Bio Exam 4

Deciduous Forest

A moderate climate and dominance of hardwood deciduous trees occurs across much of North America, Europe, and Asia. Much of this biome has been subjected to human disturbance for agriculture and urban development. There are usually 15-25 species of trees, including maples, oaks, poplars, and birches. Springtime sun passes through seasonally leafless trees to reach a diverse understory flora. Soils are rich in nutrients from annual leaf fall, (increase organic compounds) and the moderate temperatures and precipitation promote decomposition, while the cool winters promote accumulation of organic materials. Insects, birds, and mammals are relatively diverse, joined by snakes, lizards, and amphibians

Earliest Hominin

(Sahelanthropus tchadensis) This specimen was discovered in 2002 in Chad. It combines both modern human and ancestral features. It has been dated to be about 7 million years old and has a chimpanzee-sized brain but hominin-type brow ridges. Homin: Any member of one of the different species in the group leading to humans. {The time of GREATEST hominin radiation was approximately: 3-2 years ago}

Alpine

(high altitudes but with no permanent ice) The Alpine biome is similar to tundra but lacks permanent ice below the soil, and the temperatures vary more widely. Alpine areas occur throughout the world, often at about 10,000 feet at lower latitudes, but always just below the snow line. Because of their altitude, these are windy, cold places and the thin atmosphere provides only limited protection from UV radiation. Alpine grazers include mountain goats, llamas, yaks, and marmots, as well as seasonally active insects. Predators include wolves and cats such as the Himalayan snow leopard.

Two ways to measure productivity

*Biomass* fixed per area or volume per unit time *Energy* fixed per unit area or volume per unit time

Where is carbon?

1)Atmosphere 2) Ocean 3) Land 4) buried deep in the earth as decayed plant material from long ago.... Fossil Fuels such as coal, oil and gas {The levels of CO2 in the atmosphere over the last 200 years have been increasing}

The four major threats to biodiversity

1. Habitat Destruction 2.Introduced Species 3.Overexploitation 4.Disruption of interaction networks

Which of the following statements is TRUE regarding CO2?

All of these choices are correct.

Language/Consciousness

Animals are conscious and have ways to communicate and use language

Temperate Grassland

Before settlement, this biome occupied most of the Midwestern United States, where it is dominated by blue-stem and buffalo grasses. Disturbance by fire helps to maintain grass populations in this biome. Lack of precipitation prevents many species of tree from growing, and those trees that grow are usually in low areas with some moisture. Where there is enough moisture to support decomposition, the soils accumulate nutrients, providing some of the most productive agricultural lands in the world. Before colonization by humans, temperate grasslands of North America supported abundant and diverse grazers, including bison, pronghorns, horses, and mammoths. Burrowing grazers such as prairie dogs remain relatively common, although population sizes have fallen; these species support predators such as ferrets, badgers, foxes, and birds of prey

Plant Global Biodiversity

Seen mainly in the tropical rainforrest

The Airborne Fraction

The fraction of the annual anthropogenic emissions that remains in the atmosphere 45% of all CO2 emissions accumulated in the atmosphere 55% were removed by natural sinks (24% oceans, 30% land)

Human population growth - approach to K, carrying capacity

To slow r (growth rate), either birth rate decreases or death rate increases Which is preferable?? *Decrease birth rate* (EX: Northern Ghana and Zhongwei, China - forced abortions, limit the children to 1 child) Some ways to do this is through birth control

Water vapor

Water in the atmosphere is in the gas or vapor form. Water vapor also traps heat and is a GG But - It's a complicated story because vapor as clouds may cool the earth

Biome

{Broad, ecologically uniform areas with stable and distinctive collections of species} {Some of the characteristics used to describe biomes include precipitation and average temperature.}

Small population approach

•Find ways of improving migration between isolated populations •Introduce unrelated individuals to the population to reduce loss of genetic variation

Difference in mean annual temperature, 1940-1980 and 1999-2008

63 years of climate change in 15 seconds. Overall, Earth's mean surface temperature has increased by almost 1°C - 2°C this is still significant because it can change environments and how the ice caps decline which can lead to higher oceans levels and new habitats might emerge. Higher latitudes have warmed more than environments nearer the equator. According to the future global warming models the is a hypothesis based on our general trends of CO2 output there is going to be an increase of about 8 degrees. However, even if we cut off all sources of CO2 we still have a lot of it in the atmosphere so we will still feel the effects

Influence of Culture on Evolution

A body of learned behavior that is socially transmitted among individuals and passed down from one generation to the next. This adds to sexual selection, group selection, and kin selection

What controls primary productivity in an ecosystem?

A limiting factor (one that is used up first): In the deep ocean: light In the shallow ocean: one of several nutrients Phosphorous (P) Nitrogen (N) Iron (Fe)

Carbon dioxide combines with water to form a weak _____; this has caused the pH of seawater to go _____.

Acid; down

{Evolution: can only occur in the natural environment, is not seen in domesticated animals, always results in an increase in an organism's fitness, is inherently random in nature, and acts on animals but not plants.}

All False

How Do Species Vary in Survival and Reproduction?

All populations from all species do about the *same thing* This 'same thing' is surviving and producing about 1- 2 reproducing offspring per individual in the population Otherwise if less than 1 --> *extinction* or if greater than 2 --> *uncontrolled growth* (they will have exponential growth and cause a huge boom in growth) But they do so in remarkably different ways: R strategists (lots of offspring, fewer parental care )and K stategists (fewer offspring, lots of parental care)

At a minimum, primary producers require water, carbon dioxide, and light. These are things that are readily available in most ecosystems. However, we do not observe the same rates of net primary productivity in every region of the globe. Which of the following statements BEST reflects one reason why rates of productivity are not the same everywhere?

Although water is limited in certain ecosystems, nutrients that are scarce actually limit net primary productivity because they are necessary for growth.

Hominin Lineages

Ancient DNA reveals that H. neanderthalensis interbred with H. sapiens (debatable) Paranthropus is a genus of heavyboned species that eventually went extinct without leaving descendants. Ardi and Lucy are especially complete fossils. {Our ancestors were likely bipedal by at least 3.2 million years ago} {Why do we think that male Neanderthals mated with non-African ancestral Homo sapiens? Because Neanderthal nuclear DNA sequences are present in the human gene pool, and Neanderthal mtDNA sequences are not.}

Rainfall Patterns

As air rises over the mountain, it cools, releasing its moisture as rain. Once over the mountain, the air descends, warming and taking up moisture. The organisms on the side with more water are going to have less dessication than the other way.

Northward migration of Jack and Red Pines

As temperatures rose, Jack and Red Pines migrated northward to their current distribution (dark green). Red lines show how the northern limit of these species changed through time. As temperatures rose, Hickory expanded its range to its current distribution (light green). There is a general expansion northward because the climate is colder there

Charles Keeling

Atmospheric levels of CO2 show a steady increase over the last 50 years. Keeling's program to monitor CO2 levels in the atmosphere revealed two patterns: (1) CO2 levels oscillate on a yearly basis, and (2) CO2 levels have increased steadily to the present day since measurements began The amount of CO2 varies over the year because the plants do not take away the CO2 during the winter time

{What was the main premise of Ehrlich's argument?}

B>D - so we were growing towards our carrying capacity

Why are ecosystems different in transfer efficiencies?

Based on the type of food the animals will have a variable chance of surviving {Which can explain the inverted pyramid in oceans: the phytoplankton in oceans divide so quickly that a small biomass can support a larger mass of of herbivores} {Pyramid diagrams of energy and biomass distribution for forrest and grasslands differ because: trees store much of their energy in difficult-to-digest wood, whereas grassland plants produce few difficult-to-digest tissues}

The Evidence for and Against Interbreeding

Because Neanderthal mtDNA does not fall within the human family tree, we initially believed that Neanderthals and our ancestors did not interbreed. However, studies of the full Neanderthal genome revealed that there was interbreeding, probably in the Middle East as H. sapiens first emerged from Africa about 60,000 years ago. It is possible for only the males were interbreeding and the females were no

Why should we care?

Biophilia - the purest reason (E. O. Wilson). Other species are entitled to life, a pervasive theme of many religions and the basis of a moral argument for the preservation of biodiversity. Future human generations may be deprived of Earth's species richness Biodiversity is a crucial natural resource Species that we still don't fully understand or have not yet discovered could provide crops, fibers, and medicines for human use 25% of current prescription drugs in the US contain substances originally derived from plants Loss of genetic diversity Each species has unique genes Biodiversity represents the sum of all the genomes of all the organisms on Earth Protect ecosystem function, and thereby ecosystem services Purification of air and water Reduction of the severity of droughts and floods Generation and preservation of fertile soils Detoxification and decomposition of wastes Pollination of crops and natural vegetation Dispersal of seeds Cycling of nutrients Control of many agricultural pests by natural enemies Protection of shorelines from erosion Protection from ultraviolet rays Moderation of weather extremes Provision of beauty and recreational opportunities (Bees)

Are Human Populations Subjected to the Same Processes That Affect Population Growth?

Birth - yes Death - yes Immigration/emigration - yes Exponential Growth - temporary until resources, disease, predators etc, reduce realized "r" But, many ways to approach K, the carrying capacity. We do not know if we have reached the carrying capacity due to an increase in technology but we are still subjected to famine, shortages, pollution, and diseases. (Population Bomb)

Explain dilemmas faced by conservation biologists

Birth defects and bad mutations and are susceptible to the same diseases. focuses on the natural vulnerability of small populations to extinction "The extinction vortex" Small population: Interbreeding and Genetic drift Loss of genetic variability Smaller population Reduction in individual fitness and population adaptability. Higher mortality Lower reproduction (See pic)

Coral Bleaching

Bleaching, indicated by the white skeletons of dead corals, occurs when the symbiotic algae that feed the corals abandon their hosts, thereby sentencing them to death. The symbiotic algae cannot live in such acidic environment and they leave as the coral gets stressed.

detritivore food web and explain their role in the ecosystem

Break down organisms back into nutrients

Carbon

C can dissolve in water and bond with other molecules to form liquid compounds such as carbonic acid. C also bonds with other carbon molecules to form numerous compounds, for example sugars and carbohydrates, that are a part of all living organisms.

{There is a giant sequoia (Sequoiadendron giganteum) named Washington (after George Washington) that was believed to be the second largest tree in the world (253.7 ft. in height!) until it was struck by lightning in 2003. The lightning strike caused a fire at the top of the tree that reduced Washington's height to about 229 feet. The fire released carbon that had been sequestered in wood into the environment in the form of:}

CO2

How do we know if the net increase in carbon is anthropogenic or natural

Carbon isotopes: 12C, 13C, and 14C 12C is the most abundant and is preferred by plants Thus plants and fossil fuels (ancient plants and animals) have low 13C/12C - about 2% lower than atmospheric ratios As fossil fuels and plants are burned, the atmospheric ratio of 13C/12C also declines (Volcanoes have a high 13C/12C ratio As we burn more fossil fuels and destroy plants the amount of 12C ratio increases compared to 13C. The amount of 14C decreases faster than 12C and the amount of fossil fuels being burned increases the 12C {The net increase is caused mainly by human activities}

Carbon Cycle

Carbon sources & sinks Long-term records of carbon dioxide An important idea in this section is that the atmosphere, oceans and land are all connected through the cycling of elements such as carbon. The earth is one system and everything that happens on our planet becomes part of the interactions between air, water, land and life. [you are what you eat, you are made up of what you or your mom consumed] The global carbon cycle has been disrupted and is causing climate change. Carbon illustrates the interconnection of all organisms on earth, and their connection to the atmosphere and waters of the planet. Important Parts: 1) Carbon can be in the form of a gas (in the atmosphere), a liquid (in oceans) and a solid (in all living things on land, and in some rock formations). 2) Carbon forms the backbone of the biology of all life on earth. All plants and animals on land and in the water use carbon as a basic building block. To date, no life has been observed that is not carbonbased. Every living thing (organic) is made up of carbon and hydrogen

Habitat Destruction

Caused by agriculture, urbanization, forestry, mining, and pollution. Implicated in 73% of species that have become extinct, endangered, etc. Caused when a species' habitat is destroyed or fragmented. A major problem in tropical forests Slash- and burn agriculture: 98% of the tropical dry forests in Central America and Mexico have been cleared Pre-settlement prairie, Minnesota Before European settlement, almost 20 million acres of tallgrass prairie existed in Minnesota. Now, less than 1% remains. Fragmentation: Habitat reduction and forest fragmentation in a Wisconsin forest from 1831 to 1950. However, still these islands are not connected well

The Keeling curve in Figure 25.1, below, shows that while CO2 levels oscillate on an annual basis, overall CO2 levels increase from year to year. Why has this trend continued in the last 50 years?

Combustion of fossil fuels

Human activities modify energy flow

Converting forests to grassland and urban areas decreases net primary productivity. Use of fossil fuels supplements solar energy. Humans appropriate 20 percent of the average annual net productivity of Earth.

Desert

Desert occurs in continental interiors around the world north and south of the equator from 25° to 35° latitude. (Just north and south of the equator) Wind patterns prevent this biome from receiving more than a few centimeters of precipitation annually. Very hot and arrid Deep-rooted plants, such as cactus and euphorbia, are adapted to store water. Primary production is low, (convert sunlight into glucose, they do not have as much water to have a high diversity) and soils are poor in nutrients but may have high surface salt due to evaporation. Given the low rates of primary production, primary consumers tend to be small, and include diverse lizards as well as rodents. Predators include snakes, cat species, coyotes, and birds such as owls, hawks, and eagles.

Other problems

Disagreement on K, carrying capacity some argue already reached others argue technology will increase K (however it is still concerning because there are still famine and the water is polluted) Most economies growth oriented, and depend on expanding population especially care of elderly. (there is a problem because the young must take care of the elders and not spend time at work) Population size also depends on immigration/emigration Limits on population size - has many negative connotations No easy answers.

Disruption of interaction networks

E.g., the elimination of: Keystone species, Ecosystem engineers, Pollinators (nothing to pollinate the flowers so this decreases fruit and less plants Elimination of keystone species: In the kelp forest ecosystem, sea otters eat sea urchins, clams, snails, sea stars, squid, octopuses and abalone When present in healthy numbers, they keep sea urchin populations in check When sea otters decline, however, urchin numbers explode— as does their grazing pressure on bull kelp Ironically, the thick fur that sustained sea otters for hundreds of thousands of years nearly brought them near to extinction when European trappers discovered their value in the 18th and 19th centuries

Is the earth a closed system?

Earth is a closed system with respect to matter, but open with respect to energy Energy from the sun, and from radioactive decay that melts the magma in the Earth's interior, drive the processes that move materials around the planet Many of these processes are cyclic

Greenhouse Effect

Earth's Energy Balance 1) Incoming solar energy is called solar radiation 2) Solar radiation warms the earth 3) The warmed earth radiates heat. However, this is not called 'heat', but rather in scientific terms it is energy. The correct term is infrared radiation 4) The atmospheric 'blanket' is gas molecules in the atmosphere.

Laws of Thermodynamics

First Law of Thermodynamics: In the Universe, the total amount of energy remains constant; that is, energy can neither be created nor destroyed, but it can be converted from one form to another Second Law of Thermodynamics - entropy or energy conversions are inefficient The amount of useful energy present after an energy conversion is always less than the amount before a conversion At each transfer, some energy is lost from the system (respiration/heat). Biological systems obey physical/chemical laws!

Temperature/Light vs productivity

Generally, temperature & light are positively related to productivity And precipitation is positively related to productivity

Flycatcher birds that migrate from Africa to Europe feed their nestlings a diet that is almost exclusively moth catepillars. The mean dates of arrival, bird hatching, and peak caterpillar season for the years have shifted. The shift in the peak of caterpillar season is most likely due to

Global Warming

What about communities?

Global warming is also affecting distribution of species. (EX: Increased outbreaks of pests such as pine bark beetles, due to milder winters that don't kill off the beetles.) Diseases may also proliferate. Winter cold typically kills many pathogens. Warming may allow some diseases to spread to temperate regions. (EX: Dengue fever and its mosquito vector are now spreading to higher latitudes.)

{If R0 = 2.101 what is happening to the population?}

Growing

The CO2 level is _____ during winter in the northern hemisphere compared to levels in the summer.

Higher

Consequences in terms of energy and biomass

Higher trophic levels must have: lower biomass and lower energy

Human Migratory Routes

Humans arrived late in the New World. The precise dates are disputed, but the first humans reached North America about 15,000 years ago. After Homo sapiens evolved in Africa, groups moved out, beginning the colonization of the rest of the planet Predictions: multiregional hypothesis (2 mya) and the out-of-Africa hypothesis (60,000 years ago) both are wrong

Ecosystem services

Humans have modified ecosystems to increase production of some services, especially food, timber, fuel, etc. These benefits have not been equally distributed; some people, and many other species, have been harmed by these modifications. There could cause a decrease in biodiversity and the land that we are using for agriculture that other species were formerly using Short-term increases in some services result in long-term degradation of others. (EX: increased production of food and fiber has decreased the ability of some ecosystems to provide clean water, support biodiversity, regulate flooding, etc.)

How have humans altered global cycles?

Hydrological cycle: Dams, water regulation; Tapping of ground water. Ground water mining, irrigation, dams, urbanization, deforestation, alteration of wetlands all impact the hydrologic cycle (Naturally occuring hydrological cycle is evotranspiration) Carbon cycle: CO2 Contributed by Humans; Greenhouse effect (burning of fossil fuels and deforestation) and Global warming Nitrogen cycle: Eutrophication Phosphate Cycle: Limited resource

Carbon Cycling on the land: Plants and Soil

Important: Plants run the carbon cycle on land. Carbon moves in and out of plants and soil as CO2 Photosynthesis in plant leaves: Takes in CO2 and CO2 is 'food' for plants (solar radiation energy) Respiration in plant leaves, roots, and soil: Releases CO2 and CO2 is produced in metabolism and the extra is released (Glycolysis through ingestion of plants) (EX: Soils have microbes that decompose plant material when it falls to the ground. Microbes are alive and they respire as part of their metabolism.) {Which of the following will help SLOW the rate of increase of atmospheric CO2? All of these choices are correct.(turning off the light in an empty room, using solar power instead of fossil fuels to help conserve finite natural resources, AND driving more fuel-efficient cars)} {Ultimately, the nitrogen cycle is dependent on: microorganisms that convert atmospheric N2 into usable forms.}

Lucy (Australopithecus afarensis)

In 1974, researchers found an early hominin fossil in Ethiopia, dating from around 3.2 million years ago, and called her Lucy. Lucy represents the first fully bipedal hominin to habitually walk upright. She was less than 4 feet tall and had a considerably smaller brain than modern humans.

Corn Yield 1961-2007

In the United States, the area devoted to cornfields has increased only a small amount over the last 50 years, but the total corn harvest has grown steadily because of increasing yield. Globally, corn yields remain much lower than in the United States and so increasing area under cultivation continues to play a major role in increasing the corn harvest. (How can we meet the needs of a growing population? Conventionally, agronomists see two options: We can devote more land to crops, or we can increase the yield of fields already in place) We are selecting corn that is more efficient by genetic engineering them or planting the corn with a higher yield.

And Conventional Wisdom Doesn't Always Work

In theory, underdeveloped countries' birthrates should not decline until 'industrialized' But they have ... Brazil: fertility rate dropped from 6.15 to 2.27 last 50 yrs India: 600 million fewer than expected by 2100 Attributed cultural/attitude change in women controlling their own fertility - AZ Republic Article

When we think the carbon cycle and human methods. It is important to differentiate between facts and hypotheses. Which of the following can only be considered a hypothesis?

Increasing atmospheric carbon dioxide will cause mean global temperature to increase by 2 degrees celsius over the next century.

But Human Populations and Human Behavior Are Complex

Individual (choices: who/when we mate with and if/when we want to start a family) natural selection --> strong force on reproduction Political, ethical, religious, sociological, economic issues are important Human population growth is often affected by unpredictable factors ... Industrialized countries growth rate declined due to women entering professions, delaying reproduction, having fewer children In former Soviet Union, birth rates even declined below R=1 While other countries growth rates increased (India:caused by the culture, the age of women reproducing, etc)

Lifespan/life expectancy

Insects and other small invertebrates often < 1 year Annual plants < 1 year Turtles > 100 years Trees maybe 1000 years Human average lifespan Bronze age (3600-600 BC): 26 years Now: Humans live on average 48 years in Chad and 89 years in Monaco Probability of dying per unit time: Mortality rate Probability of surviving per unit time: Survival rate. This is due to increase in medication, technology, resources, climate, etc.

Introduced Species

Invasive species: species that is not native and whose introduction causes harm to environment, economy, or human health (Zebra mussels, kudzu, and brown tree snakes) Deliberate or accidental release of a species outside its normal range Free from their native predators, parasites, and pathogens, transplanted species may spread at an exponential rate Exotic species: a species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental. Not necessarily problematic Economy: Introduced species contribute to 40% of extinctions Introduced species cost to US economy ~$140 BILLION annually In the US the FDA estimates that more than US$ 5 billion is spent annually on medical treatment, damage, and control in Red fire ant-infested areas The ants cause approximately $750 million in damage annually to agricultural assets, including veterinarian bills and livestock loss, as well as crop loss The cane toad: In June 1935, 102 Cane Toads were introduced to Australia from Hawaii in an attempt to control the native Cane Beetle. Turns out, they eat EVERYTHING they can fit into their mouths except the beetle and nothing eats them! How to be a successful invasive species? Few natural enemies (predators, competitors, parasites, and diseases), Hi reproductive trait (long-lived, good dispersal, and generalists (they can live anywhere)) Pioneer species (they are brought over from other places where they are used to the other diseases that the new species are not used to and are able to take over like a pioneer.)

Deep Sea (Benthic Zone)

Kilometers below the surface, deep seawaters are cold and dark, but they are not sterile. (No sunlight) Sinking detritus supports sparse populations of animal consumers, as well as bacteria and archaeons that feed on organic particles. Despite their limited biomass, deep-sea biomes exhibit high species diversity, as high as those of shallow marine communities. However, the composition of communities in deep sea biomes differs relatively little from place to place, and so the total diversity of these environments is lower than that found within the photic zone. Dense animal populations occur locally on the deep seafloor where hydrothermal vents expel fluids containing high abundances of hydrogen, hydrogen sulfide, and methane. These compounds support locally high levels of primary production by chemosynthetic bacteria, many of them present as symbionts within the tissues of vent animals.

Lake

Lakes and ponds range in size from tiny temporary pools to the Great Lakes of North America, which contain more than 20% of all freshwater habitats in the world. They range geographically from the equator to above 80° N. Their chemistries vary with the types of terrain in which they are found, and nutrient levels can be low to extremely high. Aquatic plants and macroscopic green algae live along the shallow margins of lakes, and both algae and cyanobacteria are primary producers throughout the photic zone. Zooplankton include small arthropods and rotifers, whereas the nekton is dominated by fish. Turtles and birds also play an important role as grazers and predators in many lakes.

Climate

Latitude: difference in incoming solar energy density explains why Earth's surface is hotter at the equator and cools towards the poles. {Primary productivity in terrestrial ecosystems is highest at the equator because of: All of the other answer choices contribute to high productivity: high levels of rainfall, relatively constant temperature, high levels of direct sunlight.} High Latitude: incoming solar energy strikes Earth at an angle, resulting in lower fluxes of energy per unit area. Equator: solar energy strikes Earth directly, resulting in high influx of energy per unit area. {In either freshwater or marine biomes, which regions would you expect to have the HIGHEST productivity? near the surface where sunlight penetrates}

Warm air is _____ dense than cold air, and warm air holds _____ moisture than cold air.

Less; more

Chaparral

Like deserts, the distribution of chaparral reflects a narrow range of climate conditions, and occurs on the western edge of continents from 32° to 40° north and south of the equator. Precipitation ranges from 30 to 75 cm per year, usually falling in 2-4 months. Typical plants are annual herbs, evergreen shrubs, and small trees. Olives, eucalyptus, acacia, and oaks are typical woody species, always drought-resistant and often adapted to withstand fire. Limited precipitation means soils are not rich in organic materials.

What is the best strategy?

Long-lived, multiple reproductions, many offspring per episode, high survival of offspring (high investment/parental care), early age of first reproduction ... But, clearly this doesn't happen ....Why not? Less chance of dying and more Maximizing one trait, means another suffers or ... There are tradeoffs in each life history trait: When ever you see a trade off there is always a a comparison between The amount of resources and predators.

Atmosphere

Made up of ozone, nitrogen, carbon dioxide, methane, oxygen, helium, methane, and water. Solar energy reaches Earth's surface. The earth surface absorbs the energy and warms up

Neoteny

Making up that ~1% difference is gene regulation during development

Hydrologic cycle

More water now evaporates from land than before the Industrial Revolution. Flow of many rivers has been seriously altered by large dams. In some areas, aquifers (underground water sources) are being depleted by irrigation and other uses. Humans have had big effects on the distribution of freshwater by building dams, canals, irrigation, etc.

Neanderthals

Neanderthal brains were slightly larger than ours, but their skulls were shaped differently. The Neanderthal forehead was much less pronounced than ours, and the skull in general lower. The Cro-magnon looks more like our skulls

Nitrogen Cycle

Nitrogen fixation converts N2 to a form that can be used by plants. Chemoautotrophic bacteria gain the energy needed to fix nitrogen by oxidizing NH3, using O2 (nitrification) they are using this for energy to produce nitrogen for primary producers or NO - (anammox) this is formed by the decomposers which breaks down the dead stuff so that the chemoautotrophs can transfer it to N. they are Primary producers assimilate biologically usable N from soil or symbiotic N-fixing bacteria. In anoxic environments, some decomposing bacteria use NO3 in respiration, a process called denitrification because it converts biologically usable N back to N2. Consumers obtain N from their food. Decomposers return N to soil as ammonia

Earth's Tilt

Northern Hemisphere: receives more solar energy per unit are in July than at other times in the year Southern Hemisphere: receives more solar energy per unit are in January than at other times of the year {This causes seasons} The elliptical orbit does not affect the seasons because the tilt causes less direct sunlight

Nutrients

Nutrients pass up the food chain. They *Cycle* between the biotic and abiotic parts of the ecosystem

How do we measure the amount of primary production?

Often measured in energy per unit area per unit time (J/m2/yr)

Causes of the Declined in the Efficiency of the Ocean Sink

Part of the decline is attributed to up to a 30% decrease in the efficiency of the Southern Ocean sink over the last 20 years. This sink removes annually 0.7 Pg of anthropogenic carbon. The decline is attributed to the strengthening of the winds around Antarctica which enhances ventilation of natural carbon-rich deep waters. (more CO2 in the atmosphere) The strengthening of the winds is attributed to global warming and the ozone hole.

Molecular Analysis of Human and Chimpanzee DNA

Perfect complementarity: 95°C denaturation Some mismatch: 93°C denaturation More mismatch: 91°C denaturation {Humans and chimpanzees last shared a common ancestor around 5-7 million years ago, and our genomes now differ by about 1%} The less combination there is the lower the temperature there is to separate the DNA strands for denaturation

{Hypoxia (oxygen depletion) is a challenging problem in coastal ecosystems worldwide. If nutrient inputs, especially nitrogen, are in excess in a coastal sea, which sequence of events below could lead to dead zones as a result of hypoxia?}

Phytoplankton productivity and biomass increase, and after they die, decomposition of their dead biomass by bacteria depletes the oxygen in the deeper waters causing other organisms to leave or die.

Plant Convergence

Plants that live in Similar environments that evolved structures that are different for their environments (Cacti from AZ and

Photic Zone

Portion of the marine biome that is shallow enough for sunlight to penetrate for photosynthesis

Predictions about relative degree of productivity of ecosystems?

Predictions: Productivity should vary with amount of light/temperature AND Precipitation Primary production tends to be highest near the equator, where temperatures are warm and moisture is plentiful all year long. In places where plant growth is limited by moisture or temperatures, production is less. But even with 2 factors, still lots of variation

Depict the flow of carbon between primary producers, consumers, and decomposers

Primary producers --> consumers --> decomposers

Phosphorous Cycle

Primary producers assimilate PO43- from soil. Consumers get PO43- from their food. In shallow oceans PO43- is cycled rapidly among primary producers, consumers, and decomposers. Tectonic uplift: Decomposers release PO4 to soil; some is reincorporated by primary producers, some is leached. Assimilation: incorporating phosphorus and nitrogen into biologically usable compounds (primary producers) (the only source of phosphate fertilizer is mining.)

Primary producers are present in every biome, including the deep sea. How can there be primary producers in the deep sea when sunlight does not penetrate to these depths?

Primary producers in the deep sea use energy from chemical reactions to drive the reduction of CO₂ to organic compounds.

Declining population approach

Proactive strategy for detecting, diagnosing, and halting population declines Emphasizes environmental factors that cause a population to decline Requires that population declines be evaluated on a case-by-case basis Endangered species lists. We try to build a new environment and care for the species by observing them

How does energy flow through ecosystems?

Process: Photosynthesis; Digestion, assimilation, and growth; Excretion and death; and respiration

net primary production (NPP)

Producers use some of this production for their own metabolism; the rest is stored. The amount available for primary consumers is the amount of energy they consume.

Some strategies

Protected areas to preserve habitat and prevent overexploitation (see Theory of Island Biogeography) Degraded ecosystems and disturbance patterns can be restored (Restoration Ecology) New habitats can be created (sometimes) Using the market to influence exploitation e.g. CITES Controlling the spread of Invasive Species Using diversity to generate profit Sustainable practices in agriculture, industry, business (Reconciliation Ecology) Captive breeding for select species

Skeletons and Shells of the Ocean

Protective barriers on the bottom of the ocean created by biomineralization of carbon. The rest of the carbon lowers the pH levels in the oceans

How do we know how old fossils are?

Radioactive decay: We find this by measuring the predictability of the isotopes and look at its half-life and compare it to the surviving "parent" isotopes and the accumulating "daughter" isotopes

Rising Temperatures

Recent & Long-term Temperatures Trends; Datasets & Proxy Records The earth's temperature has increased in the last 200 years- supported by scientific evidence. The temperature increase of the last 200 years has been measured. Temperature change is not the same all over the world. In fact, some places are the same or cooler, although most places are warmer. It's the global average that's increased. Important point: The globally averaged earth surface temperature has increased, it has increased in the last 200 years, and the increase was measured by weather instruments.

Plants Respond to Global Warming

Red lines indicate the mean date of first flower formation for 33 native and 10 invasive species, as measured in three surveys over 152 years. The black bars indicate the range of flowering dates. The flowering are blooming for the purpose of reproduction earlier by 10 days. This will affect the ecosystem because the other species will have to adapt and this will cause evolution

The Great Barrier Reef

Reef corals accomplish another noteworthy feat: They make skeletons of calcium carbonate (CaCO3) that through time build the reef's three-dimensional framework. They cannot make larger skeletons because the acidification causes the coral to become stressed

What Options Exist to Manage Ecosystems Sustainably?

Reforestation (more plants = more photosynthesis), coral planting, travel less, conserve energy, eat with the seasons/less meat, tax on CO2 emission and reduce the population Government subsidies promote many unsustainable practices, such as overproduction in agriculture and excessive use of fertilizers. Government action may be needed to provide incentives for sustainable ecosystem management. Implementing the many options that exist for sustainable management will not be easy... {Which of the following are suspected environmental impacts of fracking? water table contamination and methane leakage into the atmosphere} {You are given 100 acres of land and asked to use the land for long-term reduction of atmospheric CO2, levels.

How Do Human Populations Grow (other than really fast)?

Remember that humans are recent additions At least relative to other life Estimates of population size... For most of human history, steady population size Last 250 Yrs. - exponential growth (Really due to technology advancement starting with the industrial revolution) The population is subjected to density dependent factors such as shelter and other resources

Temperature and Air

Rising and descending air organizes the atmosphere into a series of cells from the equator to the poles. High temperatures warm air near the equator. Because of its lower density, the warm air rises. As air rises and spreads outward toward the poles, it cools, eventually becoming dense enough to sink back to the surface. (Moves in a very cyclic motion)

Rivers

Rivers are freshwater biomes characterized by moving water. Rivers and streams, like lakes, vary tremendously in size and chemistry. (Rivers are flowing lakes are not) Because of currents, rivers are generally well-oxygenated, although oxygen levels may be lower in slowly moving rivers on floodplains. As with lakes, plants and large algae grow along river margins, while phytoplankton photosynthesize throughout the water column. Insects are important consumers, but other invertebrates, fish, turtles, and birds can all be abundant and diverse. Salmon and some other fish spend much of their lives in the oceans but swim up rivers to reproduce.

How many species will go extinct?

Scientists cannot accurately predict the number of extinctions in the coming century for four reasons: The number of species currently on Earth is unknown We do not know exactly where species live It is difficult to determine when a species actually becomes extinct We do not know what will happen in the future, including natural events, and what humans will do

What about longer than 200 years?

Scientists use "proxy methods" to estimate temperature and carbon dioxide concentrations PROXY RECORDS: Ice cores Ice caps and glaciers accumulated over thousands or millions of years. They contain bubbles of gas preserved from the time when each layer formed. Scientists drill cores and analyze the gas bubbles in each layer to see what the atmosphere was like at that time. Proxy records: Pollen analysis Scientists also drill cores into the sediments of ancient lake beds. By identifying types of pollen grains in each layer, they can tell what types of plants were growing there at the time. (air bubbles) Proxy indicators of temperature (from pollen, ice cores, etc.) were reviewed to establish ancient temperatures. These data (BLUE) overlapped with the direct temperature measurements (RED). (Gray shows statistical uncertainty. because it is an indirect measurement) The highest historical estimates is taking place during the 1950s - current. Climate change bioligists claim that the CO2 levels haven't been this high since 3 mya and could lead to the next extinction

Static life table

Shows the current probability of death E.g., Dall Mountain Sheep - Alaska Follow a cohort of individuals throughout their lives (and/or deaths)

What can we do?

Small-population approach. A species is designated as endangered when its populations are very small. A population's smallness alone can drive it to extinction. The small-population approach studies the processes that cause very small populations to finally become extinct

Reproductive strategies

Sockeye salmon - swim 5000 km., reproduce once, lay 1000's eggs, die. Few eggs survive, no parental care (R strategist) Elephants - Reproduce starting at age 10-12, produce 1 calf every few years, intensive parental care (K strategist) Agave - century plant. One reproductive episode, dies. Few offspring survive. Purple sea urchins. Produce many offspring each year for several years. Few survive. The optimal is a combination of r strategist and k strategist. Produce a good amount of offspring and invest a decent amount of time with each

Energy

Solar energy is the main energy source for most organisms. It enters the ecosystems via plants and photsynthesizers. Exceptions: there are a few types of ecosystems (caves, deep-sea hydrothermal vents) that use other forms of energy. Energy enters as sunlight (usually) and is turned into chemical energy (biomass) by primary producers Energy flows up the food chain as biomass is eaten Metabolic processes use energy, which is dissipated as heat Energy flows through the ecosystem *It is not recycled* (there is always some energy that is "lost") Ecosystems require a continuous input of energy to persist Fossil fuels are reserves of solar energy stored in the remains of organisms that lived millions of years ago.

Cranium Size Increase

Some of the increase in brain size is due to increase in body size, but brain size increased in hominins much faster than body size. The skull is growing and is becoming more round. This occurred due to natural selection. Our brain is the largest relative to body weight

Savanna

Tall, perennial grasses dominate this biome, which occurs in eastern Africa, southern South America, and Australia. Rain is seasonal and ranges from 75 to 150 cm per year. Scattered trees and shrubs usually drop their leaves in the dry season to conserve moisture. As in temperate grasslands, fire plays a key role in maintaining this biome. Large mammalian grazers are abundant and diverse; these include the migrating antelopes, zebras, and giraffes well known from Africa, but also kangaroos and other marsupials in Australia and large rodents in South America. (There is abundant tall grasses for them to eat) Predator diversity can also be high, as exemplified by lions and other cat species, hyenas, and wild dogs.

{If the Earth had no oceans would temperature at the equator be hotter or colder than they are now?

Temperature would be hotter; the oceans push the warm air to other areas and the water cools down the earth

Modeling Climate Change

The Earth As a System Forward & Negative Feedback Loops A closer look at the role of water vapor

gross primary production (GPP)

The accumulated energy

Cultural Influence in Other Species

The animals are using the tools we use everyday such as birds drinking out of milk cartons

Coral Reefs

The best-known reefs occur in shallow, tropical to subtropical environments where there is little water movement or accumulation of sand or mud, with the accumulating skeletons of corals building a structure above the seafloor. Nutrient levels are commonly low, but primary production is high and mostly tied to dinoflagellate algae that live within the tissues of corals. Free-living algae occur in reefs, but are kept at low abundance by grazing fish. Many species of invertebrates live within the reefs, often in nooks and crannies among coral heads that provide shelter from predators. Fish diversity can be especially high. Coral reefs also occur in the deep sea, but build gradually, as coral growth is slow in the absence of symbiotic algae.

Things to Know about Greenhouse Gasses

The biggest problem is increasing CO2, carbon dioxide. CH4, Methane, is also increasing and interacts with IR and has more "global warming potential" than CO2

Natural Selection Explains Human Differences

The climate of the different regions distinguish our characteristics (more sun = darker skin)

Evotranspiration

The combination of water coming Evaporation from bodies of water and transpiration from the soil

Energy Use Among Countries

The energy use by individuals is higher in some countries than in others because of differences in standard of living, greater amounts of travel, and the need to heat buildings in countries at high latitude. Human Development Index: (from lower to higher standard of living, with highest being 1) {In general what is the relationship between a country's ecological footprint and its overall standard of living? As the standard of living increases, so does the ecological footprint} {A college student walks down New York City's Fifth Avenue at 8:00 AM. She is late for class so she catches the bus for the last 2 miles of her commute. Did she have a larger ecological footprint when she was walking or when she was on the bus? More information is needed about, for example, the number of people on the bus and its fuel source, to accurately determine her ecological footprint in both situations.}

Elimination of ecosystem engineers

The extermination of beavers resulted in a large reduction in wetland and pond habitats across much of North America

Correlation of CO2 Levels with the Industrial Revolution

The fact that ice core data agree with direct measurements where both are available gives confidence in the CO2 curve reconstructed from ice cores. Measurements of air samples in glacial ice from the Law Dome, Antarctica, show that atmospheric CO2 varied little between 1000 and 1800. {In reviewing historical records and ice core data, researchers noted that atmospheric CO2 levels started to rise as humans began to burn fossil fuels. This is an example of what type of relationship? correlation} {Studies assessing the amounts of different carbon isotopes (12C, 13C, and 14C) in the atmosphere were important because they provided evidence that human activities were in fact adding CO2 to the atmosphere. This is an example of what type of relationship? Causation}

Becoming Bipedal

The foramen magnum, the hole in the skull through which the spinal cord passes, is repositioned so that the human skull balances directly on top of the vertebral column. The human spine is S-shaped so weight is directly over the pelvis. The pelvis is extensively reconfigured for an upright posture, with internal organs over it. Legs are longer to enable long stride length for efficient locomotion and their anatomy altered so the legs are directly under the body. The foot is narrower and has a more developed heel and larger big toe, which contributes to a springier foot. (this is for faster movement) {In addition to the shift to bipedalism, what major trend or trends do we see in hominin evolution as we look across our entire fossil record? increase in brain size and increase in body size}. Humans are more likely to look like juvenile monkeys because our body structures

What is conservation biology?

The global loss of biodiversity is a man-made crisis We examine what biodiversity is, what we have done to destroy it, and what we are doing to preserve it Conservation biology is guided by the following three principles: Evolution is the process that unites all of biology The ecological world is dynamic Humans are part of ecosystems

Overexploitation

The harvesting of wild populations faster than they can replenish. Often associated with fishing & hunting. Large animals with low reproductive rates are particularly vulnerable "European fishermen in the 1500's reported the Gulf of Maine waters so thick with cod that a man could walk to shore on their backs."

Researchers us the denaturation temperature of hybrid double helices to compare evolutionary relatedness. Complementary strands denature at 95 degrees. a researcher engineers a hybrid strand from two species and it denature at 93 degrees. What does this mean

The hybrid double helices are less complementary than the non-hybrid

Intertidal Zone

The intertidal zone lies along coastlines between mean high and low tides, meaning that organisms in this biome are exposed to the atmosphere on a daily basis. In sandy intertidal zones, or tidal flats, many animals burrow into the wet sand to escape exposure at low tide. In rocky intertidal zones, organisms may close their shells tightly—for example, mussels and barnacles. Waves can cause mortality, as well, and so, especially along rocky coastlines, both algae and animals are securely attached to the substrate. Nutrient levels can be high, favoring strong algal growth. Consumers include a variety of sea stars, sea urchins, mollusks, barnacles, and corals. Spray Zone: Usually dry High Tide Zone: wet during high tide Middle tide zone: wet and dry Low tide zone: usually wet

How Does Age Affect Growth of Populations?

The logistic model assumes: Birth/death and density affect growth instantaneously. All individuals genetically the same All individuals equal in terms of birth and death - age doesn't matter But We Know This Isn't Realistic Individuals have different probabilities of living, dying and reproducing

Iron Limits and Primary Productivity

The more iron is equal to more productivity in some parts of the ocean it is the limiting factor

Tropical Rain Forest

The most diverse of all terrestrial biomes, tropical rain forests extend north and south of the equator from 10° N to 10° S. Annual precipitation is commonly more than 250 cm, and tree diversity alone often exceeds 300 species per hectare. Trees grow tall, and many have buttressed roots for support. Lianas and other epiphytic plants are common. Most leaves are evergreen and leathery and many have long pointed tips that facilitate drainage of excess moisture {Insects are especially abundant and diverse.} (The soil Ants alone make up as much as 30% of animal biomass in rain forests, and they are the principal grazers on rain-forest trees. {Because tropical plants have very high species diversity, they also have very low population density}

Ecosystem alterations have many consequences.

The most important driver is change in land use. Natural ecosystems are increasingly converted to cropland, grazing, and urban uses. Aquatic ecosystems have also been lost. Use of pesticides in agriculture control pests but also affect other organisms, such as pollinators. Conversion of coastal mangrove (tree line) forests to agriculture contributed to tsunami damage in southeast Asia in 2004. The mangrove may have slowed the tsunami down. Hurricane Katrina, in 2005, would not have caused so much damage and flooding in New Orleans if coastal wetlands had been left intact.

biogeochemical cycles

The movements of elements through organisms to the physical environment and back again. Water and fire have important roles (allows for succession). Movement of water transfers many elements. Fire speeds the cycling of many elements.

Carbon Cycling in the Ocean

The oceans play a vital role in the global carbon cycle CO2 mixes in the ocean and cycles between the ocean surface and the atmosphere CO2 is stored in the ocean waters and in sediments of the deep ocean floor Carbon is stored in the ocean as it dissolves in sea water, and it is stored when it forms sedimentary rock in the deep ocean floor

Pelagic Realm

The pelagic realm—the part of the ocean that is neither close to shore nor close to the seafloor—forms the bulk of the oceanic system. (majority of the ocean) Organisms live within the water column, either as plankton or nekton. In the upper 200 m or so of the pelagic realm, sunlight permits photosynthesis, with diverse algae and cyanobacteria as primary producers. In deeper waters, however, sunlight is absent and life is sustained by the rain of organic particles from surface waters. Minute arthropods dominate the zooplankton, while fish and cephalopods are key components of the nekton. Fish and squids are conspicuous consumers, but recent research shows that in the upper water column, heterotrophic protists may actually be more abundant and diverse.

Disruption of the Carbon Cycle

The two human activities that add the most CO2 to the atmosphere are: Extracting the very old, buried C that is oil, coal and natural gas. Burning it for energy releases CO2 Land clearing and deforestation of tropical forests. The slash piles are burned and release CO2. The amount of CO2 is increasing because humans burn fossil fuels, the population is increasing, and deforestation {In addition to burning fossil fuels, humans return CO2 to the atmosphere faster than it can be removed by:clearing forests for agriculture.}

Elimination of pollinators

The use of pesticides, and habitat destruction, have reduced pollinator numbers and disrupted reproduction in wild and domestic plants

The water cycle is solar-powered

The water cycle: consumes one-fourth of the total solar energy striking the earth during a year: precipitation: over land exceeds evaporation by 40 teratons/yr; surplus returns to the ocean in rivers evaporation: over the oceans exceeds precipitation by 40 teratons/yr; surplus is delivered by winds to the land masses

Correlation between niches, crops, deforestation, and drug-resistant

There is a high correlation between critically endangered animals and there corresponding niches. To meet the needs of a growing population, crop and pasture lands have grown through time to cover nearly a quarter of our planet's land area. Human activities are changing the distribution of forests, decreasing the area of tropical forests while restoring forested land in the temperate zone. Drug-Resistant tuberculosis there is an extreme concern that the antibiotics we use are going to be useless

Taiga

These cool, moist forests occur from 50° to 65° N. The short summer brings rain, and most of the plants are conifers like spruce, fir, larch, and pine, with an understory dominated by shrubs in the blueberry and rose families. The soils are deep with accumulated organic matter because the low temperatures result in slow decomposition, but they are acidic and poor in nutrients. Grazers include elk, moose, caribou, porcupines, hares, and a diversity of rodents. Bears, lynx, wolverines, weasels, mink, wolves, and foxes are well-known predators.

Nitrogen and Phosphorus Cycle

Through the use of fertilizer and other activities, humans add about 140 million tons of fixed nitrogen to the biosphere each year, an amount comparable to that contributed by microbial nitrogen. Only about 10% of the nitrogen added to croplands ends up in food: Much of the nitrate fertilizer leaves fields as surface runoff and travels by rivers to lakes or the ocean. Fertilizers also use phosphate, which also leads to runoff. This leads to eutrophication as the nutrients cause an increase in phytoplankton growth causing an algae bloom, when the algae dies the

Mammal Global Biodiversity

Tropical regions: have a great diversity of different kinds of mammal, representing all of the major groups from anteaters to apes. North and South Poles: There are few mammal species mostly rodents and their carnivore predators, plus seals and whales in the sea.

Tundra

Tundra occurs close to the North Pole, above 65°N, and is the coldest biome with short days in winter that limit the growing season. (high altitudes) The South Pole is largely surrounded by the ice and seas of Antarctica, and therefore there is very little area with plants. Tundra is the coldest biome, and precipitation and evaporation are minimal. Permanent ice occurs below a few centimeters of soil. The plants are mostly mosses, lichens, herbs, and low shrubs, with grasses and sedges occurring in drier places. Plant diversity is low, and most plants are small. (There is a permanent ice structure) A tundra biome would include which of the following

Temperate Coniferous Forest

Two broad areas of temperate coniferous forests occur below 50° N in North America, northern Japan, and parts of Europe and continental Asia. Along the Pacific coast of the United States, abundant precipitation permits growth of enormous conifers such as Douglas fir, red cedar, Sitka spruce, and redwoods. Much of the undergrowth is ferns and members of the blueberry family. (they need long roots) In the interior of North America, much less precipitation and colder winter temperatures support drought-resistant conifers such as ponderosa and lodgepole pines and Englemann spruce. Insect and vertebrate diversity are all higher than in taiga forests.

Terrestrial Biomes

Vascular plants dominate primary production, although mosses, lichens, algae, and cyanobacteria also contribute. Variety of consumers

Earth Warming

Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level." {Glacial expansion correlates with _______ amounts of CO2 in the atmosphere and temperatures _______ than those measured in 1950. decreasing; lower}

Probability of death

What is the probability that an individual of that age will die before next birthday? Cohort and static life tables may be identical if the populations are in equilibrium and the environment does not change Do you know which companies are very interested in life tables???? actualial tables For ground squirrels, the death rate is highest for males in general and old folk of both sexes. This is due to sexual selection and sexual dimorphism they are flashier and easier to spot

Complete Genome Sequencing

Whole genome sequencing indicates 96% similarity (by counting each nucleotide change - such as insertions, deletions even in non-coding regions) Gene mapping indicates 98.7% similarity (by counting similarities in coding regions) Humans only have ~0.1% difference between themselves This is due from the fact that we have the same common ancestor and generally the same physiology

Consider the characteristics of terrestrial biomes. Would you expect more biomass in a tropical rain forrest compared to one from the taiga?

Yes, because there is higher productivity at the equator than at the pole

Amphibians Indicator

amphibians are like the canaries of coal mines for providing evidence for greenhouse gases

The movement of carbon between organisms in a food web and the transfer of energy between organisms in different trophic levels

carbon can be continuously cycled but energy cannot

Studies assessing the amounts of different carbon isotopes (12C, 13C, and 14C) in the atmosphere were important because they provided evidence that human activities were in fact adding CO2 to the atmosphere. This is an example of what type of relationship?

causation

Carbon exists in the atmosphere, where could it have come from? Select all that apply.

cellular respiration by bacteria and burning of biofuels or fossil fuels

{Which of the following groups of biomes is listed in order of greatest to lowest potential evapotranspiration ratio?}

desert, deciduous forest, rain forest

Radiation

energy that is propagated in the form of electromagnetic waves.

Why the Global Temperatures Rise?

global warming is very likely man-made (or anthropogenic). Virtually all climate researchers agree that global climate is changing Virtually all climate researchers agree that human fossil fuel use plays a large role in driving climate change.

Invasive species have particularly devastating effects on islands because:

island species have typically evolved with few competitors and predators.

Anthropocene Period

modern era that emphasizes the dominant impact of humans on the Earth. {Figure 49.7 shows observed temperature changes versus those predicted for natural causes of increased temperature and natural plus anthropogenic causes of increased temperature. How would the lines be different if humans were predicted to have no impact on global temperatures? The line for natural causes would be the same as that for anthropogenic plus natural causes.}

mx - fecundity, and R0 - net reproductive rate

mx - number of offspring produced by each female during each time period If R0 > 1, population is increasing (reproducing more) If R0 = 1, population is steady If R0 < 1, population is decreasing (reproducing decreasing) R0 is simply whether a female is replacing herself, or not

Dead Zone

nutrients leached from croplands and transported down the Mississippi River result in an ominously named dead zone of oxygen-depleted bottom water. Within the dead zone, fish and seafloor invertebrates die in masses. {Which of the following statements is true regarding process of eutrophication? It can result in "dead zones" devoid of aquatic life}

Consequences of Ocean Acidification

ocean acidification causes carbonate ions in seawater to decrease, making it more difficult for some marine algae and corals to build their CaCO3 skeletons {Which of the following is a result of excess greenhouse gases added to the atmosphere by activities? An increase in Earth's surface temperature, a decrease in the pH of Earth's oceans, changes in Earth's precipitation pattern, and changes in the behavior of different plant/animal species)

CO2 Levels and pH

ocean acidification: An increase in the abundance of carbon dioxide in the oceans that causes the pH of seawater to go down. This will cause a decline in biodiversity and a decrease in the food source/medicinal use

Greenhouse Gasses

play an important role in trapping the infrared radiation In order of abundance: 1. Water vapor (H2O) 2. Carbon Dioxide (CO2) [the most important because they are increasing by the higher amount than the plants can convert and is human caused] 3. Methane (CH4) 4. Nitrous Oxide (N2O ) 5. Ozone (O3) 1. The atmosphere is a layer of gaseous materials, some of which interact with infrared radiation and absorb and re-radiate that energy 2. The greenhouse gases have been in the atmosphere a long time (billions of years). They maintain the planet's global temperature in a range that allowed our life forms to evolve 3. If they have always been there, and the 'greenhouse effect' is natural, then why do we now hear about it causing the earth's temperature to rise?

Gross primary productivity

rate at which energy is incorporated into photosynthesizers.

Regional Climate vs Biome

regional climate reflects the interactions among solar radiation, global patterns of circulation, and Earth's varying topography. Biomes, in turn, reflect these variations in climate.

Because CO2 is a greenhouse gas, a rise in CO2 levels correlates with a(n):

rise in temperature.

Life tables

summarize mortality and survival rates = static life table show the current probability of death (for individuals of different ages, in the current year) Or life tables follow a cohort of individuals and measure *survival* and *fecundity* (ability and probability of reproducing) = cohort life table show the probability of death of people from a given cohort (especially birth year) over the course of their lifetime.

The common phrase "Humans evolved from chimpanzees" is inaccurate. In reality, the evolutionary relationship between chimpanzees and humans is:

that humans and chimpanzees share a relatively recent common ancestor.

Origins

{Genetic sequence data from mitochondrial and Y chromosome DNA agree that the human family is young and it arose in Africa}. We compare our place in the tree of life through comparative anatomy, through molecular analysis, and through the fossil record. The chimpanzee is the phylogenetic outlier because its common ancestor with the rest of the group is the oldest node on the tree. We can thus treat it as an outgroup and assume that its sequence represents the ancestral state. Most recent common ancestor of the four human sequences analyzed. Rebecca Cann: Both Japanese and Native American sequences share the gain of restriction site 5, implying that the site gain occurred in their common ancestor. She looked at the mitochondria DNA which was useful because you can only get it from your mother so it is almost identical and is useful for studying for long periods of time. (the sperm only donates DNA). The restrictive enzymes to show a site at a specific location All primates share a number of general features that distinguish them from other mammals: nails rather than claws together with a {versatile thumb allow objects to be manipulated more dexterously}, and {eyes on the front of the face instead of the side allow stereoscopic (three-dimensional) vision.} This gives us the ability to use tools. We believe the that the common ancestor was around 18 mya