Ecology
study of the interactions between an organism and the physical and
biotic components of its environment
micro evolution
change in allele frequencies over time
macro evolution
descent with modification
Tropical biome
constant high temperatures and abundant rainfall year-round, fostering the planet’s greatest biodiversity.
Temperate
Experiences distinct seasonal changes with warm summers and cold winters, supporting a mix of forests and grasslands.
deciduous
forest biome where trees shed their leaves seasonally to conserve water and energy during an unfavorable period like a cold or dry season.
evergreen
forest where trees retain their green leaves throughout the year, allowing for continuous photosynthesis whenever conditions permit.
conifer
A biome dominated by cone-bearing trees with needle-like leaves, which are well-adapted to cold, snowy, or nutrient-poor soils.
What factors explain the distribution of a species?
abiotic & biotic environmental suitability, and historical factors / dispersal
abiotic environmental suitability
climate and other abiotic factors must be suitable
biotic environmental suitability
there must also be sufficient
resources, and pressures from predators and competitors cannot be too
intense
niches (joseph grinell)
described the
niche as a set of environmental
conditions that restricts each species
* temperature, and other factors, including
interspecific competition
niches (elton)
defined the niche as the
“place a species occupies in a
community”; this emphasizes
interactions with other organisms
(roles)
niches (hutchinson)
is an n-
dimensional hypervolume (in
environmental space)
fundamental niche
the abiotic
conditions occupied by a species
in the absence of competition from
other species (the species’ full
tolerances)
realized niche
that portion of the
fundamental niche that the species
actually inhabits (in the face of
competition)
Absolute vs. relative
absolute: a precise, measurable quantity or a fixed state. It’s about the specific number or definitive fact.
relative: a comparison between two things. It’s about the relationship or proportion.
Density independence vs. density dependence
independence: affect a population regardless of its density. Their impact is not related to how crowded the population is.
dependence: affect a population more strongly as the population density increases. Their intensity is tied to how crowded the population is.
Exponential growth
when generations are
continuous (overlapping), and there is no limit to
growth (density-independence)
Geometric growth
constant reproductive rate,
discrete (non-overlapping) generations
Logistic growth
when generations are continuous
(overlapping), and there is a limit to growth
(density-dependence)
Aposematism
an evolutionary strategy where an animal advertises its dangerous or unpalatable nature to potential predators through conspicuous signals like bright colors, sounds, or odors
Camouflage & mimicry: what’s the difference?
Camouflage is the art of not being seen.
Mimicry is the art of being seen as something else—and that “something else” can be either a dangerous/aposematic model or a harmless object.
