Week 10.1 Evolution and Life History Trade-Offs in Organisms

Life history

Patterns of growth, reproduction, and survival.

Life history trade-offs

Compromises between incompatible traits in organisms.

Semelparous organisms

Reproduce once in a lifetime, then die.

Iteroparous organisms

Reproduce multiple times throughout their life.

Demography

Statistical study of population changes over time.

Life tables

Tools for analyzing survival data in populations.

Survival data

Information on the likelihood of survival over time.

Reproductive strategies

Methods organisms use to reproduce effectively.

Environmental constraints

Factors limiting resource allocation in organisms.

Natural selection

Process favoring optimal energy allocation for reproduction.

r (growth rate)

Maximum growth rate of a population.

K (carrying capacity)

Maximum population size an environment can sustain.

Life history traits

Traits affecting survival, reproduction, and growth probabilities.

Genotypic variation

Differences in genetic makeup affecting phenotypes.

Phenotypic plasticity

Variation in traits due to environmental interactions.

Heritability

Estimate of genetic variation in a trait.

Physiology

Study of bodily functions and processes.

Longevity

Length of life or lifespan of an organism.

Rate of living theory

Aging theory based on metabolic rate.

Telomeres

Protective DNA sequences at chromosome ends.

Cell senescence

Non-dividing state triggered by short telomeres.

Tumor protein P53

Protein regulating cell division and aging.

Mutation accumulation hypothesis

Late-acting mutations weakly selected in evolution.

Antagonistic pleiotropy hypothesis

Single gene affects multiple traits, influencing aging.

Reproductive effort

Energy invested in producing offspring.

Clutch size

Number of offspring produced at one time.

David Lack's hypothesis

Optimal clutch size maximizes surviving offspring.

Energy balances

Carried over among reproductive years.

Bioenergetic model

Model analyzing energy use in organisms.

Body size

Mass of an organism influencing its traits.

Migration

Seasonal movement of organisms for resources.

Sedentary tortoises

Tortoises that do not migrate for resources.

Crazy organisms

Unique reproductive behaviors in certain species.

North Pacific Giant Octopus

Lives 3-5 years, reproduces once.

Giant sequoia

Lives thousands of years, reproduces annually.

Sand cricket morphs

Different forms adapting to resource availability.

Age-specific reproductive investments

Resource allocation varies with age.

Age-specific mortality schedules

Patterns of death rates at different ages.

Length of life

Duration an organism lives before dying.

Physiological limits

Biological constraints on cell and tissue function.

Evolutionary responses

Adaptations based on environmental interactions.

Fitness

Organism's ability to survive and reproduce.

Population life table properties

Characteristics derived from individual success rates.

Trade-off between cancer risk and aging

Balancing longevity and cancer susceptibility.

High levels of p53

Reduce stem cell division and cancer risk.

Moderate telomere length

Optimal balance between cancer risk and cell division.