Variation in individual characters among members of the population
Variation in fitness or organism
Selection
Ecosystem are made up of various biotic (living) and abiotic (non-living) factors that contribute to selecting which variations will provide the individual with an increased chance of surviving over others
Competition
Rivalrybetween or among living things for territory, resources, goods, mates etc
Biologicalresistance
The natural or genetic ability of an organism to avoid or repel attack by biotic agents (pests, parasites, pathogens etc) or to withstand the effects of abiotic agents (chemicals, pesticides, salt, wind, heavy metals etc)
Artificialselection (selective breeding)
Process where humans identify desirable traits in animals and plants and use these traits to developdesirablephenotypic traits by breeding
Advantages and disadvantages of artificial selection
Can result in betterqualityproducts and higheryields in plants and animals that have been bred from specific characteristics
Example: increased yield of milk by cows
Can reduce the geneticdiversity
Natural vs Artificial selection
Natural
Process occurs naturally
Trait acquired increase chance for species survival
Example: animals in the wild (colour of peppered moth)
Same
Traits are inherited from parents
Results in change in genetic trait of species
Change occurs over many generations
Artificial
Desired trait selected by humans
Acquired traits don't always enhance the survival of species
Examples: dogs, livestock, or crops in agriculture
Selection agents
Any force in the environment that favours or disfavours traits
Populations subjected to different selective agents
May become so different that they are no longer able to breed with one another