Exam 2 Field Bio

detrivores

decomposers - turkey vulture

Oxygen transport in insects

spiracles

Oxygen transport in birds

air sacs and lungs

aestivation

dormant state - summer sleep; adaptation to water stress

ectotherms

adaptations to water stress

aestivation and migration

poikilotherms

wide variety of internal temperatures (e.g. salamander, fish)

homeotherms

have a small margin of internal temperature despite outside conditions

heterotherms

can switch between poikilothermy and homeothermy (torpor)

ectothermy

regulate body temp. through behavior (shade, hot rock, water)

endothermy

regulate temp. through

• insulation (fur, feathers, fat)

• behaviors (to lose heat: panting, sweating; to gain heat: shivering, burning fat)

supercooling

“anti-freeze” that stops organism from freezing

ectotherms

torpor

short term body temp + metabolism lowers

endotherms

hibernation

long-term lowered metabolism and body temperature

allele

version of gene and how it presents

gene

unit of dna

heterozygous vs homozygous

• heterozygous: different alleles (Aa)

• homozygous: same two alleles (AA or aa)

recessive vs dominant

• recessive: less likely to present

• dominant: more likely to present

heterozygous advantage

heterozygous genes are more likely to be present

4 mechanisms of evolution

1. Natural selection

2. genetic drift

3. gene flow

4. mutations

4 observations in nature that led Darwin and Wallace to develop their theories of evolution by natural selection

1. individuals in populations vary in characteristics

2. organisms produce more offspring than can survive

3. organisms struggle to survive and reproduce

4. survivors pass on genes

3 modes of natural selection and examples

1. stabilizing: average phenotype; producing 4-5 egg clutch instead of less or more

2. directional: 1 extreme phenotype; bears increased in size over time

3. disruptive: both extreme phenotypes; some lobsters are small, some big

Adaptive radiation (divergent evolution)

One ancestor species adapts to different environmental conditions over time, evolving into multiple species

convergent evolution

Two unrelated organisms develop similar adaptations to their environments

analogous vs homologous

• analogous: not similar, but same function (wings); convergent

• homologous: very similar, different function (finch beaks); divergent

genetic drift

• random, loss of genetic diversity via random events

• bottleneck effect & Founder effect both decrease genetic variation in

  populations

gene flow

increases genetic variation in a population

mutations

mechanism of novel alleles in populations: most are harmful, but some are helpful

Sympatric vs. Allopatric speciation

• sympatric: less frequent, same place

• allopatric: most frequent, different lands (eg. split from volcano)

Pros and cons of sexual vs. asexual reproduction

• sexual: harder to find mate, higher diversity

• asexual: easier to find “mate”, lower diversity

Metamorphic development: complete versus incomplete

metamorphosis costs/benefits

• costs: energy, vulnerability (cocoons)

• benefits: lack of competition between life stages, specialized body plans

Trade-offs between offspring number and offspring size, parental investment, adult survival

high number = smaller size, less investment, lower survival

iteroparity

• continuous; several reproductive events

• most vertebrates, woody plants

semelparity

• one reproductive event at end of life

• salmon, insects, annuals

Under what conditions are competitive, stress tolerators, and ruderal plants best adapted to?

• competitive: low stress + disturbance

• stress tolerators: high stress, low disturbance

• ruderal: low stress, high disturbance

Survivorship curves + examples

• I: k, humans, larger mammals

• II: birds, small mammals, reptiles

• III: r, trees, fish

phenology cues

• photoperiod: changing number of daylight hours

• temperatures: increasing spring temp. tells insects to come out

mismatch hypothesis

advantageous trait becomes harmful due to environmental factors (bird reproduction lining up with caterpillar hatching)

cosmopolitan population distribution

international

endemic population distribution

small, one area

disjunct population distribution

separate areas (elevation differences in S app)

migratory population distribution

move throughout year (breeding and wintering grounds)

distribution change causes

• natural causes: historic climate changes

• human: habitat loss + degradation, climate change, invasive species

M/N = R/C

mark-recapture

exponential population growth

Δ𝑁/Δ𝑡 = 𝑟𝑁

• Δ𝑁 = change in population size

• Δ𝑡 = change in time

• 𝑟𝑁 = growth rate x pop. size

Δ𝑁/Δ𝑡 = 𝑟𝑁 ((𝐾 − 𝑁)/𝐾)

logistic population growth; K = carrying capacity