Darwin’s Theory of Evolution and Intro to Mendelian Genetics

A comprehensive set of flashcards covering key concepts in Darwin’s Theory of Evolution and Mendelian Genetics.

Variation

Small, heritable differences between individuals in a population.

Surplus

More offspring generated than required.

Resources

Limited resources regulate population size leading to competition.

Natural selection

The process by which individuals best suited to the environment have the highest chance to reproduce.

Consequence

Advantageous traits are preferably transmitted to the next generation.

Descent with modification

Divergent species share a common ancestor, gradually diverging over time.

Evolution

A progressive change of species over time.

Generation of random variation

Observation that individuals in a population vary, indicating hereditary differences.

Natural selection of the 'fittest'

Competition for limited resources results in some individuals reproducing more than others.

Accumulative changes

Over many generations, small changes can lead to new species.

Darwin’s Problem

Darwin had no knowledge of genetics to explain structural bases of evolution.

Biodiversity

Scientific expeditions that revealed remarkably divergent species.

Comparative morphology/embryology

Study of similarities and differences in species morphology.

Palaeontology

The study of fossilized remains to understand extinct species.

Geology

Recognition of ancient Earth's processes such as erosion and sedimentation.

Georges Cuvier

Recognized many fossils represent extinct species; proposed catastrophism.

Jean-Baptiste Lamarck

Suggested that new species can develop via hereditary changes.

Alfred Russel Wallace

Independently developed the concept of natural selection.

Charles Darwin

Proposed that populations change due to random variation and natural selection.

Selective advantage

Natural selection favors traits that confer a survival benefit.

Common descent

The theory that all living organisms have a common ancestor.

Tree of life

Representation of the relationship between taxonomic groups based on descent.

Analogy/convergence

Similarity of structures based on common function.

Vestigial structure

Non-functional body parts that remain from ancestral species.

Creationism

Belief that denies Darwinian evolution, often based on biblical accounts.

Irreducible complexity

Argument that complex biological structures require intelligent design.

Adaptation

The mechanism through which species adjust to changing environments.

Complexity argument

States that complex structures develop from simpler parts over time.

Antifreeze proteins

Proteins in fish that lower the freezing point of water.

Theory

In science, a well-substantiated explanation of natural phenomena.

Hypothesis

A testable prediction stemming from a theory.

Genotype

The genetic makeup that underlies phenotypic expression.

Phenotype

The observable properties of an individual resulting from genotype and environment.

Trait

An observable feature of an organism.

Character state

The specific form or expression of a character.

Mendelian genetics

Principles regarding the inheritance of traits as identified by Gregor Mendel.

Allele

Different forms of a gene.

Diploid

Organisms that have two alleles of each gene.

Haploid

Gametes that contain one allele of each gene.

Homozygous

Having two identical alleles for a gene.

Heterozygous

Having two different alleles for a gene.

Punnett square

A diagram used to predict the genetic outcome of a cross.

Probability

The likelihood of an event occurring, ranging from 0 to 1.

Segregation of alleles

The separation of alleles during gamete formation.

Meiosis

The process of cell division that produces haploid gametes.

Random segregation

The random allocation of maternal and paternal chromosomes into gametes.

Chromosomes

Long DNA molecules that contain many genes in a linear order.

Dominant allele

An allele that expresses its trait in the heterozygous condition.

Recessive allele

An allele that expresses its trait only in the homozygous condition.

Genetic crosses

Mating of individuals to study inheritance patterns.

Self-pollination

Transfer of pollen from the same flower for reproduction.

Filial generation

Generations following the parental generation in genetic crosses.

Mendel’s conclusions

Different traits arise from different forms (alleles) of a gene.

Three-to-one ratio

Observed ratio of dominant to recessive traits in the F2 generation.

Trait segregation

Distribution of traits among offspring.

Gene

A short sequence of DNA that codes for a protein.

Mutation

An alteration in the DNA sequence leading to different alleles.

Mendel’s methodology

Experimental approach to studying inheritance through plant breeding.

Parental generation (P)

The initial generation in a genetic cross.

First filial generation (F1)

Offspring of the parental generation.

Second filial generation (F2)

Offspring produced from self-pollination of F1 plants.

Genetic determinants

Traits are determined by specific regions of DNA called genes.

Traits and environments

Interaction of genetic makeup and environmental factors leads to traits.

Evolutionary biotechnology

The application of evolutionary principles to develop new drugs.

Multi-drug resistant bacteria

Bacteria that evolve rapidly under selective pressure from antibiotics.

Transitional forms

Intermediate species that could demonstrate evolution between major groups.

Fieldwork

Research conducted in natural environments to collect data.

Scientific method

Systematic approach to understanding natural phenomena.

Expedition

A journey undertaken for a specific purpose, often scientific.

Natural variability

The range of differences within a population.

Dominance

The relationship between alleles in which one masks the expression of the other.

Fossilized remains

Preserved remnants of ancient organisms used to study evolution.

Selective pressure

Environmental forces that influence reproductive success.

Dietary adaptation

Changes in species traits in response to food availability.

Inheritance

The process through which traits are passed from parents to offspring.

Evolutionary alteration

Changes in species characteristics over time due to various factors.

Research methodology

The techniques or procedures used to conduct scientific studies.

Microevolution

Small-scale evolutionary changes within a population.

Macroevolution

Large-scale evolutionary changes that occur over long time periods.

Gene flow

The transfer of genetic material between populations.

Genetic drift

Random variations in allele frequencies within a population.

Speciation

The formation of new and distinct species in the course of evolution.

Adaptive radiation

The diversification of a group of organisms into forms filling different ecological niches.

Homologous structures

Anatomical features in different species that share a common ancestry.

Physiological adaptation

Internal changes that help an organism survive in its environment.

Genetic recombination

The exchange of genetic material during meiosis, leading to genetic diversity.

Cladistics

Method of classifying species based on evolutionary branches.

Ecosystem

A biological community of interacting organisms and their environment.

Molecular genetics

The field of biology that studies the structure and function of genes at a molecular level.

Phenotypic plasticity

The ability of an organism to change its phenotype in response to environmental changes.

Conservation genetics

The study of genetics applied to the preservation of species.

Functional genomics

The study of gene functions and interactions.

Transgenic organisms

Genetically modified organisms that contain genes from other species.

Polygenic inheritance

Inheritance pattern of traits controlled by multiple genes.

Sexual selection

Type of natural selection concerning the mating preferences of individuals.

Biogeography

The study of the distribution of species and ecosystems in geographic space and through geological time.

Interbreeding

Mating between individuals of the same species or closely related species.

Environmental adaptation

Adjustments made by species to better suit their ecological conditions.

Convergence evolution

The evolution of similar traits in distantly related species.

Adaptive advantage

Benefits that enhance reproductive success in an organism.