post midterm Flashcards
what is micro evolution
a change in the genetic makeup of a population from one generation to the next
macro evolution
the evolution of taxa above the species level (genus, family, order) large scale structures
phenotypic variation
heritable variation in appearance and/or function
phenotypic variation in garden snails
shells of garden snails vary considerably in appearance
bahaman land snails phenotypic variation
shells of land snails from a population in the bahamas look very similar
quantitative variation
individuals differ in small ways ex. variation in the number of hairs on their head (bar or curve graph)
qualitative variation
characteristics with discrete states
ex. snow geese are either blue or white and associate with other of the same colour
polymorphism
discrete variants of character ex. the background colour, number of stripes and colour of stripes or human blood types
(calculate frequency)
ways phenotypic variation within populations can be caused?
- genetic differences
- environmental factors
- interactions between genetics and the environment
environmental effects on phenotype in hydrangea macrophylla
in acidic soil produces blue flowers
in neutral soil produces bright pink flowers
what is an allele?
a variation of the same sequence of nucleotides at the same place on a long DNA molecule
what is a locus ?
location of a gene on a chromosome
what is a gene pool?
all alleles at all loci in a population (the set of all genes or genetic info)
4 distinct processes that cause evolution?
- mutation
- genetic drift
- gene flow
- natural selection
why does genetic variation exist in a population?
individuals possess different versions of the same gene (different alleles)
what is gene flow?
alleles and genotypes of a population can change due to migration into or out of the population
ex. young male baboons move from one population to another after experiencing aggressive behaviours by older males
where is gene flow most common?
in plant populations where pollen carrying wind or seed carrying animals
ex. blue jays are agents of gene flow for oaks when the birds carry acorns to new populations
genetic drift?
random changes in allele frequencies, important in smaller populations, reduces genetic variability
founder effect?
due to few individuals starting new populations because they carry only a sample of their parents populations genetic variation
population bottle neck?
reduction in alleles due to population reduction (decrease in size of the gene pool)
decrease in genetic diversity and loss of rare alleles
factors such as disease, starvation, and hunting may kill a large part of the population
what’s is mutation?
- change to the double strand sequence of DNA
- spontaneous heritable variation in DNA
- rare event significant over longer time scales
- caused by radiation, hazardous chemical, environmental factors
what is natural selection?
favours some combinations of traits over other resulting in differential survivorship and reproduction
Ernst Mayer defined biological species
- if the members of 2 populations interbreed and produce viable fertile offspring under natural conditions they belong to the same species
- their fertile offspring will produce the next generation of that species
- this explains why individuals if a species look alike
what mechanisms produce distinct species?
- microevolutionary processes alter the pattern and extent of genetic and phenotypic variation with populations
- when these processes differ between populations the populations will diverge genetically
- they may become so different that we recognize them as distinct species
what do reproductive isolating mechanisms do?
prevent individuals of different species from mating and producing successful offspring, prevent gene pools of distinct species from mixing
what are prezygotic mechanisms?
occur before zygote formation
include:
- ecological isolation from habitats
- temporal isolation from mating timing
- behavioural isolation from mating signals, sexual selection
- mechanical isolation from reproductive structures
- gametic isolation from gamete incompatibility
examples of ecological isolation?
- 2 species in different habitats in the same area may encounter each other
even though they are not isolated by obvious geographical barriers (northwestern garter snake and ribbon snake)
example of temporal isolation?
- species that their geographic range might overlap but they breed during different times/seasons cannot mix their gametes
(western spotted skunk and eastern spotted skunk)
example of behavioural isolation?
there is little or no sexual attraction between males and females of different species due to differences in behaviour of physiology
(blue footed boobies and red footed boobies)
what is mechanical isolation? and example
mating is attempted but morphological differences prevent its successful completion
ex. Bradybaena approach each other headfirst when they attempt to mate once their heads move past each other the genitals emerge, if the shells spiral in the same direction mating can occur otherwise the snails genitals will not align
what is gametic isolation?
it is difficult for gametes if different species to fuse because proteins on the surface of the eggs and sperm bind poorly to each other
ex. sea urchins
what are postzygotic isolating mechanisms?
prevent the development of fertile adults, inter species offspring are reproductively isolated if they are less fit than intraspecies offspring
- reduced hybrid inviability (species hybrids don’t survive
- reduced hybrid fertility (species hybrids do not produce functional gametes
- hybrid breakdown (F2 exhibits reduced survival or fertility
what is reduced hybrid inviability?
hybrid zygotes fail to reach sexual maturity ex. salamanders
what is reduced hybrid fertility?
hybrids fail to produce functional gametes ex. donkey + horse = mule
what is hybrid breakdown?
some first generation hybrids are viable and fertile but when they mate offspring of the next generation are feeble or sterile ex. strains of cultivated rice
what is speciation?
- the process leading to the formation of new species, also the source of biological diversity
- species of sexually reproducing organisms arise via reproductive isolation
how does geographic isolation promote allopatric speciation?
birds and other organisms that easily disperse across canyon have not diverged into different species on opposite side of the canyon
what is adaptive radiation on an island chain?
- ecological opportunities exist, may stimulate evolutionary changes
- water barrie’s restrict gene flow between populations so populations on different islands may evolve adaptations to their local environments
what is sympatric (same country) speciation?
- speciation occurs in populations that live in the same geographic area
- less common than allopatric speciation
- factors like polyploidy can promote allopatric speciation — a species may originate from an accident during cell division that results in extra sets of chromosomes
when did the planet form?
4.6 billion years ago
when did the chemical signatures of life date back to?
3.8 billion years ago
when were the first prokaryotes?
3.5 billion years ago
when did the first eukaryotes appear?
1.8 billion years ago
why was original earth inhospitable?
- the surface was molten lava
- it was bombarded by meteors and lightning
- volcanoes released gases (N2, CO2, water vapour, helium, methane, ammonia, hydrogen) NO O2
- too hot to form seas and lakes
what is a deinococcus radiodurans?
an extreme species, the toughest known bacterium, and can survive cold, dehydration, vacuum, and acid
known as a polyextremophile
what is an example of a bacteria living in the human body?
staphylococcus epidermidis
what condition on the original earth made the origin of life possible?
- the no living synthesis of small organic molecules (amino acids, DNA - adenine, thymine, cytosine, and guanine, in RNA the thymine is replaced by uracil
- the joining of these molecules into macromolecules (protein and nucleic acids)
- the packaging of these molecules into protocells
- the origin of self-replicating molecules that made inheritance possible
why were meteorites important to early earth?
they are a source of organic molecules that contain more than 80 amino acids, as well as lipids, simple sugars, and uracil
what was the first genetic material and why?
RNA
- plays a central role in protein synthesis and can function as an enzyme-like catalyst
- have shapes that enable them to replicate faster with fewer errors
- able to replicate and store genetic i for about the vesicles that carried them
once RNA sequences that carried genetic info appeared in protocells what changes would have been made possible?
- RNA could have provided the template on which DNA nucleotides were assembled
- double stranded DNA is a more chemically stable responsible for genetic info
- DNA can also replicate more accurately
- once DNA appeared the stage was set for blossoming new forms of life
what are the oldest fossils and how old are they?
- stromatolites (layered rocks that form from the activities of certain prokaryotes)
- 3.5 billion years old
why are proteins the dominant structural and functional macromolecules?
greater diversity, higher rate of catalysis, DNA is more structurally complex and stable than RNA which is better for storing genetic info
how is protein made?
info is stored in DNA — info in DNA is copied into RNA — info in RNA guides the productions of proteins
what are the first 3 eons in geologic record?
hadean, archaean, and proterozoic
what eras are in the phanerozoic eon?
paleozoic, mesozoic, and cenozoic
what were earths first organisms ?
prokaryotes (anaerobic chemoheterotrophs) that lived in the ocean
where did photosynthesis first evolve?
in photosynthetic prokaryotes similar to cyanobacteria (2.7 billion years ago)
what do eukaryotes have that prokaryotes don’t?
nuclear envelope, mitochondria, ER, other internal structures
what does the mitochondria do?
requires oxygen from breathing for cellular respiration to occur
what is cellular respiration?
the process where energy rich food molecules (sugars, fats, and other fuels) are broken down to water and carbon dioxide and the energy is captured in ATP
what are chloroplasts ?
- yellow green plastids where
- photosynthesis occurs in plant cells
they are surrounded by outer and inner boundary membranes that completely enclose the inner compartment (the stroma) - within the storms is the thylakoids (sacs) that contain chlorophyll, a green pigment that absorbs light energy and converts it to chemical energy in photosynthesis
what is the rough ER?
- many ribosomes in outer surface
- proteins made on ribosomes attached to the ER enter the ER lumen where they fold into their final form
what is the smooth ER?
- no ribosomes on surface
- synthesize lipids that become part of cell membranes
- convert drugs, poisons, and toxins in the liver into tolerable or easily removed substances
what is the golgi complex?
- made of a stack of sacs called cisternae
- proteins made in the ER enter on the cis face delivered by transport molecules that fuse with the membrane
- proteins are chemically modified by removing segments or adding functional groups or lipids and carbs
- modified proteins exit from the trans face
how did eukaryotes evolve from prokaryotes?
- endosymbiosis— when a prokaryotic engulfed a small cell that would evolve into the mitochondria
- the prokaryotic ancestor likely entered the host cell as undigested prey or an internal parasite
why would a host that was an anaerobe benefit from endosymbionts?
it could use the oxygen and over time become a single organism
where did the mitochondria and plastids descend from?
bacterial cells, the original host thought to have been an archaean
where did the mitochondria descend from ?
aerobic heterotrophic bacteria
where did chloroplasts descend from?
cyanobacteria
what are the parts of the endomembrane system and what does it do?
- the nuclear envelope, the ER, and the golgi complex
- characterized eukaryotic cells
- collection of internal membranes dividing the cell into structural and functional regions
what were the ancestors of plastids?
photosynthetic bacteria
what is the morphology evidence in the mitochondria and chloroplasts?
similar features to prokaryotic cells, inner membranes have enzymes and transport systems that are homologous to those found in the plasma membrane of living bacteria
what is the evidence of reproduction in the mitochondria and chloroplasts?
divided by binary fission the same way as prokaryotic cells, mitochondria and plastids replicate by a splitting process that is similar to that of a certain bacteria
what is the evidence of genetic info in the mitochondria and chloroplasts?
contain their own DNA with protein coding and non-coding genes essential for organelle function
how did multicellularity evolve?
differentiation of same species that congregated into colonies producing algae and ancestors of fungi, plants, and animals
what is the cambrian explosion?
many present days animal phyla appear suddenly in fossils early in the cambrian period (sponges, cnidarians, molluscs, snails, clams and relatives
what was a trait of the animals in fossils pre cambrian?
little evidence of predation, appear to have been grazers— feeding on algae, filter feeders or scavengers, not hunters
what were the discovered features of animals during the cambrian explosion?
claws and other features for capturing prey, new defense adaptations such as sharp spines and heavy body armour
what evolutionary venture helped prevent dehydration?
out of aquatic environments associated with adaptations that made it possible to reproduce on land
when do geologists estimate a new continent will form?
roughly 250 million years from now
what is the theory of plate tectonics?
the continents are part of the great plates of earths crust that essentially float on the hot underlying portion of the mantle and movements of the mantle cause the plates to move over time (continental drift)
what occurs at plate boundaries?
- many important geologic processes including the formation of mountains and islands occur at plate boundaries
- can be plates moving away from each other (the north american and eurasian plates)
- can be plates sliding past each other forming regions where earthquakes are common (california)
- can be plates colliding producing new mountains (the himalayans)
what’s a consequence of the continental drift?
promotes allopatric speciation where supercontinent ls break apart, regions that were once connected become isolated
how did the super continent of Pangaea occur and what did it affect?
250 million years ago plate movements brought landmasses together into a supercontinent Pangaea
- ocean basins became deeper which drained shallow coastal seas
- the formation of Pangaea altered the physical environment and climate which drove species to extinction and provided new opportunities for groups of organisms that survived
- organisms were also affected by the climate change
why does a species go extinct?
- its habitat has been destroyed
- it’s environment has changed in a manner unfavourable to the species
ex. ocean temps falling
how does mass extinction occur?
- disruptive changes to the global environment caused the rate of extinction to increase dramatically
- 50% or more of marine species became extinct
what happened during the permian mass extinction?
- 96% of marine animal species
- 8/27 known orders of insects were wiped out
- it occurred during the most extreme episode of volcanism half the size of western europe was covered with lava
- global climate warmed 6°C
- the rise in CO2 led to ocean acidification
- reduced the availability of calcium carbonate
- added nutrients like phosphorus to marine ecosystems stimulating the growth of microorganisms
what happened during the creative house mass extinction?
- extinguished more than half of all marine species
- eliminated all dinosaurs
- caused by a thin layer of clay enriched in iridium— common in many meteorites
- asteroid collided with earth
- clay fallout from a huge cloud that blocked sunlight and dropped global temps for years
what are the consequences of mass extinction?
- can reduce a thriving and complex ecological community to a pale shadow of its former self
- once an evolutionary lineage disappears it cannot reappear
similarities between algae and plants?
- both photosynthetic organisms
- use chlorophyll a as the main photosynthetic pigment
differences between algae and plants?
- algae lack true stems, roots, leaves, and vascular tissue
- in algae each individual cell is responsible for absorbing its own water
- plants have connective tissues for the transport of water and nutrients
how did plants enable other life forms to survive on land?
- plants supply oxygen
- they are key sources of food for terrestrial animals
- provide habitat for many organisms
what are the closest relative of plants?
green algae — charophytes ex. Zygnema
how are plants and charophytes similar?
- both have nuclear, chloroplast, and mitochondrial DNA
- both have flagellated sperm
- both have distinctive circular rings of proteins embedded in the plasma membrane that synthesize cellulose from the cell wall
how did charophytes move to land?
- inhabit shallow waters around the edges of ponds and lakes where they dry out— natural selection favours algae that can survive periods where they are not submerged
- layer of durable polymer called sporopollenin prevents exposed zygotes from drying out
benefits for charophytes living in land
- bright sunlight was unfiltered by water and plankton
- the atmosphere offered more CO2 that water did
- the soul by the water’s edge was rich in some mineral nutrients
challenges for charophytes living on land
- relative scarcity of water
- lack of structural support against gravity
when did the colonization of land by plants begin?
the ordovician period
what were the first land non-vascular plants?
bryophytes- mosses and liverworts
what was the first vascular plants and when did it appear?
Cooksonia— appeared in the middle Silurian - Devonian
what are traits of vascular plants?
- vascular tissue for transport of water and minerals from the soil to the rest of the plant
- cell walls provided above ground support
- stomata (tiny pores) that allowed gas exchange and the transportation of water vapour (water release)
- leafless and rootless
what plants produced the first trees and forests and when?
lycopods, ferns, and progymnosperms
at the end of Devonian
what did land and forests consist of during the Carboniferous period?
- land was covered by forest swamps
- forests consisted of giant club misses and tree ferns
what were terrestrial areas like in the Permian era?
- dryer and harsher
- gymnosperms (seed bearing plants) colonized many terrestrial areas because they did not need water for reproduction
when did the first angiosperms appear?
in the late jurassic
what were the first animals to move to land?
- platyhelminthes
- mollusca
- annelida
- nematodes
- arthropoda
- chordata
what were the first vertebrates to colonize land and when?
amphibians during the devonian era
when did the first reptiles appear?
at the end of the carboniferous era
and diversified during the Permian
what are birds derived from and when?
Saurischians - “lizard-hipped” dinosaurs during the jurassic period
what are the 2 groups of dinosaurs?
theropods (carnivores) and sauropods (herbivores)
what are pre human reasons for mass extinctions?
climate/temp, atmosphere, landmasses, floods, glaciation, volcanic eruptions, meteorite impacts
what’s an alphadon?
an opossum like mammal
where did the asteroid strike earth?
Yucatan Peninsula (mexico)
what were the affects of the asteroid to earth?
destroyed life in 500km radius
triggered global earthquakes, volcanic activity, large scale fires, landslide, huge tsunamis
what were the long term affects of the asteroid hitting earth?
major amounts of dust entered the atmosphere:
- shrouded the planet in darkness
- caused global winter
- photosynthesis interrupted (entire food chain affected)
- many species could not adapt to these environmental conditions
- all dinosaurs became extinct
- some reptile groups became extinct
who survived the asteroid?
some reptile, bird, and mammal groups which gave rise to a number of new species ex. birds
also a diversification of flowering plants and insects
what is functional diversity?
the biological and chemical processes such as energy flow and matter recycling needed for survival of species, communities, and ecosystems, as species interact with in another in food chains and webs
what is ecological diversity?
the variety of terrestrial and aquatic ecosystems found in an area or on earth. deserts, grasslands, forests, mountains, oceans, lakes, rivers etc.
what is genetic diversity?
the variety of genetic material within a species or a population, enables life on earth to adapt to and survive environmental changes
what is species diversity?
the number and abundance of species present in different communities
what is biodiversity?
- the variety of the earths species
- the variety of the genes they contain
- the variety of ecosystems in which they live
- the functional processes like energy flow and nutrient cycling sustain all life
why is biodiversity important?
- it is a vital renewable resource
- the biodiversity found in genes, species, ecosystems, and functional processes is vital to sustaining life on earth
why is the exact number of species unknown?
- small sizes of organisms can complicate the detection of species like bacteria
- the habitat may make counting species difficult ex. the deep sea
- tendency to study or ignore specific groups more than others
- ambiguities in scientific classification
- discovery of new species
what are biomes?
biogeographical units consisting of biological communities formed in response to the physical environment
- may span more than one continent
- a broader term than habitat: a variety of habitats
what is species richness?
the number of different species represented in a ecological community, landscape, or region
what is species evenness?
the commonness or rareness of a species, how many of each individual species
where is species richness the highest and the lowest?
highest: tropical rain forests, coral reefs, large tropical lakes
lowest: the equator toward the poles
why is species richness an advantage?
the greater it is the greater its sustainability or ability to withstand environmental disturbances and able to support a greater variety of consumer species
what are abiotic factors that influence species in terrestrial environments?
the climate:
temp, precipitation, sunlight, wind, latitude, altitude, soil
what are abiotic features that influence the species in aquatic environments?
light and nutrient availability:
water temp, oxygen concentration, light penetration, dissolved nutrient concentration, water currents, salinity
what is organismal ecology?
how an organisms structure, physiology, and behaviour meet the challenges posed by its environment
what is population ecology?
analyzes factors that affect population size and how and why it changes through time
what is community ecology?
examines how interactions between species such as predation and competition affect community structure and organization
what is ecosystem ecology?
emphasizes energy flow and chemical cycling between organisms and the environment
what is landscape ecology?
focuses on the factors controlling exchanges of energy, materials, and organisms across multiple ecosystems
what is global ecology?
examines how the regional exchange of energy and materials influences the functioning and distribution of organisms across the biosphere
what is an ecological niche and examples?
a species way of life in a community including everything that affects its survival and reproduction
ex. how much water and sunlight it needs, how much space it requires, the temp it can tolerate
*not it’s habitat but it’s pattern of living
why is the giant panda highly endangered?
habitat loss, low birth rate, its specialized diet (bamboo)
what are specialist species?
- occupy narrow niches
- can only live in one type of habitat
- use one or few types of food
- tolerate a narrow range of environmental conditions
- more prone to extinction when environmental conditions change
what are generalist species?
- have broad niches
- can live in many different places
- eat a variety of foods
- tolerate a wide range of environmental conditions
ex. flies, cockroaches, mice, rats, deer, raccoons, and HUMANS
why are cockroaches the most adaptable and survivable species?
- can live almost anywhere except polar regions
- can eat almost anything
- antennae to detect air movements
- vibration sensors in the knees so they can respond super quick
- compound eyes that allow them to see in all directions
- high reproductive rates (10 mil per year)
- genetic resistance to any poison
what are native species?
species that live and thrive in a particular ecosystem
what are non native species?
species that migrate into or are deliberately or accidentally introduced into an ecosystem
where is Mnemiopsis leidyi a native species and where is it an invasive species?
native along the western coasts of the atlantic ocean
invasive in the european seas
what is an indicator species?
species that provide early warnings of damage to a community or an ecosystem
why are trout an indicator species?
the presence or absence or trout in water at temps in their range of tolerance indicates the water quality because they need clean water with high levels of dissolved oxygen
why are birds an indicator species?
they are found almost everywhere and are affected quickly by environmental changes such as loss of their habitats and the introduction of chemical pesticides
what is a keystone species?
a species with a significant effect on the types and abundances of other species in an ecosystem, they help sustain the environment ex. pollination of flowering plant species by bees and butterflies
why are alligators, sharks, wolfs, sea otters, and lions keystone species?
they feed on and he’ll regulate the populations of other species
what is a foundation species?
a species that shapes communities by creating and enhancing their habitats in ways that benefit other species
why are elephants a foundation species?
they push over, break, or uproot trees creating forest opening in the grasslands and woodlands of Africa which promotes the growth and grass and forage plants that benefits smaller species (antelopes) and accelerates nutrient cycling rates
what is the fundamental niche of a species?
the range of conditions and resources it could tolerate and use, all the habitat potentially available to a population
what is the realized niche of a species?
the range of conditions and resources it actually uses in nature, the part of the habitat actually occupied by that population
why are realized niches smaller than fundamental niches?
- all tolerable conditions are not always present in a habitat
- some resources are used by other species
what is a competition interaction between organisms?
- the most common interaction
- when members of the same or different species interact to access the same limited resources— food, light, space, mates, water, shelter
what is the competitive exclusion principle?
no two species can occupy exactly the same ecological niche for very long
- when there is intense competition between two species both will suffer harm by having reduced access to essential resources
how do humans compete with other species?
- for space, food etc.
- we convert most of earths land and - aquatic resources to our own use
- we take over the habitats of many other species and deprive them of essential resources
what is intraspecifc competition?
competition between individuals of the same species
what is interspecific competition?
competition between individuals of different species
what is exploitation competition and example?
organisms compete indirectly through the consumption of limited resources
ex. deers and squirrels compete for acorns as a source of food
what is interference competition?
individuals interact directly with one another by physical force or intimidation
what is competitive exclusion?
the inevitable elimination of one species from a habitat by another species with identical needs for resources
what is resource partitioning?
some species evolve ways the share resources and reduce niche overlap: species competing for similar scarce resources evolve specialized traits through natural selection that allow them to used shared resources in different places, ways, and times
what are not considered predators?
Detritus feeders and decomposes because they feed on organisms have already died
what are ways pre species avoid their predators?
camouflage, chemical warfare, warning coloration, mimicry, deceptive looks, deceptive behaviour
how do clownfish use mutualism?
*both species benefit
they receive a safe place to live and even prey to eat and in return they provide food to the anemone, help ride it of parasites and cause away fish like butterflyfish that feed on anemones
how does an epiphyte use commensalism?
*one species benefits and the other is not harmed
an epiphyte is a plant that grows on the surface of another plant and derives it moisture and nutrients from the air, rain, water or debris accumulating around it
how do ticks use parasitism?
*the parasite feeds off other species by living on or in them
tick attaches to host causing irritation, painful wounds, infection, itch, hair loss
what is a lizards defense mechanism?
brightly coloured tails that break off when they are attacked giving them enough time to escape
what are the 5 levels of the food chain?
- primary producer (autotrophs)
- herbivores (eat produced and are the energy source for higher level consumers)
- carnivores (eat herbivores)
- omnivores (humans, raccoons, cockroaches can get their energy from all levels)
- detritivores and decomposers (will feed on dead organisms)
what is the conservation of energy law?
energy can neither be created nor destroyed; it is merely changed from one form into another
what is the law of entropy?
when energy is transformed from one form into another there is always a decrease in the quality of usable energy
what is the ecosystems primary production?
the amount of light energy converted to chemical energy by autotrophs during a given time period is an ecosystems primary production
what is the ecosystems secondary production?
the amount of chemical energy in a consumer’s food that is converted to their own new biomass during a given time period
what is ecological succession?
the structure and species composition of communities and ecosystems change over time in response to changing environmental conditions, some species will colonize an area and population increase while other species disappear
what is primary ecological succession?
the gradual establishment of biotic communities in lifeless areas where there is no soil in a terrestrial ecosystem or no bottom sediment in an aquatic ecosystem
what are the steps of primary ecological succession?
- lichens are the first colonists they derive nutrients from rain and bare rock, they secrete mild acids that erode rock surfaces
- slow development of soil
- mosses colonize the patches of soil and grow quickly
- moisture and nutrients increase to support the growth of trees
what is secondary succession and steps?
succession in a site that has already supported life but that has undergone a disturbance like a fire, tornado, hurricane, flood etc.
- disturbed site is ripe for colonization and contains many seeds
what is persistence living?
the ability of a living system such as a grassland or a forest to survive moderate disturbances
what is resilience living?
the ability of a living system to be restored through secondary succession after a moderate disturbance
what is a biome?
any of the worlds major ecosystem types: forest, desert, mountains, grassland, tundra, polar ice etc.
what are terrestrial biomes classified according to?
to the predominant vegetation
what are aquatic biomes classified based on?
on the physical environment
what is the difference between climate and weather?
climate: long-term prevailing weather conditions in an area
weather: a local areas short term temp, precipitation, humidity, wind, speed, cloud, cover etc. measured over days or hours
how and why does climate vary?
- global air circulation
- ocean currents distribute heat and precipitation unevenly
what 3 major factors affect global air circulates in the atmosphere?
- uneven heating of the earth’s surface by the sun
- rotation of the earth on its axis
- properties of air, water, and land
what leads to climate zones?
prevailing winds distribute heat and moisture in the atmosphere
how is heat distributed in the ocean?
winds cause ocean currents to distribute heat
when does convection occur?
when hot and wet warm air rises, cools, and releases heat and moisture as precipitation.
how are heat and moisture distributed over the earths surface?
via six giant convection cells at different latitudes; uneven distribution leads to earths terrestrial biomes
how do cities create distinct microclimates?
- bricks, concrete, asphalt, and other building materials absorb and hood heat, buildings block wind flow
- motor vehicles and heat control systems if buildings release large quantities of heat and pollutants
- cities tend to have more smog, haze, higher temp, and lower winds
which biome has the highest animal diversity?
the tropical forest
how much of the earths surface does the ocean cover?
about 75%
what provides most of the planets rainfall?
water evaporated from the oceans
what supplies lots of the worlds oxygen?
marine algae and photosynthetic bacteria
how many species are threatened with extinction?
more than 42,100
what’s the difference between extinction and extirpation?
extinction: disappeared globally
extirpation: disappeared locally
why is habitat destruction a major threat to biodiversity?
- natural habitats are being converted to land for human use
- forests being cleared
- tropical forests are burned releasing CO2 which contributes to global warming
- fewer trees leads to drying
- nutrients removed from soil
- lead to population decline
- jeopardizes the quality of habitat that still remains
- removal of natural vegetation leads to flooding
why is overexploitation of populations a threat to biodiversity?
- excessive harvesting of animal or plant species leads to population extinctions
- advanced fishing technology has allowed large numbers of fish to be harvested and changes the fish life cycle
how is climate change a threat to biodiversity?
- cause rise in sea levels leading to habitat loss
- changing temps disrupts the timing of migrations, mating, and reproduction
- males or female of species with temp dependent sex determination can be eliminated
how are invasive species a threat to biodiversity?
- increasing globalization leads to species being transported all over the world which harm native species and cause severe disruption and environmental change
how do invasive species become so successful?
- filling empty niche space in the new environment
- invading an area where they have no native predators
- using defences that are novel weapons in the new environment
- exploiting novel habitats
why is pollution a threat to biodiversity?
- chemical pollutants spread in water or air on a global scale
- winds carry airborne pollutants from power plants
- plastics don’t biodegrade
- plastics end up in digestive systems of aquatic and terrestrial organisms
what is the geographic coordinate system used for?
measuring and communicating positions directly in the earth and latitude and longitude
latitude vs longitude
latitude: lines are parallel to the equator
longitude: lines are perpendicular to the equator
what are the sustainable development goals?
- achieve a better and more sustainable future for all
- address global challenges like poverty, inequality, climate change, environmental degradation, peace and justice etc.
- to leave no one behind achieve all goals by 2030
what does goal 14: life below water state?
conserve and sustainably use the oceans, seas, and marine resources for sustainable development
what does goal 15: life on land state?
- protect, restore, and promote sustainable use of terrestrial ecosystems
- sustainability manage forests
- combat desertification
- halt and reverse land degradation
- halt biodiversity loss
what is the ecocentric or bio centric view?
defined natural resources as aspects of the environment valued simply because of their existence and right to exist:
humans have a moral responsibility to actively protect species, all species rights are to be protected
what is the anthropocentric view?
the value of natural resources is defined relative to human interests, wants, and needs
what is intrinsic value?
- nature has value in and of itself apart from its value to humans
- it is our ethical responsibility to protect what are our only known companions in the universe
- humans derive enormous psychological/aesthetic benefits through preserving biodiversity
what are extrinsic values?
- humans depend on plants, animals, algae, and microorganisms for a wide range of food, medicine, and industrial products
- all species in a community combine to maintain the vital ecosystem that make human life possible - oxygen, water, and food
what does the rose periwinkle do?
- contains alkaloids that inhibit cancer cell growth
- treat 2 deadly forms of cancer (lymphoma and childhood leukaemia)
what is the convention on international trade in endangered species?
- one of the longest standing treaties
- establishes list of species for which international trade is to be controlled or monitored
- restricting trade in certain endangered wildlife species
- *global ban on the ivory trade
what canadian species are listed under CITES?
lynx, bobcat, cougar, polar bear, river otter, and burrowing owl
