BIO 001 - Midterm 1

Null Hypothesis

assumes or predicts no relationship between variables

alternative hypothesis

assumes or predicts a relationship between the variables

Who developed theory of evolution?

Charles Darwin + many past and present scientists

Properties of Life

- Order and organization

- energy processing

- growth and development

- evolutionary change

- regulation (homeostasis)

- reprodiction

- response to stimuli

What is ecology?

how species (and individuals) interact with one another and with the environment

What is evolution?

relates to genetic changes in populations through time

Species levels (broad to most specific)

Kingdom; phylum; class; order; family; genus; species

species richness

a measure of how many species are present in a particular habitat at a particular time

species eveness

a measure of how evenly represented species are in the habitat

Hadley cell

rotating cycles of hot/cold wind create weather patterns

rainshadow effect

as air masses move they encounter the mountains and must rise over them. As air masses rise, the water vapor in them condenses into liquid water and rains out on the 'front' (windward) side of the mountains. As the air masses movedown the 'back' (leeward) side of the mountains, they produce dry conditions on theeastern side of the mountains.

Tropical rainforests

high precip with little/no seasonality, high temp with no seasonality

desert

extremely low precipitation with little/no seasonality, high temp with high seasonality (extreme temperature fluctuations)

grassland

high seasonality in temp and precip; wet season is during the warm season

boreal forest

low precip (but not as low as a desert) with some seasonality; generallylow temperatures (~6 months below 0 C) and high seasonality in temp

tundra

low precip (but not as low as a desert) with some seasonality; very low

mediteranean

high seasonality in temp and precip; wet season is during cold season.

temperate deciduous forest

medium precip (higher than grassland but not as high asrainforest) with no seasonality; medium temp with seasonality

Axial tilt

Causes seasons, equinoxes, and solstices

Principle of Allocation

organisms must make decisions about how to invest resources in different life functions

Offspring size vs number

> size = < number

Semelparous

organisms that reproduce once and then die

iteoparous

organisms that reproduce many times

root:shoot ratio

shoot for gathering ingredients for photosynthesis; root for water and nutrients

R selected

small body size; short life expectancy; rapid growth; early reproduction; produce many small offspring; little or no parental care; extreme juvenile mortality; unpredictable or variable environment; boom/bust population growth

what are R selected organism pop size controlled by?

controlled by R (growth rate)

K selected

large body size; long life expectancy; slow growth; delayed reproduction; produce few large offspring; high parental investment; low juvenile mortality; predictable/stable environments; population size steady

what are K selected organism pop size controlled by?

controlled by K (carrying capacity)

Type 1 survivorship curve

Most individuals survive to old age

Type II survivorship curve

constant risk of mortality

Type III survivorship curve

most individuals die young

ectotherms

body temp controlled primarily by external conditions

endotherms

body temp controlled primarily by metabolic energy

acclimation

change in phenotype; within an individual; short term

adaptation

change in genotype; across generations; long term

How is thermoregulation affected by body size of an organism?

heat production driven by volume; heat loss driven by surface area

Fundamental niche

abiotic conditions in which a species can survive and reproduce

Realized niche

biotic conditions in which a species can survive and reproduce

Autotrophs

self feeding (photoautotrophs/chemoautotrophs)

Heterotrophs

other feeding

(herbivores, carnivores, detrivores)

Liebig's law of the minimum

plant growth is not determined by the total amount of all resources available, but by the amount of the resource that is most scarce compared to what the plant needs

Optimal foraging theory

maximizing energy benefit:cost ratio of feeding decisions

osmoregulation

freshwater fish -> pee a lot

saltwater fish -> drink water excrete salt

Nx

number of individuals

Nxoff

number of offspring

Ro

net reproductive rate - mean # of offspring produced per individual across their lifetime

G

generation time, avg age of parents across all offspring produced

r

population growth rate

can estimate using lnRo/G

Ro>1

r is positive -> population is growing

Nt = No + B - D + I - E

Nt = pop size (N) at time t

No = pop size (N) at time 0

B = birth

D = death

I = immigration

E = emmigration

Nt = No * e^rt

Nt = pop size (N) at time t

No = pop size (N) at time 0

e = base of natural log

t = time

r > 0

r < 0

r = 0

pop growing; pop declining; steady pop

Density independent controls

factors affecting pop size that DO NOT depend on pop size, usually abiotic factors

Density dependent controls

factors affecting pop size that DO depend on pop size, usually biotic factors

Logistic growth

K = carrying capacity

when No is large, growth is slow

when No is small, growth is close to exponential

How to estimate N using marked individuals?

total marked individuals/total pop = recaptured marked individuals/second sampling size

What to ensure for estimating N using marked individuals?

closed pop (no emigration/immigration); random mixing; no effects of marking; marks must remain intact

genotype

the complete set of an individual's genetic makeup

phenotype

an organism's observable traits

Mutation

a change in an organism's DNA sequence that can be caused by errors during cell division or exposure to mutagens like UV radiation

Natural selection

the process by which organisms with traits better suited to their environment survive and reproduce more successfully, passing those advantageous traits to their offspring

competition

the interaction between organisms or species that requires the same limited resources, such as food, water, mates, or space

mutualism

an ecological interaction where two different species benefit from the relationship

commensalism

a symbiotic relationship where one species benefits while the other is neither helped nor harmed

parasitism

a symbiotic relationship in which one organism, known as the parasite, benefits at the expense of the other organism, called the host

species diversity

a measure of the variety of species in a given area, considering both the number of different species and their population sizes

weather vs climate

Weather is the short-term, day-to-day atmospheric conditions in a specific location

Climate is the long-term average of those weather conditions over a long period

biodiversity hotspot

a biogeographical region that is both incredibly rich in endemic species and under severe threat of destruction

Survivorship

the proportion of individuals in a population that survive to a certain age

Fecundity

the potential reproductive capacity of an individual or population

Photorespiration

A metabolic process in plants that uses oxygen and releases carbon dioxide, reducing the efficiency of photosynthesis.

How does the earth's tilt cause seasons

the northern and southern hemispheres do not always receive the same amount of solar energy. from march to september, the northern hemisphere is tilted towards the sun and receives more solar energy than the southern hemisphere, and so this time of the year is the warmer seasons in the northern hemisphere (and the colder seasons in the southern hemisphere). from september to march, the opposite occurs in the northern hemisphere

How are greenhouse gas levels now compared to the past

atmospheric concentrations of greenhouse gases have been increasing since we have been directly measuring them and CO2 levels are much higher than the oscillations that occurred

Adaptations/strategies for resource acquisition

root:shoot ratios, optimal foraging theory, and photosynthetic pathways

Adaptations/strategies for reproduction

semelpartiy vs iteroparity and the tradeoff between offspring size and number

Why do we study ecology and evolution together?

ecological interactions can drive evolutionary changes, and genetic changes can influence or alter ecological interactions

Why can't amphibians disperse across the ocean

sensitive to osmoregulatory issues since their skin is very permeable, which is why they are only found in freshwater or low salt environments.