Darwin Theory

Chapter 7

evolution

Change in the frequency of genes or alleles in a population over time.

How does evolution occur?

Through natural selection, where individuals with favorable traits survive and reproduce.

Who published On the Origin of Species and when?

Charles Darwin, 1859.

What did Darwin introduce?

The concepts of evolution and natural selection.

What did Aristotle believe about species?

Species are unchanging (immutable).

What did Lamarck propose?

Species change over time.

What did Lyell contribute?

Earth changes gradually over long periods.

What is overproduction?

More offspring are produced than can survive.

What are limited resources?

Resources like food and water are finite.

What is competition?

Individuals compete for limited resources.

What is variation?

Individuals in a population are different.

What is heritability?

Traits can be passed to offspring.

What is natural selection?

Organisms best adapted to their environment survive and reproduce.

What are the 4 steps of natural selection?

Overproduction, variation, competition, selection.

What is fitness?

Ability to survive and reproduce.

Does natural selection act on genotype or phenotype?

Phenotype.

Do individuals evolve?

No, populations evolve.

Does evolution have a goal?

No.

What traits does natural selection act on?

Heritable (genetic) traits.

What is artificial selection?

Humans selecting traits in organisms.

What are the 5 lines of evidence?

Fossil record, biogeography, comparative anatomy/embryology, molecular biology, lab/field studies.

What are fossils?

Preserved remains of organisms.

Why is the fossil record incomplete?

Fossilization is rare and soft tissues decay.

What is radiometric dating?

Determining absolute age using radioactive isotopes.

What is comparative anatomy?

Comparing body structures of organisms.

What does embryology show?

Similar early development suggests common ancestry.

What does DNA evidence show?

Closely related species have similar DNA.

What is bioinformatics?

Using computers to analyze genetic data.

What is genetic drift?

Random changes in gene frequency.

What is the bottleneck effect?

Population drastically reduced.

What is the founder effect?

Small group starts a new population.

What is gene flow?

Movement of genes between populations.

What is sexual selection?

Selection based on mating success.

What is microevolution?

Small-scale changes in gene pools over generations.

What is macroevolution?

Large-scale evolutionary changes.

What is speciation?

Formation of new species.

What is allopatric speciation?

Speciation due to geographic isolation.

What is sympatric speciation?

Speciation without geographic isolation.

What is gradualism?

Slow, steady evolution.

What is punctuated equilibrium?

Rapid changes with long stable periods.

What is a species?

Group that can interbreed and produce fertile offspring.

What is behavioral isolation?

Different mating behaviors.

What is habitat isolation?

Live in different areas.

What is temporal isolation?

Breed at different times.

What is mechanical isolation?

Physical incompatibility

What is gametic isolation?

Gametes can’t fuse.

What is hybrid weakness?

Offspring are weak or sterile.

What is taxonomy?

Classification of organisms.

What are the 3 domains?

Bacteria, Archaea, Eukarya.

What are the classification levels?

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.

What is binomial nomenclature?

Two-part scientific name (Genus + species).

What is a phylogenetic tree?

Diagram showing evolutionary relationships.

What is a clade?

Group with a common ancestor and all descendants. (example: mammals, birds)

How do you find relatedness on a tree?

Look for the most recent common ancestor.

What are tectonic plates?

Large pieces of Earth’s crust.

How do tectonic plates affect evolution?

Change habitats and isolate populations.