Lecture 8 Flashcards
Natural selection elements
function and design
natural selection is done through a – process
blind
Natural selection was proposed by
Charles Darwin
Intelligent design
the theory that life or the universe cannot have arisen by chance and was designed and created by some intelligent entity
Intelligent design follows a
creationist religious argument
Darwins alternative to intelligent design was
design by the mindless process of natural selection
selection happens blindly by
the enviorment
Natural selection
the process whereby organisms better adapted to their environment tend to survive and produce more offspring
Process of natural selection has no
goal
Teleology
the explanation of phenomena by the purpose they serve rather than by postulated causes
evolution appears directed by design to
some goal, but it is not
the future cannot cause
material events in the present
Adaptation
a characteristic that enhances the survival or reproduction of organisms that bear it relative to alternative character states
All variations cannot
be environmental, some have to be genetic so it can be heritable
Evolution by natural selection occurs if 3 conditions hold
there is phenotypic variation in the populations
there is differential fitness among the phenotypes
the fitness is heritable
fitness
reproductive success as measured by the average per capita rate of increase
fitness quote
survival of the form (phenotypic or genotypic) that will leave the most copies of itself in successive genetations
Fitness 2 parts
survival
reproduction
Natural selection is not an
external force or agent, and certainly not a purposeful one
Natural selection is a name for
statistical differences in reproductive success among genes, organisms, or populations
3 levels of selection
genetic, individual, and group
Which level of selection is most controversal
group selection
which levels of selection are most important
genetic and individual
Richard dawkins the selfish gene popularized
the idea of the gene is an important level of selection
Genetic drift is due to
chance
Natural selection is the opposite of
the chance events
Fitness differences are the
average differences in the probability of survival and reproductive sucess
for fitness there has to be a consistent difference in
survival and reproduction associated with a particular phenotype
distinguish selection of objects from selection for properties
balls are selected for the property of small size because of there small size, not selected for color, yet all the small balls are red
There has been a selection of organisms with important features
but it was the features themselves that were selected for
aposematism
a warning signal to potential predators that prey are toxic or noxious
Birds tend to avoid the bright colors the
most
Batesian mimicry
the resemblance of a non toxic species to a toxic species, makes themselves look toxic, gives good protection
mullerian mimicry
the resemblance of a toxic species to a toxic species, normally a mild toxic resembles a very toxic
Competative exclusion principle
two competing species that use the exactly the same resources cannot coexist indefinitely, one will become extinct
Resource pardoning
happens with competitive exclusion, species divide the limited resources to reduce the competition, also known as niche partitioning
Character displacement definition
differences among similar species whose distributions overlap geographically are accentuated in regions where the species co-occur, but are not minimized or lost where the species distributions do not overlap
Character displacement simple def
natural selection drives a wedge between 2 different species that are in sympathy (living in same area) to make them different. This doesn’t happen with alopatry (species living in different area)
