lecture exam 2 study set
Describe the four hormones that control the estrous cycle, where they originate, how they vary across the cycle (e.g. when they are high or low) and the consequences of those hormones to various stages of the cycle
FSH: Anterior pituitary LH: Anterior pituitary Estrogen: Ovary Progesterone: Ovary Days 0-7: menstrual flow phase - low estrogen and progesterone - high FSH and low LH (FSH>LH) = tells ovary to develop egg - egg development Days 7- 14: proliferative phase - follicle at certain growth level causes: - estrogen increases rapidly --> when at peak LH production increases rapidly - LH>FSH = induces ovulation - ovulation occurs follicle releases egg and egg travels down fallopian tube - progesterone low Days 14 - 28: Secondary phase - Estrogen decreases after ovulation - ovum reaches uterus --> high-ish LH levels induce development of corpus luteum - corpus luteum development = mammary glad production and increased endometrium - corpus luteum = progesterone levels increase
How is the appendicular skeleton modified for a running specialist?
Fewer digits & elongated bones = increased running speed Elongated, smooth bones + Axis close to muscle force
Define the following terms: - Follicle stimulating hormone - Luteinizing hormone - Estrogen - Progesterone
Follicle stimulating hormone: from anterior pituitary → stimulates the follicle to secrete estrogen Luteinizing hormone: development hormone for the egg Estrogen: triggers the anterior pituitary gland to produce more LH. Progesterone:
To generate force, where does the axis need to be in relationship to the resistance? How is that shown in the bodies of digging mammals? And in swimming mammals?
Force → axis is close to resistance Movement joint is closer to where you are digging → axis of movement closest to area of movement Digging: - Limb adaptations: - Shortened, thickened bones - High sculting, spines, extensions for muscle attachments - Enlarged stocky muscles - Wrist joints rotated outwards - Abduction and extension muscles are lateral digging strokes - Recovery stroke by rotating limb downwards Swimming: - Limb adaptation: - Most of movement at joint between arm and shoulder girdle - Hand modified into broad, flay paddle with strong thumb for leading edge
What are the four functional requirements of a type of locomotion to be viable?
Functional requirements: 1. Support and stability 2. Propulsion 3. Maneuverability 4. Endurance
In comparison to eutherians, is a greater or smaller proportion of the development of the young in gestation or lactation for marsupials?
Greater portion of the development is during lactation
How long are monotreme eggs incubated? How long until offspring are weaned? Is there parental care?
1-3 eggs produced per season Weaned at 4-6 months Only mother parental care
What are five ways mammals have evolved to delay this reproductive cycle? Why are they advantageous?
1. Induced Ovulation: copulation first then ovulation → dont waste resources on egg - Cats, rabbits, some mustelids, desert rodents, etc. 2. Delayed fertilization: Copulate and then store sperm (via dehydration until after hibernation) and delay the ovulation and fertilization - Insectivorous bats 3. Delayed implantation: Delay implantation of fertilized egg to uterus - Obligate: always copulate and fertilize egg before hibernation and delay implantation - Facultative: delay implantation when resources are low - ursids, mustelids, skunks, etc 4. Delayed development: Implantation and beginning of gestation and fetus development that is then halted - Growth resumes normal rate in spring or with flush resources - bats only 5. Embryonic Diapause: embryonic embryo development is halted mid-way - Advantageous for living in drought-prone habitats → hedging their bets - only in marsupials like kangaroo
What are the three main reasons that marsupials have a short gestation period?
1. gas exchange a problem 2. danger of immune response 3. Progesterone doesn't inhibit FSH ("Tyranny of the Estrous Cycle")
What are the seven steps in the common mammalian reproductive cycle for females?
1. ovulation (gametogenesis) 2. copulation (insemination) 3. fertilization (formation of diploid zygote) 4. implantation (attachment to endometrium) 5. gestation (intrauteran development) 6. birth 7. lactation
Are there trends in abundance among species in a community?
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What are some potential limitations of a line map?
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Define the following terms: - Abundant-Center Hypothesis - Log-normal abundance distribution
Abundant-Center Hypothesis: Abundant-center distribution = highest abundance near the center of range in optimal conditions and fewer individuals towards range boundaries Log-normal abundance distribution: log-normal distribution provides an accurate description of the abundances of species in a community, and this distribution is therefore frequently used to model the relative abundance of species in communities
Define the following terms: - Altricial - Precocial
Altricial: Altricial: requiring nutrition - Require a long period of development Precocial: Young more developed at birth
Describe the differences in the 10 locomotion types in mammals, give specific examples for each (part 1)
Ambulatory: walking and scampering - Bear, capybara, human - Quadrupedal (seen in most mammals) - Bipedal (seen in humans) Cursorial: Running and fast animals - Cheetah, horses, antilope - Both predator and prey - Long gait with by moving their body and by their altered legs Saltatorial: Jumping and ricochetal - Jumping → using all four feet (rabbita) - Ricochetal → jump on hind two feet (kangaroo) - Being fast in a different way Arboreal: climbers - Sloths, breachiator monkeys - Specialized morphology in feet, ankles, wrists for climbing/swinging in trees Secondarily arboreal: Move primarily on the ground or something but can to go up trees Tree kangaroo
Define the following terms: - Bacula - Os penis - Bifurcated vagina + penis - Scrotal, non-scrotal
Bacula/Os penis: Bacula: penis bone → a bone that resides in the abdomen of some animals. It is moved by muscles into the shaft of the penis when the animal is aroused Bifurcated vagina + penis: penis or vagina that is forked Scrotal, non-scrotal:
How does the total amount of energy consumed by a mammal change with body size? + How does the mass-specific amount of energy consumed by a mammal change with body size? Why are those two patterns so different?
Basal metabolic rate increases with smaller mammals Total Energy required increases with mass → bigger animals need to eat more BUT Energy per kg of body mass decreases with increasing mass
How does the abundance or density of mammal individuals vary across body sizes from small to large? Is this trajectory in body size and population size similar for other animals?
Biggest Predictor of Abundance is Body Size Population density decreases with increasing body size - Body size related to several other aspects of mammalian biology like reproductive output
Describe the differences in the 10 locomotion types in mammals, give specific examples for each (part 2)
Brachiation: moving through the trees - More specialized adaptations to live in trees → Long limbs, wrists that can turn in the trees - Trade off → species is so specialized for brachiation that they aren't fast on the ground Fossorial: specialized diggers - Moles, naked mole rat, gopher - Live the entire life in the ground essentially Modified front feet for digging, small/reduced eyes, torpedo shaped (like aquatic mammals → not shedding water they're shedding dirt) Semi-fossorial: general diggers - Prairie dogs, badger, marmot - Not really locomotory specialization → usually ambulatory with digging behavior Glissant: gliders - Need flaps of skin between arms and legs - Many different orders that do this gliding but not many species Volant: true flyers - Chiroptera - More variation in wing shape in microchirpotera for different things (fast or agile)
How are choriovitelline and chorioallantoic placentas different? Why was the latter a major evolutionary advantage for eutherians?
Choriovitelline placenta: Enlarged yolk sack, Relatively little attachment to developing fetus Embryo cant get very big, much less intimate contact with developing fetuses than Eutherians Chorioallantoic placenta: Villi extend deeply into uterus, Tight connection between mother and fetus - Trophoblast: prevents autoimmune attack - More efficient (less energy than lactating)
Define the following terms: - Cloaca - Choriovitelline placenta - Chorioallantoic placenta
Cloaca: Single opening for reproduction and waste - Same arrangement as most other vertebrates, including birds Choriovitelline placenta: much less intimate contact with developing fetuses than Eutherians Chorioallantoic placenta: Villi extend deeply into uterus + Tight connection between mother and fetus
What 3 factors determine the rarity of a species? (Abundance, range size, habitat specialization)
Combo of abundance, range size, and habitat specificity - Rare → small range - Threatened → combination of low abundance and habitat destruction
Define the following terms: - Corpus luteum - Tyranny of the estrous cycle - Monestrous - Polyestrous
Corpus luteum: cells that form around the egg to tell the body not to attack Tyranny of the estrous cycle: why marsupials have such under-developed babies Monestrous: 1 cycle/year Polyestrous: multiple cycles/year
What are the best predictors of latitudinal diversity in mammals? (climate, specifically productivity)
Correlation models show most of the global mammals distribution correlates very strongly with productivity and not as strongly with temperature alone (deserts as an example of high temp but low productivity) -Relationship between all of climate and richness is ~78% (draw the h2o availability vs temp vs elevation graphs)
How is delayed implantation a useful adaptation for some mammals? What is the variation in time that implantation is delayed?
Delayed implantation: Early cleavages of blastocyst + Development arrested; doesn't implant in uterine endometrium (100-400 cells) - Obligate: always copulate and fertilize egg before hibernation and delay implantation - Facultative: delay implantation when resources are low - 2.5 months ~ 11 months
Define the following terms: - Ecological Biogeography - Species distribution - Species Range
Ecological biogeography: Examine current species distributions in context of recent ecological setting Species distribution: where a species occurs latitudinal range, elevational range, and patchiness within that area Species Range (ideally): line maps - Distributional Limits, Show patchiness, Abundance within those limits
Define the following terms: - Endothermic - Ectothermic - Homoethermic - Heterothermic
Ectothermic: Regulation of body temp through behavioral adjustments Endothermic: Mammals are able to regulate their body temps using physiological mechanisms Homoethermic: Maintaining a constant body temperature Heterothermic: Mammals capable of dormancy, torpor, and/or hibernation
Describe embryonic diapause and why some marsupials have three offspring in various stages of development at any time.
Embryonic diapause: Embryo development halted mid-way - ONLY IN MARSUPIALS - Mother may mate when joey~6 months old but Suckling prevents development of 2nd joey in uterus - If she mates again ( bifurcated uterus and vagina) Female can have 3 offspring dependents at a time
Define the following terms: - Estrous cycle - Anterior pituitary hormones - Ovarian hormones
Estrous cycle: Reproductive cycle of adult female - Hormonal, Physiological, Behavioral Anterior pituitary hormones: Follicle Stimulating Hormone and Luteinizing Hormone Ovarian hormones: Estrogen and progesterone
How does a eutherian mammal avoid an immune response to the embryo? A marsupial?
Eutherians: The Corpus luteum forms around ovum and Trophoblast cells prevent immune response from mother Marsupials: choriovitelline placenta less efficient and does not really protect young, fetus cannot grow too large or there is a risk of immune attack from mothers body
What is the Hutchinson definition? Be able to describe it with a figure
Evelyn Hutchinson (1957): Niche =Multidimensional space or "hypervolume" within the limiting environmental variables of a species (look at notes graph)
What are some aspects of evolutionary history that have been proposed to explain mammalian diversity?
Speciation, extinction, colonization dynamics - Colonization dynamics example: great american interchange - The latitudinal diversity gradient is ancient → can pick up the lat divesity gradient in fossils - Even millions of years ago the diversity gradient seen today was occurring
Define the following terms: - Species richness - Latitudinal diversity gradient - Elevational diversity gradient
Species richness: # of species Latitudinal diversity gradient: describes the pattern of increasing numbers of species from the poles to the equator (also observed in sea mammal patterns with some variation bc they can swim around) Elevational diversity gradient: Mammal diversity increases around mountain ranges. Typically a mid elevation peak is observed.
What is the species-area relationship, and is there support for it latitudinally or elevationally?
Species-area relationship: the more area you have the more species there are Possibly one of the explanations for the latitudinal diversity gradient - Problem → looking at habitat size not land area - Area isn't the most abundant around equator → have much more area in the higher latitudes (Northern and Southern hemispheres) - Area theory NOT well supported for latitude
To generate speed, where does the axis need to be in relationship to force? How is that shown in the bodies of running mammals? And in swimming mammals?
Speed: Axis close to muscle force Running: Elongated, fused bones, Muscle attachment at bone ends, Elongated muscles, Joints restricted to single plane, Spinal flexion Swimming: Most of movement at joint between arm and shoulder girdle - Hand modified into broad, flat paddle with strong thumb for leading edge - Tail is adaptation for speed, front limbs are adaptation for power
What are the differences between mammalian stances and mammalian locomotion?
Stance: mode of standing / organization of limb bones Locomotion: mode of movement
How does a mammal increase its stride length? How does a mammal increase its stride rate?
Stride length: - Elongation of bones - Walk or run on your toes or tiptoes - incorporating Scapula in limb + lose clavicle - lots of flexion Stride rate: - Reduction of distal weight → bone fusion and reduction - Stability: limb joints restricted to single plane - Muscles inserted close to joints move the joint through a widerAngle (increases stride length) also makes bones on which they insert move faster
How do you calculate surface area? How do you calculate volume?
Surface area = length x width Volume = length x width x height
What are the main types of hypotheses proposed to explain latitudinal and elevational diversity?
Temperature: warmest around the tropic and colder away from equator Water: rain and snow fall differ more than temp but typically there is higher water levels in the tropics Productivity: where you have the most plants year round - A combination of temperature and precipitation - Much more green around the tropics with decreasing productivity as you move away from the tropics
Do surface-area to volume ratios increase or decrease with body size? What does that mean for heat loss to the environment?
The LARGER an animal the LOWER its surface area to volume ratio Larger animals have lower surface area to volume ratio → Smaller mammals lose more energy
Define the following terms: - Trophoblast - Gestation - Lactation - Embryonic diapause
Trophoblast: first cells around dividing embryo;becomes the amniotic sac - Prevents immune response by mother to embryo (layer of cells) Gestation: amount of time that fetus is within body Lactation: production of milk Embryonic diapause: embryonic embryo development is halted mid-way
How is the appendicular skeleton modified for a digging specialist?
True diggers: moles, gophers, armadillo Evolve to move earth → big scoop at the base with short limbs Skeletal adaptations: 1. Extension of scapula for large muscles pulling leg back to dig 2. Large scapular spine for muscles moving arm out 3. Short, stout clavicle 4. Short string bones 5. Shorter wider front limb for digging 6. Shortened, thickened bones 7. High sculting, spines, extensions for muscle attachments 8. Enlarged stocky muscles 9. Wrist joints rotated outwards 10. Abduction and extension muscles are lateral digging strokes 11. Recovery stroke by rotating limb downwards
How is metabolic rate usually estimated?
Usually calculated while fasting (when the organism is not digesting) - Heat production, Oxygen consumption, Heart rate comparisons
Why does volume increase faster than surface area?
Volume increases as a cubed measure, whereas Surface Area increases as a square measure
Are mountains important for understanding patterns of mammal diversity?
YES Have a different mammal diversity pattern than for latitude Mid elevational peak is where diversity is generally observed
How is mammal diversity spread over the globe? Where is it highest and lowest?
generally, mammal diversity is highest at the equator (0° latitude) Mammal diversity lowest typically at the poles
How did the climate change over the last 2 million years and last 700 thousand years during the Pleistocene?
glaciation cycles → >20 cycles in 2 million years Increased in intensity last 700,000 years (~100,000 year periodicity)
What other traits have evolved in digging and swimming mammals to make them efficient in moving through soil or water?
literally just went over this wtf is the point of this question
What are we describing when we talk about a "mammal abundance pattern"?
mammal abundance pattern: Number of Individuals in a Population - Biggest Predictor of Abundance is Body Size
How does litter size vary among marsupials and eutherian mammals? What is the main determinant of this variation?
marsupials: Litter size highly variable 1-13+ Eutherian: ??? Nipple placement and number ?
What does the log-normal abundance distribution show about community abundance patterns in mammals?
most species have an intermediate abundance within a community + normally distributed
What is the evidence for and against each hypothesis for the megafaunal extinction?
Human overkill: - against: - Weak evidence of hunting specialization to focus primarily on large game by early peoples (Colvis) - Coincident timing of human arrival on the continent + estimate of mega-faunal extinction questioned - Kill sites only document a minority of the species that went extinct - Some evidence that some of these species/genera went extinct before 1st people arrived - For: - Models of hunting alone predict the number of megafauna species that went extinct - African megafauna evolved with human hunting pressures → africa doesn't have an abundance of megafauna because of humans - timing of humans arrival correlates with extinctions Climate change: - against: - Why did these species survive several previous cycles of climate change? - Why were African megafauna less susceptible to climate change? - Why weren't other mammals, plants, vertebrates, invertebrates going extinct from climate and habitat change? - Why were extinctions so fast? -For: - La
Describe the two main explanations for megafaunal extinction?
Human overkill: humans just killed everything - Humans moved across the continents during the Pleistocene - The timing of human arrival at continents and the mass extinction of large animals correlate - Hunting size bias Climate change: the last glaciation was big, and the interglacial came quickly → what tipped the scales - Habitats shifted, enlarged, or shrank → nonanalog habitats and climates - Large ranges shrunk → Large mammals need large amounts of area individually - Competition increased with habitat shifts - Habitats changed quickly → many species that were spread out had to shrink back and compete for the smaller habitat and less abundant resources - Large species → large ranges, low population sizes, low fecundity (less resilient to change), higher climate ex
Define the following terms: - Hypothermia - Hyperthermia
Hypothermia: If the core body temperature drops BELOW the lower critical temperature and heat production insufficient Hyperthermia: If the core body temperature rises ABOVE the upper critical temperature and heat loss is insufficient
What aspects of a species range should be shown in a distribution map? Why is that not always achieved?
Ideally species ranges should show Distributional Limits, Show patchiness, and Abundance within those limits not always achieved because ???????
what if the egg is fertilized ?
If fertilized progesterone stays high → pregnancy Fertilized eggs embeds into lining of uterus and progesterone stays high to signal that a fetus is developing
What happens if the egg is not fertilized?
If not fertilized, progesterone declines and cycle repeats - Progesterone declines and corpus luteum degrades and egg is absorbed by the uterus - Uterine lining sheds and breast tissue development reverts - Cycle repeats
How is induced ovulation a useful adaptation for some mammals? What are some examples?
Inducing ovulation is beneficial because you don't waste resources on an egg if you dont have resources or a partner Cats, rabbits, some mustelids, desert rodents, etc.
Who coined the term niche? What was his definition?
Joseph Grinnell (1917): coined term "Niche" "all the sites where organisms of a species can live"
Is gestation or lactation more costly to mammal females? How might that effect eutherians and marsupials differently?
Lactation is much more costly to females than gestation Because marsupials spend more time on average lactating than Eutherians, it is a way more serious energy expenditure for marsupials vs eutherians.
Across body sizes, how do metabolic rate, life span, reproduction rate & # of offspring per season vary?
Large: - Low metabolism - Few offspring/season - Low reproductive rate - Low abundance - Local - Across range - Long life Small: - high metabolism - Many offspring/season - High reproductive rate - High abundance - Local - Across range - Short life
How did those changes (pleistocene climate changes) influence habitats and mammalian species' ranges in the Northern Hemisphereand the rest of the continents?
Late Pleistocene warming +Glacier retreat + Seasonality increased + Precipitation patterns variable → Habitats shifted, enlarged, or shrank (nonanalog habitats and climates) Large ranges shrunk → Large mammals need large amounts of area individually Competition increased with habitat shifts Large species → large ranges, low population sizes, low fecundity (less resilient to change), higher climate exposure
What parts of the body are most changed by evolution for locomotion specialization?
Limbs evolve for change in locomotion: front legs, hind legs, pelvis, shoulder - Trade offs between power and speed - Strong influence of locomotion medium ( land, water, or air)
Define the following terms: - Line Map - Diversity - Niche
Line Map: Diversity: Diversity = Species richness (# of species) and abundance Niche: all the sites where organisms of a species can live ( Joseph Grinnell 1917), Multidimensional space or "hypervolume" within the limiting environmental variables of a species (Evelyn Hutchinson 1957)
How do various combinations of these factors result in "seven types of rarity"? Be able to give examples of mammals for various combinations of the seven types of rarity.
Low abundance: - Large range - Habitat specialist → polar bear - Habitat generalist → mountain lion - Small range - Habitat specialist → giant panda (Highest rarity ) - Habitat generalist → tasmanian devil High abundance: - Large range - Habitat specialist → water shrew (Lowest rarity) - Habitat generalist → NOT RARE - Small range - Habitat specialist → banner tailed kangaroo rat - Habitat generalist → solodonts
What are some of the evolutionary tradeoffs of becoming highly specialized in locomotion?
Many mammals have highly specialized modes of locomotion The more specialization → the more tradeoffs You get really good at moving in one specific environment so if you have to move in another environment you are now incredibly inefficient or cannot move
Define the following terms - Metabolism - Surface-Area to Volume Ratio (SAVR) - Basal or resting metabolic rate
Metabolism: set of chemical reactions that occur in living organisms to maintain life. - Cellular respiration, Making proteins, amino acids, hormones etc. - These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Surface-Area to Volume Ratio (SAVR): Heat loss → Surface Area to Volume Ratio - Volume increases as a cubed measure, whereas Surface Area increases as a square measure - The LARGER an animal the LOWER its surface area to volume ratio Basal metabolic rate (BMR) / resting metabolic rate (RMR): the amount of energy expended while at rest in a neutral environment
Describe the differences in the five stances in mammals, give specific examples for each, and discuss the pattern of how the stances evolved
Plantigrade: Flat feet - Bears, rodents, less rapid carnivores, humans Digitigrade: on digits → Fast animals that are not hooved - Mountain lions, dogs, cheetah Unguligrade: on nail/hoof →On the hoof which is connected to the phalange - Elk, horses, deer Graviportal: Sort of digitigrade with tissue surrounding - Elephants, rhinos - "Collumnar" leg evolved to hold the huge weight - Thicker and denser bones to deal with weight Pendant: Hanging upside down - Bats - Pretty normal back foot with specialized front foot - Toes do the most gripping Evolution of stance: Plantigrade → digitgrade → unguligrade
Define the following terms: - Plantigrade - Digitigrade - Unguligrade - Graviportal - Pendant
Plantigrade: flat Digitigrade: on digits Ungiligrade: on nails/hooves Graviortal: biggest mammals Pendant: upside down hanging appendages
What was the mammalian Megafaunal Extinction, when did it happen, and on what continents?
Pleistocene megafaunal extinction: The largest animals across the globe went extinct - Mostly N America, S America, and Australia - Many animals that made it from south to north went extinct - Occurred around 13,000 - 12,000 years ago
Define the following terms: - Pleistocene - Pleistocene megafaunal extinction - Human Overkill Hypothesis - Climate Change Hypothesis
Pleistocene: 2.5 mya - 0.012 mya. epoch with glaciation Pleistocene megafaunal extinction: The largest animals across the globe (mostly N America, S America, and Australia) went extinct Human Overkill Hypothesis: human arrival led to pleistocene megafaunal extinction Climate Change Hypothesis: warming+ glacial retreat+ seasonality caused the pleistocene megafaunal extinction
Describe how the progesterone cycle in eutherian differs from the progesterone cycle in marsupials
Progesterone stays high in eutherians to signal that there is a pregnancy and to inhibit FSH production in Marsupials, the progesterone doesn't inhibit FSH production which means a new follicle will develop even if pregnant
What is contained in milk? How do the percentages of those components vary among mammals and why?
Protein, fat, sugar, and ash Arctic Environments: High protein and fat percentages for fattening up baby to endure cold Percentages of fat, protein, sugars vary based on environment and length of time that the young are nursed.
Are threatened species just an identification of rare species? If not, what other factors are measured that influence those species?
Rare → small range Threatened → combination of low abundance and habitat destruction
How do rare and threatened mammal patterns differ from the pattern of total mammal diversity?
Rare: no latitudinal gradient observed Threatened: A bit of latitudinal gradient observed
What are some examples of mammal taxa with bacula and without?
Rodents Chiroptera Sorciomorpha Erianaceomorpha Primates (not humans) Carnivores (most developed)
Speed is generated by improving what two factors?
STRIDE LENGTH X STRIDE RATE If you want to go fast, you need to increase one or both of these
Why is shape important to SAVR? Does a long, thin mammal and a blocky mammal of the same overall weight have the same SAVR?
Shape helps to either lose or conserve body heat. Long appendages and limbs help to lose head where as shorter bulkier body shapes help to conserve heat Different body shapes have different SAVR (Weasels have metabolic rates 50 - 100% higher when cold stressed than wood rats of similar mass) Bergmann's rule: mammals are larger at colder temperatures - thus at high latitudes and high elevations - At cold temps bigger size allows for heat conservation and starvation buffer - Starvation buffer: if you're bigger you can "consume more of your body" → allows you to starve for a sec
What are the best predictors of small mammal and bat diversity on mountains, how do they differ?
Small mammals: these organisms are almost always the most diverse on the mid elevation of the mountains - The peak varies at different elevations on different mountains → where you see the moust cloud cover Bats: diversity was strongly relates to H2O and temperatures (Wet based or arid based mountains) - Dry based mountain: low water availability at low elevations +high elevation → higher water availability at mid elevation - Where theres a cross over of h20 availability and temperatures → see high diversity of bats - Few bats are adapted to the more extreme habitats of the high or low elevations - Wet based mountain: At the base it is wet and warmer, at the top there is a lot of water but cold temperatures
How does heart rate change with metabolic rate and body size?
Smaller mammals tend to have much higher herat rates than larger mammals
Describe how some bats use delayed fertilization and delayed development in their reproductive cycle?How is this advantageous?
Delayed fertilization: Dehydrate the sperm and store it until after hibernation when they go back to ovulating and have resources Delayed development: Implantation and beginning of gestation and fetus development that is then halted - Growth resumes normal rate in spring or with flush resources
What are the three keys to natural selection? (trait is heritable, trait is variable, and individuals with an advantageous trait live longer and produce more offspring)
Three keys of evolution: 1. Trait must be heritable 2. Trait varies within a population 3. Individuals with advantageous trait live longer and have more offspring
Define the following terms: - Cursorial - Fossorial - Glissant - Natatorial - Semi-aquatic - Volant - Saltatorial
Cursorial: Running and fast animals - Cheetah, horses, antilope - Both predator and prey - Long gait with by moving their body and by their altered legs Fossorial: specialized diggers - Moles, naked mole rat, gopher - Live the entire life in the ground essentially - Modified front feet for digging, small or reduced eyes, torpedo shaped (like aquatic mammals → not shedding water theyre shedding dirt) Glissant: gliders - Need flaps of skin between arms and legs → some have flaps between hind legs/tail too - Many different orders that do this gliding but not many species Natatorial: swimmers - Cetartyodactyla, sirenia, carnivora - Torpedo shaped, no hindi limbs → tail, little to no hair, fins Semi-aquatic: quadrupedal swimmers - Beavers, platypus - Adaptations to be swimmers but nothing hindering them from moving on land Volant: true flyers - Chiroptera → megachiroptera and microchirpotera - More variation in wing shape in microchirpotera for different things (fast or ag
Talk more in depth about days 0 - 7 of female cycle
Days 0-7: menstrual flow phase (ouch) - Estrogen and progesterone low before estrus - When low → involves higher FSH in Anterior pituitary - Higher FSH stimulates the follicle developing in ovary - FSH > LH tells the ovary to develop the follicle or telling follicle to develop into an egg
Talk more in depth about days 14 - 28 of female cycle
Days 14 - 28: Secondary phase - Ovum reaches uterus → LH results in the development of the Corpus luteum - Corpus luteum forms around the ovum → stimulates mammary glands - Mammary glands producing milk - Tells the uterus to start proliferating the uterus lining - Progesterone is now being produced by ovaries as well (higher than estrogen)
Talk more in depth about days 7- 14 of female cycle
Days 7- 14: proliferative phase - Once follicle reaches a certain level of growth → estrogens in ovary start to increase rapidly - When estrogens peak → triggers the anterior pituitary gland to produce more LH. - Spike of LH above FSH after peak of estrogen - LH spike induces ovulation - Follicle releases egg and egg travels down the fallopian tube - Once ovulation happens estrogen declines
What are the four patterns in elevational diversity?
Decreasing: Line trending down with highest diversity at low elevations Mid elevational peak: bell curve w/ most diveristy at mid elevations Low plateau: diversity is highest at lower range, slowly decreasing until mid elevation where it decreases more steadily until high elevation (just draw it) Low PlateauWith Mid-Peak: similar shape as low plateau but there is a mid elevation peak in diversity as well (draw)
What is the minimum and maximum range of intervals between pregnancies in mammals? Examples?
Minimum: 3-4 WEEKS - Rodents Maximum: 3-4 YEARS - Sirenians, Elephants•, Rhinos
How does the male & female reproductive anatomy vary among monotremes, marsupials, & eutherians?
Monotremes: Cloaca, Only left ovary is functional in platypus and two uteri, bifurcated penis Marsupials: A few have cloaca, Most have a bifurcated penis and vagina (Not all - kangaroos) Scrotum is in front of penis (even in Virginia opossum) Eutherians: Testes paired → sperm development, Usually hang outside body, Cooling of sperm, Many species → internal when non-reproductive, Bacula
How is the appendicular skeleton modified for a swimming specialist?
Most of movement at joint between arm and shoulder girdle Hand modified into broad, flay paddle with strong thumb for leading edge Tail is adaptation for speed, front limbs are adaptation for power Early sirenia used quadrupedal swimming → reduced hindlimbs and pelvis Aerodynamic: - Fusiform body - Reduced pinnae - Reduced hind limbs - Tail: enlarged into rudder/propeller
Describe the differences in the 10 locomotion types in mammals, give specific examples for each (part 3)
Natatorial:swimmers - Cetartyodactyla, sirenia, carnivora - Torpedo shaped, no hindi limbs → tail, little to no hair, fins Semi-aqautic: quadrupedal swimmers - Beavers, platypus - Adaptations to be swimmers but nothing hindering them from moving on land
Do more muscles increase speed? how how how not ?
No, if multiple muscles are working on a single joint → INCREASES FORCE Yes, if multiple muscles are working on a multiple joints → INCREASES VELOCITY If different muscles move different joints in the same direction, the total motion is greater
What elevational diversity patterns do terrestrial mammals exhibit? Bats?
Non-volant Terrestrial Small Mammals: mid elevational peak (seen in 99% of mountains) higher elevation peak (observed in 1% of mountains) Bats: little data to support, but from what has been seen, 50% show decline (mountains with wet humid bases), and 50% see mid elevational peak (mountains with dry arid bases)
Are there predictable patterns in abundance across a species' geographic range or elevational range?
Not always predictable Abundance varies across space and time but is very complicated - Elevationally → mid range abundance peak isnt always the case - abundance across ranges is highly variable - Because abundance is so constrained they are not as predictable as initially expected
What are some examples of species that are obligate and some that are facultative delayed implanters?
Obligate: Grizzly bear, polar bear, harbor seal, Facultative: many rodents and shrews
Is that diversity distribution the same for rodents and marine mammals? If not, how do they differ?
Order rodentia, family muriodea: the most diverse mammal family + order also see a similar pattern of richness distribution -Worldwide distribution - Diversity again focused around mountain ranges Sea mammals diversity gradient: pattern not as precise/localized (because they can move around more) but generally see more diversity around the equator and around coasts
Define the following terms: - Thermal neutral zone - Upper Critical Limit - Lower Critical Limit
Thermal neutral zone: Temperature range within which metabolism rate is minimal Upper critical limit: Increase heat loss (panting, conduction) , increase evaporative heat loss (sweating) Lower critical limit: Increase metabolic rate & reduce heat loss(or go into torpor or hibernation)
Why should we be concerned about patterns in species diversity?
can help to conserve species, predict threats to species, research, some of this applies to us as well, etc
