Introduction To Evolution Flashcards
What does H-hemagglutinin do in influenza?
Provides specificity for the cell- its the virus binding to the cell
What does N-neuraminidase do in influenza?
Affects how readily the virus is transmitted (virus released from the cell)
What is reassortment?
Different flu strains infecting the same cell can swap different parts of their genetic material
Which strain of flu predominated in 2018?
H3N2
Can animal and human virus mix and reassert in the same cell?
Yes (COVID)
Give the definition of evolution
Accumulated, heritable changes within a population over generations which give rise to a new species
Give some small mistakes that happen during DNA/RNA replication
- Small duplications
- small insertions
- small deletions
- base substitution
Give some big mistakes that happen during DNA/RNA replication
- Large DNA duplications
- chromosome rearrangements
- large deletions
- viral insertion
- insertion of transposable elements
Species that share the more recent common ancestor will have (more/less) differences than those that are more distantly related?
Less
What is phylogenetics?
Since new species arise from earlier species, they must share relationships
What is systematics?
Classification of living things
What is taxonomy?
Naming of groups into taxa
What is classification
Arranging taxa into an ordered, hierarchical system
What is phylogeny
Determination of ancestral relationships of organisms and their evolutionary history
What is natural selection?
Organisms better adapted to their environment survive to produce more offspring
What is genetic drift
Variation in relative frequency of different genotypes in small populations due to chance
What is applied selection?
Plant or animal breeding
Antibiotic, drug or pesticide resistance
Give the steps for the ecoli evolution experiment
- Get 12 ecoli colonies from a single clone.
- Put one in each flask
- every day for 30 years take 10% of the colony and place it into a new flask
- freeze culture samples every 500 generations (75 days)
How many generations have been observed in the ecoli experiment?
73000
Give the details of the ecoli experiment
- Low amounts of glucose in growth medium
- they evolved very efficiently to use citrate in oxygen after about 30000 generations
What was the ecoli experiment testing for?
The ability to grow in citrate in the presence of oxygen as they can’t very efficiently use citrate in the presence of oxygen
How did the ecoli get around the citrate problem in the ecoli experiment?
The citrate and RNK promoter is duplicated and then turned on in oxygen (as a pose to Normal when it would be off)
What allows us to track evolution in real time?
Large scale genome sequencing
Do mutations at the 3rd base normally affect the phenotype?
No
What is the mutation that causes sickle cell anaemia? (SCA)
Mutation in the beta globin gene- glu6val (glutamic acid on 6th residue has been mutated to a valine)
What happens to the mutant hb molecule in sickle cell anaemia?
- aggregate and form crystals when deoxygenated
- cells with the characteristic sickle cell shape
- the sickle shaped cells don’t pass through smaller blood vessels and capillaries
What type of gene is SCA?
Autosomal recessive
Why do heterozygous SCA people have improved malarial survival rates?
They have lower levels of Parasites in the blood so there are fewer severe complications
