Evolution and Species: Key Concepts for Biology Students

What is the modern theory of evolution?

The change in the genetic characteristics of a population over generations.

Who proposed the theory of evolution by natural selection?

Charles Darwin

What significant work did Charles Darwin publish in 1859?

On the Origin of Species

What is an adaptation?

An organism's ability to survive and reproduce in a particular environment.

What are the three types of adaptations?

Structural, physiological, and behavioral adaptations.

What is convergent evolution?

When organisms that are not closely related independently evolve similar characteristics due to similar environmental pressures.

Provide an example of convergent evolution.

Birds and bats both have wings used for flight, despite having different ancestors.

What is divergent evolution?

When populations that share a common ancestor become increasingly different over time due to different environments or selective pressures.

What are homologous structures?

Structures that have similar underlying anatomy inherited from a common ancestor, even if they have different functions.

Give an example of homologous structures.

The forelimbs of humans, bats, whales, and cats.

What are vestigial structures?

Reduced structures that have little or no current function but were functional in an organism's ancestors.

Name an example of a vestigial structure in humans.

The human coccyx (tailbone).

What is a common misconception about evolution?

That evolution is 'just a theory' and not a well-supported explanation.

What is the correct concept regarding the theory of evolution?

It is a well-supported explanation of natural phenomena, backed by extensive evidence.

Did humans evolve from modern monkeys?

No, humans and modern apes share common ancestors, but humans did not evolve from modern monkeys or apes.

Why do organisms evolve?

Organisms evolve due to genetic variation and natural selection, not because they 'need' to.

What is speciation?

The formation of new species.

What are prezygotic reproductive barriers?

Barriers that prevent mating or fertilization between species.

What are postzygotic reproductive barriers?

Barriers that occur after fertilization, affecting the viability or fertility of the offspring.

What is allopatric speciation?

Speciation that occurs when populations are geographically isolated.

What is sympatric speciation?

Speciation that occurs without geographic isolation, often through behavioral or ecological differences.

What role does genetic variation play in evolution?

It provides the raw material for natural selection to act upon.

What is the significance of natural selection in evolution?

It favors inherited characteristics that increase survival and reproductive success.

What evidence supports the theory of evolution?

Fossils, genetics, molecular biology, comparative anatomy, embryology, biogeography, and direct observations of evolutionary change.

What does the biological species concept define as a species?

A group of organisms whose members can potentially interbreed under natural conditions and produce viable, fertile offspring.

What are viable offspring?

Offspring that survive and develop normally.

What are fertile offspring?

Offspring capable of reproducing.

What are some limitations of the biological species concept?

It does not work well for asexually reproducing organisms, fossil organisms, or organisms whose reproductive behavior cannot be observed.

What must occur for speciation to happen?

Populations must accumulate genetic differences and become reproductively isolated.

What is mutation in the context of genetic variation?

A change in DNA that can introduce new alleles into a population.

What is genetic recombination?

The process that produces new combinations of existing alleles during sexual reproduction.

What is natural selection?

The process that favors inherited characteristics that increase reproductive success in a particular environment.

What is genetic drift?

Random changes in allele frequencies, which have a stronger effect in small populations.

What is gene flow?

The movement of alleles between populations

What is a prezygotic barrier?

A barrier that prevents fertilization from occurring.

What is habitat isolation?

A type of prezygotic barrier where organisms live in different habitats and rarely encounter one another.

What is temporal isolation?

A type of prezygotic barrier where organisms reproduce at different times.

What is mechanical isolation?

A type of prezygotic barrier where physical differences prevent successful mating.

What is gametic isolation?

A type of prezygotic barrier where sperm and egg cannot successfully fuse.

What is a postzygotic barrier?

A barrier that occurs after fertilization and reduces the success of hybrids.

What is reduced hybrid viability?

A postzygotic barrier where hybrid offspring have reduced survival or do not develop normally.

What is hybrid breakdown?

A postzygotic barrier where first-generation hybrids may be viable and fertile, but later generations have reduced viability or fertility.

What is polyploidy?

Having additional sets of chromosomes, which is particularly important in plant speciation.

What are the Natural Sciences?

Fields like biology, chemistry, physics, and earth science that aim to understand the natural world using systematic, evidence-based approaches.

What is empirical evidence in science?

Scientific knowledge based on observable and measurable evidence.

What does it mean for scientific explanations to be testable?

Scientific ideas must be able to be proven wrong through experimentation.

Why is repeatability important in scientific experiments?

To ensure reliability.

What is objectivity in scientific research?

The aim to reduce bias and rely on data rather than personal opinions.

How is scientific knowledge described as tentative and self-correcting?

Scientific knowledge can change with new evidence and research.

What role do models and theories play in science?

Models help explain complex systems, while theories are well-supported explanations.

What is the first step of the Scientific Method?

Observation: Noticing something in the natural world.

What is a hypothesis in the Scientific Method?

A testable prediction about the outcome of an experiment.

What is the difference between independent and dependent variables?

Independent variables are what you change, while dependent variables are what you measure.

What is the purpose of data collection and analysis in experiments?

To record and interpret results to determine if the hypothesis is supported.

What are some common challenges in scientific experiments?

Small sample size, uncontrolled variables, and bias in data collection.

What is cellular organization in living organisms?

All living things are made of one or more cells.

What is metabolism?

Chemical reactions that use energy, such as breaking down food to produce energy.

What does homeostasis refer to?

The ability to maintain stable internal conditions.

What is the significance of growth and development in living organisms?

It refers to the increase in size and complexity over time.

What is reproduction in biological terms?

The ability of organisms to produce offspring.

How do organisms respond to stimuli?

They react to environmental changes, such as plants bending toward light.

What is evolution in the context of biology?

The process by which populations change over generations

What are the levels of organization in biology from smallest to largest?

Molecule, Organelle, Cell, Tissue, Organ, Organ System, Organism.

What is a population in ecological terms?

A group of the same species living in one area.

What is an ecosystem?

The interaction of living and nonliving components in a specific area.

What is the biosphere?

All life on Earth.

Alfred Russel Wallace

Independently developed the idea of natural selection.