Evolutionary Biology Overview

Evolutionary Biology

Evolution by Natural Selection: Organisms with traits better suited to their environment are more likely to survive and reproduce, passing those traits to their offspring. This leads to gradual changes in populations over time.
Mechanisms of Evolution: Natural selection isn't the only mechanism; genetic drift (random changes in gene frequencies), gene flow (movement of genes between populations), and mutations also drive evolution.
Adaptation: Traits that enhance survival and reproduction in a particular environment are adaptations. These can be physical, behavioral, or physiological.
Speciation: The formation of new species. This can occur through allopatric speciation (geographic isolation) or sympatric speciation (isolation within the same geographic area).
Phylogenetics: Study of evolutionary relationships among species. Genealogy and classification of organisms. Tree-like diagrams (phylogenetic trees) represent evolutionary relationships.
Fossil Record: Provides evidence of past life and evolutionary changes. Demonstrates extinct species and the gradual evolution of existing lineages. Shows the progression of life from simple to more complex organisms.
Comparative Anatomy: Comparing the body structures of different species reveals evolutionary relationships and adaptations. Homologous structures (shared ancestry) and analogous structures (similar function but different ancestry) are important concepts.
Molecular Biology and Evolution: Comparison of DNA sequences among organisms reveals evolutionary relatedness. The greater the similarity in DNA sequences, the closer the evolutionary relationship.
Phylogeography: A blending of evolutionary biology and geography, allowing researchers to track migration patterns and evolutionary history of species.

Ecology

Ecosystems: A community of living organisms interacting with their physical environment. Includes biotic (living) and abiotic (non-living) components.
Energy Flow: Energy from the sun is captured by producers (plants), transferred to consumers (herbivores, carnivores, omnivores), and eventually lost as heat. Food chains and food webs represent energy flow.
Nutrient Cycling: Essential elements (carbon, nitrogen, phosphorus) are constantly recycled through the ecosystem, flowing through organisms and returning to the environment.
Biomes: Large geographic areas with characteristic climate, vegetation, and animal life. Examples: tropical rainforest, desert, tundra.
Population Ecology: Studies how populations interact with their environment. Factors like population size, growth rate, carrying capacity, and limiting factors are crucial.
Community Ecology: Concerned with the interactions among different species in a community. Competition, predation, symbiosis (mutualism, commensalism, parasitism) are central concepts.
Conservation Biology: Addresses the loss of biodiversity and the protection of species and ecosystems.
Human impacts: Human activities, such as deforestation, pollution, and climate change, significantly influence ecological processes.

Genetics

DNA Structure: DNA is a double helix with a sugar-phosphate backbone and nitrogenous bases (adenine, thymine, guanine, cytosine).
Gene Expression: Genes specify the sequence of amino acids in proteins. Transcription (DNA to RNA) and translation (RNA to protein) are key steps.
Mendelian Genetics: Traits are inherited through discrete units (genes) passed from parents to offspring. Concepts of dominant and recessive alleles, heterozygous and homozygous genotypes.
Chromosomes: Structures composed of DNA and proteins that carry genes. Differences between somatic and sex chromosomes. Meiosis and sexual reproduction.
Molecular Genetics: The mechanisms by which genes control cells. Techniques for manipulating and studying DNA, such as PCR, gel electrophoresis, and gene cloning.
Gene mutations: changes in DNA sequence. Different types like insertions, deletions, substitutions and their impacts
Inheritance Patterns: Various patterns of inheritance such as autosomal dominant, autosomal recessive, sex-linked inheritance (X-linked).
Population Genetics: How genetic variation is distributed within a population over time, and its effects on evolution. Hardy-Weinberg equilibrium (a baseline for comparison).

Molecular Biology

Structure of Nucleic Acids: Nucleic acids (DNA and RNA) are composed of nucleotides, each containing a sugar, phosphate group, and a nitrogenous base. Different types of RNA have different roles.
Central Dogma of Molecular Biology: The flow of genetic information from DNA to RNA to protein.
Methods of Genetic Engineering: Techniques for modifying genes. Recombinant DNA technology, gene cloning, and CRISPR-Cas9.
Biotechnology: Applications of molecular biology principles in industry, medicine, and agriculture. Includes genetic engineering and genetic screening.
Protein Structure and Function: Proteins have different levels of structure (primary, secondary, tertiary, quaternary) which determine their function in the cell. They have varying roles in cell processes, including catalysis (enzymes), transport, and structure.
Cell Signaling: How cells communicate with each other. Signaling pathways involve cascades of molecular events.
Regulation of Gene Expression: Mechanisms by which cells control the production of proteins. Includes transcriptional regulation, translational regulation, and post-translational modification.
Molecular Mechanisms of Disease: Many diseases are caused by defects in genes, proteins, or signaling pathways.
Genetic Screening: Methods for identifying genetic predispositions to diseases or detecting mutations.