2.2 b) Evolution - Fitness + Co-Evolution Flashcards
Define the fitness of an individual.
What can fitness be used to infer?
its ability to survive and reproduce.
the fitness and survivability of potential offspring.
The fitness of an individual is an indication of its ability to ___ and ___.
Fitness can be used to infer the ___ and ___ of ___ ___.
survive and reproduce.
fitness and survivability of potential offspring
Fitness can be defined in ___ or ___ terms.
absolute or relative
Fitness refers to the contribution made to the ___ ___ of the next ___ by individual ___.
gene pool, generation, genotypes
What is absolute fitness?
the ratio between the frequency of individuals of a particular genotype after and before selection.
If the absolute fitness of a genotype is 1, then…
the frequency of that genotype is stable
An absolute fitness greater than 1 indicates…
An absolute fitness smaller than 1 indicates…
an increase in that genotype.
a decrease in that genotype
What is relative fitness?
the ratio of the number of surviving offspring of a particular, and the most successful genotype.
Absolute fitness is:
The ___ of individuals with a particular genotype ___ ___ / the ___ of individuals with that genotype ___ selecton.
frequency, after selection / frequency, before
Relative fitness is:
the number of ___ ___ per individual of a particular ___ / the number of ___ ___ per individual of the most ___ ___.
surviving offspring, genotype / surviving offspring, successful genotype
Co-evolution is the process by which ___ or ___ species evolve in response to ___ ___ imposed by ___ ___.
two or more, selection pressures, each other
What is co-evolution?
the process by which two or more species evolve in response to selection pressures imposed by each other.
In co-evolution, a change in the ___ of one ___ acts as a ___ ___ on the other ___.
traits, species, selection pressure, species
Co-evolution is frequently seen in…
pairs of species with a symbiotic relationship
Co-evolution occurs between a ___ and its ___.
parasite, host
What is symbiosis?
an intimate co-evolved relationship between members of different species
The impacts of symbiotic relationships can be ___, ___ or ___ for the individuals involved.
positive (+), negative (-) or neutral (0).
What are the three types of symbiotic interactions?
mutualism, commensalism and parasitism
Describe mutualism.
both organisms in the interaction are interdependent on each other for resources, and they both benefit
(+/+)
Describe commensalism.
one of the organisms benefit, whilst the other is unaffected (+/0)
Describe parasitism.
the parasite benefits in terms of energy or nutrients and the host is harmed as a result of the loss of these resources
(+/-)
What is the Red Queen hypothesis?
The idea that organisms must constantly adapt in order to survive.
it states that, in a co-evolutionary relationship, changes in the traits of one individual act as a selection pressure on the other individual.
(‘Futurama - Evolutionary Arms Race’ on YouTube)
Species involved in a co-evolutionary relationship must ___ to avoid ___.
adapt, extinction
The RQ hypothesis states that species must constantly ___ to avoid ___.
evolve/adapt, survive
Fair warning: the word ‘symbionts’ exists; and it refers to a pair of organisms (of different/the same species) in a ___ relationship.
(different), symbiotic.
2017 P2 Q7a)i): “Explain why the hairworm and the cricket can be described as symbionts.”
Answer: they are involved in a close/intimate association
AND
are two/different species.
