organisms in an environment

Populations Number of organisms of the SAME species, living within a certain area at a particular time. Populations grow when birth rate exceeds the death rate.

Limiting Factors anything that keeps a population from growing indefinitely/forever

What would be a Limiting Factor for these baby birds?

Examples of Limiting Factors: Food Water Available Space Predators Disease Air

Population Growth Curve Graph is S shaped

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.

Graph won t always be perfect. Why?

Species Interactions Competition 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

https:// youtu.be/ ZWucOrSOdCs

90 Hares and Lynx Populations Hares (x1000) Lynx(x1000) 80 Number of pelts in thousands 70 60 50 40 30 20 10 0 1900 1902 1904 1906 1908 1910 1912 1914 1916 1918 1920 Year

Symbiosis Notes

Symbiosis Species Interactions Cooperative relationship Close interactions between organisms Symbiosis video

Mutualism (a type of symbiosis) J and J Pollinators and the plants they pollinate a cooperative symbiotic relationship that occurs when both species benefit The birds and mammals derive a food benefit by eating the berries and fruits. The plant, in turn, disperses its seeds.

Parasitism (a type of symbiosis) a cooperative relationship that occurs when one organism benefits, and the other organism is harmed J and L Parasites feed on a host organism, and may not kill the host immediately. Wasps video ² Ectoparasites ² external parasites; do not enter the host s body ² fleas, ticks, lice, leeches, mosquitoes ² Endoparasites ² internal parasites; enter the host s body ² bacteria, protists (malaria parasites, tapeworm, roundworm)

Endoparasites - (inside) Ectoparasites (outside)

Commensalism (type of symbiosis) One species benefits while the other species is not affected And Sea Cucumber & Pearlfish Boxing crab and anemones crab wears anemones for protection no apparent harm or benefit for anemones Whales and barnacles barnacles get a ride and protection no harm, no benefit for the whale

Cooperative Relationships v Mutualism v Both species benefit v Parasitism v One species benefits, one is harmed v Commensalism v One species benefits, one is not affected

Competitive Relationships Scarcity of resources (abiotic or biotic) will result in organisms competing. Whenever organisms share resources (overlapping niche), there will be competition for food and territory. Organisms are forced to occupy more specific niches in the environment in order to avoid competition. Organisms will avoid competition through cooperative relationships within the ecosystem. Example: Predator / Prey

Ecology Notes Part 3

EVOLUTION The change of heritable characteristics in populations through successive generations. change over LONG periods of time

Evidence of Evolution v Structures of Organisms v DNA Sequences v Fossils

Comparative Anatomy The study of similar structures in different organisms Homologous Structures indicate a shared common ancestor

Fish with Fingers Fossil Record

Comparative Anatomy The study of similar structures in different organisms Vestigal Structures organs or parts that appear to have no known function tailbone and appendix in humans leg bones in python

Comparative Biochemistry The study of the related biochemical aspects in different organisms Proteins DNA the more similar the amino acid and DNA sequences, the more closely related (indicates a shared common ancestor)

Jean-Baptiste Lamarck Inheritance of Acquired Characteristics Offspring will inherit traits that the parents acquired during their lifetime. Giraffes have long necks because the parents stretched their necks.?????

Charles Darwin Explained evolution through Natural Selection Believed organisms with superior traits will live, and those with inferior traits will die Those with superior traits pass on those traits to their offspring Giraffes with long necks out-reproduced the short necks. Short necks slowly become extinct. Studied organisms on the Galapagos Islands

Natural Selection

Darwin s Finches v Each species of finch lives on a different island, each island has a different environment. v Certain beaks are an advantage - based on the food available on that island.

Survival of the fittest All organisms want is to survive & reproduce If they reproduce more they pass on their better traits Natural Selection could not occur without GENETIC VARIATION (competition). Populations change over time by Natural Selection.

http:// www.teachersdo main.org/asset/ lsps07_int_nowh erehide/

Adaptations Inherited trait (characteristic) that improves the chances of survival (better suited to environment) and reproduction of an organism. Reproduction Producing offspring Pass on inheritable traits If an organism can t reproduce Will not pass on traits Extinction of species

Defense Mechanisms

Left monarch Right viceroy (not poisonous) If red touches yellow, you re a dead fellow, if red touches black, you re okay, Jack!

Poison Ivy Thorns