Evolution of Biodiversity Flashcards
Evolution occurs when…
something genetically happens that is not random
Evolution per se
populations and species are not static (things change over time)
Gradualism
evolutionary changes occur in small steps and not leaps
Darwin’s 5 Contributions
Evolution, Gradualism, Population Level Changes, Natural Selection, Common Descent
Population Level Changes
all the changes we observe
Natural Selection
some traits create an advantage or disadvantage, so the advantageous traits increase in frequency over generations
Common Descent
all species related to each via ancestral relationships; splitting and divergence leads to speciation
Homology
different species have similar structures meaning they have a common ancestral origin
Anagensis
change within a lineage (species) over time
Cladogenesis
formation of 2 lineages (species) from 1
Allopatric Speciation
geographical isolation leads to split in ancestral species
Sympatric Speciation
split in ancestral species occurs despite lack of geographical isolation
Polyploidy
more than one set of chromosomes
Disruptive Selection
organisms with intermediate traits reproduce less, so the organisms with extreme traits reproduce more
Morphological Divergence
a lineage splits and the results have different anatomical features
Life History Divergence
diverge due to when and how they breed and how many offspring they have
Physiological Divergence
diverge and create differences in how they deal with temperature, pH, oxygen, etc.
Behavioral Divergence
diverge and create different behaviors
Biological Species Concept
a population of organisms that can interbreed to produce viable, fertile offspring
Reproductive Isolation
to be separate species, you can’t breed with each other
pre-zygotic
prevent formation of zygote
gametic
mating occurs but gametes incompatable
post-zygotic
zygote forms, but isn’t viable or is infertile
hybrid infertility
hybrids can’t reproduce
