Zusammenfassung der Ressource
EVOLUTION
- Adaptation
- The adjustment of an
organism to its environment,
or the process by which it
enhances its fitness for that
environment.
- Adaptive Radiation
- Special case of divergent evolution. Occurs when one
ancestral species gives rise to many new species
(occupying different niches)
- Allopatric and Sympatric
Speciation
- Allopatric
- New species forming because
they are geographically
isolated from the parent
population.
- Sympatric
- Closely related species whose
distribution overlaps with the
parent population
- Analogous and
Homologous structures
- Analogous
- Similar structures developed
by species that are not
related but instead faced the
same selection pressures
and share similar
environment. Usually have same
functions
- Homologous
- Are remnants of ancestor
species, and are present in
related animals - pentadactyl
limb. Does not always serve
same purpose
- Types of Evolution
- Convergent
- Similarity present in
appearence of
organisms that are not
closely related by
share similar habitat
type
- Parallel Evolution
- Development of a similar
trait in related, but distinct,
species descending from the
same ancestor, but from
different clades.
- Divergent
- One ancestral species,
over time, giving rise to
several new species each
in their own niche.
- Cladogenesis
- The
branching off
of a new taxa
- Macroevolution
- Evolution above the
species - on a greater
scale
- Microevolution
- Small scale - changes in
allele frequencies that occur
over time within a
population
- Natural slelection
- One of the basic
mechanisms of evolution,
along with mutation,
migration, and genetic drift
- Evolutionary Change
- Gradualism
- Populations slowly
diverge by
accumulating adaptive
characteristics in
response to different
selective pressures.
- Punctuated Equilibrium
- Most species in
existence spend time in
stasis and little time is
spent in active evolutionary
change
- Isolation and
Speciation
- Reproductive isolation
- Prevents
interbreeding and
therefore gene
flow between
species. Most
species have
more than one
- Temporal
- Individuals may be active
during different times of the
day/week/month/season
- Gamete Isolation
- Gametes may
be
incompatible
- Behavioural
- Different
courtship
rituals
- Mechanical Isolation
- Structural differences in
the anatomy of the
reproductive organs
- Postzygotic
- Sterility
- Inviability
- Hybrid breakdown
- Phylogeny
- The history of the evolution of a species
or group, especially in reference to lines
of descent and relationships among
broad groups of organisms
- Population
- A summation of all the organisms
of the same group or species,
who live in the same geographical
area, and have the capability of
interbreeding
- Speciation
- The formation
of a new
biological
species
- Extinct
- Extant
- Still in existence
- Having no living member or no
longer being in existence