BISC 130 - Chapters 18/19: Evolution

What is a hypothesis?

A suggested explanation for an observation which can be tested.

What is a scientific theory?

A tested and confirmed explanation for observations or phenomena, based on reproducible experimentation and/or observation.

What does a scientific law describe?

Describes a phenomenon that occurs consistently under specific conditions, typically answering 'what' happens.

What is evolution?

The change in the genetic makeup of a population over time (generations).

How does evolution occur?

Evolution occurs at a population level; individuals do not evolve.

What causes variations in populations?

Variations can be caused by different alleles in individuals, mutations can create new alleles.

What is natural selection?

The process where individuals with advantageous traits survive and reproduce, leading to an increase in favorable alleles in the population.

What is the bottleneck effect?

A drastic reduction in population size due to a natural disaster, causing random changes in allele frequency.

What is founder effect?

When a small group of individuals starts a new population, possibly changing allele frequencies.

What is sexual dimorphism?

Phenotypic differences between male and female populations.

What is stabilizing selection?

A type of natural selection that favors intermediate variants and acts against extreme phenotypes.

What does macroevolution refer to?

Broader scale evolutionary changes that occur over long time periods.

What is speciation?

The formation of a new species through evolutionary processes.

What is allopatric speciation?

Speciation that occurs due to geographic barriers.

What is sympatric speciation?

Speciation that occurs without geographical barriers, often through different adaptations arising from selective pressures.

What are fossils?

Preserved remains or traces of organisms from the past, contributing to our understanding of evolutionary history.

How is the age of fossils determined?

Through various dating methods that provide insights into the time period when the organism lived.

What is adaptive radiation?

An evolutionary process where organisms diversify rapidly into a wide variety of forms to adapt to new environments.