How can we help?
You can also find more resources in our
Select a category
Something is confusing
Something is broken
I have a suggestion
What is your email?
What is 1 + 3?
Macroevolution is the phenomenon of _______ over _________ _____
evolution, geologic time
Macroevolution is observed at the ________ level
In Macroevolution, species...
...arise from others through transformation (descent w/modification)
Macroevolution relies on _____, ___________ analysis, and ___________ or clades.
fossils, molecular, phylogenies
The biological species concept says that...
...species can interbreed w/viable offspring
Gene flow maintains ______ w/in species
Reproductive isolation prevents ___ ___, which leads to ______ _______, or differing species.
gene flow, genetic divergence
Reproductive Isolating Mechanisms include (5)
1 Geographic barriers
2 habitat isolation
5 hybrid inviability/infertility
All RIMS act to STOP ____ ____, which is necessary to _______ the _______ of a species.
gene flow, maintain, integrity
The ecological species concept says that species...or...
...interbreed but maintain species boundaries,
...or don't interbreed btwn species but maintain species coherence
The ecological species concept emphasizes the ____ for ________ ________s to change...
need, selective pressure
The ecological species concept was developed to decrease emphasis solely on __________.
What are 3 ways we can categorize nature?
2 gene flow
3 genetic relatedness
Morphological similarities refer to similar ________, or ____________al similarities
process through which new species are formed, arise
The 2 issues (for anthro's) with speciation are:
1. need fossil records, too slow to observe in geological time scale
2. occurs too quick to detect in fossil record
Speciation events are indicated on cladograms by:
Microevolution influences speciation through 4 methods (i.e. mechanisms of change)
1. gene flow
2. natural selection
3. genetic drift
Microevolution, in light of speciation, occurs over a very ____ ____ of time
Natural selection affects speciation through ______ ________ affecting _______ _______
specific pressures, reproductive success
The 2 models of speciation are:
Allopatric speciation = _____ __________ + __________ __________
geographic separation + directional selection
In allopatric speciation, there is no ____ ____
Directional pressures in allopatric speciation emphasize the fact that ________ have the highest ________, because different __________s lead to different advantages.
extremes, fitness, phenotypes
An example of directional selection extremes include _____ fish and _______ fish
Parapatric speciation = ___ ___ + ____ ________ ________
gene flow + strong directional selection
There IS ___ ___ present in parapatric speciation
In parapatric speciation, there is selection AGAINST _____s
There are 4 theories of how macroevolution works:
2. Punctuated Equilibrium
3. Successive Speciation
4. Adaptive Radiation
______ theorized Gradualism, which stated...
...species evolve at a slow, steady rate
_________ states that species evolve at a _____ rate, resulting in _______ change
Punctuated equilibrium states that species...
...remain unchanged, and then undergo rapid & major change
Punctuated equilibrium is due to _________ ________s
Successive speciation states that...
...one single population has been breeding for many generations
Successive speciation involves 2 things:
1. many adaptive mutations
2. progressive change in the entire population
Successive speciation results in __________
Adaptive radiation states that a species...
...diversifies to fit available niches
patterned resource exploitation by a species
In adaptive radiation, speciation depends on the ________ of available ______s.
Adaptive radiation results in ___________.
There have been _ major extinctions in the fossil record
Mass extinctions influence future speciation, specifically through the method of adaptive radiation, by leaving many ______s __________ed.
There are 2 basic ways to classify, or taxonomize animals:
Phenetic grouping groups based on similar ________s.
________ grouping does not always overlap with _________ relationships.
Phenetic grouping is based on _________ traits
the acquisition of the same biological trait in unrelated lineages
Cladistic grouping is based on ________ traits
the acquisition of similar traits due to shared ancestry
Cladistic grouping does so by _________ categories
Tree of life = _________
___ __ ____ = Phylogeny
the arrangement of species that share common ancestor
Phylogeny is the application of ________
_________ is the application of cladistics
The Great Tree of Life video used the method of __________ speciation
The Great Tree of Life video used the example of __________ _________s leading to __________s resulting in purple bunnies
The Great Tree of Life video used the example of selective pressures leading to mutations resulting in _______ _________s
In the Great Tree of Life video, there was a massive _______ resembling human flesh.
In the Great Tree of Life video, there was a massive flower resembling _______ ______
The fossil record is ________, with always more _______ _____ than known ones
The fossil record is incomplete, with always ____ missing links than ____ ones
Fossilization is quite ____
_________________ is quite rare
Fossils are _____ not _____
______ are stone not bone
The number of fossils discovered come from all different parts during a ________'s ____________.
The number of _______discovered come from all different parts during a specie's development.
There are many evolutionary _____ ____s in the process of speciation because it involves working with ____ events.
dead ends, rare
only __% of fossil species are known
Phylogeny and evolution often ___________ with each other, which hinders our ability to know which _____ are our ancestors
__________ and evolution often interfere with each other, which hinders our ability to know which fossils are our _________s
what represents dead ends in a cladogram?
the discontinuation of branching, or nodes
what do the branches in a cladogram represent?
An example in class of there being many different ways something can fit into a phylogenetic tree was _______ _____
Filling in phylogenetic relationships involves ________ _________
Filling in __________ relationships involves evolutionary biology
Neanderthal DNA is now __% sequenced
__________ DNA is now 20% sequenced
some scientists believe the Neanderthals were an ___________ ____ ___
some scientists believe the ____________s were an evolutionary dead end
_________ tell us much about what it means to be human
primates tell us much about what it means to be ________