Selection and Adaption Flashcards
What is artificial selection?
process of humans deliberately choosing certain varieties of an organism over others by implementing breeding programs that favour one variety over another
What is a phenotype
observable properties of an individual due tot heir genotype
What is speciation
process by which a population evolves due to an environmental change
- sympatric - diverging forms co exist
- allopatric - geographically separate populations change through local adaption
Give an example of natural selection
hunting in wild dogs
dogs that hunted in packs got more food so could produce more offspring. if offspring also prefer to hunt in packs, trait will increase in frequency over time
What 3 process have to occur for natural selection
- variation in the trait. can be due to genes e.g mutation, genetic recombination when mating, migration (other population have genetic diversity)
- fitness consequences - trait has to have an advantage that allows easier reproduction
- mode of inheritance - must be able to be passed down
Give 2 ways to measure heritability
- truncation selection - maths
- parent offspring regression - parents pass on genes to their offspring. e.g Browns - cliff swallow birds. the group size birds lived in was similar to their biological parents, even when raised by other birds
What is an adaptation
a trait associated with the highest relative fitness in a given environment
Give 3 examples of adaptations
- Guppies - low predation sites produce less but larger offspring and shoal tighter. high predation sites produce more smaller offspring
- naked mole rats.live in large groups. more cooperative and altruistic as high level of relatedness e.g digging tunnels, grooming queen, defending from predators
- humans. women are choosier. cost of producing larger gametes and internal gestation. have to pick male that will provide resources
