Biodiversity and Evolution Notes

Biodiversity: Refers to the variety of life forms on Earth including species diversity, genetic diversity, and ecosystem diversity.

Carolus Linnaeus: Introduced the system of taxonomic classification.
Georges Louis Leclerc de Buffon: Proposed that organisms share common ancestors.
Erasmus Darwin: Suggested that all living beings are descended from a common ancestor.
Jean-Baptiste Lamarck: Proposed that all organisms evolve toward perfection and complexity.
Charles Darwin: Formulated the Theory of Evolution by Natural Selection which states that species evolve over time through a process of natural selection.
Herbert Spencer: Coined the phrase "Survival of the Fittest".

Variation: Heritable differences among individuals within a species.
Overproduction: Many offspring are produced, but not all survive.
Adaptation: Traits that improve an organism's chances of survival in a changing environment.
Descent with Modification: The passing of traits from parent to offspring.

Darwin's Finches: Different species evolved from a common ancestor based on adaptive traits suited for different food sources (e.g., tool-using finch).

Embryology: Similarities in embryonic development indicating common ancestry (e.g., gill slits in various vertebrates).
Homologous Structures: Physical structures with a shared evolutionary origin, like forelimbs of humans, whales, and bats.
Vestigial Structures: Remnants of structures that had important functions in ancestors, e.g., pelvis in whales, vestigial toes in horses.

Genetics: The study of heredity; similar nucleotides and proteins support evolutionary relationships.
Fossils: Remains of organisms provide a historical record of life on Earth and evolutionary transitions over 3.5 billion years.

Organisms produce more offspring than can survive.
There is variation among individuals.
Those better adapted to their environment are more likely to survive and reproduce.
Favorable traits are passed on to the next generation.

Gene Flow: Movement of genes between populations when individuals breed in new areas.
Genetic Drift: Changes in allele frequencies in a population due to random events.
Mutation: Changes in DNA that create new alleles and genetic variation necessary for evolution.

Allopatric Speciation: Occurs when populations are separated by physical barriers (e.g., mountains).
Sympatric Speciation: Divergence of species occurs within the same geographic area due to behavioral, temporal, or ecological factors.
Parapatric Speciation: Limited gene flow occurs between two species that may diverge after hybridization.

Reproductive Isolation: When two populations can no longer interbreed due to behavioral, temporal, or geographical factors.
- Behavioral Isolation: Differences in mating rituals prevent interbreeding (e.g., songs of eastern and western meadowlarks).
- Temporal Isolation: Species reproduce at different times (e.g., different breeding seasons of frogs).
- Geographical Isolation: Physical barriers prevent interbreeding (e.g., environments altering ecosystems).

Key factors include changes in atmosphere, temperature, glaciation, cosmic events, diseases, and spread of invasive species.

Balance of Nature: All components of the ecosystem must balance each other.
Diversity and Stability: Greater diversity often leads to increased ecosystem resilience.
Finiteness of Resources: Natural resources are limited and must be conserved.
Stewardship: Responsibility to manage and care for the environment.