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73 Cards in this Set
- Front
- Back
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What is our planet ? |
part of a universe made up of numerousself-organized systems; systems occur at various scales and arethemselves made up of subsystems called components |
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. The First Law of Thermodynamics |
states that energy is conserved (i.e. that it is not lost but only changesstate). This energy is captured by matter and thenorganized into various states in a dynamic equilibrium |
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The Second Law of Thermodynamics |
asserts that as energy flows through systems itchanges state, from higher to lower states, and moves toward a non-dynamicequilibrium, or a totally disorganized condition known as entropy. |
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Entropy is avoided by |
converting a stream of electro-magnetic energy(sunlight) into chemical energy (sugars) |
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What are the four components of the Earth |
Lithosphere, Hydrosphere, Atmosphere, and the Biosphere |
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What planet includes Biosphere and well-established Hydrosphere |
Earth |
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The term "Biosphere" |
was coined by Austrian geologist Edward Suess in1885 but it was Vernadsky who expanded Biosphere concept in 1926 |
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James Love1ock |
Love1ock - an atmospheric scientist and inventor- proposed a hypothesis that postulates that the atmosphere co-evolved withlife and that, through positive and negative feedback mechanisms, lifemodulates the atmospheric envelope, enabling life on Earth to exist |
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"Gaia hypothesis" |
the Earth functions in a manner similar to a"super-organism", modifying climatic temperature and atmosphericcomposition |
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what do green house gasses, particularly CO2, prevent |
prevent reflected infrared radiation (heat)from escaping into space and keep the planet's surface warmer |
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Where is carbon most abundant |
The ocean is also a majorsink for carbon (it holds approximately 60 times more than the atmosphere) |
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What do forests do |
annually soak up 100 billion metric tons ofcarbon and return approximately the same amount to the atmosphere through plantrespiration, death and decay |
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glacial and interglacial cycles |
These cycles average about 100,000 years ofglacial climate to 20,000 years of inter-glacial warnings triggered both extinctions and episodes ofspeciation |
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"Big Bang" |
beginning of the universe....13.7 billion years ago |
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what are the heavier elements that provide the buildingblocks for organic life |
(i.e. oxygen, nitrogen, carbon, phosphorus,calcium, potassium, etc.) are generated by fusion reactions in exploding stars,particularly super novae |
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Star life cycle |
building in energy from hydrogen fusion intosuperheated expansive stars, called red giants, collapsing into dense starscalled white dwarves, and then exploding into super novae if the star is oflarge enough mass |
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four fundamental forces |
electromagnetism, gravity, strong nuclear interactions,and weak nuclear interactions |
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dark matter |
mass that helps hold galaxies together |
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dark energy |
energy that is causing the universe toexpand |
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Hadean Earth |
(no life) lasting from 4.6 to 3.8 billion years ago |
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how was early evolution of life developed |
membrane covered cells -> RNA -> DNA replaced |
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Archean (Early Life) |
evidence of bacteria in the fossils 3.8 billion years ago an early atmosphere of carbon dioxide, ammonia,nitrogen and methane had created a greenhouse warming of the planet's surface. Archean seas were initially anaerobic (withoutoxygen) |
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oxygen revolution |
it created the ozone (O3) layer, a stratosphericlayer of ozone gas that protects our planet from ultra-violet radiation |
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‘Cambrian explosion’ |
530 mil years ago an enormous amount of evolutionary innovationoccurred, particularly in the animal kingdom |
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Phanerozoic (visible life) Eon |
the emergence of modern eukaryotic life formsand all of their remarkably varied descendants |
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Dinosaurs & sharks arrive & leave |
225 million years 65 millions ago dinosaurs extinct |
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Modem Homo sapiens |
has been on the planet for approximately 250,000years, about the last one-tenth of the Pleistocene |
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Biodiversity |
the Biosphere is composed of biodiversity (genes, species, and ecosystems) and containdifferent trophic levels (producers, consumers, and decomposers) that captureenergy and circulate nutrients through time |
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framework for all life |
molecular genetic variation |
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ecosystem diversity |
All species live in habitats that are embeddedin natural communities of organisms that occupy ecosystems over largerlandscape units |
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DNA |
long sequences of DNA that code for certainamino acids that then build up special proteins that specify metabolic pathwaysleading to physical and behavioral traits |
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diploid |
containing two sets of homologous chromosomes;i.e. chromosome pairs |
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haploid |
containing only one set of chromosomes |
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heterozygous |
two gene copies, or alleles, contain differentsequences 1 dominant 1 recessive |
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Homozygous |
genes are identical |
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phenotypes |
individuals with expressed traits |
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Heterozygosity importance |
Heterozygosity in individuals and populations isgenerally of value for individual survival (resilience), reproductive viabilityof individuals over several generations (reproductive fitness) and it is alsoimportant for the adaptiveness of lineages over evolutionary time |
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how many species recognized today |
1.7 million over half insects - almost half is beetles |
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number of unknown species |
about 90% of the species on earth arepresumably yet to be scientifically described. 8.7 million species on planet |
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Species richness |
the number ofspecies in a given area or ecosystem |
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highest number of species |
occur in tropical areas, including rain forests,dry woodlands and scrub, large lakes, and coral reefs |
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species evenness |
is the number, or abundance, of individuals ofspecies per unit area |
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ecological diversity |
The combination of richness and evenness in acommunity |
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ecosystems |
organisms and their network of relationships tophysical and biotic processes consist of energy flows and nutrient cyclingthrough the interaction of multiple species embedded within their particularhabitat |
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trophic levels |
Energy follows different pathways |
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primary producers |
plants |
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primary consumers |
herbivores eat plants |
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secondary consumers |
carnivores |
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omnivores |
eat plants & animals |
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decomposers |
fungi, bacteria, and microscopic insects that break down dead organic matter and recyclenutrients back into the system |
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keystone species |
anchor entire food webs andtheir removal from an ecosystem can cause cascades of losses of other specieswhich are dependent upon them or other species that are secondarily dependentupon the latter. |
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ecological succession |
processes such as disturbance regimes (as infires, floods, landslides, climate changes etc.); migrations of differentmobile species impacting different kinds of habitats (as in grazing); cycles ofdrought or freezing weather which may destroy certain vulnerable communities;and episodes of communities rebuilding |
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conservation biology |
is a multidisciplinary science that hasdeveloped in response to the modern extinction crisis |
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California Sea otter |
Ex. of Keystone species Protection of the California sea otter promotesdiverse kelp forest communities which support a large number of differentnative species |
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“Flagship species” |
acts an an ambassador such as bald eagles (our national symbol)motivate the public to protect bald eagle habitat |
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and “economic species” |
such as salmon motivate water shed protectionand protection and restoration of spawning habitat in freshwater streams andrivers |
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“sensitive species” |
vulnerable species due to small populations can be recognized as indicators (such asElephant Seals) of special habitat conditions that contain many other specieslikely to be threatened if that habitat is not protected |
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metapopulations |
an array of populations distributed in a mosaicof habitats in a larger landscape |
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bipedal hominids |
large primates that evolved a two-legged form oflocomotion homo sapiens last surviving member closely related to the great apes |
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Australopithecus afarensis |
One of the earliest hominid species, datesback at least 3.9 million years ago. had a relatively small brain size,about one third of modern humans, primitive ape-like teeth, and a more ape liketorso |
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Homo habilis |
This was the first true human ancestor Approximately 2.5 million years ago, anotherimportant fossil was discovered that had greater cranial capacity, more humanlike teeth, and other features more typical of modern humans |
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Homo erectus |
had a modern chest cavity, allowing for a moreathletic body, used sophisticated rock tools, and is presumed to have beenprimarily a meat eater first hominid to migrateout of Africa and spread all the way to Asia and Europe. |
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Homo sapiens |
200,000 years ago has a larger cranial capacity and there isevidence from tool sites that this new species became the first of the big gamehunters |
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Eve hypothesis |
suggests that all modem humans arose frompopulations of H. sapiens in Africa. This means that there was aremarkably rapid migration of modem humans into areas formerly occupied byarchaic derivatives of H. erectus. |
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Clovis people |
that the migration with the most profoundconsequences was by an early group were highly advanced big game hunters 12,000 years ago |
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"Blitzkreig”, or “Overkill Hypothesis" |
based on numerous archeological sites showingtypical Clovis spear points and bone assemblages containing extinct large mammals,Martin suggested that this technologically advanced hunting race found astressed fauna that was probably "tame" because of lack of exposureto humans in the past |
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cause of bas extinction |
The combination of over harvesting, introductionof invasive species, and habitat alteration and loss due to human practices |
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recorded species extinction |
816 since 1600 It is estimated that 99% of these 816 speciesbecame extinct due to human influence |
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average life span for species |
1 million years |
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ultimare causes |
usually set the stage for extinction |
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proximate causes |
are more random and unpredictable and resultwhen species are highly vulnerable due to limited population numbers and highlyrestricted distributions |
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HIPPO (human caused extinction) E.O. Wilson |
H – Habitat Destruction andFragmentation I – Invasive Species (including diseaseorganisms) P – Pollution (e.g. acidrain, climate change, nitrogen deposition, etc.) P – Population (theultimate driver of all of these factors is the increasing human population) O – Over-exploitation (suchas over-hunting, over-fishing, and deforestation) |
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fragmentation |
breaking down populations become small and isolated |
