Bio 112 Exam 2
pollution
Mass Extinction Events: In the present, people that we're looking at extinction rates. Our extinction rates are not looking like those background rates, but they're starting to approach the rates of some of these other big extinctions. This sixth mass extinction is related to human activity. This includes things like habitat loss, pollution, overfishing, invasive species, etc... Those are the species that end up in an area where they didn't evolve and they can often wreak havoc. Often what we see for most species is they're not just facing one thing. Example: Marine species may be facing both habitat loss, ____, and overfishing.
Benthic zone
bottom of the ocean at all depths -bottom of an aquatic ecosystem; consists of sand and sediment and supports its own community of organisms
piloting
Many species use ___ to find their way by using familiar landmarks • In some species of migratory birds and mammals, offspring seem to memorize the route by following their parents south in the fall and north in the spring
M/N = m/n (M= # of Marked Individuals N= Total Population Size m= # of Marked Individuals in the recapture n= Total # of Individuals, marked and unmarked, in the recapture)
Mark Recapture Equation
Density-dependent factors
change in intensity as a function of population size and are usually biotic -limiting factor that depends on population size
Compass orientation
movement oriented in a specific direction
Ecological Niche
temperature rains, precipitation, and sunlight. -All those things are going to influence certain species. -the sum of a species' use of the biotic and abiotic resources in its environment
Population Biology
where is a population found about its distribution, what is its abundance, which is sometimes easier to figure out than other times ● Some different ways of figuring out abundance, are transects and quadrat ● If they're big it's easier -the study of the interrelationships between population characteristics and environments
behavior
response to a stimulus
Piloting
use of familiar landmarks
Species diversity
weighted measure that incorporates a species' relative abundance -The number and relative abundance of species in a biological community.
1. competition for resources (food, water nesting sites, oxygen, territory, light, nutrients) 2. disease and parasitism (stress-related degradation of health, infectious disease, parasitism) 3. Predation (increased predation as prey density increases) 4. Toxic wastes (ammonia, uric acid, alcohol, CO2) 5. Social Behavior (stress-mediated, dominance, mating, parental-care, predator-avoidance)
what are 5 Density-Dependent Factors That Limit Population Size?
Coastal Runoff
when As water moves from mountains down, it picks up lots of nutrients from the surface of the Earth and carries them along in the water to where the river meets the ocean called estuary -As water rushes down mountains and streams get wider and slower, nutrients gather, sink, and collect at the bottom as debris
Mutualism
- Considered plus-plus relationships - Both species benefit from the interaction -Can also be context-dependent -A relationship between two species in which both species benefit
Geographic distribution
- Distribution and abundances are two fundamental concepts in ecology
Gyres
- ____= massive ocean current cycles, bring warm water to colder latitudes and vice versa
estuary
-A habitat in which the fresh water of a river meets the salt water of the ocean. -This combination of shallow areas where rivers meeting the ocean carrying a bunch of nutrients in and highly productive, high productivity in those areas and ocean upwelling -Highly productive and often find lots of species, high species diversity, and we also often find them to be acting as nurseries for a variety of species and particular fish and sharks -They tend to be shallow, and the areas where there are immense nutrient inputs
Epiphytes
-A plant that lives on another plant -They do not take anything from it, they just live on top and they have these roots that actually are pretty much only found in the rainforest -Photosynthetic plants that grow on other trees rather than supporting themselves
Commensalism
-A plus zero interaction and this is a little tricky to find in the wild -An example is an orchid which is called an epiphytes
metapopulations
-A population made up of many small, physically isolated populations connected by dispersal. Set of small populations connected through dispersal Smaller pops can link on and off Overall pop maintained through dispersal Source pop - has individuals that can go to other spots, produce/birth individuals. Through dispersal → move into sink populations Metapopulation within a single species Conservation biology ex) roadkill from highwaysOccur in areas in which suitable habitat is patchily distributed and is separated by intervening stretches of unsuitable habitat
quadrat
-A square frame used for sampling in field work. -A square or rectangular plot of land used to mark off at random a physical area to isolate a sample and determine the percentage of vegetation and animals occurring within the marked area. -ex) Can't use with zebra's. They're moving
Precipitation
-Abiotic Factor -It is like rainfall -Any form of water that falls from clouds and reaches Earth's surface.
Temperature
-Abiotic Factor -To know-how is the pattern of the rainfall -A measure of how hot or cold something is.
Bogs
-Become really acidic and they are actually nutrient-poor -low swampy lands
Consumption
-Includes parasitism -A plus-minus interaction -the using up of a resource
Mimicry
-Is just copying -Ability of an animal to look like another more harmful animal -Batesian, Mullerian
Ecological Opportunity
-Marked by availability of more or new types of resources -Has driven a wide array of adaptive radiations -Example: Few other flowering plants were on the Hawaiian Islands 5 mya, so silverswords could diversify into many vacant niches
ocean Upwelling
-Nutrients that have fallen into the benthic regions are brought to the surface by currents that cause upwellings -As the surface water moves away from the coast, it is steadily replaced by nutrient-rich water moving up from the ocean bottom -process in which warm surface waters are replaced by colder waters from below
Parasitism
-One organism benefits and the other is harmed -organism that lives in or on a host taking resources from it
Ocean Acidification
-Problems of marine debris and then chemicals being released into the environment -The ocean is absorbing a lot of the excess carbon dioxide, which is changing the acidity of the ocean, which in particular has a really negative impact on things like animals with shells -decreasing pH of ocean waters due to absorption of excess atmospheric CO2 from the burning of fossil fuels
Present Abiotic Factors
-Temperature precipitation Acai Palm also benefits from some sort of periodic flooding, but they can't understand saltwater. They have a particular range of a particular niche that they need. -These are things like two cans that now also disperse the seeds. There's going to be competition amongst other plants for space, for water, for sunlight, in particular in the rainforest.
niche differentiation
-This change in resource use is called ___ ___ or resource partitioning -an evolutionary change in resource use, caused by competition over generations
Past Abiotic Factors
-This includes past events like continental drift, the rise of the Andes Mountains, sea-level changes, the closing of the Isthmus of Panama. -Animals are also important dispersers. -Example: Giant Ground Sloth dispersing Acai palm by defecating the seeds. The sloth is munching on some seeds here, heads down the road, and poops them out. The plant then has been able to distribute its offspring. It is important because it's going to increase their range, because the plant may even find a better habitat where it will be more successful. If the seeds were dropped off next to the parent and siblings, they will rot and will compete for food. Acai Palm also benefits from some sort of periodic flooding, but they can't understand saltwater. -Acai palms were eaten for a long time.
range
-To know the range not just the average of the rainfall -abiotic -Distance between highest and lowest scores in a set of data.
Exponential Growth
-Unchecked growth, not limited by density -Exponential growth curves are typically described as Jshaped - when growth is not limited by density -Even though r is constant, exponential growth adds an increasing number of individuals as the total number of individuals, N, gets larger: -Growth pattern in which the individuals in a population reproduce at a constant rate If r = 0.02 and N = 100, just 2 individuals are added in a year Every year, add 2 individuals. Rate of increase If r = 0.02 and N = 1 billion, over 20 million individuals are added to the population in a year
bottom-up influences
-When abiotic factors such as amount of nutrients, sunlight, or water determine the abundance of primary producer -Particular species at the "bottom" of the food web can have a major effect on community structure -The feedforward influence of the external environment on the resulting perceptual experience.
Co-evolution
-Where they are tightly intertwined -If this nematode can only infect one species and its future is closely tied -Process by which two species evolve in response to changes in each other
Batesian mimicry
-Which is when they look dangerous, but they are not actually dangerous, and they are sort of species that are stealing coloration that signals danger -A type of mimicry in which a harmless species looks like a species that is poisonous or otherwise harmful to predators.
Weather
-_____is a short-term pattern that is fairly unpredictable. It is a short-term pattern based on various conditions locally. -consists of specific short-term atmospheric conditions of temperature, precipitation, sunlight, and wind
niche
-is an ecological space where they find their resources. -An organism's particular role in an ecosystem, or how it makes its living.
ecology
-is the study of how organisms interact with each other and their environment___ ___ is the study of how organisms interact with each other and the environment. It is about looking at both the abiotic factors and the biotic factors and thinking about how all these things merge to influence species distribution and abundance. -ex) impacts humans have on the environment
Ocean Upwelling
-rising of deep ocean waters that occurs when prevailing winds blow along surface waters near a coastline -Often areas where humans have fished for thousands of years -Often see high numbers of things like marine mammals and seabirds because there is so much productivity, there is so much food available that high concentrations of species in the areas of upwelling
foraging
-searching for food -Animal ___ behavior (or simply ____) is an aspect of the animal feeding behavior in natural environments, where various activities are undertaken in order to search for, identify and catch food, and include behaviors concerned with its handling and storage. -Behavior associated with recognizing, searching for, capturing, and consuming food.
Behavioral ecology
-subset of organismal ecology: • The study of the behavioral adaptations that evolved in response to ecological selection pressures -*Researchers ask questions about genetics, hormonal signals, neural signaling, natural selection, evolutionary history, and ecological interactions -the study of the ecological and evolutionary basis for animal behavior
oceanic zone
-the "open ocean;" deepwater region beyond the continental shelf -vast open ocean from the edge of the continental shelf outward
climate
-the prevailing long-term weather conditions found in an area -the long-term large-scale pattern in weather conditions. Example: Looking at what September has been like for the last 50 years.
Macroevolution
-thinking about large-scale changes in patterns we see on Earth in terms of speciation or extinction. -Evolutionary change above the species level. -Large Scale changes in Life's Patterns types: Adaptive Radiation, Extinction
Proximate and Ultimate (A proximate cause is an event which is closest to, or immediately responsible for causing, some observed result. This exists in contrast to a higher-level ultimate cause, or distal cause, which is usually thought of as the "real" reason something occurred.)
2 Fundamental Levels: ___ and ___ Causation
Adaptive Radiation, Extinction
2 types of Macroevolution?
random, clumped, uniform
3 types of spatial distribution
-Evolution and ecology are closely intertwined -Species interactions in communities are an important driver of evolutionary change -Individual species interactions combine to create a complex web of interactions that change over time and space -These ideas have many practical implications as climate change and other human impacts are causing changes to communities worldwide
4 Global Patterns in Species Richness
Why Do Some Populations "Crash"? Case Study: Reindeer of St. Paul Island
40 reindeer were placed on island as food source for people In 30 years, reindeer population grew to 2,000 animals 12 years later only eight were left Several variables such as density-independent and densitydependent were examined Concluded that key cause of crash was over foraging of food supply
1) % marked is equal to the average % marked "recaptured" 2) Individuals don't move in/out of study area 3) Individuals mix between captures 4) No capture bias 5)Individuals do not learn to avoid capture 6) Individuals do not change behavior b/c of being captured
6 Mark Recapture Assumptions:
density independent
In exponential population growth, population size does not limit growth rate; this means it is ___ ___
-Most of the five massive mass extinctions are related to changes in volcanic activity. -Changes in the continental plates. -Shifting into colder areas -Cold terrestrial conditions for most of life on Earth. -Meteor Impact -human activity
6 Mass Extinction Events
microevolution
=Evolutionary change within a small group or species over a short amount of time • E.g. allele frequencies changing from 1 generation to next
they weight the cost of capture in their meal choices as well as benefits
A Test of Optimal Foraging in Cuttlefish Research questions: Can cuttlefish count? Can they distinguish: •different numbers • sizes • quality of prey, and cost of capturing them What about costs and the time and energy to capture and subdue prey? • Researchers compared cuttlefish that were hungry with cuttlefish that were satiated Results: • Hungry cuttlefish more willing to risk capturing larger shrimp that satiated cuttlefish • Suggest that ....
mass extinction
A ___ ___ is the rapid extinction of a large number of diverse species around the world At least 60% of the species present are wiped out within 1 million years ___ ___ are caused by catastrophic events They are the opposite of adaptive radiation -caused by extraordinary, sudden, and temporary changes in the environment - Species die due to exposure to exceptionally harsh short-term conditions, for example, volcanic eruptions
fossil
A ___ is the physical evidence from an organism that lived in the past
disturbance
A _____ is any strong, short-lived disruption to a community that changes the distribution of living or nonliving resources: >Forest fires, floods, and disease epidemics are all examples of disturbances
community
A biological ___ consists of all the populations of interacting species living within a defined area
Parasite-Host Coevolution
A nematode species parasitize an ant species Infected ants hold up their abdomens in a "flagging" posture, making them look like berries Nematodes can complete their life cycle inside the birds
Inducible Defenses
A physical, chemical, or behavioral defensive trait the in manifested only in response to the presence of a consumer (predator, herbivore, parasite) or pathogen. -defensive traits produced only in response to the presence of a predator
Metapopulations
A population made of up many small, physically isolated populations connected by dispersal.
(∆N / ∆t) = Births Deaths+Immigrants Emigrants
A population's overall growth rate, or change in population size (ΔN) per unit time (Δt), is a function of birthrates, death rates, immigration rates, and emigration rates WITH THIS EQUATION: ∆ means change
Carnivores
A predator kills and consumes all/most prey. They are typically ____ (meat-eaters), but seed predators consume and kill plant embryos
fitness
Ability to survive and produce viable, fertile offspring
Biogeography
Abiotic Factors and Biotic Factors -Example: Marsupial Distribution It is where you need to go back in time and understand how things like continental shifts and extinction events influence where they are today. -___ is the study of how distribution has changed throughout time and how various geological events influence distribution; study of how organisms are distributed geographically and through geologic time
Biotic (Living)
Abiotic or Biotic factors? Predators, Prey, Competition, Decomposers
Abiotic (Non-Living)
Abiotic or Biotic factors? Water, Air, Sunlight, Climate
coastal runoff
As water rushes down mountains and streams get wider and slower, nutrients gather, sink, and collect at the bottom as debris
climate change
Behavioral flexibility is a hot topic of research for ___ ___: Species whose behavior has higher flexibility predicted to survive rapid changes in temperature, precipitation, and shifting interactions with other species
higher flexibility
Behavioral flexibility is a hot topic of research for climate change: Species whose behavior has ___ ___ predicted to survive rapid changes in temperature, precipitation, and shifting interactions with other species
cost-benefit analysis
Behaviors have Costs and Involve Trade-Offs: • An animal can't maximize both the energy invested in finding food and in finding mates • Biologists use framework of __-___ ___ to link condition dependent behavior to fitness • Two important concepts to keep in mind: 1. Choices are not usually conscious 2. The behavior of individuals' traits varies among individuals
1. Choices are not usually conscious 2. The behavior of individuals' traits varies among individuals
Behaviors have Costs and Involve Trade-Offs: • An animal can't maximize both the energy invested in finding food and in finding mates • Biologists use framework of cost-benefit analysis to link condition dependent behavior to fitness • Two important concepts to keep in mind:
1. Piloting is the use of familiar landmarks 2. Compass orientation is movement oriented in a specific direction 3. True navigation is the ability to locate a specific place on Earth's surface
Biologists distinguish three categories of navigation:
coral reefs
Biologists use water depth and light to define zones in oceans: - Intertidal zone—submerged at high tide, exposed at low tide - Neritic zone—from the intertidal zone to about 200 m, defined by the continental shelf—the gently sloping, submerged portion of a continental plate; __ ___ can be found here
average annual temperature, precipitation, and variation
Biomes are governed by ...
Is It Food or Predation?
Bottom-up hypothesis: When their populations reach high density, hares use up all their food and starve; in response, lynx also starve Hares, primary consumer Food web Top-down hypothesis: Lynx populations reach high density in response to increases in hare density; at high density, lynx eat so many hares that the prey population crashes
NOT
Carrying Capacity (K) Is ____ Fixed and Can Be Overshot
Alternate
Case Study How is climate change going to influence the distribution of the Acai palm? Null Hypothesis: Climate change isn't going to change the geographic distribution of the Acai Palm. _____ Hypothesis: Climate change will cause a change in the distribution. The information collected are the following: Annual mean temperature The annual range of temperatures Precipitation in the wettest month, the driest month, and the warmest month. The mean and the average temperature are important to know how wide an area will be found. Another important reason is it can help figure out where it's most productive and what are the conditions the Acai palm can tolerate. The researchers took some climate modeling projections for 2080 for South America and they constructed a map. The prediction is Acai palm is going to have more habitat in 2080. Climate change influences different species in different ways. There may be more habitat in The future is based on climate change predictions than there are now. Niche Modelling is about getting an idea of what are all the conditions that the Acai Palm lives in and then looking for those conditions in the future based on climate modeling.
Toxoplasmosis
Cats Pregnant woman should not clean litter, parasite dangerous to fetus Protist from mouse, cats eat mice, infection causes mice to no longer fear mice -changes brain chemistry -a parasite that is most commonly transmitted from pets to humans by contact with contaminated animal feces
absence
Commensalism is a +/0 interaction:- Challenging to demonstrate because it is hard to show an ___ of effect on fitness
+/0
Commensalism is a ____interaction
radically
Community composition and structure may change ___ in response to changes in abiotic and biotic conditions
-The total number of species -The sum of interactions among all species -The relative abundance of those species -The physical attributes of the community, including abiotic factors—like size or altitude gradient—and biotic factors—like physical structure provided by the primary vegetation type
Community structure has four key attributes:
1. The total number of species 2. The sum of interactions among all species 3. The relative abundance of those species 4. The physical attributes of the community, including abiotic factors—like size or altitude gradient—and biotic factors—like physical structure provided by the primary vegetation type
Community structure has four key attributes:
1. Animals' visual systems may be able to detect it through a chemical reaction that involves electron transfer among molecules 2. Or they may have small particles of magnetic iron—the mineral called magnetite—in their bodies, allowing them to detect changes in Earth's magnetic field
Compass Orientation During cloudy weather, birds and fish appear to orient using Earth's magnetic field. There are two hypotheses for how animals detect magnetism:
circadian clock
Compass Orientation • Using the sun, stars and magnetic field to determine where north is • Most animals have a ____ ____ that maintains a 24-hour rhythm of chemical activity - use this along with sun's position • On clear nights, migratory birds in the Northern Hemisphere can use the North Star to find magnetic north
■ Food ■ Water ■ Nesting sites ■ Oxygen ■ Territory ■ Light ■Nutrients
Competition for these 7 resources:
−/−
Competition is a ___interaction that lowers the fitness of both individuals involved -The act of competing uses resources, so those resources are not available for other activities to increase fitness
lowers
Competition is a −/− interaction that ___ the fitness of both individuals involved: - The act of competing uses resources, so those resources are not available for other activities to increase fitness
proximate causation
Consolation behavior in prairie voles: • Voles will lick and groom group members that experience stressful event—but not strangers • Blocked oxytocin receptors = consolation behaviors no longer exhibited • Normal self-grooming continued • Demonstrates ___ ___
- Cryptic coloration and object resemblance - Escape behavior -Toxins and other chemicals - Schooling and flocking - Defense armor and weapons
Constitutive or standing defenses are defenses that are always present and include:
+/−
Consumption is a __interaction that occurs when one organism eats part or all of another
• Resources required to grow antlers • Energy to croak all night • Fitness to grow long tail feathers • Weaker animals (starvation, sickness) lose
Cost of Showy Traits: Organisms use showy traits as a signal of good genes, health. •Reliable signal for good genes- pay a cost to make it 4 things:
Sampling Methods: Mobile Species
Counting organisms that are mobile is harder Numbers along transect can change constantly as individuals move If individuals can be captured and tagged, the size of the population can be estimated using mark-recapture method
range loss
Current Extinction and Decline in Vertebrates; graph of cumulative extinction rate Another reason is that, in 1800, people hunted deers, birds, etc... for food. It is shown in the graph that a lot of extinction is occurring. The gray line shows what the background extinction rate should have been. ___ ___ is a problem for a lot of species, but for some species, range loss is almost at 100%.
Fitness trade-offs
Every individual has a restricted amount of time and energy at its disposal―its resources are limited Example: Female devotes a lot of energy to producing many offspring; she cannot devote that same energy to her immune system, growth, nutrient stores, or other traits that increase survival A female can maximize fecundity, maximize survival, or strike a balance between the two
Extinction
Decreases species diversity - Mass vs. Background -A term that typically describes a species that no longer has any known living individuals.
Life Table
Demographic info can be combined in a: ___ __ -Biologists used ___ ___ to determine whether lizard populations in different environments vary in basic demographic features: - By monitoring a population daily for seven years, biologists were able to calculate the number of individuals that survived each year in each particular age group as well as how many offspring each female produced
logistic population growth and thus define a habitat's carrying capacity
Density-dependent changes in survivorship and fecundity cause...
Intraspecific and Interspecific interactions
Density-dependent factors can be based on:
Density-Dependent Factors Limit Population Size
Density-dependent factors can be based on: Intraspecific ("within-species") interactions, such as competition among members of a cohort for food Interspecific ("between-species") interactions, such as predation, parasitism, or competition among species for food Density-dependent changes in survivorship and fecundity cause logistic population growth and thus define a habitat's carrying capacity
High fecundity, low survivorship
Describe the fitness tradeoff that is taking place in the life history pattern of the N. Pacific giant octopus (Enteroctopus dofleini)? The female lives 3-5 years, lays 1000s of eggs in a single event, cares for them to hatching and dies.
reproductioN
Dictyostelum discoides*: To cope with starvation, individual slime molds converge to form a slug, which then grows into a stalk with a patch of spores on top during ___. *Protista
Yes, because the ones in the middle have that lower fitness, they're partitioning the niche, they're dividing it up, but it's not a conscious choice. It's a result of who survives and the individuals with traits that lead them to lower competition because they're not overlapping with a competitor are going to survive. ●Evolution doesn't act on individuals.
Do you think niche differentiation involves a choice by those species?
niche
Early work on interspecific competition focused on the concept of the _____: - The range of resources that the species is able to use or the range of conditions it can tolerate - It can be envisioned by plotting habitat requirements on a series of axes, such as temperatures tolerated, food requirements, etc. - Because not all individuals are the same, the "population thinking" perspective is important
seed size
Draw your own niche model for a species that consumes mostly the smallest seeds, only rarely medium-sized seeds, and never large seeds. ***go to Lecture 12, 10/19 to see drawing*** answer: seed size
-You cannot get DNA out of a lot of fossils depending on how old the Fossil is. -It can be hard to get any DNA once they are mineralized. -There are limitations in terms of what type of tissue the species have. >Example: It will be a lot harder to find a fossil record of jellyfish than a turtle. -There are sort of set conditions that are required for fossilization to happen.
Drawbacks of Fossil Record:
facilitation, tolerance, inhibition
During Succession: existing species have one of these 3 effects on subsequent species:
Population clock
Emigration, immigration, births, deaths influence World → only look @ births, deaths Resouces unlimited→ exponential growth -Invasive species -Bacteria -After disaster Plateau - carrying capacity Births = deaths
Monogamous
Emperor penguins: ____ mating system: In a mating season, birds of this species form male-female pairs; Pairs may reunite over several breeding seasons; Both sexes use time and resources for parental care Environment is so extreme it takes 2 parents for offspring to survive!
Fitness Trade-Offs
Every individual only have a certain amount of time and energy ○ Female devotes a lot of energy to produce many offspring ■ She can't devote that same energy to other things like her development, her immune system, and her survival ○ When we're thinking about these trade-offs, you can sort of maximize your reproductive output or maximize your survival and get to some size right before you start reproducing ○ This lizard species are found in various habitats, right with various stressors ■ They did a comparison of lizards living in Austria and then lizards living in Brittany, France ■ They found this is sort of a harder place to live, Austria ● It's a higher elevation and colder ■ If you're down in France, low elevation and mild weather ○ The more harsh environment, there's lower fecundity but high survivorship ○ Why do you think you'd want bigger offspring if you're living in Austria? ■ They're more likely to survive ■ The trade-off is that you don't have as many ■ Having fewer offspring, but they're bigger and that's going to increase their survival ○ In the less harsh environment ■There's early maturity, and many offspring are smaller
-Temperature -Elevation -Environmental cues -There were more plant species and there wasn't as much opportunity to diversify.
Example of adaptive radiation: Silver Swords They are found in the Hawaiian Islands. The estimate is that they arrived about 500 million years ago and they were able to radiate into many vacant niches. They were able to differentiate into different groups. There's a couple of hallmarks There was this event and there was rapid speciation. They diversified into different niches. 30 species of these plants came from a different group or an ancestral group of plants called the tarweeds, which are found along the coast of North America. Why do you think there is less tarweed in North America? -____ -____ -_____ -____ The hallmarks are a monophyletic group, which means that when you look at that phylogenetic tree, there's an ancestor in all its descendants. They have all these unique traits because what they've done is they've diversified to fill those various niches. (05:40, an image of three different kinds of silver swords was shown to the class.) This is the opposite of convergent evolution.
Competition (-/- interaction) No, not a conscious choice - who survives
Explain whether niche differentiation (resource partitioning) involves a conscious choice by the species that are interacting. (15:01 lecture 12 10/19)
number of individuals
Exponential Growth Exponential growth curves are typically described as J- shaped - when growth is not limited by density Even though r is constant, exponential growth adds an increasing ___ ___ __ as the total number of individuals, N, gets larger: - If r = 0.02 and N = 100, just 2 individuals are added in a year - If r = 0.02 and N = 1 billion, over 20 million individuals are added to the population in a year K = carrying capacity N = # of individuals\ r = rate of increase d = change
J- shaped
Exponential growth curves are typically described as __-___ = when growth is not limited by density
Metapopulation Dynamics Depend on Extinction and Recolonization (Hanski)
Extinct, then reoccupied Source pop Dispersal, move back into extinct places and go back to old spots
on small islands far from shore because fewer resources are available and fewer individuals arrive
Extinction should be highest...
Community dynamics
Fires and floods are important to maintain community structure Their instinct was to prevent those processes from happening
physical evidence
Fossil Record: Fossils are direct evidence about what types of life forms lived at various points during the Earth's history. It is very helpful in finding out when certain traits arose, what types of species lived with each other or near each other, and at what time period. It's the ___ ___ of those different organisms living at different times. It informs us of various trends throughout time frames for different species
1. Salinity 2. Water depth 3. Water flow 4. Nutrient availability
Four abiotic factors: -Types of Aquatic Biomes
Niche model for 3 bird species.
Frequency of nests (y-axis) Branch height (x-axis) Reproduction A and B compete most with each other, overlap on graph (19:00 lecture 12 10/19)
Metapopulation Dynamics Depend on Extinction and Recolonization How Do Metapopulations Change through Time? Butterflies in Finland
Glanville fritillaries are an endangered species of butterfly native to the Åland islands off the coast of Finland They occupy isolated patches of habitat within their geographic range Research by Ilkka Hanski and colleagues illustrates the consequences of dynamic metapopulation structure for endangered species Hanski observed, butterflies occupied patches within range Mark recapture study Mark-recapture studies showed that migration rate is high enough to suggest that patches where a population has gone extinct will eventually be recolonized Over time, the overall population size was relatively stable even though populations came and went
How Do Metapopulations Change through Time? Butterflies in Finland
Glanville fritillaries are an endangered species of butterfly native to the Åland islands off the coast of Finland • They occupy isolated patches of habitat within their geographic range • Research by Ilkka Hanski and colleagues illustrates the consequences of dynamic metapopulation structure for endangered species
Graph
Graph in Lecture 14, 10/26: ■ The red part showed you the different values of our when we were seeing exponential growth which means density, independent growth, it doesn't matter how many individuals they are ■ At some point, as we approach carrying capacity right this, we see a slowing down growth begins to slow ■ When we see that plateau, that's showing us we've hit carrying capacity ■ The value can change, it's not static ● It's related to other interactions with other species ■This can be hard to estimate in the real world but the idea is that we know we can see populations that are at carrying capacity
Logistic Growth
Growth impacted by density, growth rate is density dependant When population density gets very high, population's per capita birthrate decreases and the per capita death rate increases, causing r to decline. This type of growth is density dependent Carrying capacity (K) is the maximum number of individuals in a population that can be supported in a particular habitat over a sustained period of time Every species has K -Growth pattern in which a population's growth rate slows or stops following a period of exponential growth
Shannon's Diversity Index
H ■ It represents the Shannon Index value. ○ Example ■ Species A ● How many individuals of species? ○ 17 ● How many individual A's? ○ 10 ● 10 17 = 0.59 ○ Take the natural log. ■ - 0.53 ● Multiply 0.59 and - 0.53 ○ - 31 ■ Species B ● How many out of those 17 belong to species B? ○ 1 ● One out of seventeen. ○ 0.06 ■ Natural Log ● - 2.8 ● 0.06 x - 2.8 ○ - .17 ■ Species D ● 3 17 = 0.18 ○ Natural Log ■ .31 ■ Add all together. ● It will be - 1.47 ● Multiply it by -1 ○The diversity measure will be 1.47.
Lecture 15 October 28th
Hare-Lynx study ■ Lynx populations ● Reach some sort of high density ● They eat so many hares that the prey population crashes ■ Null hypothesis ● Is that the cycle is not driven by predation, food, habitability, or some combination of these two ● None of this matters in terms of that cycle ■ Bottom-up hypothesis ● Is that the food so the plants are going to control this cycling top-down is the reverse ● It is that the predators are going to control this cycle maybe it is some interaction of the two ■ Control plot ● It does not get the treatment ● Nothing is being done there ● No manipulation happening ● They have a plot where they exclude the links ● Now the hares are in there ● They are not subjected to being eaten ■ Extra food ● They are still predators in these ● The final plot is where they actually exclude the links ● They did this for years, from 1987 to 1994 ○ To perhaps catch the cycle ● If you just did it for one year and what if that is like the worst snowiest year on record ○ You want to do multiple years ○ You kind of capture any variability in there ○ You can have more confidence that what you are seeing is not a reflection of some single year event, but what is happening in these plots over the years ○ You kind of capture any variability in there ○ You can have more confidence that what you are seeing is not a reflection of some single year event, but what is happening in these plots over the years ■ Find ● No links and extra food together had the highest hair survival rate ● Even if you sort of added those two values together, you still do not get to this ● They found was it was some combination ● There are both top-down and bottom-up effects happening ■ Synergy ● There that those hairs, when they have both extra food and no predation, can survive ■ Hare survival ● You have to remember that many predators are also prey ● They also may be hosts ● They may have mutualistic relationships, they may have parasites ■ Density ● Independent factors ● Carrying capacity ● Focusing on density-independent factors or things like a volcano erupts or something like that ● So it is irrelevant to the density of whatever population are looking ■ Pixi hormonal changes ● Promote higher death rates in a crowded population ● Individuals voluntarily stop mating, said overcrowding does not occur ■ Surviving and reproducing ● Producing offspring that survive ● Unlikely that there would be some mechanism that would stop that so voluntarily stop mating ■ Predator-prey cycles, there is another really important type of population dynamic
Population Cycles: The Hare and Lynx Case Study
Hares eat plants, lynx eat hare Axes units
biotic factors
Henry Gleason contended that the community found in a particular area is neither stable nor predictable - largely a matter of chance; he downplayed the role of ___ ___like species interactions in structuring communities
low survivorship. and Vive versa
High fecundity →
1) Invasive species such as the zebra mussel have been transported 2) Fisheries have been overexploited, leading to cascading food-web effects 3) Debris is intentionally and unintentionally disposed of in aquatic biomes, clogging creeks and creating masses of trash in the oceans 4) Chemicals have been released into aquatic habitats 5) Global climate change is leading to ocean acidification, which has negative effects on many species
How Are Aquatic Biomes Affected by Humans? 5 ways:
ocean floor
How do we know mass extinction and background evolution happened? You can see signals in the rocks. Often we look in the oceans, we core the ___ ___ This is when you will send a big metal tube down that will pull out a whole core of the ocean floor. You will look at the number of usually marine invertebrates like clams and snails.
Demography in life history
How many individuals are presently based on 4 different processes? ○ The two processes are going to increase population size and it's going to be pretty intuitive ■ Populations are going to grow due to birth and immigration ■ Populations are going to shrink due to deaths and emigration ● Is it easy for those grey squirrels to get from one forest to the next in Massachusetts? ● Do they have to cross highways in strip malls and housing tracts? ● Do you have enough nutrients? ● Have you matured enough that you can actually give birth? ○ Deaths are going to be related to those same things ■ What is the competition like? ○ Example ■ It is labor-intensive to collect this information for many species ○ Biologists monitored the population daily ■ They looked at who survived and who reproduced ■ For females, when can you first lay eggs? ○ In age 1, how many lizards survive to age one? ■ Half of these lizards do not even survive to be one year old ■ Survivorship is the percent surviving from the original thousand ■ In overall contribution to reproduction, do they contribute a lot? Why? ○ Age cohorts ■ What is the distribution? ■ What are the numbers of individuals in these different cohorts? ■How reproductive are they?
MacArthur and Wilson
How their seed can survive? ○ Forest fire wipes out everything above the soil and there are seeds that can germinate and recover ● Patters of diversity ○ Theory of island biogeography ■ It is useful in predicting what types of diversity you might see ■ It is elated to the size of your habitat and how close it is to other habitats ■ How close it is to the mainland? ■ ___ and ___ thinks about theoretically ●The islands are the same size but fewer species
Wildlands
Human Land Use Is Displacing Natural Biomes Natural biomes result from 3.5 billion years of interplay among geology, climate, evolution, and ecology Explosion of human populations is creating impacts so significant that some researchers have called this a new epoch of history, the Anthropocene Over 75% of Earth's ice-free land shows evidence of direct alteration by humans: - Examples: farming, logging, and urban development - ___ account for just 11% of terrestrial NPP
Human Land Use Is Displacing Natural Biomes
Human Land Use Is Displacing Natural Biomes •Natural biomes result from 3.5 billion years of interplay among geology, climate, evolution, and ecology •Explosion of human populations is creating impacts so significant that some researchers have called this a new epoch of history, the ___ • Over 75% of Earth's ice-free land shows evidence of direct alteration by humans: - Examples: farming, logging, and urban development - Wildlands account for just 11% of terrestrial NPP
estuaries
In ___, where freshwater rivers meet the ocean, nutrients are plentiful: - In ___, sunlight is also plentiful, making them among the most productive environments on Earth
1. Organisms 2. Populations 3. Communities 4. Ecosystems 5. Biosphere
In ecology, researchers work at five main levels:
Optimal Foraging
Hypothesis that individuals make decisions that have the effect of maximizing the amount of usable energy they take in given the costs of finding and ingesting their food and the risk of being eaten while they're at it. -natural selection favors those who choose foraging strategies that maximize the differential betwen cost and benefits
(K-N) / K
If a population of size N is below the carrying capacity K, the population should continue to grow; specifically, a population's growth rate should be proportional K = carrying capacity N = # of individuals\ r = rate of increase d = change
positive (+)
If a species gains a fitness benefit, it is:
dN / dt = rN
If ecologists are interested in understanding what is happening to populations at a given moment in time, they can calculate the instantaneous growth rate WITH THIS EQUATION: N = population size t = time
negative (−)
If the species incurs a fitness cost, it is:
• island size • how far it is from the mainland
Immigration and extinction should also vary depending on:
You need to think about when it comes to island biogeography is the size of the island and how far it is from the mainland
Immigration is going to be highest on large islands that are near the mainland because they're easier to get to ○Extinction is going to be highest on small islands far from the shore because there are fewer resources
• Individuals that arrive are more likely to represent a species that is already present • Competition should prevent new species from becoming established when many species are already present on an island
Immigration rates should decline as the number of species on the island increases because:
on large islands near the mainland because immigrants are more likely to find them
Immigration should be highest...
The Reindeer on St. Paul Island Overshot the Island's Carrying Capacity
In 1910, K was 600 Ate rapidly → reindeer population grew due to overgrazing → K dropped
1. Colonization of a new habitat: A few individuals colonize a new habitat with plentiful resources 2. Recovery after a disaster: A population has been devastated by a storm or some other type of catastrophe and then begins to recover, starting with a few surviving individuals
In nature, exponential growth is common in two circumstances:
low
In soils with __ nitrogen: - Plants invest resources in root nodules to support large colonies of nitrogen-fixing bacteria
high
In soils with ___nitrogen: - The costs of supporting the nitrogen-fixing bacteria colonies may outweigh the benefits, turning a + / + interaction into a + / − interaction
# of Marked Individuals
In the Mark Recapture Equation, M/N = m/n What does M stand for?
Total Population Size
In the Mark Recapture Equation, M/N = m/n What does N stand for?
# of Marked Individuals in the recapture
In the Mark Recapture Equation, M/N = m/n What does m stand for?
Total # of Individuals, marked and unmarked, in the recapture
In the Mark Recapture Equation, M/N = m/n What does n stand for?
wind
In the spring, the lake melts; as the surface warms, it becomes denser and begins to sink, aided by ___
Linet Zone
In which is sort of the offshore area
oxygen
In winter, surface water is colder but higher in ____, while the water at the bottom is warmer, denser, and higher in nutrients
nutrients
In winter, surface water is colder but higher in oxygen, while the water at the bottom is warmer, denser, and higher in _____
Adaptive Radiation
Increase species diversity -burst of massive speciation -Example: Galapagos finches This ancestral finch managed to get to the Galapagos Islands and adapted to all different types of life. Some of them live in trees, some of them live on the ground, some eat seeds or insects, etc... When that ancestral population got to the Galapagos, there was no competition to live in a tree or live on the ground; or eat nuts, seeds, or eat insects. They were able to radiate into all those different ecological spaces. -An evolutionary pattern in which many species evolve from a single ancestral species
clumped spatial distribution
Individuals associate in social groups for feeding, mating, and/or avoiding predators; or resources are patchy. -Positive interactions among individuals (e.g., sociality) Attraction to common resources
uniform spatial distribution
Individuals distance themselves from each other as they compete for nutrients, nesting space, or other resources. -type of population dispersion; ex. orchards, flocks of birds
Migration
Individuals move in search of food, mates, shelter, and other resources. ___ is the long-distance movement of a population associated with a change of seasons.
inflexible
Innate behaviors tend to be ___ to environmental changes
1. Sense insects by tiny hairs which releases electrical signals to other cells 2. Molecular events inside the pads causes them to shut 3. Enzymes digest the prey
Insectivorous Plants: Venus Fly Traps *responding to insect touch. 3 things that happen:
Competition
Is a key factor in thinking about how evolution plays out -the struggle between organisms to survive in a habitat with limited resources
Thermocline
Is going to trap things -a layer in a large body of water, such as a lake, that sharply separates regions differing in temperature, so that the temperature gradient across the layer is abrupt.
Lake Turnover
Is sort of a similar dynamic, but it really is just dependent on what we call a thermocline right in -The yearly rising and sinking of cold and warm water layers in a lake.
MacArthur-Wilson Model
Island biogeography model that predicts an equilibrium between those species immigrating to an island and island occupants becoming extinct
Species Diversity
It is a weighted measure that incorporates not just the number of species, but their relative abundance.
Disturbance
It is part of life. ○ It can be a necessary part of life. ○ Some types of disturbances may cause really radical changes in certain areas. ■ Forest fire ■ Flood ■ Disease ● Natural fires that are burning every other year get rid of a lot of scrub brush and fuel for fires. ●If you're damming rivers, you're also stopping nutrients from getting downstream.
Oceanic Zone
It is the deepwater area -beyond the continental shelf
Primary Succession
It is when the disturbance removes everything.
Secondary succession
It is when the disturbance removes the organisms, but the soil is still intact.
more
based on picture pn October 7th lecture video at 53:24, will acai have more or less habitat in 2080?
Carrying Capacity Is Not Fixed and Can Be Overshot
K changes over time due to fluctuations in food availability, space, and other density-dependent factors Variability in growth data is common and expected Populations may dramatically overshoot the carrying capacity and then crash or cycle in intervals above and below carrying capacity
CoevolutioN
Knit co-evolved species are tied to each other ○ If you are a keystone species, you may not be the most abundant but you have an important role ■ Example ● The wolves in the Yellowstone had been hunted out and they would be stored in the 1990s ●It decreased those other herbivores which allowed some of the native plants to recover
Rain Shadows
Large Scale Process: ___ ___ (59:07 in October 7th lecture 9) This is the Cascade Mountains around the Pacific Northwest. A lot of moisture comes in off the ocean and because of these mountains, the air rises. Just like those Hadley cells, as it cools off, it rains back down and that prevents moisture from getting over the mountain ranges. What happens is it's very rainy areas on the ocean side of a mountain range and then dry areas on the inside or the other side. ___ ____ is the side where there's not a lot of rain that gets over the mountain range. There are large patterns where there are big mountain ranges that prevent that precipitation from moving further on to the landmass.
Tend to grow quickly, reach sexual maturity at a young age, and produce many small eggs or seeds
Life-History Patterns Vary across Species •Organisms with high fecundity:
Tend to grow slowly, invest their energy and time in traits that reduce damage from enemies, and increase their own ability to compete for resources
Life-History Patterns Vary across Species •Organisms with high survivorship:
-Austria is harder to live in (cold, low fucundity but high survivorship) than France for Lizards. -Austria - fewer but bigger offspring, more likely to survive in colder/harsher environment. Tradeoff: not as many offspring
Life-History Patterns in Zootoca Vivipara Differ in Populations that Experience Harsh and Mild Conditions
Character displacement
Mechanisms of Coexistence: Niche Differentiation • Galápagos finches provide an important example of ___ ___ • Galápagos finches are well known for having a diversity of beak shapes: - These different shapes allow birds to specialize on particular food types, like small or large seeds
extinction and recolonization
Metapopulations are Dynamic: There is a balance between ___ and ___
dynamIc
Metapopulations are ___: There is a balance between extinction and recolonization
Secondary Succession in Temperate Forests
More forests in MA now than 200 years ago Community recovered Climax community → long lived Pioneering species get outcompeted Early successional community Mid-successional community
Range
Most species identification guides show the ___, or geographic distribution, of different species: -Abiotic and biotic factors both determine ___
+/+
Mutualisms are ____interactions that involve a wide variety of organisms and rewards
Continental shelf
Neritic zone—from the intertidal zone to about 200 m, defined by the ___ ___
NPP
Net Primary Production or ___ ● Rate that initial energy produced by those primary producers, and that is the energy that goes up those trophic levels ●The more NPP, the more primary consumers, and secondary consumers and apex predators and all those things, it is a tiered system
adaptive
Not all behaviors are ___ in all environments:
Lynx and hare experiment
Null hypothesis: Cycle not driven by predation or food availability Control - nothing being done 1987 - 1994 Many results to capture variability No lynx & extra food → high hare survival rate Both top down and bottom up happening ○ Hare seat ■ This is hairs per kilometer squared ■ This is links per 100km squared ■ But there is this 10-year cycle ■ Where the hair has sort of a boom and then a bust, and then the links follow two years behind two hypotheses: 1. hares use up all their food when their populations reach high density and starve; in response, lynx also starve 2. Lynx populations reach high densities in response to increases in hare density. At high densities, lynx eat so many hares that the prey population decreases experimental set up: 3 control plots, 1 plot w/o lynx, one plot with extra food, and one plot w/o lynx AND extra food conclusion: hare populations are limited by food and predation. When predation and food limitation occur together, they have a greater affect than either factor does independently
75
Ocean Currents Have Regional Effects on Climate About ___% of the Earth's surface is covered by the ocean. The ocean has a moderating effect on temperature. We get the adhesion and cohesion because of the bonds that keep happening between water molecules. In addition to that water is a good solvent. Water can absorb a lot of heat without changing its temperature. it takes a fair amount of time for ocean temperatures to change. The ocean is at its warmest every September as it is at the end of the summer. It takes the whole season of summer and all that warm heat from the sun to warm the water. There are lots of ocean currents happening that are moving massive amounts of ocean water around. Large gyres or cycles influence various parts. North Atlantic Gyre warm water comes up the east coast of North America, but then it goes across the Atlantic towards Europe. Large ocean currents are also important and have a big influence even on terrestrial conditions.
Nutrients
Ocean Upwelling Brings ____to the Surface
finding and ingesting
Optimal Foraging= Hypothesis that individuals make decisions that have the effect of maximizing the amount of usable energy they take in given the costs of ___and ___ their food and the risk of being eaten while they're at it.
high survivorship
Organisms with ___ ___: - Tend to grow slowly, invest their energy and time in traits that reduce damage from enemies, and increase their own ability to compete for resources
reproduction
Organisms with high survivorship, spend a lot of time and energy growing first ○Getting to some size and being able to compete for resources before they start shifting and putting resources into ____
biotic
Past and Present Biotic Factors • The distribution of a species is often limited by____ ("living") factors related to other organisms • Interactions may be beneficial or harmful: - Examples: ▪ Pollinators▪ Pests▪ Predators▪ Parasites▪ Competitors
light, gravity
Plants sense their environment in two ways:
gravity
Plants sense their environment: - Roots grow down, not up
light
Plants sense their environment: -Speed up growth if rival begins to overshadow
4 (You have average annual temperature and average annual precipitation, and the blobs represent the ranges of different biomes. If you're looking at that, which would you designate the biome with the highest rainfall? Y-axis= temperature; X-Axis= precipitation The Biome that has the highest rainfall is letter A. Which has the highest variation in temperature? The highest variation in temperature is number 4.)
Poll question from lecture 9 october 7th at 1:09:53: In the figure in the picture, which number would designate the biome with the highest rainfall? 1, 2, 3, or 4?
High fecundity, Low survivorship
Poll: Describe the fitness tradeoff that takes place in life history pattern of North Pacific giant octopus? Female lives 3-5 years, lays 1000s of eggs in a single event, cares for them to hatching and dies
b: Earthquake (Other are dependant → related to how much food and how many people there are Diseases - closer people are, easier to transmit disease)
Poll: Which of the following could be a density-independent factor limiting human population growth? a) ebola infection, b) earthquakes, c) epidemic measles d) famine
the more energy the female devotes to offspring, the less that can be devoted to surviving
Poll: Why can't a female lizard have both high fecundity and high survival?
Answer: density-dependent factors lead to fewer births and increased mortality (Disease, less food/resouces -Females may delay birth with lack of resources Density independent- volcanoes erupt)
Poll: Why do populations grow more slowly as they approach their carrying capacity?
A) may change as environmental conditions change
Poll: a population's carrying capacity___ a) may change as environmental conditions change b) generally remains constant over time c) increases as the per capita growth rate (r) decreases d) can never be exceeded
communities 2 and 4
Poll: where do you find the highest species richness? in figure 1, lecture 12 10/19 at 42:57
Specialists or Generalists
Pollinators and Flowers Can Be ___ or ___ in Their Mutualisms
sinks
Population with negative growth rates are ______
deaths and emigration
Populations decline due to ___ and __
birth and immigration:
Populations grow due to ___ and ___
immigration
Populations grow due to birth and ____: - ____ occurs when individuals enter a population by moving from another population
maintained
Populations may blink on and off over time, but the overall population is ____ at a stable number of individuals
sources
Populations with positive growth rates are ____
Predation
Predator kills and consumes the prey -An interaction in which one organism kills another for food.
1. "Rovers" move after feeding in a particular location 2. "Sitters" stay in one location to feed
Proximate Causes: Foraging Alleles in Drosophila melanogaster Fruit fly larvae exhibit one of two behaviors during feeding:
foraging (for)
Proximate Causes: Foraging Alleles in Drosophila melanogaster: Fruit fly larvae exhibit one of two behaviors during feeding: • "Rovers" move after feeding in a particular location • "Sitters" stay in one location to feed • Experiments determined that this feeding behavior is inherited via the ____ gene; the rover allele is dominant to sitter • Adult flies express the same foraging alleles as larval flies—rover flies disperse more often and farther than sitter flies
proximate mechanism
Proximate Causes: Foraging Alleles in Drosophila melanogaster: Results link a ___ ___ with an ultimate outcome: • In this case, presence of certain alleles is responsible for a difference in fitness in specific types of habitats
Sitter allele
Proximate Causes: Foraging Alleles in Drosophila melanogaster: ___ ___ is favored at low population density: • do not waste energy searching for food
Rover allele
Proximate Causes: Foraging Alleles in Drosophila melanogaster: • ___ ___ is favored at high population density: • more likely to find unused food patches
how
Proximate-___ it occurs
dynamic
Ranges are ___—in constant flux as abiotic and biotic factors change over time
1. Intersexual selection: When individual of one sex choses individual of another sex as a mate 2. Intrasexual selection: Two individuals of the same sex compete with one another for mates
Sexual Selection: Favors individuals possessing traits that increase ability to obtain mates Two types of sexual selection:
Type 2
Reminder to go to Lecture 14 from 10/26 to watch lecture video at 24:00 Plotting out survivorship from: "Life Table for Zootoca Vivipara Females in the Netherlands*" What kind of survivorship does this look like? Plot and see what survivorship would look like by plotting age class vs number of survivors
Logistic Growth Equation
Reminder to look at powerpoint slides to see the Logistic Growth Equation K = carrying capacity N = # of individuals\ r = rate of increase d = change Answer: Logistic Growth Equation
nematode
Round worms. The first animals to have a full digestive tract (2 openings).
parts per thousand (ppt)
Salinity • The proportion of solutes dissolved in water determines its salinity, measured in ___ ___ ___ • Salinity has dramatic effects on osmosis and water balance in organisms: - Species are adapted to specific ranges of salinity - It is a major determinant of species distributions
- Species are adapted to specific ranges of salinity - It is a major determinant of species distributions
Salinity has dramatic effects on osmosis and water balance in organisms:
transects
Sedentary species can be counted along lines of known length called ___ or in plots of known size called quadrats
quadrats
Sedentary species can be counted along lines of known length called transects or in plots of known size called ___
Why Do Some Populations Cycle?
Snowshoe hare and lynx in Northern Canada is a classic case of population cycling among two species Snowshoe hares = herbivores Lynx = predators Populations cycle every 10 years on average, but changes in lynx density lag behind changes in hare density by about two years
1000
Some estimate that the current extinction rate is ___ times higher than background—the highest since the asteroid impact
neutral (0)
Some interactions have no effect on fitness, which is:
coevolution
Species act as agents of natural selection when they interact; this is ____—a pattern of evolution where two species influence each others' adaptations
distribution, abundance
Species interactions may affect the __ & __ of a particular species
interchangeably
Species richness and and Species diversity are often used ___
400 = total population size M=200, # of Marked Individuals N= ???, Total Population Size m= 75, # of Marked Individuals in the recapture n= 150, Total # of Individuals, marked and unmarked, in the recapture 200/x = 75/150 solve for x, algebra
Suppose you trap and mark 200 fish in a Massachusetts pond. One month later you recapture 150 fish and 75 are marked. Estimate the total population size. Lecture 13, 10/21, @ 56:45
survivorshIp
The Human Population Has Been Growing Rapidly: It took all of human history (~200,000years) to reach a population size of 1 billion in 1804 and only 123 years to reach 2 billion • Due to changes in ___
bycatch= accidentally caught in fishing nets Sea turtles have high bycatch rates Reproduce on land
The Mortality of Adult Sea Turtles in Fishing Nets Dramatically Affects Sea Turtle Populations
ecosystems
The Water/Energy/Food Nexus • Water, energy and food essential for human well-being • It is about balancing different resource user goals and interests - while maintaining the integrity of ___ (FAO)
Eight-foot Zone
The area where sunlight is no longer reaches
character displacement
The change in species' traits is called ___ ___ -enables species to exploit different resources and makes niche differentiation possible -Tendency of characteristics to be more divergent in sympatric populations than allopatric populations.
Both evolution and ecology are closely intertwined
The history of a place is important ○ The abiotic and biotic factors are going to influence what species you see ○ The species interactions can drive evolutionary change ■ Competition may drive some sort of change ●The potential for hybridization
extinction
The opposite of speciation is ____. This will decrease species diversity. There are two kinds of ___: mass ___ and background ____. Mass ___ is a huge event when the dinosaurs were wiped out. Mass ____ is a big event that wipes out a large percentage of the population. At least 60% of the species present are wiped out within one million years. These events are caused by some sort of catastrophes such as massive volcanic activity, earthquakes, or asteroids.
dynamic, conditional
The outcome of interactions among species is __ and __ ___, ____
random spatial distribution
The dispersal of seeds, gametes, or larvae is random due to variation in factors such as wind and currents. -Neutral interactions among individuals Random distribution of resources
direct
The fossil record provides ____evidence about what organisms from the past looked like, where they lived, and when they existed
Uniform distribution
The important about a population when it comes to evolution is to define a population ● The human population is growing quite rapidly ● Population dynamics ○ How is it changing? ○ When you are thinking of a population, there are exposed to the same sets of conditions ● There is always individual variability ○ It is the key in terms of what happens to a population ○ It allows the population to adapt and survive ○ There are some adaptability as well as conditions change ● Distribution and abundance ○ First, you need to figure out where are they and how many are there? ● The abiotic factor that would determine the range of a species is temperature ○ Precipitation ○ Sunlight ● The biotic factors that are going to influence the distribution and abundance are pollinators ○ They expand and contract based on different things ● Population density ○ Depending on what species you're looking at ○ Example of dandelions ■ A plant that is distributed by wind ■ The wind isn't going to particularly pick up a seed and plant it down then pick up another seed and plant a foot away ○ Clumped ■ Safety in numbers ● Example ○ Schooling fish or birds that are flying together ○ ___ ____ ■ It relates to decreasing competition among individuals ● Spreading out in an even manner ● Example ○ Nesting bird ● Species that are sedentary ○ It is straightforward figuring out how many there are and where they are? ○ When species move, you can't go put a quadrat on a seal ■You can't use those quadrats or line transects because the numbers are changing
Shannon Index
The index most commonly used to describe species diversity quantitatively.
CommunitieS
The interaction of all those living spaces ○ These interactions can sometimes benefit one and neither benefit nor harm the species. ○ Example is the Treehoppers ■It is a type of insect ■ They have this predator, the jumping spiders. ■Ants are protecting them.
birth, death, immigration, and emigration
The number of individuals present in a population depends on four processes:
positively
The number of species is usually ____ correlated with habitat size: • Larger mainland habitats have more niches and should support higher numbers of species • However, islands in the ocean have smaller numbers of species than do areas of the same size on continents
● Mutations ● Selections ●Isolation
Two Populations 1. Homozygous Dominant Individuals 2. Homozygous Recessive Individuals -These two populations look more similar because of that mixing. -When mixing stops, they can go ontheir own separate paths. ■ They're going to be subjected to all those processes. __ __ ___
top-down influences
The presence of certain consumers can also affect the species present in a community: e.g. when a consumer limits a prey population -the influence of context and an observer's knowledge, expectations, and high-level goals on perceptual experience
salinity
The proportion of solutes dissolved in water determines its _____, measured in parts per thousand (ppt) -has dramatic effects on osmosis and water balance in organisms: >Species are adapted to specific ranges of salinity > It is a major determinant of species distributions
Total Number of Species
The sums of those interactions.
niche
The term _____describes the range of resources that a species can use and the range of conditions that it can tolerate
reproductive event
The trade-off in the life history of North Pacific giant octopus ○ The female lives about 3 to 5 years ■ It lays thousands of eggs at once ■ She gets them to hatch and then she dies ○ High fecundity but low survivability ○She puts so much of her resources into that ___ ___ that the cost is that she doesn't survive
Bycatch
The unintentional catch of nontarget species while fishing
Island biogeography can be used to make some predictions or model species richness basis both the size and the distance of the island
There are 2 different lines ■ Purple is extinction ■ Blue is immigration ○ There are 2 different rates happening on the same graph ○ Equilibrium is where extinction and immigration are equal ■ On some islands, there are 3 species and another island has thousand species ○ You can predict the immigration and extinction rates when you take into account the size of the island and the distance to the mainland ■ There is more competition ■ They're going to be outcompeted by other similar species ○In human development, we are creating a lot of islands of habitat
How they're going to influence species diversity?
There are 2 important process ■ Immigration ● Species getting to a new site ● Immigration rates should decline as the number of species increase and there are 2 reason ○ As more species are already on the island, the chances that an individual is coming from a new species go down ○ Competition ■ Extinction ● It should increase as richness increases ●Extinction rates will go up because a new species gets to the island, but it goes extinct very quickly and it can't compete with the spaces that are already there
● The highest diversity near the equator is zero degrees latitude
There are terrestrial mammals ○ The most sun hit on Earth is the equator and it is important because there's more energy to drive the photosynthesize ■ There are primary producers ○Research has shown that there appear to be higher speciation rates near the equator
biomass
___ refers to the total mass of organisms, primary producers in this case
Stages of Recovery in Glacier Bay in Alaska
There are three different areas ■ Lower bay ■ Middle bay ■ Upper bay ○ As the sort of the height of the glacial period, the glacier was down all the way towards the lower bay ○ Lower Bay has been exposed for about 150 to 200 years ○ The Middle Bay Area has been exposed for about 100 years ○ The Upper Bay has been exposed for about 20 years or even less ○Multiple things can be a play as the systems recover
1. Predation 2. Herbivory 3. Parasitism
There are three major types of consumption:
Top Down
There's a presence of some consumers that limits prey in a way that allows for species diversity to exist.
Mullerian mimicry
They are really dangerous -Evolution of two species, both of which are unpalatable and, have poisonous stingers or some other defense mechanism, to resemble each other
Keystone Species
They keep the population sizes and the species present in balance. ○ Example of a keystone predator: ■ Seastar ● A sea star was removed in the rocky intertidal. ○ The number of species plummeted when the sea star was removed. ● Remove the keystone predator and species diversity falls. ○Predators often exert a certain amount of pressure that keeps diversity up. -a species that has an unusually large effect on its ecosystem
dN / dt = rN [(K - N) / K]
This equation/ expression is called the logistic growth equation and takes into account the carrying capacity of the environment. K = carrying capacity N = # of individuals\ r = rate of increase d = change
continental drift
This has influenced where species are found today, depending on when and where they lived and how their distribution was changed as landmasses moved to their current positions. -Example: Central American land bridge When that formed right, that meant terrestrial species now had a bridge to connect, but this didn't allow fish to mix with other fish. -The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations
Benthic Zone
This means the bottom of the body of water, and 500 feet of water -the muddy bottom of a lake, pond, or ocean
- Age structure—number of individuals of each age - Number of individuals of different ages likely to survive to the following year - Number of offspring produced by females of each age
To make predictions about the future of a population, biologists need to know:
- Commensalism - Competition - Consumption - Mutualism
To study species interactions, biologists begin by analyzing effects of one species on the fitness of another: (4)
• Increased health • Increased access to resources • Decreased vulnerability to threats
Traits that strengthen social bonds favored by natural selection leads to higher evolutionary fitness (3 things):
Density-Dependent Factors That Limit Population Size
Trees compete for light/water/ nutrients Social distance to prevent disease transmission Close → parasite can move from one host to next easier More individuals → more impactful Less space → more competition
magnetic field
True Navigation (Map Orientation) Use Earth's ___ ___ (not just magnetic north) as a source of precise positional information
compass orientation
True Navigation (Map Orientation) • Researchers changed the magnetic field • When simulated a location 337 kilometer north of Melbourne Beach, turtles swam south • When simulated a location 337 kilometer south of Melbourne Beach, turtles swam north • Direction of magnetic north did not change in either case, so ___ ____ alone could not account for the ability of the turtles to navigate
extrinsic factors, intrinsic factors
Two Different Mechanisms of Adaptive Radiation
Extrinsic
____ Mechanism of Adaptive Radiation -favorable new conditions in the environment -New conditions in the environment. -The ancestral population managed to move to a new environment where there was lots of ecological space and very little competition.
consolation behavior
Type of Proximate Cause -an increase in affiliative contact in response to and directed toward a distressed individual, such as a victim of aggression, by an uninvolved bystander, which produces a calming effect -ex) Example: You see your friend in distress -Biological causation responses include ___ ___ such as speaking softly or physical caresses: • If person is a stranger, consolation is reduced
why
Ultimate - ___ it occurs
time, energy, predation risk
Ultimate Causes: Why Do Animals Migrate? • Migratory movements can pose enormous challenges and costs in terms of __, ___, & ___ __ • Hypotheses for why individuals migrate include increasing reproductive success and increasing access to food resources • Rigorous testing of these hypotheses is hard because it requires populations where some animals migrate and others do not
increases
Water absorbs and scatters light, so the amount and types of wavelengths available to organisms change dramatically as water depth ____
Every individual has a restricted amount of time and energy at its disposal―its resources are limited (Ex: Female devotes a lot of energy to producing many offspring; she cannot devote that same energy to her immune system, growth, nutrient stores, or other traits that increase survival -A female can maximize fecundity, maximize survival, or strike a balance between the two)
What Are Fitness Trade-Offs?
specific heat
What Effects Do Oceans Have on Climate? • Oceans have a moderating effect on temperature• Water has a high ___ ___, or capacity for storing heat energy: - Water absorbs atmospheric heat in the summer and releases it in winter - Coastal areas generally have more moderate climates than inland areas - Gyres, or massive ocean current cycles, bring warm water to colder latitudes and vice versa -The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree celcius
Density-independent factors are usually abiotic and change birthrates and death rates irrespective of population size Density-dependent factors change in intensity as a function of population size and are usually biotic
What Factors Limit Population Size?
both are important
What do you think is more important? Food or predation, and Why?
H' = -Σ pi ln pi (In the Shannon index, p is the proportion (n/N) of individuals of one particular species found (n) divided by the total number of individuals found (N), ln is the natural log, Σ is the sum of the calculations, and s is the number of species)
What is the equation for Shannon index? (Lecture 12, 10/19) Reminder to look at lecture!!!!
ΔN∆t= Births−Deaths+Immigrants−Emigrants
What is the equation for populations growth rate? N = population size t = time A population's overall growth rate, or change in population size (ΔN) per unit time (Δt), is a function of birthrates, death rates, immigration rates, and emigration rates:
dN/dt = rN
What is the exponential growth equation? • If ecologists are interested in understanding what is happening to populations at a given moment in time, they can calculate the instantaneous growth rate: N = population size t = time K = carrying capacity N = # of individuals\ r = rate of increase d = change
K
What is the symbol for Carrying Capacity?
Population-Level
What level does evolution act?
Open
When Else There Might Be ____ Ecological Space? -After a Forest Fire -Volcano eruptions -Any Genetic Drift >Any event that's going to remove most species from an area that's going to open up ecological space. -Example: Dinosaurs and Mammals >When the dinosaurs were wiped out mammals became predominant. >Since mammals were small they didn't fill a lot of ecological space and when the dinosaurs were almost all wiped out, that's when mammals could diversify into other roles of being the apex predator.
foraging
When animals seek food, they are ___ • Most animals have a relatively wide range of foods that they exploit over the course of their lifetime • Species that eat limited foods still make choices: e.g. Giant pandas eat almost entirely bamboo, but they still have to choose which plants to harvest
foraging
When animals seek food, they are ____ • Most animals have a relatively wide range of foods that they exploit over the course of their lifetime •Species that eat limited foods still make choices: >e.g. Giant pandas eat almost entirely bamboo, but they still have to choose which plants to harvest
density dependent
When population density gets very high, population's per capita birthrate decreases and the per capita death rate increases, causing r to decline. This type of growth is ___ ___ -Referring to any characteristic that varies according to an increase in population density.
growth
When your actual population numbers each carry equal carrying capacity, ____ is going to stop
C (The other choices are wrong because they are not biotic)
Which of the following are biotic factors that can affect the structure and organization of biological communities? a) precipitation/wind b) nutrient availability, soil pH c) predation, competition d) temperature, water
Competition
Which one of those species interactions causes niche differentiation? Negative negative ○ It is a cost to both groups. ●Individuals are not making choices.
sunlight
Why Are the Tropics Warm and the Poles Cold? -The tropical areas are warm and the poles are cold because of the amount of ____ it receives. There is lots of direct ___ near the equator as you move either north or south. The tropic also tends to be wet. When you think about tropical rainforests you would notice that they are mostly located near the equator. The reason that happens is because of Hadley cells. On the other hand, we also have a drier condition at about the 30-degree latitude line because of Hadley Cells again. Process: Looking at the equator where there's all ___, warm air rises, and as it cools or as it rises into the atmosphere that's when the precipitation forms. The waterfalls back down in the form of rain right at the equator or around the equator. The next step is that dry air or cool air is pushed poleward, it moves down and raindrops air keeps moving. It then drops down at about that 30-degree mark and becomes dry and then it moves back towards the equator where it picks up water rain forms. Hadley cells are the large-scale patterns of wet areas near the equator and then drier desert-like areas towards the poles. It is the large-scale movement of air and distributing precipitation and then dry air.
They only have limited resources and they need to choose where they go
Why can't a female lizard have both high fecundity and high survival?
● The bottom line is to alway sremember that things change. ●Traits that we may think of as being really adaptive may not be in a certain environment..
Why don't the Biggest and Strongest Individuals Always Produce the Most Offspring?
-Temperature is related to the amount of sunlight. -Temperature is very important for those primary producers. -The primary production or photosynthesis just slows down and doesn't work as well, often at colder temperatures.
Why would the temperature be important in terms of primary production?
Fertility
Will Human Population Size Peak in Your Lifetime? • ___ rates are used to make projections about future growth — ____ rate is the average number of surviving offspring a woman has over her life • The UN makes estimates based on ____ rates • 2.5 (high) children per woman • 2.1 (medium) children per woman • 1.7 (low) children per woman ~Lecture 14 slides PDF has graph~
Mark recapture
You mark some subset of the population and you keep going back out and recapturing and you can use those numbers to estimate the total population ○ The percent mark is equal to the average and marked when you recapture ■ Example ● In sex, capture all-female seals or all-male seals and have a representation of the whole population ○ You need to make sure individuals don't start avoiding recapture and they're not changing their behavior ○ The idea of mark-recapture is the ratio of the number of individuals to the total population size is going to equal the ratio of the number of marked individuals when you go back out and recapture ○ Mark recapture can be fairly invasive ■ Example ● Photo ID ○ In an equation, N is the total population size and n is the number of marked individuals in the recapture ○ The capture doesn't change their behavior ○You've captured a variety of individual
Quadrat
You might have a physical square ○If you're looking at some plot in a forest and you want to see all the different plants and fungi and invertebrates right, you'd put down your square or you could use it in the intertidal -A square made of wire used to estimate population size of plants or slow moving animals. It may have smaller squares of wire within it.
Mark-recapture studies
__-___ ___ showed that migration rate is high enough to suggest that patches where a population has gone extinct will eventually be recolonized • Over time, the overall population size was relatively stable even though populations came and went
Frederick Clements
___ ___ hypothesized that biological communities are stable, integrated, and orderly entities with highly predictable composition
Null Hypothesis
___ ___ in Extinction Rate A ___ ___ is a hypothesis in which nothing happens or changes or whatever you are testing, it won't have any influence. If the ___ ___represents current extinction rates represent background extinction rates, what would the graph look like if the___ ___ were true? ___ ___ is that extinction rates that we're seeing in these mammals and birds invertebrates are no different than background extinction.
Biological causation
___ ___ in consolation behavior • Neurons in your brain process sensory information and cause changes • Brain signals adrenal glands to produce cortisol • Neural signals in pituitary signal hormone oxytocin
Consolation behavior
___ ___ in prairie voles: • Voles will lick and groom group members that experience stressful event—but not strangers • Blocked oxytocin receptors = consolation behaviors no longer exhibited • Normal self-grooming continued
Behavioral flexibility
___ ___ is a hot topic of research for climate change: Species whose behavior has higher flexibility predicted to survive rapid changes in temperature, precipitation, and shifting interactions with other species -the ability to alter behavior to adapt to new situations and to relate in new ways when necessary
Conservation biology
___ ___ is the effort to study, preserve, and restore threatened populations, communities, and ecosystems -This is about understanding these relationships. -Thinking about how to restore some of these different systems that have been negatively impacted by various human activities. -Integrates ecology, physiology, molecular biology, genetics and evolutionary biology to conserve biological diversity.
Henry Gleason
___ ____ contended that the community found in a particular area is neither stable nor predictable - largely a matter of chance; he downplayed the role of biotic factors like species interactions in structuring communities
Life TablE
___ ____ for Zootoca Vivipara Females in the Netherlands -Age classes (years old) -How many individuals in each age class and their reproductive output -Based on females -fecundity= reproductive output -2 and 3 produce 80% of births, most important -At age class 0, 1000 lizards born -Log base 10 makes it easier -Values from Life table above -Looks like type 2 survivorship, scatter plot line
immigration rates
___ ____ should decline as the number of species on the island increases because: • Individuals that arrive are more likely to represent a species that is already present • Competition should prevent new species from becoming established when many species are already present on an island
Extinction rates
___ ____ should increase as species richness increases because niche overlap and competition for resources will be more intense
Carrying Capacity (K)
___ ___changes over time due to fluctuations in food availability, space, and other density-dependent factors -Variability in growth data is common and expected -Populations may dramatically overshoot the carrying capacity and then crash or cycle in intervals above and below ___ ___
secondary succession
___ ___occurs when a disturbance removes some or all of the organisms from an area but leaves the soil intact, including the seeds and microorganisms within
Mutualisms
___ are +/+ interactions that involve a wide variety of organisms and rewards
seasons
___ are regular, annual fluctuations in temperature, precipitation, or both -The reason we have ____ is because of the tilt in the Earth. In the northern hemisphere in June, it is warmer because the northern hemisphere is tilted towards the sun. During winter, the northern hemisphere is tilting away from the sun and the southern hemisphere is tilting towards the sun. Since the Earth is tilted on its axis, that's how we get our_____
Proximate
___ cause answers the question: how do they know where to go?
Ultimate
___ cause answers the question: what are the benefits of this large scale movement?
Coevolution
___ is a major driver of evolutionary change
adaptive radiation
____ ___ is the rapid production of many descendant species from a single lineage: - These descendant species have a wide range of adaptive forms - May be inferred by phylogenetic analysis or observed in the fossil record as the sudden appearance of related diverse species
Primary succession
____ ___ occurs when a disturbance removes the soil and its organisms, as well as organisms that live above the soil surface (e.g. volcanoes)
Convergent Evolution
____ _____ is when you go to a desert you will see different succulent plants. They all look similar because they have certain traits that allow them to live in the desert, but they may have these varied backgrounds or various evolutionary paths. They aren't necessarily closely related but they look alike because they're adapted to that environment.
fossil record
____ ____provides direct evidence about what organisms from the past looked like, where they lived, and when they existed -total collection of fossils that have been found throughout the world
biomes
____ are regions characterized by distinct abiotic characteristics and dominant vegetation types • The nature of the ___ that develops in a particular region is governed by: - Average annual temperature and precipitation- Annual variation in temperature and precipitation
Organismal
____ level of ecology -It is about looking at individuals and starting to collect information about their role, as well as how they make a living in their environment. How are they interacting with other individuals and then the physical environment? how do individuals interact with each other and their physical environment
Population
____ level of ecology -how and why does population size change over space and time -where we can think about what is happening to a certain population. Is it increasing? Is it decreasing? What are the threats to this population? What's influencing the trajectory it's on? Is this a ___ that we should list as an endangered species and trigger the various protections that the country is giving them? This is when evolution happens. This includes thinking about population size and changes over time. ____ are really important in understanding ecology and conservation biology.
community
____ level of ecology -how do species interact, and what are the consequences? -This is when you start thinking about how different species were interacting. Oftentimes it focuses on predator and prey. Other roles include decomposers Decomposers are the ones that eat dead things. This includes fungi and sometimes insects. Decomposers are important as they return nutrients to the cycle. There's a lot of symbiotic or mutualistic relationships where species depend on each other to survive. Example: parasites, microbiome, pollinators, primary producers such as plants.
ecosystem
____ level of ecology -how does energy flow and how do nutrients cycle through the local environment -At this level, you are looking at patterns in these broad areas and you're thinking about how species are influenced by both biotic and abiotic processes. Example: Nutrient cycling The larger scale at which you can study ecology is at this global scale. This is when we're thinking about things like water cycles and carbon cycles and how are those influencing species abundance and distribution Example: Worldwide populations of salmon are affected by changes in the water flow and temperature.
global
____ level of ecology -how is the biosphere affected by global changes in nutrient cycling and climate? - ex) worldwide populations of salmon are affected by changes in water flow and temperature due to global climate change
Oxytocin-mediated consolation behavior
____-____ ___ ___ in highly social prairie voles observed; but not in less social meadow voles
Intrinsic
_____ Mechanism of Adaptive Radiation -These are evolutionary changes within the species that allow for diversification as well. -such as evolution of key morphological, physiological, or behavioral traits
Microevolution
_____ is the study of those changes that are happening in the allele pool from one generation to the next. These are processes such as natural selection, a drift, a bottleneck, etc... ____ is looking at how allele frequencies are changing on a small scale. Those processes over time are what can lead to new species or potentially lead to species extinction.
Darwin
_____ was first person to demonstrate that plants have behaviors
learning
____is an enduring change in behavior that results from a specific experience (e.g. you learn to drive a car, read, tie your shoes)
Succession
___is the recovery that follows a severe disturbance
Type II survivorship curve
a pattern of survival over time in which there is a relatively constant decline in survivorship throughout most of the life span ex) birds
Type I survivorship curve
a pattern of survival over time in which there is high survival throughout most of the life span, but then individuals start to die in large numbers as they approach old age ex) humans
Type III survivorship curve
a pattern of survival over time in which there is low survivorship early in life with few individuals reaching adulthood ex) ants
coevolutionary arms race
a repeating cycle of reciprocal adaptation -When predator and prey interact over time, a ___ ___ __results - Consumers evolve traits that increase their efficiency - In response, prey evolve traits that make them unpalatable or elusive - Selection then favors consumer traits that counter the prey adaptation, and so on
Hadley Cell
a system of vertical and horizontal air circulation predominating in tropical and subtropical regions and creating major weather patterns -The tropical areas are warm and the poles are cold because of the amount of sunlight it receives. There is lots of direct sunlight near the equator as you move either north or south. The tropic also tends to be wet. When you think about tropical rainforests you would notice that they are mostly located near the equator. The reason that happens is because of ___ ___. On the other hand, we also have a drier condition at about the 30-degree latitude line because of ___ ____ again. Process: Looking at the equator where there's all sunlight, warm air rises, and as it cools or as it rises into the atmosphere that's when the precipitation forms. The waterfalls back down in the form of rain right at the equator or around the equator. The next step is that dry air or cool air is pushed poleward, it moves down and raindrops air keeps moving. It then drops down at about that 30-degree mark and becomes dry and then it moves back towards the equator where it picks up water rain forms. ____ ____ are the large-scale patterns of wet areas near the equator and then drier desert-like areas towards the poles. It is the large-scale movement of air and distributing precipitation and then dry air.
True navigation
ability to locate a specific place on Earth's surface
Density-independent factors
are usually abiotic and change birthrates and death rates irrespective of population size -limiting factor that affects all populations in similar ways, regardless of population size
FDA (Food and Drug Administration)
an agency in charge of ensuring the safety of all foods sold except meat, poultry, and seafood -○ Which is the Food Agricultural Organization, which is a part of the U.N. that is in charge of basically combating malnutrition and lack of food and access to food and water security ○ They describe it as balancing different resource user goals and interests while maintaining the integrity of the ecosystems ○ Desalinization ■ Use convert energy to make water and use energy to do things ■ It is very expensive but energy-wise ■ Humans use water to create food ● Food processing and cooking ■ Use energy right to grow food, whether that thing like agricultural practices or moving food around regions or parts of the world ■ All of these things interact together and are intertwined ○ Human carrying capacity ■ First must be higher than the current human population size because everyone alive today must have enough resources to survive ■ Sometimes populations can exceed carrying capacity ○ Famine ■ Not be a density-independent factor ■ Famine is there's no food available or not enough food available, so that is going to be related to how much food there and how many people
per capita growth rate
birth - death / total population -for some interval, the added number of individuals divided by the initial population size -the number of individuals added during some interval divided by the initial population size
Mark Recapture
capturing and marking organisms, then recapturing them and counting how many are marked
endoparasite
consumes a relatively small amount of tissue or nutrients from inside a host, typically over a long period -found inside the host body and an example of this is tapeworms hookworms -parasite living on the inside of its host -Tapeworms hookworms: >They do not even have their own digestive tract because they live in the intestines of their host, and they just absorb the nutrients that are flowing through there
ectoparasite
consumes a small amount of tissue or nutrients (often fluids) from outside a host, typically over a long period -A parasite that feeds on the external surface of a host. -found outside of the host body on the surface -ex: Ticks and lice >They tend to attach, maybe drain some blood from the host, often not fatal
herbivore
consumes plant and algal tissues such as leaves, stems, fruits or roots, but typically no entire organisms -A consumer that eats only plants.
constitutive or standing defenses
defenses that are always present. includes: - Cryptic coloration and object resemblance - Escape behavior -Toxins and other chemicals - Schooling and flocking - Defense armor and weapons
logistic Growth Equation
dN/dt=rN(K-N/K)
Tolerance
effect on subsequent species: Existing species will not affect the probability that future species will become established
Facilitation
effect on subsequent species: Makes conditions more favorable of future species arrival
inhibition
effect on subsequent species: The presence of a species prevents the establishment/ regrowth of another
Cambrian
evolution shows the origin of life including cells with a nucleus, multicellular organisms, etc... 540 million years ago was when something called "the ____ explosion" took place. It was a time period when there was a massive diversification of animal body forms in the ocean, which then led to a lot of diversification of all sorts of life forms. There are a couple of extinctions like the Ordovician, Devonian, Permian, and Triassic.
Tradeoff
ex) Growing → less time reproducing -Process of giving up something for gaining something else
Intraspecific interactions ("within-species")
ex: competition among members of a cohort for food
interspecific interactions ("between-species")
ex: predation, parasitism, or competition among species for food -relationships between species in a community
Proximate Causation (mechanistic)
explains how actions occur: • genetics, neurological, hormona -"how" a behavior occurs or is modified
fecundity
fertility; fruitfulness -The potential reproductive capacity of a female
low fecundity and high survivorship
few offspring large offspring late maturity large body size high disease resistance high predator resistance long life span
Parasitoids
free living as an adult but endo- or ectoparasitic as larva, hatching from an egg laid inside or on a host and consuming the host, eventually killing it -organisms that lay eggs inside other organisms - Have sort of multiple life stages, they are free moving when they are adult -They are often fatal to the host
Niche Model
graph at 48:51 - October 7th lecture video -This is when you go out and collect information on the species and then you pull that all together and recognize that it is what the species needs. (47,35, a graph about the temperature and proportion of individuals. ) Coconut Palm (blue) has a wider tolerance of temperature than our Acai Palm. Acai Palm and the Coconut palm overlap in their temperature niche, but the coconut palm has a wider range and can live in more areas. The temperatures are going to limit where the Acai Palm is found more than the Coconut palm.
population
group of individuals from the same species that live in the same area at the same time
Fixed Action Pattern (FAP)
highly inflexible, stereotypical behavior patterns (sneezing, yawning, and jump-back behavior in kangaroo rats) -A sequence of behavioral acts that is essentially unchangeable and usually carried to completion once initiated.
Terrain
important in terms of primary vegetation -(n.) the landscape, especially considered with regard to its physical features or fitness for some use; a field of knowledge
adaptive Radiation
in ___ ___... This is the idea where an ancestor of a species reaches a new area and because there's a wide-open ecological habitat or wide-open niches ___ ___happens. Niche is an ecological space where they find their resources. Over time, they can look quite different and the descendant species won't necessarily be similar because they've likely adapted into various conditions or niches.
Background extinction
it is the lower, average rate of extinction ___ ___ is the average rate of species turnover that is part of what happens with selection. Things change a little bit in the habitat and they either move, adapt, or go extinct. ___ ___ is just normal, it's related to all those species interactions that we have predation, diseases, etc...
Keystone species
keep things in balance -single species that is not usually abundant in a community yet exerts strong control on the structure of a community ex) kelp forest food web. Kelp eaten by sea urchin, sea urchin eaten by sea otters. Kelp is the foundation species and the primary producer. Sea urchins are dominant species because most abundant, sea otters are keystone predators to keep the urchins in check. Sea urchins are also decomposers. When otters were hunted, there was a trophic cascade (shift)
Rangeland
land used for grazing livestock ● It is where cattle, sheep and goats, and whatever other livestock are being raised ● A different type of land use and different dynamics than what was historically there ● Even it is not like a city or a highway, it is still a change from what had evolved in that place
high fecundity/low survivorship
many offspring small offspring early maturity small body size low disease resistance low predator resistance short life span
dispersal
metapopulations= A population made of up many small, physically isolated populations connected by ___
Niche Partitioning
natural division of resources based on competitive advantages Each species becomes a sort of more focused because individuals in that area where they're overlapping have lower fitness.
Species richness
number of species present in a given community -the number of different species in a community
Intraspecific competition
occurs between members of the same species -competition between members of the same species
Emigration
occurs when individuals leave a population to join another population -movement of individuals out of an area
Interspecific competition
occurs when members of different species use the same limiting resources -competition between members of different species
parasite
organism that lives in or on a host, taking resources from it
keystone species example
otters (keystone species) nearly eliminated, kelp nearly vanished b/c urchin pops went crazy Example ■ Sea Otters ● Food web A with sea otters and all these other invertebrates. ● Food web B where all the things that are great out are no longer in the system. ● Which has more species diversity? ○ Food web A. ● Sea otters were being hunted. ● Sea otters, eat all sorts of things, including urchins. ○ Urchins, eat kelp and other algae. ● So when the sea otters were gone, there was no one else eating the urchins. ○ So the urchin population really dramatically increased. ■ Wolves ● When wolves had disappeared around that same time, aspen trees had declined as well. ● Wolves eat deer and elk. ○ By adding wolves, the number of deer, and elk decreases. ● Deer and elks eat aspen trees, cottonwood, and willows. ○ So when these herbivores decreased, these plants were allowed to recover. ■ You can see that the presence of one species has an impact at multiple trophic levels. ●Nothing is static in nature and life.
Vegetation
plant life ● The estimate in these is somewhere between one and three degrees Celsius ● Change is shifted away from Arctic species to more temperate species ●As things move, species may be replaced by others as conditions change
types 1-3
reminder to look at survivorship curves in lecture 13, 10/21 Answer: types 1-3
tropics
regions close to the equator The temperature really steady throughout the year You only look at the average that is going to help understand what do they need to be adapted to a range of conditions
Population ecology
study of how and why the number of individuals in a population changes over time -Recognizing variation among individuals in a population is key to understanding how populations change over time in response to their habitats -the study of factors that cause populations to increase or decrease -*populations evolve
intertidal zone
submerged at high tide, exposed at low tide -Portion of the shoreline that lies between the high and low tide lines
primary producers
the first producers of energy-rich compounds that are later used by other organisms Biomes: The number of predators you're going to have is going to be influenced by how many ___ ___ you have because they're the basis of that food web. When measuring biomass in different biomes, what we refer to is measuring that plant which is the ___ ___ They use energy to make their living. Whatever extra energy they have goes into building their body is growing their bodies, and that's what gets eaten by those primary consumers. Those ___ ___ are really important, they are the basis. If you have lots of ___ ___, there's going to be a lot of energy to keep going up to those different levels. If you have very few ___ __, everything else is going to be fewer-- fewer consumers, fewer predators, etc... (01:06:25, a figure from your book is shown to the class) The Y-axis is not always the same. In the tropical rainforest, the average temperature is the same, but the precipitation decreases over time. The Boreal Forest has a huge range in temperature, but precipitation is fairly constant. Depending on where you are in the world, the range in precipitation and temperature will influence primary production which influences everything else.
continental shelf
the gently sloping, submerged portion of a continental plate; -A gently sloping, shallow area of the ocean floor that extends outward from the edge of a continent
Food Nexus
the interconnection between the resources energy, water, food, land and climate. Such interconnections enable to address trade-offs and seek for synergies among them. Several policy areas (e.g. bio-based economy, circular economy) increasingly consider the ___ ___ concept.
mating systems:
the length and number of relationships between males and females
Carrying capacity (K)
the maximum number of individuals in a population that can be supported in a particular habitat over a sustained period of time -Maximum population size that a particular environment can support.
Anthropocene
the modern geological era during which humans have dramatically affected the environment - If you look over 75 percent of the Earth's surface, which is ice-free shows some evidence of human activity Wildlands at this point only account for about 11 percent of terrestrial net primary production
1. They are a monophyletic group 2. They speciated rapidly 3. They diversified ecologically into many niches
three hallmarks of an adaptive radiation: ex) The 30 species of Hawaiian silverswords evolved from tarweed
1. Mating systems vary a lot among species, and even in individuals 2. Mating systems are not always as they appear 3. Mating behaviors can serve functions other than producing offspring: • Mating behavior in humans can function to create and maintain social bonds
three important insights about mating systems:
endoparasite, ectoparasite, parasitoid
three types of parasites:
Biomass
total amount of living tissue within a given trophic level Biomes: Dominant vegetation types are those plants that are tolerant of certain types of environments. Biomes are governed by average annual temperature, precipitation, and variation. It is very important to understand the variation in conditions. Temperature and moisture are important when we're thinking about that range in temperature, and range and precipitation because they influence something called net primary productivity. This is about how productive the plants are and not only making a living but producing extra ____
Intrasexual selection
type of sexual selection: Two individuals of the same sex compete with one another for mates
Intersexual selection
type of sexual selection: When individual of one sex choses individual of another sex as a mate
Ultimate causation (evolutionary)
why actions occur: • evolutionary consequences and history, like any other phenotype in that it can evolve by natural selection
C, where the plateau is
~Go to Oct 26 lecture 14 video at 54:10~ Poll: which of the arrows in pic represents the carrying capacity?
Three Bird Species A, B, and C
~Lecture 12, 10/19~ What are you measuring about these birds? ■ The frequency of nest in the branch height. ○ Why are nests important? ■ Nests are important because they can protect the birds against land predators. ■ It is for reproduction. ○ Which species A, B, or C has the broadest branch height? ■ A ● Because it can be found from one and a half meters all the way to eight. ○ Who has the most narrow area? ■ B ○ Who do you think is going to compete for the most with each other? ■ A and B. ●A is overlapping with B.
Aphotic zone
—areas that do not receive sunlight -permanently dark layer of the oceans below the photic zone
Neritic zone
—from the intertidal zone to about 200 m, defined by the continental shelf—the gently sloping, submerged portion of a continental plate; coral reefs can be found here -Area of ocean that extends from the low-tide line out to the edge of the continental shelf
Innate behavior
—inherited; passed genetically from parents to offspring -A behavior that is developmentally fixed. -* Doesn't involve learning!
Photic zone
—regions that are sunlit; these include the intertidal and portions of the neritic, oceanic, and benthic zones -Portion of the marine biome that is shallow enough for sunlight to penetrate.
1. Choices are not usually conscious 2. The behavior of individuals' traits varies among individuals
• An animal can't maximize both the energy invested in finding food and in finding mates • Biologists use framework of cost-benefit analysis to link conditiondependent behavior to fitness • Two important concepts to keep in mind:
cost-benefit analysis
• An animal can't maximize both the energy invested in finding food and in finding mates • Biologists use framework of __-___ ____ to link condition dependent behavior to fitness
- Normal environmental change -Emerging disease -Predation pressure -Competition with other species
• Background and mass extinctions have contrasting causes and effects • Background extinction reduces certain populations to zero due to:
zones
• Biologists use water depth and light to define ____ in oceans: - Intertidal ___—submerged at high tide, exposed at low tide - Neritic ____—from the intertidal zone to about 200 m, defined by the continental shelf—the gently sloping, submerged portion of a continental plate; coral reefs can be found here
1) preserve biodiversity 2) preserve ecosystem function 3) create an environment that people want to live in
• Biologists want to know how communities work and how to manage them to: (3)
Population Cycles: The Hare and Lynx Case Study:
• Bottom-up hypothesis: When their populations reach high density, hares use up all their food and starve; in response, lynx also starve •Top-down hypothesis: Lynx populations reach high density in response to increases in hare density; at high density, lynx eat so many hares that the prey population crashes
Yellowstone ecosystem
• In the 1990s, ecologists realized: • Aspen trees in the ___ ___ had begun to decline around the time wolves had disappeared • Was there a link? • After wolves were reintroduced, ecologists monitored aspen trees to see if wolf populations increased: • Although wolves number only about 400 individuals now, there is already an increase in aspens and other effects on the food web
thermocline
• In winter and summer, the temperature in these lakes varies along a vertical gradient called a ____: - In winter, surface water is colder but higher in oxygen, while the water at the bottom is warmer, denser, and higher in nutrients - In the spring, the lake melts; as the surface warms, it becomes denser and begins to sink, aided by wind
high fecundity
• Organisms with ___ ___: - Tend to grow quickly, reach sexual maturity at a young age, and produce many small eggs or seeds
succession: The Development of Communities after Disturbance
• Succession is the recovery that follows a severe disturbance Primary succession occurs when a disturbance removes the soil and its organisms, as well as organisms that live above the soil surface (e.g. volcanoes) Removes everything Secondary succession occurs when a disturbance removes some or all of the organisms from an area but leaves the soil intact, including the seeds and microorganisms within Some things still intact
net primary productivity (NPP)
• Temperature and moisture influence ___ ___ ___, or total amount of biomass generated by the carbon that is fixed per year minus the amount oxidized during cellular respiration -The energy captured by producers in an ecosystem minus the energy producers respire
populatiOn
○ The four different parameters ■ The processes that might influence what a __ is doing 1. Immigration 2. Emigration 3. Births 4. Deaths
Vertical Migration
■ A lot of species ■ There is lots of photosynthesis happening during the day and then things may sink down at night ■Feeding happens at all different times because species move in and out of those zones -daily movement of small marine animals between the photic zone and lower depths
Intertidal Zone
■ Different terms to define these large areas related to water depth and light ■ That is the area where the water is all the way out the ocean is at low tide and the ocean is at high tide ■ Requires some unique adaptations ■They need to be able to live both in the water and out of the water -the area of shoreline between low and high tides
Lymphatic Zone
■ Folks on up top and in the bottom ■Can move vertically as well
Nutrient Availability
■ Is going to influence primary production ■That is going to influence all those other trophic levels -saprotrophic decomposers ensure the constant recycling of inorganic nutrients within an environment
Invasive species
■ It is in a new habitat where it can potentially exploit resources or after a disaster ■ A similar idea when they are sort of wide-open ecological space because resources are unlimited ■ That period of unlimited resources only lasts so long
Photosynthesis
■ That is going to limit where species are found as well ■Is the beginning of the food web -Conversion of light energy from the sun into chemical energy.
Littoral Zone
■ They do not have that intertidal, the lakes are small ■It is where plants can actually take groups of fairly shallow plants can take root and photosynthesis is happening there -a shallow zone in a freshwater habitat where light reaches the bottom and nurtures plants
Food Zone
■ This is where photosynthesis can happen ■That is where sunlight still reaches down
Neuritic Zone
■ Which is about 200 meters out and it is often referred to as the continental shelf ■That is where things like coral reefs are found -The region of shallow ocean water over the continental shelf.
trophic
○ Predators and prey ■ They follow these cycles and the more prey ■ The predator population do in response to more prey increases ○ Bottom down or top up drivers ■ A bottom-up hypothesis ● When the hares reach high density because when thinking about the hares in the links is about bottom-up ● Working within that context of those ___ relationships when you are thinking of building up that food web ● The Bottom-up is that they overeat all the food
Climate change shifts habitats
○ Some species are more adaptable ○ Some species have a wider tolerance of conditions ○For some species there may be more habitat available
Exponential GRowth
○ That is where you see that curve look and density does not matter ○ More individuals are in an area, right resources become more limited ○ Plateaus population act ■ Carrying capacity ○ Examples are robins and the squirrels, spiders on the school campus ■ They are not growing exponentially ■ Great resources are limited ■ It is rare to see exponential growth ■ Bacteria often showed exponential growth
Life table
○ A life table experiment for a lizard ○ This was a labor-intensive project ○ People run out every day for 7 years and they collected information and it allowed them to develop what we call a life table ○ This is birth ages 1 through 7-year-old, 7 years as the oldest ○ When we're thinking about life tables, what we're thinking about is how many individuals are in each age class and then what is their reproductive output ○ Life tables are based on females because they're the ones who are reproducing ■ Oftentimes reproduction is limited by the number of females ○ We looked at survivorship, it was just basically how many of those original lizards are surviving from 1 age to the next ○ Which age classes are the most important in terms of producing the next generation? ■ 2 and 3 because they're producing almost 80 percent of that next generation ○ Plotting out survivorship for the lizards ■ How many lizards were born? ● 1000 ■ How many made it to age 1? ● 428 ■ Age class 2 ● 308 ■ Age class 3 ● 158 ■ Age class 4 ● 57 ■ Age class 5 ● 10 ■ Age class 6 ● 7 ■ Age class 7 ● 2 ■ (23:10, Graph of life table is shown to the class. Please provide photos/videos of the board so we could take higher quality notes.) ■ What kind of survivorship? ● Type 2 ○ This is based on trade-offs of, when do you reproduce and when do you grow ○When something like humans, we have high survivorship early on because we have a lot of parental care
Factors affecting population size
○ Density-independent factors ■ It is usually abiotic and change birthrates and death rates irrespective of population size ○ Density-dependent factors ■ It usually changes in intensity with how many individuals there are right and what types of interactions are happening ■ There can be either intraspecific, which means within the species interactions ■Interspecific when individuals might compete for food or mates, or space Density-dependent changes in survivorship and fecundity cause logistic population growth and thus define a habitat's carrying capacity
DisturbancE
○ Everything is gone, including the soil and any of the living things ○ Existing species may have different impacts on newly arriving species ○ Weedy species have a quick life history strategy ■ They are able to kind of come in and colonize and reproduce quickly ■ A weedy species will provide a little bit of cover, and keep a little bit of humidity closer to the ground ■They can facilitate the arrival and establishment of future species
Population growtH
○ Formula ■ Capital N is the population size ■ Small case t is time ■ Small case r times N ● It tells us what a population ○ The change in population over time is all of these things together ■ Births ■ Deaths ■ Immigrants ■Emigrants
Salinity
○ Is basically the proportion of soil use or mineral salts dissolved in water ○ Big impact in terms of what types of species can live there ○ A cell that put it in a really salty solution the water is going to move out of the cell and the cell is going to dry up ○ All sorts of organisms that moved out of the level of salinity they are adapted to ○Really determines a lot of the range of many species
Behavior
○ Is the most basic level in just a response to some sort of stimulus ○ Example of behavior ○ Squirrels ■ Very acorns ○ Camouflage ■ Something that allows you to just escape a predator ○ They have a food source, certainly going to increase your fitness if you have food stored away ○ You are only active at night because most of your predators are active during the day or you do something to escape predation ● Ultimate cause ○ It is because it is going to increase its survivorship ● Neurological messages ○ Those nerves in your hand send that message extremely quickly to your brain ○ You are burning down ○ And your brain pulls your hand away ultimately, you want that to happen because you don't want to get hurt ○ You do not want to get burned ● Complex behaviors ○ Mostly about animals and certainly where you see complex behaviors ○ That plant is responding to stimuli, responding to the light, and growing towards it ● Behavioral adaptation ○ The selective pressure in that environment evolved in the plant ○ Slime mold ■ This is kind of not a very nice name, but it is a protest ● Constellation behavior ○ It is when you sort of react to someone else's stress or distress ○ For example, your friend comes into class, they are very upset about whatever it was, their lab report ○ You can see they are stressed ○ Depending on how close you are to this individual in distress, your reaction is going to be more or less intense ● Hormone oxytocin ○ Can make you happy, it makes you bond ○ This is the hormone that right after a woman has a baby too ○ There are high levels of oxytocin that ensure bonding with that newborn ○ Oxytocin ■ Collected some balls and they blocked the receptors ■ Could not travel around and carry its message ● Behavioral traits ○ Variability in behavioral traits ○ About behavioral traits, there is a spectrum of behaviors so you can have innate behaviors ○ They can be beneficial and adaptive because you do not need training ○ Chimpanzee ■ Who's learned to use a branch to find food ■ You can see a lot of variability in learned behavior within a population ○ Behavioral flexibility ■ How much flexibility is there in terms of where you choose to eat? ■ Is important as well
Exponential growth
○ It happens when growth is not limited by the density ○ It's growth that is unchecked ○ It's going to grow no matter how many individuals there are ○ If there's 100 hundred people or a thousand people on an island, their growth rate is going to be the same because resources are so unlimited that it's not going to be checked by density ○ When you start with an even bigger number, you're adding more individuals ■ This is what they call the J-shaped curve, that sort of really quick increase ○ The reality is, exponential growth is fairly rare to find in nature ○ There are 2 scenarios where we might find these, generally speaking 1. It is when a species colonize this new habitat ●Things like adaptive radiations, when a species gets somewhere and there's sort of wide-open ecological space
Logistic growth
○ It is when growth eventually is impacted by the density of the population ○ If there are more and more individuals right, there are fewer resources to go around and those limited resources are going to increase things like birth rate and death rates ○ How would limited resources impact something like the birth rate? ■ For example, the females don't have enough food, and so instead of having a nest when they're 2 years old, they have to wait till they're 3 ○ How would limited resources increase the death rate? ■ Through competition ● If there are fewer resources, competition goes up ● You're spending time competing, you're not spending time growing and resting and so your death rates are going to go up ○ The growth rate is density-dependent and the growth rate is going to change based on what that density is ○ Carrying capacity ■ It is denoted by the letter K ■ It is the maximum number of individuals in a population that can be supported in a particular habitat over a sustained time ■ The individual resource is going to dictate what carrying capacity is, absolutely and in particular with humans ● How much water and fossil fuels and different things do individuals use, and that varies throughout the world ■ It's related to the prey that is available and the available predators ■Other things that may cause individuals to shift around and the carrying capacity is important because it is this sort of stable state of how many individuals a system can generally sustain over time
plateaued
○ Population growth is zero when you are ___ there ○ Balance ■ Which process is outweighing another
toxoplasmosis
○ The mouse is the intermediate host and when it's infected, the protest takes over the mouse's decision-making. ○ Definitive host ■Cat -a parasite which is most commonly transmitted from animals to humans by contact with contaminated feces
Water Depth and Sunlight Availability
○ These are interlinked ○The deeper the water, the less sunlight that is available -Water absorbs and scatters light, the amount and types of wavelengths available to organisms change dramatically as water depth increases, as does light intensity Light has a major influence on productivity—the total amount of carbon fixed by photosynthesis per unit area per year
Bottom-Up
○ Things that might influence production at that bottom level. ○It is where photosynthesis is happening.
Growing right now in the US, four different parameters needed to include when thinking about
○ What is the human population doing? ○ Is it growing, shrinking, staying the same?
predators
● An increase in prey can increase in ___ ● Carrying capacity (continuation) ○ It is not always fixed and sometimes it can be overshot ○ Sometimes we can have a population that grows so quickly that they overshoot carrying capacity ○ Carrying capacity in the system can change ○ A population's carrying capacity may change as environmental conditions change ● In thinking about this interaction of predators and prey or changes in resources ○ Hare and lynx ■ Researchers realized that these two populations were so closely related and they exhibited similar cycling through kind of booms and busts ■ The hare will increase and the lynx will also increase ■They found was there was a cycle every 10 years on average, but the changes in the link lynx lagged behind ● We're measuring hare per kilometer squared ● We're measuring the lynx per 100 kilometers squared ●The cycle occurs every 10 years
Terrestrial Biomes
● Are that precipitation and temperature and those things really shape how much primary production occurs and that shapes the biome itself in aquatic biomes ●They are very different than terrestrial habitats -Biomes on land (forests, taiga, tundra, etc.)
2 Selections
● Disruptive Selection ○ Where an increase rate because that's selecting for those extremes and balancing just keeps it the same, where it made that variation is maintained. ● Stabilizing Selection ● What impact does it have on genetic variation? ○The overall effect of the 2 selections is it is reduced.
Fitness
● Evolutionary success ● Surviving and reproducing ○ Mating opportunities are really important when talking about evolution. ■ It's the individuals who meet in the parents' generation that's going to influence what typesof alliels are found and then what frequency in the next generation. ■ Example is widow Bird ● Male widow birds ○ They have a very long tail that is correlated with body condition. ○The tail is the signal that they could be a good mate.
population clock
● It's a combination of understanding different birth dates, birth rates, death rates, immigration, and emigration ● There's information for the U.S. population and then the world population and so you can see sort of how quickly these things are changing ● In the U.S., there's 1 birth in every 8 seconds, there's 1 death every 11 seconds, 1 international migrant every 670 seconds, and there's a net gain of 1 person every 29 seconds ● Population grow through births, immigration, and death ●The human population is growing at a pretty rapid clip -The World population is the total number of humans alive on the Planet Earth at a given time
offspring
● Organisms with high fecundity mean high reproductive output ○They mature early and they tend to have a lot of ____
Sexual Selection
● Special version of natural selection that's related to increasing mating opportunities. ● Example: Toptamarins ○ Primates with tufts of long white hair. ○ Males with long hair get more opportunity to mate. ○ In terms of figuring out the importance of hair ■ Is the presence or absence of hair influencing mating opportunities? ● Shaving their hair is the best way to figure out the traits that influence mating opportunities. ○ Shaving half the primates heads, males heads they have no mating opportunities.
Selection
● The change in allele frequencies that some traits are determined by some value that is favored. ○ Examples are the pale blue bird and dark blue bird ■ In just a couple of generations,they were almost dark blue birds. ●something's happening there that blue color is being selected for.
Communities
● The interactions and relationships amongst different species ● It is when everyone starts looking at interactions ● A population that's just individuals of one species ● Understanding those relationships of species ●Preserve biodiversity and ecosystem function
Genetic Variation
● The source is mutation ● It's all those accumulations oflittle changes that end up changing different phenotypes ● The accumulation of mutations is what led to thediversity of life. ●Remember, it's these accumulation of changes that's reallyimportant in thinking, understanding the variety of life and the source of genetic variation.
Decreased Gene Flow
● They are not moving around or mixing around. ● an increase in differentiation. ● Patrick speciation ○So dispersal stops, two groups may become so different that they become two different species.
age classes
● Thinking about those ___ ___ and why it's really important is because oftentimes we need to think about who in the population is most important, in particular when we're thinking about conservation issues ○ If we're looking at populations and the populations are declining and potentially because of some sort of human interaction ○It's really important to understand if we're going to if we can't protect the whole population and all of its habitat -pre-reproductive, reproductive, and post-reproductive The sea turtles are a classic example of this and that sea turtles historically have been had high bycatch rates ○Bycatch is when they're incidentally or accidentally caught in fishing nets Subsequent analysis, in particular looking at bycatch, realized that there are so few sea turtles that get to be adults ○ This is the age class where conservation efforts needed to go because there's so much natural mortality for those babies that if that wasn't where effort needed to be ○Our effort needed to be in conserving the animals that were able to get to maturity and were able to reproduce
Hardy Weinberg Equilibrium
● This is just knowing the frequencies doesn't tell if something's that hardy weinberg equilibrium, seeing what the frequencies do over time that what it tells. ● That the population is not evolving ● The allele frequency didnt change because ○ Evolution isnt happening ○ Selection isn't happening. ○Drift inbreeding
Founder Event
● When a small group of individuals moves to a new site, a new area,and doesn't have any more contact, there's no more flow. ● Bottleneck is some event happens in only a few individuals survive, it has a similar impact on the genetics ● These are really important concepts, and I know they're sort of similar and they are related to drift rate because both founder events and bottlenecks are related to drift, because they're random events. ●They can dramatically change nearly all frequencies of apopulation and its most prominent in really small populations. -A type of bottleneck that occurs when only a few individuals establish a new population.
Arctic Tundra
● Where you can see that it is predominated by sort of low scrubby plants ● Is towards the Arctic, towards the poles, and it is cold, does not get as much light as other areas ●These little sorts of tent-like things, what they are doing is they are actually serving to increase the temperature in these little plots -Biome that encircles the Earth just south of ice-covered polar seas in the Northern Hemisphere
Increased Gene Flow
● things that are moving around. ● The more movement there is, the more the two populations are going to be genetically the same. ●dispersal and mixing homogenize is genetic frequencies
Morpho Species Concept and Biological Species Concept.
●Morpho Species Concept ○ Physical traits ■ Colo ■ Size ■ Unique traits ■ It has disadvantages where a miss species called Kryptos Species where they look similar but functioning differently. ● Biological Species Concept ○ Reproductive isolation ○It would be called one species if it can interbreed and the offspring can reproduce.
