Chpt.4 Environmental Science

Life CharacteristicsOrganizationEcosystems

Ecosystems / EvolutionDiversity of Life

Characteristics of Life• Circulation transport of materials within the

body• Locomotion movement• Adaptation • Reproduction• Respiration• Lifespan, Stage in Life• Growth Repair and Maintenance• Response to the Environment• Energy Use-• Organization• Composed of cells

Organization• Quarks, Leptons

and Neutrinos• Electrons• Protons, Neutrons• Atoms• Molecules,

Compounds• Virus• Rickettsia and

Mycoplasms

• Cells (Prokaryotic)• Cell (Eukaryotic)

organelles• Cell (Eukaryotic)• Tissue• Organs• Organ Systems• Organisms, Species• Populations• Communities• Ecosystems• Biomes• Biosphere• Solar system• Galaxy• Universe (Made of Q,L,N)

Ecosystem

• Ecosystems- all of the organisms living within a specified area and the abiotic factors

• Abiotic-non living factors, streams, soils, rocks

• Biotic-living factors

Interconnections

• Organism-individual living thing• Species-a group of organisms that can

interbreed successfully• Population-are the member of a species in

a specific area in a specific time.• Community are populations that live

together in the same specific area• Ecosystem is a community of organism

and the non living factors in a certain area.

Habitat

• A habitat is a areas or situation where certain organism live.

• Niche- description of either the role played by a species in a community, or the total set of environmental factors that determine that species distribution.

• Most habitats have specific abiotic conditions and specific biota.

• Most organism are well adapted to their specific habitat • Harsher environmental conditions make the organisms

specifically adapted for those conditions.

Who Live Where and Why?

• Why does a particular species live where it lives?

• How is it able to live where it does?• How does it deal with the physical

resources of its environment?• How does it interact with other species

present?• What gives one species an edge over

another species in a particular habitat?

Critical Factors and Tolerance Limits

• Every organism has limits to the environmental condition it can endure.

• Environmental factors must with in appropriate levels for life to persist.– Temperature– Moisture levels– Nutrient supply– Soil and water chemistry– Living space

Evolution

• Evolution is the gradual change in the genetic characteristics of a population over a long period of time.

• Natural Selections- Nature selects for certain characteristics over other. Survival and reproduction was a big point in Darwin/Wallace theory of Evolution.

Natural Selection, Adaptation, and Evolution

• Species acquire traits that allow them to be adapted to their environment

• The term adapt can be used in two ways– Acclimation:limited range of physiological

modifications available to individual organisms• Individuals can adapt to a certain degree, but change is

not permanent• Changes cannot be passed to offspring

– Evolution:Operates at the population level, brought about by inheritance of specific genetic traits that allow specific genetic traits that allow species to live in a particular environment

Change• Species (populations) change gradually through

two mechanisms– Competition for scarce resources

– Natural selection members of a population that are best suited for a particular environment will survive and produce offspring more successfully than their ill-suited competitors

• Acts on preexisting genetic diversity created by a series of small, random mutations that occur spontaneously in every population.

• Where resources are limited or environmental conditions place some of the selective pressure in a population, individuals with those advantageous traits become more abundant in the population, and the species gradually evolves or becomes better suited to that environment

• Examples of natural selection;European pepper moth, finches as observed by Darwin,

Environmental Factors that cause Selective Pressure

• Environmental factors that cause selective pressure and influence survivorship or fertility in nature.– Physiological stress– Predation including parasitism and disease– Competition – Luck

Law of Competitive Exclusion

• No two species will occupy the same niche and compete for exactly the resources in the same habitat for very long.

Coevolution

• Coevolution is the process of two species changing genetically in response to long term interactions with each other

• The Yucca moth was predicted long before it became a fact.

Artificial Evolution

• Artificial Evolution is when you have changes done not for natural selection but due to the whims of humans.

• Horse Breeders, Dog Breeders

Resistance

• Resistance-is the ability of organisms to tolerate a particular chemical designed to kill it

• DDT-Insects

• Antibiotic resistant bacteria MRSA (Staph aureous) Buzz Aldredge, Jack Snow, Mike Martz

Isolation

• Given enough geographic isolation or selective pressure, members of a population can become so different from their ancestors that they can be considered a new species that has replaced the old

• Alternatively, isolation of population subsets by geographic or behavior factors that prevent exchange of genetic material can result in branching off of new species that coexist with their parental line.

• Convergent evolution unrelated organisms coming to look and act very much alike due to natural selection and adaptations(bat, butterfly, bird)

• Divergent evolution related species fan out and adapt to other environments, don’t appear to be similar.

Taxonomy History

• Botanist-herbalist- use the correct medicine, aspirin-willow, snake bite cure

• Aristotle-2000 years ago classified about 1000 organisms, divided into 2 groups plants and animals. The subdivision was habitat land, sea, air

• Linnaeus, Carolus, used structure and used a two-name system called binomial nomenclature.

Names

• Use only Genus species variety

• Italicize name if written

• Underline both genus and species

• Genus is capitalized, species is small

Modern Evolutionary Classification

• Similarities-Fins, bones, fins, covering, lungs, gills• Evolutionary Classification-evolutionary history,

phylogeny. Grouping of organisms with a similar ancestor.

• Cladograms-is a diagram that shows the evolutionary relationship among a group of organisms. Derived characters show up in newer members but not in older members

• Similar Genes• DNA evidence• Molecular clock-mutations in DNA

Hierarchical System of Nomenclature

• Domain-Archaea, Bacteria, Eukarya• Kingdom- Plant, Animal, Fungi, Protistia,

Archaebacteria, Eubacteria• Phylum-Division (plants only)• Class• Order• Family• Genus• species

Domain Bacteria

• Cells, unicellular, prokaryotic

• Thick cell wall of peptidoglycan

• Free living or parasitic

• Aerobic, anaerobic

Domain Archaea

• Cells unicellular, prokaryotic

• Harsh environment

• anaerobic

Domain Eukarya

• Cells are eukaryotic, more complex, larger

• Organelles, mitochondria, chloroplast, Endoplasmic reticulum

• Cell have DNA in the nucleus

Protistia

• Cells eukaryotic, unicellular, multicellular

• Plant, algae

• Animal

• Fungi, water fungi

Fungi

• Cell eukaryotic, chitin cell wall, singular, multicellular

• Feed on dead or decaying organic matter.

• Heterotroph, secretes enzymes, and absorbs molecules.

Plantae

• Cells eukaryotic, cell wall of cellulose, multicellular

• Photosynthetic autotrophs

• Nonmotile

• Mosses, Ferns Cone-bearing, flowering, plants

Animalia

• Cells eukaryotic, no cell wall, multicellular.

• Motion at least during some part of life cycle.

• Heterotrophic