Speciation Flashcards
Definition: Humans breed organisms for specific traits, such as cows that produce more milk or faster racehorses.
Artificial Selection
Definition: Scientists design genes on a computer to direct evolution, inserting them into organisms to create new traits.
Synthetic Biology
Detection: E. coli modified to glow green when detecting disease-related chemicals, aiding in cancer detection.
Genetic Modification Example
Definition: Corn genetically modified to resist herbicides, allowing farmers to kill weeds without harming crops.
Herbicide-Resistant Corn
Definition: The process where one population accumulates enough genetic differences to become a new species, often involving geographic isolation.
Speciation
efinition: A population that can interbreed naturally and produce fertile offspring, but is reproductively isolated from others.
Species
Key Point: Requires reproductive barriers, preventing gene flow between populations for new species to form.
(This is like speciation in nature. When a group of animals or plants gets separated, they can change in different ways until they become two new groups, or species, that are unique from each other.)
Speciation Process
Concept: Strong evolutionary pressures discourage mating outside the species to avoid unsuccessful offspring.
Selection Pressures in Speciation
Definition: Physical barriers like rivers or mountains prevent populations from interbreeding, aiding speciation.
Geographic Isolation
Example: Scarlet and black oaks occupy different habitats and rarely cross-pollinate, aiding speciation.
Habitat Isolation
Definition: Species reproduce at different times, preventing interbreeding (e.g., frogs with different mating seasons).
Temporal Isolation
Example: Unique mating signals prevent interbreeding between different species, like firefly light patterns.
Behavioral Isolation
Definition: Incompatible reproductive structures prevent mating between species (e.g., dragonfly claspers).
Mechanical Isolation
Example: Sperm may not survive in another species’ reproductive system, preventing fertilization.
Gametic Isolation
Example: Hybrid offspring (e.g., mules) are often sterile, preventing gene flow between species.
Post-Zygotic Isolation
