Test Review chapter 19 & 21

Carolus Linnaeus

Founder of taxonomy.

Taxonomy

Science of classifying and naming organisms.

Binomial nomenclature

Two-part scientific naming system (genus + species).

Classification hierarchy

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

Strata

Layers of rock containing fossil records.

Charles Lyell

Proposed that Earth’s geological processes are slow and constant, suggesting the Earth is very old.

Paleontology

Study of fossils and ancient life.

Jean-Baptiste de Lamarck

Proposed species evolve by use/disuse and passing on acquired traits (flawed idea).

Use and Disuse

Parts used grow stronger; unused parts deteriorate.

Inheritance of Acquired Characteristics

Idea that organisms can pass on traits gained in their lifetime.

Charles Darwin

Developed the theory of natural selection and studied Galápagos species.

Natural selection

Nature selects traits that enhance survival and reproduction.

Adaptations

Traits that increase fitness in an environment.

Artificial selection

Humans select desirable traits, for example, in dog breeding.

Homologous structures

Similar structures that arise from a common ancestor.

Embryonic homologies

Similar embryos across species indicating shared ancestry.

Vestigial organs

Leftover structures that have lost most of their original function.

Molecular homologies

Shared DNA/protein sequences among different species.

Convergent evolution

Unrelated species evolve similar traits due to similar environments.

Analogous structures

Similar function but different origin, e.g., bat vs insect wings.

Biogeography

Study of the distribution of organisms and the factors influencing it.

Continental drift

Movement of Earth's plates that explains species distribution.

Endemic species

Species found only in one specific location.

Microevolution

Change in allele frequencies within a population over time.

Mutation

Source of new genes and alleles.

Point mutation

Change in a single DNA base.

Chromosomal mutation

Alterations to whole chromosomes.

Crossing over

Exchange of DNA between homologous chromosomes during meiosis.

Independent assortment

Random distribution of chromosomes during meiosis.

Population

Group of individuals of the same species that interbreed.

Gene pool

All alleles present in a population.

Fixed allele

When there is only one allele for a gene, indicating no variation.

Population genetics

Study of allele frequency changes in populations.

Hardy-Weinberg Equilibrium

Condition under which allele frequencies remain constant; includes specific criteria.

Genetic drift

Random change in allele frequencies, especially in small populations.

Founder effect

When a small number of individuals start a new population.

Bottleneck effect

A disaster that reduces the population size leading to a loss of genetic diversity.

Gene flow

Movement of alleles in and out of populations.

Sexual selection

Certain traits improve an individual's chances of mating.

Relative fitness

The contribution of an individual to the next generation's gene pool.

Directional selection

Favors one extreme phenotype in a population.

Disruptive selection

Favors both extreme phenotypes over intermediate phenotypes.

Stabilizing selection

Favors average phenotypes in a population.

Adaptive evolution

Increase in traits that enhance an organism's survival.

Heterozygote advantage

Heterozygotes have greater fitness compared to homozygotes.