ECOLOGY - Biology 1B; Fall 2018

Archaea

Distinct clade of prokaryotes more closely related to Eukarya than Bacteria

Halophile

"Salt-loving" archaea that live in environments that have very high salt concentrations ex. colorful ponds south San Francisco Bay Type of extremophile

1º producers, 1º consumers, etc

1º producer: autotroph level of producers 1º consumer: second level overall is the first level of consumers Then secondary consumer (2º), tertiary consumer (3º), quaternary consumer (4º) Food chains typically end after 6 levels

Tree of Life

3 major domains: Bacteria, Archaea, Eukarya Archaea more closely related to Eukarya than Bacteria Archaea and Eukarya share a most recent common ancestor

Windward, leeward (rain shadow)

@ cloud: air rises, cools, condenses, releases moisture

Biofilm

A community of microorganisms that adheres to a surface (ex. rocks in a streambed, soil on a desert floor, tooth plaque) Major type of ecosystem on the early Earth when only prokaryotes existed Many today include eukaryotic organisms Stages of formation... 1. Absorption to a conditioned substrate 2. Growth of a polysaccharide matrix 3. Flow of water and nutriment (nourishment) through the matrix's interstices

Hadley cells

A convection current in the atmosphere that cycles between the equator and 30° N and 30° S.

Conservation biology

A field of applied ecology that is focused on the management and protection of organisms and ecosystems

Global climate change

A global increase in temperature has been documented in both hemispheres at many sites around the world, Arctic ice sheet shrinking

Cohort

A group of individuals in a sample, usually from the same generation

Metapopulation concept

A group of spatially separated populations that interact through immigration and emigration, a population of subpopulations, ex. Glanville fritillary butterflies of Finland

Guild concept

A group of species that exploit the same class of environmental resources in a similar way ex. sympatric carnivores of Israel with different tooth size

Species richness

A measure of how many different kinds of organisms live in that place, the number of species Often used a proxy for diversity

Ecotone

A mixed community that exists between two distinct, adjacent communities Very diverse Foster interactions between species from both communities

Ecological disturbance

A physical or biological factor that alters the structure and species composition of the community The time it takes for communities to recover from disturbances is positively correlated with the scale of the disturbance The recovery of an ecosystem from a disturbance is a process of ecological succession

Haber-Bosch process

A process to synthesize ammonia (by combining nitrogen and hydrogen) on an industrial scale. Developed by German chemists Fritz Haber + Carl Bosch, the process has enabled humans to double the natural rate of nitrogen fixation on Earth and thereby increase agricultural productivity, but also altered the nitrogen cycle

Mutualism

A relationship between two species in which both species benefit, phenomenon of interspecific mutualism was neglected or denied by ecologists until the late 20th century,

Amensalism

A relationship in which one organism is harmed and the other is unaffected, often by accident ex. a buffalo steps on a lizard oops Effect on X: 0 Effect on Y: -

Greenhouse effect

A scientific analysis of this effect was published by a famous Swedish scientist in 1896, and an author outlined the problem very clearly in the magazine Popular Mechanics in 1911! CO2 acts like the glass ceiling of a greenhouse: solar radiation passes down through this layer/ceiling without much obstruction, but the radiation reflected back from the Earth gets absorbed and re-directed by the greenhouse gas molecules, thereby trapping heat and warming the atmosphere, oceans, and terrestrial systems alike

Dominant species

A species that is numerically abundant in individuals or biomass is a dominant species Removed from ecosystem? ex. Chestnut blight caused buy a fungus wiped out chestnut tree species, influential

Life table

A table of data summarizing mortality in a population

Boreal forest (Taiga)

Amount of carbon atoms in the atmosphere dips markedly each year when the great conifer forests of the taiga enter the growing season and conduct photosynthesis, pine/fir/spruce

Density-independent factors

Abiotic disturbances, impact the number of individuals in a population without reference to population density, typically environmental

"The powers of ten"

An adventure in magnitudes. Starting at a picnic by the lakeside in Chicago, this famous film transports us to the outer edges of the universe. Every ten seconds we view the starting point from ten times farther out until our own galaxy is visible only as a speck of light among many others. Ends inside a proton of a carbon atom within a DNA molecule in a white blood cell

Malthusian predicament

Human population will expend all of the Earth's resources

Global air circulation

Air moves through the atmosphere in massive cells Six air cells that characterize the vertical structure of the Earth atmosphere, with three in the northern hemisphere and three in the south Hadley cells: rising columns of hot air, rise then expand and cool, water vapor condenses and falls into tropics Hadley cells move about 30º North and South latitude, where they descend, the dry air is compressed, captures and holds water molecules in gaseous phase, releasing little precipitation Air masses move north/south at low altitude (Ferrel Cells), rises again at 60º N and 60º S, at 60ºN/60ºS it rains (ex. Seattle, Washington), descending Polar Cells generate arid conditions in Arctic/Antarctica (just like at 30ºN and S latitude, but in much colder conditions

Biogeographic realms

Alfred Russell Wallace, one of the biologists who was inspired by Humboldt to travel the world and conduct research on living organisms, interested in the spatial distribution of organisms—animals in particular—and Wallace's zoogeographic divisions (distribution of organisms) of the terrestrial world form the basis for our categorization of the major biogeographic realms (identified first 6) 1. Nearctic and Neotropical in the New World 2. Ethiopian region south of the Sahara (usually referred to as the Afrotropics) 3. Palearctic region of Eurasia and the Middle East plus North Africa 4. Oriental region of the Indian subcontinent and southeastern Asia including the Phillipines and the Indonesian archipelago west of the Lombok Strait 5. Indomalayan region including the Indonesian islands east of the Lombok Strait plus New Guinea 6. Australian region with Australia and New Zealand 7. islands of the south Pacific (Oceania) 8. Antarctica

Inverted pyramid

All major terrestrial ecosystems are structured in this way, but some aquatic systems are inverted, with the 1º producers smaller, or narrower, than the 1º consumer level (i.e. with zooplankton and phytoplankton, the zooplankton could have consumed the phytoplankton before the water was removed/observations made)

Ecosystem services

All the freebies that humans get from healthy ecosystems, such as waste dissipation in local waters, decomposition of waste in dynamic soils, supplies of clean drinking water, sources of pollinators for crops, breeding grounds for predators on crop pests, sources of sustainable food, and much more

Hydromodification

Alteration of the natural flow of water through a landscape, and often takes the form of channel modification or channelization

Community concept

An ecological community is a set of species that live in sympatry and interact Includes all of the species in a local area

Heterotroph

An organism that cannot make its own food

Ecosystem engineer

An organism that has a major physical impact on a local ecosystem (positive or negative) ex. beavers (could make dams that flood roads or other areas), elephants (destroy trees in Kruger NP), humans (actually shafting every ecosystem on the planet and space)

Autotroph

An organism that makes its own food

National Monuments

Antiquities Act of 1906 authorizes the US president to permanently protect federal lands with "objects of historic and scientific interest." Teddy Roosevelt signed the Antiquities Act, established Grand Canyon

Trophic guild

Any group of species that exploit the same resources, or who exploit different resources in related ways; it is not necessary that the species within a guild occupy the same, or even similar, ecological niches

Wetland

Any land area that is perennially/seasonally inundates so that it can support vegetation with aquatic adaptations

Intertidal zone

Area between low and high tide lines, varies depending on if the substrate is sand/rock/vegetation

BD model

Assume immigration and emigration are relatively equal (cancel each other out) Calculate rate of growth in terms of change in number of individuals per time interval = B - D, so ∆N/∆t = B - D (works for populations that grow in discrete time intervals

Ghost of competition past

Attributing a pattern in nature, such as resource partitioning or character displacement between closely related species, to competition that occurred in the past

Allelopathy, allelochemicals

Beneficial or harmful effects of one plant on another plant from the release of biochemicals

Brood parasites

Between birds and fish, the female of a parasite species lays its own eggs in the clutch of a host species, mother of the host species is tricked into raising the baby parasites, in Berkeley Brown-headed Cowbird

Latitudinal diversity gradients

Biogeographic zones near the equator generally have more species per unit area, and in general there is a gradient in diversity with increasing species richness as one moves from the poles to the equator Climate: warm and wet, abundant sunshine, less climactic variation across the seasons, greater ambient energy, moisture, more productive in terms of construction of new biomass, not subject to extensive glaciation during recent ice ages, vast area with a lot of land

Life history strategies

Biological characteristics of a species (for example, life span, fecundity, maturity rate) that influence how quickly a population can potentially increase in number

Aquatic biomes

Biomes in bodies of water

Density-dependent factors

Biotic factors 1. Competition: biological success, including growth rate, survival, and reproductive output 2. Waste production: exceptionally high population density may lead to the deleterious effect of waste products on the population that produces them 3. Parasites/pathogens: often find greater success as a result of the ease with which they propagate across individuals that live in close proximity 4. Predation: as a species becomes more numerous and dense, predators shift their focus to that species because it is easier to locate, and the predator expends less energy in its pursuit ex. Song Sparrows in British Columbia, females lay fewer eggs when the population is dense, negative correlation between reproductive success and density

Global birth rates

Birth rates remain high in countries nearer the equator, the so-called 'developing world'

Cyanobacteria

Blue-green algae, clade of photosynthetic bacteria, relatives/ancestors were important components of early earth biofilms Oxygen produced by them contributed to the oxygenation of ancient oceans, atmosphere Endosymbiotic Theory: chloroplasts of plant cells that can be traced back down to once free-living cyanobacteria cells, prokaryotes + cyanobacteria merged Bloom in warm, nutrient-rich waters Some produce toxic byproducts (cyanotoxins)

Thermocline

Boundary that blocks circulation between upper and lower levels in the water column (summer: cold water beneath, winter: cold water between ice and the boundary, warm water below)

Charles Elton

British ecologist, Oxford, ecology is scientific natural history

Global element cycles (C, P, N)

C: atmosphere holds about the same amount of carbon as the surface waters of the ocean, rates of exchange between atmosphere and ocean are approximately equal, plants and soils hold large stores of carbon, rates of soil and plant respiration combined are roughly equal to the amount of carbon that is captured and fixed in photosynthesis, therefore the exchanges among the major pools of carbon on Earth are roughly in balance, tremendous stores of carbon in fossil fuel deposits in Earth's crust P: global cycle does not have a significant atmospheric compartment, erodes naturally from bedrock and gets into biological systems slowly, removed in slow sedimentation processes, currently mined and used as fertilizer/other industrial applications N: hugely abundant (78% oh atmosphere), abundant in proteins and DNA

Desert

Cactuses (in the Americas), lizards, birds, spring bubbling out of a hillside, blazing hot day and blistering cold night, bats, kangaroo rats, morning dew for lizards to drink, biotic crusts

Marine layer, advection fog

California Current generates a dense layer of cool fog (a "marine layer") as it flows south In the summertime in the Bay Area, this marine layer is not content to stay over the ocean. Instead, high temperatures inland generate rising columns of air that form a sort of vacuum—a suction—at the ground level. The air that flows in to fill this void does not come from the east (where it is blocked by the Sierra Nevada), rather it comes from the open ocean to the west, and that is a cool marine layer, often with heavy fog Summer season in the Bay Area is the dry season in terms of precipitation (Mediterranean climate), dry season is fog season Supports coast redwood trees that grow year-round: water drips off leaves into soil, humidity from dense fog limits amount of water lost through leaf stomata

California Current

California coast receives a cold water influence from the Gulf of Alaska that creates cool conditions from British Columbia to the San Francisco Bay Area. As it flows south, this cold California Current interacts with the warm air of the lower latitudes, and the interaction of cold surface water and warm air generates a dense layer of cool, marine fog Upwelling of cool subsurface water in the Gulf of Alaska contributes to the California Current, influencing the temperature of that water (the ribbon that reaches California is shown in red, but make no mistake, it is pretty darn cold); upwelling currents are not only cold, they also bring nutrient-rich waters to the surface and contribute to the explosion of biomass in areas such as the Gulf of Alaska and along the Pacific northwest coast, particularly in the warmer summer months

Interspecific interaction types

Can be classified according to the effect that they have on the participants (positive, negative, neutral)

Logging roads

Can cause increased rates of erosion, alters local hydrology, reduces the size of resident populations, removes a sink for CO2, creates a network of edge habitat

Tracking distribution and behavior

Captured, handled, marked Sticker on the wing of a butterfly

Carbon dioxide (CO2), methane (CH4)

Carbon dioxide (CO2): most potent greenhouse gas Methane (CH4): 25 times more effective at trapping heat than CO2 over a 100-year period, cattle farts, natural gas mining Observatory high on Mauna Loa in Hawaii, documented intra-annual cycles of CO2 concentration in the atmosphere, as well as a relentless long-term increase in CO2 concentration Intra-annual cyclicity of CO2 concentrations in Earth's atmosphere caused by photosynthetic ability of plant organisms, summer: plants are storing carbon from the atmosphere and allocating it to growth and reproduction leading to a net decrease in atmospheric carbon, winter: plants photosynthesize less and the greater effect is the release of CO2 from organisms which results in increased atmospheric levels of CO2,

Climate and weather

Climate: pattern of variation in local or regional weather conditions over a long time period, statistical average of weather patterns over an extended time and area Weather: atmospheric conditions over short time scales, such as the expected temperature and precipitation tomorrow Walter climate diagram: double-y-axis plot of temperature (ºC) and precipitation (mm) in relation to time. Each interval of 10ºC in temperature is set equal to an interval of 20mm in precipitation, and time is measured in months, plants are expected to produce new biomass (positive net primary productivity) when the precipitation line exceeds the temperature line, as long as the temperature is above freezing (> 0ºC) Large water bodies have a big effect on air temperature because of water's high specific heat capacity (measure of the amount of heat necessary to raise the temperature of a substance) Large water bodies heat up and cool down more slowly than land masses; as a result, large water bodies dampen the seasonal fluctuations of temperature in adjacent land areas

Commensalism / facilitation

Commensalism: an interaction where one organism benefits and the other is unaffected Effect on X: + Effect on Y: 0 Facilitation: ex. plant that helps soil remain damp and shaded when it's sunny, other plants will flourish, facilitates like for other species Effect on X: + Effect on Y: 0

Seasonality, seasonal change

Community change is correlated with seasonal change in regions with distinct seasons Not ecological succession ex. vernal pools in the Central Valley of California, winter rains hydrate these systems, and spring snow melt may add even more water to them, more green growth and proliferation of microorganisms, as summer passes the system becomes desiccated, vegetation dies, organismal activity pauses until wet season again

Community and individual metabolism

Community metabolism: ecologist often treats the whole system as having a sort of metabolism, ecosystem acquires energy, and some of that energy is assimilated and some of it is respired, some of it is excreted and some of it is passed along to other parts of the system, usually joules or kilocalories, biomass values are usually given in dry weight, analyze biomass after water removed

Biosphere

Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere

Fertility rate vs GDP

Correlation between monetary wealth and fertility Negative correlation between gross domestic product and fertility rate During depressions and recessions—during times of high unemployment—fertility rate plunges

Direct estimation of N

Counting actual organisms

Indirect estimation of N

Counting something that indicates an organism was there, not the actual organism

Tangled Bank metaphor

Darwin, metaphor for a dynamic ecological community (an ecosystem), final paragraph of On the Origin of Species: "It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us."

Food chain

Darwin: clover leaves to bees to mice to house cats therefore clover plants can only flourish where there are a lot of cats ex. Swedish lake, small invertebrate (mountain shrimp), small fish (bleak), big fish (perch), even bigger fish (pike), bird (osprey), shrimp eats autotroph

Temperate seasonal forest

Deciduous forest, chlorophyll in the leaves of plants breaks down and is resorbed by the stems each year in preparation for the cold winter when solar energy is weak and water is unavailable because it is frozen, accumulation of dead organic matter (DOM) on the forest floor, over the decades and centuries, can build a deep humic layer in these forests, flowing and standing water systems may occur

Territoriality

Defense of a space against encroachment by other individuals

Delta and estuary

Delta: forms within the slowing of a river, rich ecosystem because of nutrients transferred by the rivers Estuary: where rivers join the sea, brackish conditions (salt + fresh water), high productivity (particularly in warm climates)

Mangrove forest

Dense forests in shallow marine waters on tropical/subtropical coasts, deterrent to storm surge, breeding ground for marine life

Zonation in lakes and oceans

Different regions in the lakes and oceans

Quadrats, transects

Direct counts of individual organisms in a small area and extrapolate to a larger area, ex. grid cells, assume even distribution of organisms

Eukarya

Domain of all organisms whose cells have nuclei, including protists, plants, fungi, and animals

Earth rotation and tilt

Earth is tilted on its axis at about 23.5º Earth spins on its own tilted access once per day (once per 24 hours), and the Earth orbits the sun once per year in an ellipse, not a perfect circle Because of the 23.5º tilt, there is a point in the Earth's orbit when the distance of the northern hemisphere to the sun is minimized, and that is summer time in the north (and when it is summer in the north, it is winter in the south, with the southern hemisphere tilted away from the sun) As a rule of thumb, land surface temperature declines ~1°C for every 145 kilometers of gain in latitude (or ~1°F for every 50 miles). But topography also plays an important role in determining ambient temperature, and temperature declines ~1°C for every 220 meters of gain in elevation (or ~1°F per 400 feet)

Energetic hypothesis

Ecosystems are limited in productivity, food chain length, and species diversity by how much energy enters the system at the base ex. tree hole ecosystems

African elephants in Kruger NP

Elephants were protected, population boomed, highly destructive in their pursuit of food and topple small trees to access the upper branches, hunters brought in to limit the population, public backlash was forceful so now they don't try to regulate the population, growing exponentially

Chemoautotroph

Energy source: inorganic substances Carbon source: carbon dioxide Domains: Archaea, some Bacteria

Chemoheterotroph

Energy source: organic molecules Carbon source: organic molecules Domains: all 3

Photoautotroph

Energy source: sunlight Carbon source: carbon dioxide Domains: all 3

Photoheterotroph

Energy source: sunlight Carbon source: organic molecules Domains: some bacteria

Net primary production (NPP):

Energy used by primary producers for respiration Global productivity: study amount of biomass produced via satellite, based on measurements of the amount of chlorophyll that is present in terrestrial and aquatic communities As precipitation increases in an ecosystem, NPP generally rises, but exceedingly high rainfall amounts correlate with reduced productivity Warmer systems exhibit increased productivity, but productivity tails off in exceptionally hot areas

Population size (N), density (N/V)

Estimate population abundance, relative estimate may be sufficient

Hydrological cycle

Evaporation from oceans > precipitation over oceans; precipitation over land > evaporation from land

Charles Darwin

Evolutionary biology, wrestled with ecological problems

Ecological niche concept

Explains how so many species can coexist

Agricultural runoff, eutrophication

Fertilizers are loaded with N-P-K (Nitrogen-Phosphorous-Potassium, primary macronutrients required for organismal survival in large quantities), leach into adjacent ecosystems and flow downstream into wetlands/lakes/oceans Eutrophication: occurs in freshwater and coastal ecosystems as a result of agricultural runoff, bloom of cyanobacteria and other photoautotrophs at base of the food web, creates dead zones because the blooms of phytoplankton create massive quantities of dead organic matter that remoce oxygen from the system because the decomposition process is an oxygen sink, results in massive die offs

Joseph Grinnell

First director of the Museum of Vertebrate Zoology at UC Berkeley, monographic studies on vertebrates, wrote a niche concept about the California thrasher Grinnellian niche: based on the adaptations of a species to a particular habitat, including all of the behavioral, physiological, morphological, and even psychological connections to that an organism has to its local environment

Pteridophyte forests

First major woody forests on Earth, grew prolifically in the Paleozoic Era (300 million years ago), ancient relatives of modern club mosses and horsetail ferns, grew in boggy soils where decomposition was relatively slow, high NPP, vast stores of dead organic matter accumulated in the sediments, these fossil deposits were subject to high pressure and temperature when buried deep in Earth's crust, this is how fossil fuels were made

Orographic effects

Formation, structure, and influence of hills and mountains on determining climate effects

Freshwater, brackish, marine

Freshwater 1. Frozen (mountain glaciers and polar ice caps) 2. Ground water in aquifers in the Earth's crust 3. Surface waters (may be frozen at ground level as a permafrost, or they may occur in liquid form in lotic or lentic systems)

Ecological niche: fundamental & realized

Fundamental: theoretical niche Realized: actual niche based on interactions with other organisms ex. on the rocky coast of Scotland, two species of barnacle are common

n-dimensional hypervolume

G. Evelyn Hutchinson, axes of the hypervolume represent dimensions in the organism's relationship to the environment, most important adaptations of an organism are quantified in an n-dimensional space or array, ex. an aquatic organism might have tolerance to salinity on one axis, temperature tolerance on another, diet composition on another, position in the water column on another, and so forth

Nitrogen fixation, nitrification

Gaseous nitrogen not readily available for plants because they can't split the bonds in dinitrogen molecule, plants form a mutualism with nitrogen fixers by hosting them in nodules in their roots, other nitrogen fixers live in soil, nitrogen fixing prokaryotes convert nitrogen gas into a form that's used by plants, nitrogen cycled through food webs, major limiting nutrient (relatively scarce), humans learned how to fix nitrogen using the Haber-Bosch process

Protected areas

Geographic spaces on land or at sea recognized, dedicated, and managed to achieve the long-term conservation of nature Countries that have significant protected areas: Costa Rica (becoming decarbonized, 25% land protected), Gabon (West Africa, 13 national parks)

Haeckel (ökologie, oikos)

German biologist, artist, champion of Darwin's ideas, writer, defined Ökologie (Ecology) as the science of the relationship of the organism to the environment, ancient Greek words oikos (meaning "home") and logos (meaning "to study")

Habitat alteration and loss

Global expansion of humans, prolific appetite for natural wealth has drastically altered natural habitats through development and resource acquisition

Predator-prey relations

Graph of predator prey interaction based on Lotka-Volterra dynamics Peaks of prey abundance precede the peaks of predator abundance, which are followed by minima in prey abundance, which are followed by minima in predator abundance, and so on

Temperate rainforest

Great density of biomass (like a tropical rainforest), abundant epiphytes and dynamic microbial/fungal action, soils are heavier than in the tropical forest because of reduced rates of decomposition in the cooler climate, conifer trees, ferns and bryophytes ex. Washington state

Kelp forest

Grow in the deeper water outside of the intertidal zone, requires cold water, buffer the land against the force of the surf, nursery ground for invertebrates and fish

Global population growth

Growth rate declined from 1950-2010 but human population is still growing exponentially because even though the growth rate declined it's still positive and people are still being born

Life history trade-offs, constraints

Growth vs Reproduction: Douglas Fir, western US/southern Canada, as they produce more cones, the relative width of annual rings decrease Survival vs Reproduction: European kestrel, both male and female parents care for the young, removed eggs from some nests, added these eggs to other nests, and left some nests untouched (controls), in comparison to parents with unaltered nests, parents with artificially enlarged broods were less likely to survive the year, and kestrel parents with artificially reduced broods had the highest rates of survival

Oceanic trash gyres

Gyres are large systems of circulating ocean currents, kind of like slow-moving whirlpools, they're also drawing in the pollution that we release in coastal areas, known as marine debris

Ocean currents

Have a major impact on terrestrial climate Antarctica: cold circumpolar currents north Atlantic Ocean: warm equatorial currents flow through the Caribbean and along the southeastern United States in the form of the Gulf Stream warm water systems in the Atlantic contribute moisture and energy to the massive storms and hurricanes that have hit the Gulf of Mexico and the eastern seabord in recent years

Colony collapse disorder

Honeybees, major pollinator for plants, pesticides responsible, pesticide type = neonics: applied to agricultural land to kill harmful pests, but they make their way into plants and into plant nectar, where the bees acquire them, create chronic problems for the bees

Horse latitudes and deserts

Horse latitudes: located at about 30 degrees north and south of the equator, common in this region of the subtropics for winds to diverge and either flow toward the poles (known as the prevailing westerlies) or toward the equator (known as the trade winds), diverging winds are the result of an area of high pressure, which is characterized by calm winds, sunny skies, and little or no precipitation; global distribution of deserts falls near where Hadley cells end their cycle (at horse latitudes)

Spatial scale

How an ecologist classifies the dispersion pattern of species depends on the scale on which the species is observed and measured ex. local scale (within a single park) vs larger scale (entire state)

Trophic modes

How organisms obtain energy and carbon

Earth's carrying capacity

Human consumption rates include: food, plant matter, clean air and water, minerals and metals, fossil fuels, space Necessities for ^ create the Malthusian predicament of Earth's natural resource crisis

Microbiome

Human microbiomes ex. mouth, airways, intestinal tract

Human population growth

Human populations are growing at an unsustainable pace The threat of a human "population bomb" that would strip global resources and create societal unrest led to calls for action to curb the trend

Anthropogenic

Human-induced changes on the natural environment

Space debris

Human-made objects that orbit Earth and are no longer useful ex. exploded satellites and spent rocket stages

Competitive exclusion principle

If two competing species co-exist in a stable environment, they do so as a result of ecological differentiation ​(if there is no such differentiation, then one species will eliminate or exclude the other)" This became a theory of limiting similarity in which sympatric organisms were predicted to differ by some minimum distance in niche space in order to maintain stable coexistence

Scientific natural history

Importance of quantification and experimentation in the study of organisms under natural conditions

White nose syndrome

Important for pollination and insectivory, many of the individual bats exhibited a white fuzz on their noses caused by a fungal infection, could be a symptom rather than a cuase

Salt marsh

In tidal zones, drain with low tide to expose mud flats, filling with high tide as fish enter from open ocean/bays, marsh grasses/other plants in this ecosystem are halophilic, extremely productive + desirable for human development (conditions may make it hard to develop though)

Savanna

Increased rainfall from temperate grassland, trees widely spaced among grasses, ungulates graze, fires in the tall grass in the dry season, vultures, domestic cattle grazing

Experimental Lakes Area, Canada

Inputs of phosphorous can trigger blooms of photoautotrophs, cause bottom-up effects, ecologists created a barrier between 2 sides of a lake and put phosphorous on one side, the bloom on the P-side caused a huge algae bloom (hypoxic conditions), this led to changes in legislation about use of Phosphorous

Food web

Interconnections among food chains create a complex trophic network

Interference & Exploitative

Interference: Competition that involves direct antagonistic interactions is classified as interference competition Exploitive: Organisms that do not interact physically but that rely on the same resources may face exploitative competition when those resources are limited

Isle Royale (wolves & moose)

Island in Lake Superior, when the lake is freezing mammals walk from the mainland to the island, moose and wolves established themselves there, wolves eat moose, issues with disease and stuff so the wolves declined in size i.e. moose population rose

Terrestrial biomes

Land biomes

Lichen, zooxanthellae, honey guide

Lichen: the product of a mutualistic interaction of fungi and green algae or cyanobacteria, superorganism, capable of absorptive nutrition and helps to maintain a grip on the substrate, and the algal or bacterial component is capable of photosynthesis Zooxanthellae: a group of dinoflagellate algae that live within the coral polyp body (endosymbiosis), dinoflagellates are capable of photosynthesis, and they contribute some of the sugars that they synthesize to the host coral, diversity of coral reefs is based on this basic mutualism between corals and dinoflagellates Honeyguides: honeyguides find beehives in African savannahs, gets a honey badgers attention, honeyguide forages on scraps

Species distribution (range)

Limits of its distribution in space ex. Cattle Egret that used to be in the Old World (Africa and southern Asia) follow large mammals and got caught in a storm and now they're in South America

Extremophile

Live in extreme environmental conditions ex. thermal vent, acidic gut of an animal Most belong to Archaea, some in Bacteria and Eukarya Organisms had to have extremophilic adaptations

dN/dt = rN(K-N/K)

Logistic growth model

Lotic, lentic

Lotic: flowing waters, including springs, streams, and rivers Lentic: more stagnant bodies, including swamps, marshes, ponds and lakes

Biome concept

Major regional or global biotic community characterized by convergences in vegetation physiognomy and organismal adaptations based largely on similarity of climate

Parasitism

May have more than one host individual or host species, and the relationship is not normally lethal, "Life is good for the tapeworm as long as its host remains strong enough to eat well" i.e. the parasite benefits as long as its host is a healthy organism

Bacteria

May play a big role in atmospheric dynamics May affect weather by altering the temperature at which water crystallizes into snow/ice Deep underground Bacterium found under a gold mine in South Africa also found under Death Valley in California, no sunlight, oxygen so they obtain energy, food from radioactive decay of uranium, synthesizes organic molecules from water, inorganic carbon, nitrogen from ammonia (chemoautotrophic thermophile)

Population regulation

Mechanisms that determine population size by density dependent/independent processes

Coral reef

Most diverse/productive of all marine ecosystems, coral polyps are filter feeders, ocean acidification and global warming kills them, cold and warm water

Florida panther

Mountain lions used to be widespread, panther suffered from inbreeding which led to skeletal malformations and low survivorship, translocates mountain lions from Texas to Florida, panthers numbers increased

Hubbard Brook Experimental Forest (HBEF)

New Hampshire, heavy forests in HBEF area have deciduous species from the temperate zone and evergreen species of the boreal system, bedrock is impermeable granite, water accumulates on the rugged hills and ravines will accumulate in discrete watersheds (little exchange of liquid between them), foresters cut the all species of trees trees for lumber, ecologists study the effect on nutrient cycling in the watersheds, build concrete weird at the base of watersheds to control outflow of water, water monitored for chemical composition, watersheds that had been clearcut (all species of tree) vs those selectively cut (with only the valuable, target species removed) there was a difference in the amount of nitrogen released from the systems, affected amount of nutrients in the creek

Carrying capacity (K)

No populations can sustain positive exponential growth indefinitely,

Tundra

North of the Taiga, frozen soils where the roots of trees fail to support above-ground growth in the short growing season, lichens/land mosses/tenacious forbs may flourish, large grazers ex. caribou, musk, analog of the tundra biome can be found high on many mountains in the form of alpine tundra

Keystone species

Not numerically abundant, but a keystone species exerts strong control on community structure and function

Instantaneous growth (dN/dt)

Not realistic to model population growth in discrete time intervals (i.e. many organisms do not breed in distinct seasons, and individuals have overlapping reproductive cycles), so you can find their growth rate at a specific time dN/dt = rN

Obligate, facultative

Obligate: both species require their partner for mutual survival Facultative: both participants benefit from the partnership when it occurs, but the relationship is not vital for survival

Glacier Bay, Alaska

Observe (1) pioneer stage with cyanobacteria/lichen, (2) dryas stage with weeds/willows/cottonwoods, (3) alder stage with thick strands of alder trees, (4) spruce-hemlock stage with heavy conifer trees Early plant species tend to be r-selected, later are K-selected

Oligotropic, eutrophic

Oligotrophic: nutrients in short supply Eutrophic: dark and dense with plankton

Thermophile

Organism that has adapted to living in very high temperatures ex. thermal vents such as in Lassen Volcanic Park Type of extremophile

Non-native species

Organisms that enter a landscape in which they did not evolve

Littoral, limnetic, benthic, pelagic

Pelagic zone: open water component (oceans) Limnetic zone: open water component (lakes) Benthic zone: deep water zone at the level of the substrate that is inhabited by a distinctive biota (the benthos) Littoral zone: nearshore of a lake where the water is shallow enough that aquatic plants can remain anchored by roots

Pioneer species, climax species

Pioneer species: the first to colonize previously disrupted or damaged ecosystems, beginning the chain of ecological succession Climax species: plant species that will remain essentially unchanged in terms of species composition for as long as a site remains undisturbed, K-selected

Alexander von Humboldt

Polymath (a "renaissance man") and his travels to the New World (1799-1804) made him famous as a travel writer and scientist, launched a new field of study of organisms with respect to the physical environment: biogeography, measured environmental variables such as temperature and pressure as he climbed (in Ecuador), and he recorded the time of his observations so that his readings could be compared with his assistant's measurements at the base of the mountain, collected and recorded the distribution of plants as he climbed, inspired Darwin and Wallace

Predation, parasitoids

Predation: the process of an organism consuming another organism, and the relationship is lethal for one participant True predators have many prey items Parasitoids: species in which the larvae feed on (or in) a single insect host, and the relationship is lethal to the consumed, important in the regulation of insect pests Ectoparasitoids: lay eggs on the outside of the prey Endoparasitoids: lay eggs inside of prey

Intermediate disturbance hypothesis

Predicts a positive effect of disturbances of intermediate intensity and intermediate frequency on community diversity

Primary, secondary, degradative

Primary: begins in an area that is devoid of life ex. after a volcanic eruption Secondary: follows a disturbance that does not eliminate all of the living organisms in an area, very common ex. fire (seeds remain) Degradative: Proceeds on dead organic matter as it decomposes ex. big mammals like pigs and humans undergo succession as their carcasses rot

Prokaryote

Prokaryotes are ubiquitous Within plant cells and outside of them, bacteria are central

Ecology of social groups

Pros: strength in numbers (defense), predators could be better at hunting as a group, may alter local environment (ex. penguins huddle to protect the ones in the middle from wind) Cons: more likely to transmit pathogens/infectious disease/parasites, larger groups more easily seen, competition more severe

Many-eyes hypothesis

Protection/vigilance, the more people in a group the more eyes and ears and noses there are to detect a threat, ex. Wood Pigeons in Europe (larger the flock of pigeons, the greater the distance at which their predators were perceived to attack them)

Shannon Diversity Index (H)

Provides a means for quantifying diversity and comparing communities directly Takes into account both richness and evenness pA = proportion of species A ( # A out of total from all species i.e. if 1 A, 1 B, 1 C, 1 D, there are 4 total, pA is 25% i.e. 0.25)

Coal deposits (fossil fuel)

Pteridophyte forests were turned into coal and other fossil fuels

Northern elephant seal

Pushed to the brink of extinction, protected, growing exponentially

RFID, PIT, telemetry, camera traps

RFID: Radio-frequency identification PIT: Passive Integrated Transponder RFID, PIT are small tags injected under the skin with a syringe, don't have a battery so the animal has to be recaptured for the chip to be scanned or pass a scanner in the field Telemetry: track animals in real time as they move around a landscape, battery powered radiotransmitter attached to animal Camera traps: operate unobtrusively, can be left in remote locations

Random, uniform, clumped

Random: very few organisms do this, ex. chaotic wind disperses seeds from a species Uniform: more common, individuals of a species occur with relatively even spacing among them, ex. cheetahs are territorial and mark the edges of their territory which creates a pattern of non-overlapping ranges of similar size (i.e. uniform), may result from a competition for resources or chemical inhibition such as allelopathy Clumped: most common dispersion, organisms occur in relatively discrete patches

Whole ecosystem science (macrocosm)

Raymond Lindeman was one of the first to study a whole ecosystem in the field, Cedar Bog Lake in Minnesota

Edge effects

Refers to the transition zone between an intact ecosystem and an area developed for human activity, result of habitat fragmentation

Survivorship curves: Types I, II, III

Reflects the death rate of a species population over an average individual lifespan (males/females usually modeled separately) y-axis: death rate on a logarithmic scale x-axis: individual age Type I: organisms that produce a small number of fat young that the parents feed and protect. Survival of these species is high early in life, but a the maximal life span is reached, individuals senesce rapidly and surivorship declines steeply Type II: equal chance of dying at any point in life Type III: organisms produce a large number of offspring, the majority of which fail to survive after birth Can be constructed for extinct species

Methanogen

Rely on anaerobic respiration and produce methane as a waste product Type of extremophile

Demographic transition

Represents a characteristic pattern of human population growth that is evident in many countries, and it helps to explain the explosive growth trajectory during the phase of urbanization and industrialization that marks the 'modern' period in developing countriesHuman population size has grown exponentially Phase 2: rapidly falling death rate and a sustained high birth rate Phase 3: death rates continue to plunge, birth rate begins to drop, but the difference between birth and death rates is enough to maintain explosive growth

Ecological pyramid

Represents the number of individual organisms, or the biomass, or the total energetic value of each trophic level in a community

Resource acquisition

Resources are acquired by an organism in ecological time based on strategies that the organism's ancestors acquired over evolutionary time

Resources and conditions

Resources: physical, chemical, or biological materials that are consumed by organisms ex. phosphorus for a plant, small sticks for a nest-building woodrat, or krill for a blue whale Conditions: all of the environmental factors that affect organisms, but these factors are not used by organisms ex. ambient temperature, water salinity, or wind speed

Diversity: richness and evenness

Richness: total number of species Evenness: relative balance of individuals in each species Diversity takes into account the relative numbers of individuals of each species, i.e., evenness

G. F. Gause

Russian biologist from the Soviet era, primary inspiration for the Competitive Exclusion Principle

Sea star, sea otter, orca

Sea star: keystone predator, eats mussels, when they aren't there the mussels become too abundant, when they are there the diversity of an ecosystem as a whole is greater Sea otter: keystone predator, eat urchins that will eat entire kelp forests, ecosystem crumbled, need sea otters to keep urchins under control Orca: ate sea otters, caused a trophic cascade effect (which has a positive impact on the 1º producers when the number of levels is odd) i.e. positive when you have sea otter, urchin, kelp but negative impact on the 1º producers when the number of levels is even i.e. killer whale-sea otter-urchin-kelp

Consumer-resource relations

Self-explanatory

Semelparous, iteroparous

Semelparity (Semelparous): death after first reproduction Iteroparity (iteroparous): living to reproduce repeatedly

Sea grass bed

Shallow water environments in the subtropics/tropics, sea grasses anchor into the substrate, leaves of the grasses covered by organisms

Effective number of species

Shannon-Diversity index can be converted into a metric called the effective number of species or simply, true diversity True diversity = exp(H) i.e. e^(Shannon Diversity calculation)

Physiognomy

Shape or morphology of the whole landscape can be described in terms of the visible plants, as well as the general topography, the outcropping of rocks, and the existence, or not, of flowing or standing water Macroscopic perspective Physiognomy of an ecosystem is its external appearance on a landscape scale

Shrubland (chaparral, fynbos)

Shrubs and small trees Small and tough leaves with a thick cuticle, leaves stay on all year Form dense thickets Thorns to deter herbivores Adapted to the recurrence of fire (mostly at the end of fall i.e. end of the dry season)

Tropical seasonal rainforest

Similar temperature profile to a tropical rainforest but with distinct seasons of precipitation, including a short or long dry season, rich in species

Competition

Single most important interspecific interaction

Allee effect, extinction vortex

Small patches contain small populations, and small populations are vulnerable to increased extinction risk This is because small populations... 1. Are more likely to be wiped out in a catastrophic storm 2. Are more vulnerable to predators if they rely on group defense strategies 3. Have trouble obtaining food if they rely on a social network when foraging 4. May have trouble finding mates if individuals are widely separated ex. tigers, giant pandas 5. Suffer from inbreeding depression Allee Effect: Warder Clyde Allee (ecologist from UChicago) found evidence in natural populations for reduced rates of growth in small populations No Allee Effect: traditional models of population growth (exponential model, logistic model) predict that small populations will grow rapidly because of reduced competition and a surfeit of resources Weak Allee Effect: small populations grow very slowly or not at all Strong Allee Effect: growth rate is actually negative If the growth rate of a small population is negative, it enters an extinction vortex and is predicted to disappear

The soap opera effect

Soap operas have had a considerable effect on reproductive rates in developing countries i.e. no time for kids

Solar radiation (latitudinal/seasonal)

Solar energy most directly strikes the middle of the earth (near the equator) The sun's rays strike the Earth more obliquely at high latitudes, and this results in less energy concentrated per unit area toward the poles This is referred to as the Cosine Law of Solar Radiation, and it relates to why you want your solar panels to face the sun directly rather than at a steep angle Variation in day length is greatest at higher latitudes

Canadian lynx & snowshoe hare

Solar flares cause plants to form a thick protective film on leaves to prevent radiation from damaging chloroplasts, hares can't eat the leaves because they're too think, hares all die, lynx have nothing to eat so they die Classic predator prey relationship where predator line on graph lags behind prey

Enemy free space

Space is a finite resource for some organisms ex. urchins emerge from reefs at night to forage on seagrass and algae, and they return to interstices in the reef at night for protection, urchins directly compete for these enemy free spaces, and the number of urchins on a reef may be constrained by the number of available hiding places

Population dispersion

Spatial relationship among the members of a population on a surface or in a volume of air, water

Mark-recapture technique

The capture and tagging of animals so they can be released and recaptured, allowing an estimate of population size, assume there are no deaths/births/immigration/emigration that would change population size

Community boundaries

Species respond to the environment based on the adaptations and actions of their constituent populations and individuals Disjunctions in abiotic factors create discrete boundaries in community composition and structure, such as the edge of forest, or the transition from a lake to a grassland. In those cases, community boundaries are relatively clear

Invasive species

Species that enter new ecosystems and multiply, harming native species and their habitats

Acidification

Steady emission of CO2 greatly affects oceans In water, dissolved CO2 forms carbon acid (H2CO3)

Temperate grassland

Steppe biome Warmer than northern tundra biome but not much wetter, horses, birds of prey, dry grasses sparked by lightning strikes, southern temperate grasslands with decent rainfall = agriculture

Natural history

Study of natural phenomena based on observation/description, encompasses organisms/physical universe

Biogeography

Study of past and present distribution of organisms

Climograph

Summarizes the distribution of terrestrial biomes on the basis of temperature and precipitation

Immigration, emigration, birth, death

The 4 factors that determine N (total population size)

Net primary productivity (NPP)

The amount of energy that plants pass on to the community of herbivores in an ecosystem GPP - respiration = NPP

Evapotranspiration

The combined amount of evaporation and transpiration

Resource partitioning

The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species

Lotka-Volterra equations

The logistic model of population growth can be modified to account for interspecific interactions using these

Trophic cascade

The propagation of indirect effects between nonadjacent trophic levels in a food chain or food web Top-down: many top predators can trigger trophic cascades when their populations steeply decline or increase. Because these effects propagate down the trophic hierarchy, they are referred to as top-down Bottom-up: something happens at the lowest level that affects all levels above i.e. plant species goes extinct

Human consumption

The rate of human consumption of the products of photosynthesis varies across the globe Consumption rates are high everywhere, but per capita consumption is highest in the United States and the wealthiest countries

Restoration ecology

The study and implementation of restoring damaged ecosystems ex. Flambeau Copper Mine in Wisconsin

Biogeochemistry

The study of biologically mediated chemical transformations

Solstice and equinox

The summer solstice marks the longest day of the year—with the most hours of sunlight—and the winter solstice marks the shortest day of the year Equinoxes mark the days of the year when the northern and southern hemispheres receive approximately equal illumination, and day and night are of roughly equal duration across the planet Equinoxes mark the 4 seasons

Character displacement

The tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species ex. Please recall the example of the Galápagos finches, Geopiza fuliginosa and G. fortis. Members of the Geospiza group are primarily seed consumers. G. fuliginosa and G. fortis occur in isolation (allopatrically) on two Galápagos islands (Los Hermanos & Daphne), and they occur sympatrically on two other islands (Santa María & San Cristóbal). In allopatry, the two species exhibit similar average beak size. In sympatry, they do not overlap in beak size. Remember, beak size is correlated with food size: large beaks are capable of cracking the largest seeds, and small beaks are most efficient at processing small seeds

Gross primary productivity (GPP)

The total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time

Ecosystem concept

The whole system (in the sense of physics) including but not only the organism-complex, but also the whole complex of physical factors forming what we call the environment or the biome - the habitat factors in the wildest sense" - Tansley

Life history and succession

There is a general and consistent pattern in which r-selected species are successful early in succession and K-selected species are most successful late in succession ex. New England forest, late successional tree species such as oak and maple eventually germinate and overtop the pioneering pin cherries

Population growth models

Track the overall number of individuals in a population, population size

Urchin barrens

Urchins in high densities can completely remove kelp forests

Age structure pyramid

Useful for summarizing population structure and assessing future trends at a glance Individuals are censused and divided into age groups with separate histograms for females and males In growth phase: bottom heavy, majority of population in pre-reproductive age classes In slow growth: balanced distribution ex. US Growth declining: top-heavy ex. Italy, Japan

Parasitic plants

Usually accomplish their thievery by inserting absorptive haustoria into the phloem of the host plant, robbing it of sugary sap, takes the other plants energy so it can photosynthesize because it cannot naturally

Herbivory

Wacky amount of herbivores

Mediterranean climate

Warm (temperate) wet winter, hot (warm) dry summer 1. California coast, central valley 2. Western tip of South Africa 3. Central Chile 4. Coast of southwestern Australia 5. Mediterranean region

Watershed, stream, river

Watershed: precipitation collection area, gathers rain/snow into a coherent system of interconnected waterways (streams + rivers) River: most major ones reach the sea, ex. Okavango Basin of Botswana forms a huge delta because of tectonic uplift

Mountain lion and Zion NP

Were top predators in North and South America before human arrival, now fear humans and avoid human activity, mountain lions in Zion are rare in areas with human traffic, deer are scared of mountain lions so where mountain lions are rare, deer are abundant, deer eat cottonwood trees, when cottonwood trees heavily browsed their roots can't hold the soil and erosion rates are high which impacts other plants/insects/amphibians/causes sedimentation that hurts fish

Hydrothermal vent

Where tectonic activity generates columns of hot and chemically rich gas that push through the sea floor, thermophilic chemoautotrophic prokaryotes and other organisms can tolerate their extreme conditions, relatively productive

Food chain length

Won't go over 6 levels

Tropical rainforest

World's jungles, dense green biomass, plants festooned on other plants (epiphytes), soaking wet a lot of the time, microbial activity is hyperdynamic, dead organic matter is quickly decomposed and recycled, soils are relatively thin, called the lungs of the earth, contribute more than any other terrestrial biome to the conversion of solar energy to primary biomass

Aedes aegypti

Yellow fever mosquito (has white striped legs), vector for several other diseases, including dengue fever, Chikungunya virus, Zika Has begun to live in climates that are getting progressively warmer to due global warming

Per capita birth rate (b), death rate (d)

b = per capita birth rate (B/Nt) d = per capita death rate (D/Nt )

Associated species

ex. Peregrine Falcons are difficult to track but the presence of them is correlated with the absence of Arctic Foxes (falcons eat foxes), foxes feed on eggs/chicks of Red-breasted Geese, so a nesting colony of geese where there is an absence of foxes means peregrines

Species abundance

ex. Red Kangaroo (relationship between distribution and abundance), can tolerate hot environments through behavioral/ecophysiological adaptations, lick wrists, can succeed in hot arid areas of Australia

Tracks and sign

ex. footprints and feces left behind, crayfish chimneys

Population fluctuations & cycles

ex. overshooting K (carrying capacity) and oscillating around it

Ecological succession

gradual change in living communities that follows a disturbance 3 types: primary, secondary, degradative 3 mechanisms: Facilitation, Inhibition, and Coexistence

N=mn/x

m = number of organisms caught in first sample, released n= number of organisms caught in second sample x = number of marked individuals (marked from the first sample) that are recaptured N = number of organisms in the population as a whole

Per capita growth rate (r)

r = per capita growth rate (intrinsic rate of population growth), replaces b-d

Reproductive strategies

r-selected vs K-selected

r-selected, K-selected species

r-selected: produce many, small offspring, most of which die early in development, with the survivors developing rapidly and reproducing at a young age, small mammals are usually r-selected (ex. Berkeley voles) ex. pin cherry (small tree), produce small cherries that birds eat and seeds widely distributed, germinate everywhere K-selected: produce few, large offspring that are well-provisioned for survival, and these offspring grow slowly to the age of first reproduction, and they continue to produce a small number of offspring each season over the course of their long lives, parental care ex. most large mammals

Levels of organization concept

subatomic particles, atoms, molecules, cells, tissues, organs, organ systems, organisms, populations, metapopulations, communities, ecosystem, biomes, biosphere

Principle of Allocation

the principle that if an organism allocates energy to one function, such as growth or reproduction, it reduces the amount of energy available to other functions, such as defense or maintenance

Origin of universe

~ 13.8 Ga (billion years ago)

The Oxygen Revolution

~ 2.7 Ga (billion years ago) Photosynthetic activity of cyanobacteria/other photoautotrophs (on rocky surfaces/soft sediments in the ancient oceans), photosynthetic activity flooded ancient oceans with oxygen gas, oxygen molecules bound to dissolved iron in the oceans and rusted ("oceanic rust"), after the oceans were saturated the oxygen gas bubbles into atmosphere (stratosphere specifically), UV rays split some of the molecules, some formed ozone, ozone layer shielded earth from UV radiation Most of the organisms at the time were anaerobic (doesn't need oxygen), oxygen gas was poison

Stromatolite

~ 3.5 Ga (billion years ago) Microrganismal films accrete mineral layers and grow toward energy source (the sun) Round, pillowy shape Accretionary bands when cut in a section, typical layers of a biofilm that accumulates material as it grows Technically a type of biofilm Still exist today ex. Shark Bay, Australia

Origin of life/ecosystems

~ 4.0 Ga (billion years ago) Primarily carbon dioxide, nitrogen, water vapor. Hyperactive volcanism contributes methane and ammonia and hydrogen sulfide, hydrogen gas escapes to space Planet cools, water vapor condenses to form early oceans "Warm little pond" theory (Darwin) or molecules from outside of our solar system for life on Earth to occur Earliest evidence of life is from shallow water marine environments

Origin of Earth

~ 4.6 Ga (billion years ago)

Interaction coefficients

α: proportional effect of species 2 on species 1 β: proportional effect of species 1 on species 2 (α or β) are negative (-) for competitive effects, but they can be made positive (+) for beneficial interactions such as mutualisms

Fixed interval growth (r-delta)

∆N/∆T = r∆N is the model of population growth over discrete time intervals