Understanding:
• Individuals that are better adapted tend to survive and produce more offspring while the less well adapted tend
to die or produce fewer offspring
The variation that exists within a population is heritable (i.e. genetic) and determined by the presence of alleles
- These alleles may be passed from parent to offspring via sexual reproduction
Alleles encode for the phenotypic polymorphisms of a particular trait and may be beneficial, detrimental or neutral:
- Beneficial alleles will better equip the organism to survive and hence produce more offspring (encodes beneficial adaptations)
- Detrimental alleles will harm the survival prospects of an organism, leading to fewer viable offspring
- Neutral alleles will not affect the organisms survival prospects
Due to natural selection, the proportion of different alleles will change across generations (evolution)
- As beneficial alleles improve reproductive prospects (more offspring), they are more likely to be passed on to future generations
- Conversely, detrimental alleles result in fewer offspring and hence are less likely to be present in future generations
If environmental conditions change, what constitutes a beneficial or detrimental trait may change, and thus the allele frequencies in a population are constantly evolving
Changing Allele Frequencies (Evolution)
