Study Guide Exam 2 Flashcards
What do life history traits represent?
The schedule of an organism’s life
Life history traits include aspects such as growth, reproduction, and survival strategies.
What is parity?
The number of times an organism reproduces
Parity includes concepts such as semelparity (one-time reproduction) and iteroparity (multiple reproductions).
What is fecundity?
The reproductive capacity of an organism
Fecundity refers to the potential number of offspring an organism can produce.
Why do lifespans vary?
Due to factors such as species, environment, and life history traits
Lifespan variations can also be influenced by predation, resource availability, and reproductive strategies.
How does parental investment contribute to life history traits?
It affects the survival and development of offspring
Higher parental investment often leads to fewer offspring but increased survival rates.
What species have high parental investment?
Species like elephants, humans, and certain birds
These species typically invest significant time and resources in raising their young.
What is the tradeoff between parental care and parental survival?
Increased parental care can lead to decreased parental survival
Investing heavily in offspring may expose parents to greater risks from predators or resource scarcity.
What is the principle of allocation?
Resources are allocated to growth, reproduction, and survival
Organisms must balance these competing demands based on environmental conditions.
Fill in the blank: Offspring size vs. _______.
Offspring number
Larger offspring may have better survival rates but fewer can be produced.
What is a brood parasite?
An organism that relies on others to raise its young
Brood parasites often lay their eggs in the nests of other species.
What are tradeoffs between growth and age at sexual maturity?
Faster growth may lead to earlier maturity but reduced size
This tradeoff can affect reproductive success and lifespan.
What is the difference between indeterminate and determinate growth?
Indeterminate growth continues throughout life; determinate growth stops at maturity
Indeterminate growers can keep growing as long as resources are available.
How do organisms differ in the number of times that they reproduce?
Some reproduce once (semelparity), others multiple times (iteroparity)
Differences in reproductive strategy can influence population dynamics.
Do all organisms eventually become senescent?
Yes, senescence is a common feature of most organisms
Aging processes can vary significantly among species.
What is semelparity?
Reproducing only once in a lifetime
Examples include certain species of salmon and insects.
What is iteroparity?
Reproducing multiple times throughout life
Many mammals and birds exhibit this reproductive strategy.
How have life history traits been impacted by climate change?
Altered reproductive timing, growth rates, and survival
Climate change can lead to mismatches in timing between species and their environments.
How have life history traits been impacted by other environmental factors?
Factors like predation, resource supply, and climate affect growth and reproduction
These environmental pressures can shape evolutionary adaptations in species.
Why does sexual selection favor traits that facilitate reproduction?
Sexual selection favors traits that enhance the chances of successful mating and reproduction.
What is the difference between polygamy, polygyny, polyandry, and monogamy?
Polygamy: multiple partners; Polygyny: one male, multiple females; Polyandry: one female, multiple males; Monogamy: one male and one female.
What are the advantages of sexual reproduction?
Genetic diversity and adaptability to changing environments.
What are the disadvantages of sexual reproduction?
Energy expenditure and finding a mate.
What are the advantages of asexual reproduction?
Quick population growth and no need for a mate.
What are the disadvantages of asexual reproduction?
Lack of genetic diversity and vulnerability to environmental changes.
Compare sex strategies in plants and animals.
Plants: often use pollination; Animals: utilize various mating systems.
What are the different asexual methods of reproduction?
Budding, fragmentation, and binary fission.
How can organisms evolve as separate sexes or as hermaphrodites?
Evolution can lead to specialization for reproduction efficiency and resource allocation.
What factors influence sex ratios?
Environmental conditions, parental investment, and social structure.
Can sex ratios be modified by natural selection?
Yes, natural selection can influence sex ratios based on reproductive success.
What are the advantages of monogamous mating systems?
Increased parental investment and stability in offspring rearing.
What are the advantages of polyamorous mating systems?
Increased genetic diversity and access to multiple resources.
What is the benefit of having different mates?
Increased genetic variation and adaptability in offspring.
What is ecological niche modeling?
Ecological niche modeling is a method used to predict the distribution of species based on environmental conditions.
What are the five important characteristics of population distributions?
- Density 2. Dispersion 3. Age structure 4. Sex ratio 5. Growth rate
What are the types of surveys used to estimate population properties?
- Complete counts 2. Sampling surveys 3. Mark-recapture surveys
Each type is used based on the population size and accessibility.
How are range and density impacted by abundance and body size?
Range and density are influenced by the abundance of individuals and their body size, affecting resource availability and habitat use.
Why is dispersal essential to colonizing new areas?
Dispersal allows populations to spread to new habitats, reducing competition and increasing genetic diversity.
What are factors leading to patchy distributions of populations?
Factors include habitat fragmentation, resource availability, and environmental conditions.
What are the different measures of dispersion?
- Variance 2. Standard deviation 3. Range 4. Quartiles
What are density independent and density dependent factors?
Density independent factors affect populations regardless of size, while density dependent factors have effects that vary with population size.
What is Logistic growth?
Logistic growth is a model where population growth slows as it approaches carrying capacity.
What is Geometric Growth?
Geometric growth is a model of population increase where the population grows by a constant proportion at each time period.
What is Exponential Growth?
Exponential growth is a model where the population increases continuously at a constant rate.
What is the relationship between λ and r?
λ (lambda) is the finite rate of increase, while r is the intrinsic rate of increase; they are related through the equation r = ln(λ).
What is an inflection point?
An inflection point is where the growth rate of a population changes direction, often indicating a shift in growth dynamics.
What is carrying capacity?
Carrying capacity is the maximum population size that an environment can sustain indefinitely.
How and why do populations fluctuate naturally over time?
Populations fluctuate due to factors like resource availability, predation, and environmental changes.
What is an overshoot?
An overshoot occurs when a population exceeds its carrying capacity, leading to resource depletion.
What is a die-off?
A die-off is a rapid decrease in population size, often following an overshoot.
Why do chance events cause small populations to go extinct?
Chance events can have a larger impact on small populations, leading to loss of genetic diversity and increased vulnerability.
What are stochastic events?
Stochastic events are random occurrences that can affect population dynamics, such as natural disasters.
What is delayed density dependence?
Delayed density dependence refers to the lag in population response to changes in density, causing cyclic population patterns.
What are metapopulations?
Metapopulations are groups of spatially separated populations that interact through immigration and emigration.
What is the source-sink population model?
The source-sink model describes how some populations (sources) provide individuals to others (sinks) that cannot sustain themselves.
Why are metapopulations important for conservation?
Metapopulations enhance genetic diversity and resilience, crucial for species survival, exemplified by the ferret conservation efforts.
What would make a metapopulation stable?
A stable metapopulation has balanced immigration and emigration rates, ensuring persistence of subpopulations.
