Chapter 8 - Molecular and evolutionary ecology (CHAPTER + SLIDES) Flashcards
slides notes are included!!
What role do molecular markers play in molecular ecology?
They help identify subdivision within species and the degree of separation between closely related species.
What was the limitation of visual markers in species identification?
Only experts could reliably use them, whereas molecular markers provide higher resolution.
What factors influence the choice of a molecular marker?
The mutation rate in the DNA region being studied.
What is the purpose of Polymerase Chain Reaction (PCR) in molecular ecology?
It amplifies target DNA regions for analysis and allows for non-invasive sampling.
What is the key difference between nuclear DNA and mitochondrial DNA?
Nuclear DNA is inherited from both parents, while mitochondrial DNA is inherited only from the mother.
Why is mitochondrial DNA useful for tracing lineages?
It has a higher mutation rate, offering finer resolution.
What are microsatellites, and why are they important?
They are nuclear DNA regions with repeated base sequences that vary among individuals, allowing for fine-scale differentiation.
Compare Sanger sequencing and next-generation sequencing.
Sanger sequencing is slow, while next-generation sequencing is fast.
What are conserved gene regions, and how do they differ from variable regions?
Conserved regions show little variation and are functionally important, while variable regions are subject to weaker selection and drive differentiation.
What are Single Nucleotide Polymorphisms (SNPs), and what are they used for?
SNPs are single base pair variations in DNA used to determine genetic relatedness and construct relatedness trees.
How does DNA barcoding work?
It uses specific DNA sequences to identify species based on a ‘barcoding gap’ where interspecific differences exceed intraspecific ones.
What is coevolution?
The reciprocal evolution of two or more species that influence each other’s selective pressures.
What is a coevolutionary arms race?
An antagonistic interaction where adaptations in one species drive counter-adaptations in another.
How do plants and herbivores engage in an evolutionary arms race?
Plants evolve defensive chemicals, while herbivores evolve adaptations to detoxify or bypass them.
Why are plants relying on toxins more likely to be involved in arms races?
Because toxins require specific counter-adaptations from herbivores.
How does coevolution apply to parasites and their hosts?
Parasites evolve greater infectivity, while hosts develop increased resistance, leading to a genetic arms race.
What laboratory example illustrates host-parasite coevolution?
The interaction between bacteria and bacteriophages.
What is mutualism?
An interaction between species where both organisms benefit.
How is mutualism often viewed in evolutionary terms?
As reciprocal exploitation.
Give an example of a mutualistic protector relationship.
Cleaner fish remove parasites from client fish, benefiting both.
How do ants protect plants in exchange for food?
They defend the plants from herbivores.
How does farming exemplify mutualism?
Humans farm crops and livestock, while ants farm aphids for honeydew.
What are true mutualisms in seed dispersal and pollination?
When plants provide rewards (fruit, nectar) in exchange for dispersal and pollination.
How do mutualistic gut microbes benefit both host and microbe?
Microbes get a stable environment and nutrients, while hosts receive help with digestion and pathogen resistance.
