Lecture 28 Flashcards Preview

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Flashcards in Lecture 28 Deck (10):
1

Ecological genetics:

- Understanding genes in natural environments
- Adaptation and how organisms undergo adaption
- Survival and reproduction
- Evolutionary processes in nature and the extent to which species are able to adapt
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2

Quantitative genetic diversity:

- Traits associated with many genes
eg) size is measured on a quantitative scale and is associated with multiple genes and is under selection

3

Allozyme variation in butterflies and PGI:

- PGI is an allozyme with different forms across the population
- The gene is protein coding
- Heterozygotes are more active at cooler morning temperatures
- The quantitative behaviour is flight behaviour
This gene has a big effect on flight behaviour.

4

Early flight provides a reproductive fitness advantage

- Functional studies show that PGI heterozygotes fly better in the cold
- 3/4 heterozygotes perform better, in the field and in the lab
- This will maintain variation in the population

5

PGI variation is ubiquitous in insects flight ability:

- This allows extension from gene to trait
- Balancing selection is maintained here

6

Chromosomal rearrangement:

- Inversions
- polymorphisms for chromosomal rearrangements such as inversions exist
- Inversions can be studied

7

There are many example of genetic polymorphisms under selection:

- Several allozymes
- Chromosomal rearrangements
- Insertions/deltions
- SNPs

8

Multiple polymorphism scans allow us to determine how adaptable a particular genome is:

- Carried out across time or (usually) across space
- Ideally this will be replicated across time or space to determine a difference
- Fst analyses can be used to identify outliers and loci with very large Fsts are looked for

9

Arabis alpina is a plant studied in relation to elevation:

- Fst was studied and two peaks were found
- This means there are two genomic sequences associated with elevation
- What genes are these? How do they effect the polymorphism?

10

Genome Wide scans are

- Markers are available across entire genomes
- They may involve re-sequencing or markers such as RADs
- It is important to separate population processes, such as admixture
- Functional analyses of identified polymorphisms are needed
- This identification does not indicate how important a polymorphism is for a trait without additional functional analysis
- How many other genes are involved and what fraction of the variation in the trait is determined by that particular gene?