If a defensive compound is always present in an organism, then it must be a constitutive defense.
false
LECTURE 15
adaptive radiation
natural
... [Show More] selection accelerates the rate of both speciation and adaption leading to rapid evolutionary diversification, occurs when there are many ecological opportunities available After the KT extinction (extinction of dinosaurs), mammals, birds (from Saurischian dinosaurs), and crocodiles most prominently took advantage of the open ecosystem
animals
a living organism that feeds on organic matter
???
Archaeopteryx
a prominent example that shows the clear relationship between birds and dinosaurs (similar morphological traits: pelvis, braincase, and winglike forearms and experimental reconstructions) shares MRCA with birds (theropods)
Aves
the class birds are in, linean definition (same as theropods)
body fossils
shows what the organisms looked like
includes: fossilized bones, teeth, shells pollen, spores, organisms preserved in ice (mammoths), amber (insects), petrified wood
End-Cretaceous extinction
extinction of the dinosaurs
approx. 65 MYA, an asteroid that struck near Mexico was the cause of the extinction
- led to the rise of new species and organisms
also known as the KT extinction
- 75% of all species went extinct
- thick layer of clay high in element of iridium (which is abundant in asteroid but very rare on earth)
extant
still existing (opposite of extinct)
fossil record
provides hard copy evidence of previously existing organisms
geologic timescale
the series of time divisions that marks Earth's long history
Hadean Eon
- Earth formed 4.5 BYA
- bombardment by meteors
- high volcanism
- no evidence of life
- atmosphere (no oxygen)
- after cooling, liquid water (4.3 BYA)
Archean Eon
4 to 2.5 BYA
- oceans
- volcanism
- no oxygen in atmosphere
- first cells (prokaryotes, unicellular only)
chemical signs (3.8 BYA)
first Bacteria (3.5 BYA)
- origin of oxygenic photosynthesis (cyanobacteria, 3.5 BYA)
Proterozoic Eon
2.5 BYA to 542 MYA
- stromatolites (made by cyanobacteria) are common
- atmosphere and surface of oceans are oxygenated (2.4 BYA)
- oxygen catastrophe, mass extinction
- first eukaryotic cells (1.8 BYA)
- first animals (sponges) (approx. 600 MYA)
Phanerozoic Eon
**MEMORIZE TIMELINE
- caused by an asteroid impact (approx. 65.5 MYA)
- 75% of all species go extinct
- all non-avian dinosaurs go extinct
- crater formed from impact was found in 1990's (in Gulf of Mexico)
- thin layer of clay from sediments over the Earth, contains high amounts of Indium (abundant in extraterrestrial things but rare on Earth)
half-life
time for half of parent isotope to decay to daughter isotope
K-T impact/extinction
allowed for adaptive radiation
- asteroid struck sulfur-rich rock (in Gulf of Mexico) and led to sulfuric acid "rain"
- acidified the ocean, which is bad for marine organisms w/ skeletons
- Asteroid caused "impact winter" major radiation and heat, major dust cloud that blocked sun and prevented photosynthesis for approx. 1 year
mammals
one of the groups that bloomed extensively after the K-T extinction (End-Cretaceous Extinction/dinosaurs)
mass extinction
widespread rapid decrease in the amount of life on Earth
Ornithischian dinosaurs
one of two major groups of dinosaurs, non-avian, different hip orientation from saurischian dinosuars (bird-hipped)
radioactive decay
used by paleontologists to predict the age of the geological time scale and organisms
Saurischian dinosaurs
one of the two major groups of dinosaurs
lizard-hippped dinosaurs, phylogenetically led to theropod dinosaurs
Theropod dinosaurs
birds are derived from theropod dinosaurs because an experiment on chickens show that they failed to create beaks, made snouts similar to ancestral species, meat-eating dinosaurs
trace fossils
shows indirect evidence of ancient life
includes: burrows, footprints, coprolite (poop), tracks
explain how fossils form and the limitations of the fossil record; describe the two main types of fossils
burial of an organism (covered in sediment or mud) and over time, the sediments harden into rock
fossils preserve the hard part of organisms (features that do not decay after death), thus biological factors limit the completion of the fossil record. Most marine organisms are fossilized as opposed to organisms on land because more sediments are likely to harden into rock in river banks or streams (EX. amoebas, nematodes, and flowers are not usually fossilized)
Explain how paleontologists and geologists can estimate dates of important events in Earth's geological history using radioactive decay of different isotopes (such as 14C and 238U)
Carbon created from photosynthesis of plants and trees will be consumed by heterotrophs (animals who cannot produce their own food), when that animal dies and decays the carbon will also break down to a more stable isotope of nitrogen, which occurs every 5730 years (called a half life). By comparing the age of an organism (EX. rings on a tree, coral growth) to the amount of carbon remaining, paleontologists and geologists can determine how old it is.
Scientists determined the geological timescale mostly through the radiometric age of volcanic fossils in sedimentary rocks
Describe the relative order and approximate time the following events occur:
formation of Earth
first molecular & fossil evidence of cells
evolution of photosynthesis
development of oxygen-rich environments
first eukaryotic cells
first animals
colonization of land by plants and fungi
colonization of land first by arthropods then tetrapods
End-Cretaceous extinction
diversification of birds & mammals
4.5 BYA formation of Earth (Hadean)
3.5 BYA first molecular & fossil evidence of cells (Archaean)
3.5 BYA evolution of photosynthesis (Archaean)
2.4 BYA development of oxygen-rich environment (Proterozoic)
1.8 BYA first eukaryotic cells (Proterozoic)
600 MYA first animals (fossil sponges) (Proterozoic)
542 MYA Cambrian explosion (End of Proterozoic)
475 MYA plants and fungi on land (Phanerozoic)
420 MYA arthropods on land (Phanerozoic)
365 MYA tetrapods (vertebrates) on land (Phanerozoic)
65.5 MYA End-Cretaceous extinction (K/T extinction) (Phanerozoic)
after 65.5 MYA diversification of birds & mammals (Phanerozoic, currently)
Describe the main events that occurred in the Hadean, Archaean, and Proterozoic eons.
Hadean:
- Earth formed
- high volcanism
- no life
- no oxygen in atmosphere
Archaean:
- first evidence of life (molecular fossils)
- first bacteria
- photosynthesis
- no oxygen in atmosphere
- oceans
- volcanism
- first cyanobacteria
Proterozoic:
- atmosphere and surface of oceans become oxygenated
- first eukaryotic microfossils/cells
- first animals (sponges)
Phanerozoic:
-
Describe the adaptive radiations that followed the End-Cretaceous mass extinction.
Since all dinosaurs were wiped out and many pre-existing plants and animals went extinct, new ecological niches and opportunities opened the door for new organisms to come about, most commonly being mammals, crocodiles, and birds
Describe the likely cause of the End-Cretaceous mass extinction and the evidence that supports that cause.
Researchers are fairly certain that an asteroid was the cause of the End-Cretaceous extinction
***
Give evidence for birds being derived dinosaurs, including their shared, derived traits.
birds and dinosaurs are related due to morphology and experiments
shared derived traits:
- hollow, pneumatic bones filled with air
- S shaped beak
- tridactyl foot
- digit grade posture (stand & walk on toes)
- furcula (wish bone)
traits common to all theropods:
- everything above ^
- presence of a sternum
- semilunate carpal (wrist bone)
Describe the functions of the semilunate carpal, keeled sternum, feathers, and cloaca in birds and/or dinosaurs.
- cloaca: birds have only one opening for everything (eating, peeing, reproduction, etc.) EX. found in cranes
-feathers: in birds mostly serve for flight, in dinosaurs they couldn't fly but they used them for courtship rituals and insulation
-keeled sternum: where flight muscles attached
-semilunate carpal: important in flight stroke
-ONLY LIVING BIRDS ARE TOOTHLESS
-long arms and keeled sternum***watch lecture
Describe the conservation challenges for Kirtland's warbler, as well as the reasons behind this species' recovery.
- species spends part of its yearly life cycle found in the lower part of upper peninsula of Michigan
- severely threatened in 1970's ~200 mating pairs, in the 1990's they were protected and began doing habitat restoration
- males become brightly colored during breeding season and they have a particular song to lure females and to protect their territory, they eat primarily insects but some grasses
- they need a specific habitat -- young-jack pines can only germinate after the gymnosperm cone has been exposed to fire
- people have been creating fires to burn competing vegetation that also leads to the germination of young-jack pines, leading to recovery
- ground nesters, vulnerable to feral dogs and cats and larger birds (nest parasitism EX. warblers raise bigger, needier cowbird chick eggs instead of their own eggs)
- long migration that causes mortality
Describe the Sandhill crane's reproductive strategies, including courtship rituals. Also describe how they produce the trumpeting call.
- sister to plovers (both prefer wet habitat)
- feed in wetlands, caused decline in both cranes and plover
- very light but tall
- 6 to 7 feet wingspan
- courtship dances, males teach youngsters and practice before mating, mating at 3-5 years of age
- omnivores
- cloaca (one opening for eating, peeing, etc.)
- cloaca mating (tissue around cloaca swells, male and female have to touch for sperm transfer)
- trumpeting sound comes from coiled trachea (only found in cranes)*****
Describe how piping plover restoration efforts work, and how the Great Lakes population has responded to those efforts.
- cranes are its closest relative
- nests on shores of oceans or great lakes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- protecting eggs and chicks by using fencing or signs
- captive breeding and then releasing back to wild
- monitor population size (want to see efforts having an effect)
- attracting birds to suitable lakeshore habitats
- target is 150 mating pairs for 5 years, not there yet but population has been increasing
- currently have 100 in Michigan, 50 in other great lake states
- 5 year average of 1.5-2 chicks per mating pair
- stable population for at least 10 years (growing or staying the same) before delisting from threatened species list
LECTURE 16
carrying capacity (k)
ONLY INTRASPECIFIC COMPETITION REGULATES THE POPULATION AT K (for limiting resources) (DENSITY DEPENDENT FACTORS LIKE RESOURCES SUCH AS FOOD, WATER, HABITA) or disease and only in logistic growth graphs OTHER Factors regulate the population BELOW K at a new equilibrium size: predation, parasitism, pathogens, INTERSPECIFIC competition NOT MUTUALISM NEVER REGULATES
density-independent factor
abiotic factors
events that are are not affected by the population size
EX. severe drought, extreme weather, earthquakes, pollution/poison
density-dependent factor
biotic factors
events that depend on the population size
EX. disease/parasites, predation, competition, mutualism (cannot regulate population size, +/+), limited resources ??
emigration
- individuals of a species LEAVING a habitat
exponential growth
pattern of population increase WHEN R IS CONSTANT OVER TIME
the number of individuals added to the population in any time interval is proportional to the size of the population at the start of the interval
geographic range
how widely a population is spread out
geometric rate of increase
lambda (discrete growth)
immigration
+ individuals of species COMING into a habitat
intrinsic rate of increase (rmax)
the maximum per capita growth rate for a particular species under ideal conditions (unlimited resources, no competition, no predation, etc.)
logistic growth
an example of density-dependent growth because eventually the resources necessary run out and competition ensues, leading to the growth of the population size falling to 0 (graph looks like a stretched out "S")
lambda (λ)
geometric growth rate
λ>1 or r>0, populations are growing
λ=1 or r=0, populations are stable
λ<1 or r<0, populations are shrinking
per capita growth rate (r)
GROWTH RATE PER INDIVIDUAL
population's growth rate over a interval of time
λ>1 or r>0, populations are growing
λ=1 or r=0, populations are stable
λ<1 or r<0, populations are shrinking
r = b + i - d - e
population
groups of individuals belonging to the same species that live in the same region at the same time
population density
loosely defined as the amount of organisms in an area divided by the amount of area
population size (N)
only four things can change a population size: birth, death, immigration, and emigration
vital rates: b, i, d, e
birth, immigration, death, emigration
interspecific competition
individuals within a species compete
intraspecific competition
individuals from different species compete
describe how birth, death, immigration, and emigration influence population growth rate and population size, and how absolute numbers of births, deaths, and immigrants, and emigrants relate to birth, date, immigration, and emigration rates, respectively
birth and immigration increase population growth rate and size whereas death and emigration decrease population size
B = # of births (b) between times 0 and 1
D = # of deaths (d) between times 0 and 1
E = # emigrants (e) between times 0 and 1
I = # immigrants (i) between times 0 and 1
BDIE = actual # of individuals
b d i e = represent the rate
define the geometric growth rate of increase, λ, and per capita growth rate, r, and describe how they can be used to understand how populations change over time (lecture notes)
lambda gives us discrete population growth and can describe a population's growth rate over a discrete time interval (ex. 1 year), if less than one shrinking
r gives us a continuous growth rate and can describe a populations growth at any particular instant in time, if less than zero shrinking
r is the natural log (ln) of lambda
explain the relationship between lambda (λ) and r
λ=e^r
r=lnλ
apply the discrete, exponential, and logistic growth equations to predict population growth rate and population size in the future
PRACTICE
recognize that population growth rate is constant under exponential growth, but that population growth rate slows as population size increases under logistic growth
PRACTICE
explain why populations do not grow exponentially forever
carrying capacity (k) (with competitions only)
identify exponential vs. logistic growth curves
exponential growth curves are a backward, curved capital L
logistic growth curves are a stretched out S with a carrying capacity (k)
explain the factors that influence the per capita growth rate (r) of populations undergoing logistic growth
# births
# deaths
# immigration
# emigration
compare and contrast density-dependent and density-independent factors, recognize a factor as density-dependent or density-independent and analyze a graph to determine if a density-dependent or density-independent factor is influencing population growth
density-dependent factors (biotic) (events that are possible based on the population size)
- predation
- competition
- parasitism
- mutualism (CANNOT REGULATE POPULATION SIZE)
density-independent (abiotic) (events that are not affected by the population size in any way)
- temperature
- disturbance
- precipitation
- pollution
- salinity
- pH
define population regulation and summarize the factors that regulate population growth
-biotic and abiotic factors (ONLY BIOTIC FACTORS EXCEPT MUTUALISM REGULATE POPULATION SIZE)
-biotic: predation, competition, parasitism, mutualism
-abiotic: temp, disturbance, precipitation, pollution, salinity, pH, natural disasters
-all act as corrective actions to keep population in line with it's set point (optimal conditions)
LECTURE 17
commensalism
a relationship between two organisms in which one organism benefits and the other receives no harm or benefit (+/-)
community
a group of organisms or population of different species interacting with each other and the environment
constitutive defense
defense that is always present in plants
ectoparasite
a parasite that lives outside of the host's body (EX. fleas)
endoparasite
a parasite that lives inside another organism (EX. tapeworm)
facultative
most of the time: one or both of the participants in a mutualism can survive without the other
herbivory
a relationship in which a primary consumer (herbivore) eats plants, leaves, etc. (+/-)
influences:
- plant population size/growth rates
- individual growth rates
- plant evolution (constitutive and inducible defenses)
- plant community structure (# of species present and abundance of each species)
inducible defense
energetically efficient but takes longer to produce, defenses that grow stronger with experience/encounters
macroparasite
parasites that DO NOT multiply and are large enough to be seen by the human eye
microparasite
parasites that multiply within the host
obligate
when one or both sides of a mutualism cannot survive without the other (ex. aphids and bacteria)
parasitism
a relationship similar to predation except there is a host and parasite, the parasite lives or feeds off of the host and may or not kill their host (if they do it is usually over time/slowly) (+/-)
predation
a relationship in which one organism kills and/or eats the other (+/-)
- compare and contrast herbivory, predation, and parasitism
- be able to compare these with mutualism, competition, commensalism, and symbiosis
- understand what the general term "enemy-victim" means
- enemy-victim indicates a -/+ relationship and includes predator-prey, parasite-host, and herbivore-plant
compare and contrast inducible and constitutive defenses
inducible defenses are activated when a plant senses danger or a threat while constitutive defenses are always activated
explain how plant defenses can be co-opted by their herbivores
butterflies using the poison in plants to protect themselves (essentially use plant's defenses to protect themselves)
describe how predators and parasites can regulate prey population sizes
predators can affect prey behavior, which affects vital rates:
- decrease in emigration: prey leave habitats where predators are present
- increase in immigration: prey do not immigrate into areas where predators are present
- decrease in birth: prey have reduced/non optimal feeding times because predators are nearby and cause them to get stressed, stress hormones reduce birth rates
- increase in death: predators kill and consume prey
50% of species are parasites, host-parasite coevolution is very common
explain how predators can change prey behavior and influence all vital rates, and how they can exert strong selection on prey
predators can affect prey behavior, which affects vital rates:
- decrease in emigration: prey leave habitats where predators are present
- increase in immigration: prey do not immigrate into areas where predators are present
- decrease in birth: prey have reduced/non optimal feeding times because predators are nearby and cause them to get stressed, stress hormones reduce birth rates
- increase in death: predators kill and consume prey
explain why plants must have colonized land before animals
plants must have colonized land before animals because animals need plants as a source of food/energy in order to survive
- explain how parasites can change host behavior and influence host population size
- explain their importance in food webs and how they can dominate biomass in ecosystems
- parasites directly control the host's decision-making mechanisms and motor skills to promote the transmission of the parasite
- not bound to a single trophic level, they feed on both autotrophs and heterotrophs, any organism that benefits it
explain how the nature of interactions between species can change as environmental conditions change
when mutualism turns into parasitism????
describe the features that distinguish arthropods from other animals, the diversity of arthropods, and some drivers of arthropod diversity
1.type of bilateral-->bilateral symmetry and complex organs
2. Have a cuticle made of protein covering their bodies to provide them with flexible, lightweight protection,
3. External skin made of chitin
4. Most diverse animal group
5.Mostly made up of insects(80%)
6.They have three key adaptations that allow them to live in diverse habitats: desiccation-resistant eggs, wings, and metamorphos
7. Driver of arthropod diversity: Plant- pollinator and plant-herbivore coevolution have been key drivers of arthropod and plant diversity.
8. COLLAGEN
give defining characteristics of Hexapods (insects) and explain their importance in mutualistic and consumptive interactions
3 part body: head, thorax with 6 leg, and abdomen
-subphylum of arthropods
???
LECTURE 18
character displacement
competition causes species to diverge/evolve overlapping character traits
evolutionary change in species traits/morphology in which allows co-occuring species to use different resources
competition
a relationship in which both organisms expend energy in fighting over resources, food, etc. (-/-)
competitive exclusion
two species with identical niches CANNOT coexist
fundamental niche
the entire range of food resources and climate conditions that allows a species to survive
land plants
plants that live on land, 90% form associations with mycorrhizal fungi
mutualism
a relationship in which both organisms benefit (+/+)
fundamentally important to the evolution of land plants
mycorrhizae
symbiotic relationship between host plants and mycorrhizal fungi: the fungi provides added nutrients and water while the plant provides carbohydrates
mycorrhizal fungi
helps plants take up phosphate and other nutrients, plants supply mycorrhizal fungi with carbohydrates (glucose and other sugars)
more than 90% of land plants have associations with mycorrhizal fungi [Show Less]