D4.1 Natural Selection Flashcards
Explain natural selection
More offspring than the environment can support>variation among offspring>some well-suited and some less-suited>feautures of well-suited are inherited by their offspring
What are the origins of genetic variation?
1) Mutation>new alleles>larger gene pool
2) Sexual reproduction (Meiosis> new allele combos, fertilization>different combinations of gamete genomes)
in order to be passed on, traits must be…
coded for by base sequences and therefore heritable
Adaptdation
Change that makes an organism better suited for their environment
Fitness
how adapted an individual is
Explain natural selection through through intraspecific competition
fittest individual survives>live longest>produces moire offspring>higher chance of passing on their gene pool
Selection pressures
Factors that cause some individuals in a population to have higher survival rates, can be biotic or abiotic
Examples of selection abiotic pressures:
- Availability of dissolved nitrogen (density-D)
- ## Temperature (density-I)
Biotic selection pressure
Sexual selection
What species is ribbon-tailed astropia
bird of paradise
Where does ribbon-tailed astrapia live
paua new guinea rainforests
How do male birds of paradise attract females?
Males use elaborate courtship displays, bright plumage, and specific behaviors to showcase their fitness and attract potential mates.
What is sexual selection in birds of paradise?
It is a process where individuals with certain traits (like vibrant colors and elaborate displays) are preferred by mates, leading to the evolution of these traits.
Guppies
Fish native to freshwater habitats in northeast of south american
Outline the Endler Guppy experiment (1):
1) Guppies transferred to no predator pond.
2) an Average number of spots increased (sexual selection)
3) Transferred to predator pond (pike-cichlid), number of spots decreased. (predator selection)
Outline Endler study two
1) Transferred to the pond with weaker predators
2) Number of spots increases
Gene pool
All the genes and their different alleles in a population
Population
Group of individuals living on an area
What happens when an individual dies
Alleles are lost from the gene pool
How do geographical barriers impact populations?
Geographical barriers prevent interbreeding, leading to separate gene pools and differing allele frequencies.
What resource can be used to study allele frequencies?
The Allele Frequency Net Database provides data on allele frequencies across different populations.
What did Gregor Mendel discover?
That genes are inherited
What did wesimann discover?
