Module 4 - Genetic diversity and adaptation Flashcards
How is genetic diversity increased in a population?
Gene flow - new alleles entering the population through migration
Mutations - The creation of new mutations
What is a big aim for a population?
To increase the number of advantageous alleles in a population so that more organisms have a higher chance of survival and ability to reproduce.
What is a genetic bottleneck and what is the effect of it?
This is when there is a huge decrease in the population of an organism. This can decrease the number of alleles in a population so genetic diversity decreases
What is the founder effect?
When a few organisms in a population starts a new colony which causes there to be fewer numbers in the populations gene pool. Rare alleles may become more common for example in the Amish population
What is an advantageous allele?
This is when there has been a mutation within an organism in a population. This means that they are more likely to survive and reproduce. As a result these advantageous alleles will be passed down. This is how evolution happens
Examples of behavioural adaptations?
Some animals play dead to prevent being attacked by a predator
Examples of physiological adaptations?
Processes that happen inside a body to help with survival.
Conserving energy
Hibernating in cold seasons
Storing water etc
Examples of Anatomical adaptations?
These are structural adaptations that some organisms have:
- Thick layer of fur to keep them warm
- Long noses etc to increase SA
What is directional selection?
Individuals with alleles of an extreme type are more likely to survive and reproduce
Give an example of how directional selection occurs in real life
Bacteria. When bacteria is exposed to antibiotics, majority of them will die because they haven’t gained resistance. However, one bacterium may have a mutation where they develop a resistant allele. This will then mean this bacterium survives. They can reproduce and produce a colony of resistant bacteria.
What is stabilising selection?
Where individuals with characteristics towards the middle of the range are more likely going to survive and reproduce.
Give an example of how stabilising selection occurs in real life
Human birth weight. A baby with a larger birth weight may be hard to give birth too so may be unlikely to survive and reproduce. Babies with a small birth weight may find it hard to maintain body temperature. This therefore means babies with a middle weight are most likely going to survive and reproduce.
