Speciation 1
A group of organisms capable of breeding with each other is known as a ________________
Species
Red and purple sea urchins occupy the same area, and therefore require this type of reproductive isolation to prevent fertilization when they release their sperm and eggs into the same water column.
Gametic isolation
Systematics is a combination of which two other fields?
Taxonomy and phylogenetics
_______________ _________________ is the study of similar structures between two groups of organisms to determine their evolutionary relatedness
Comparative morphology
Clades on a cladogram are separated by shared derived characteristics, also known as ___________________
Synapomorphies
____________________ is the type of large-scale evolution that leads to the formation of new species over long periods of time
Macroevolution
When incompatible anatomy prevents organisms from breeding with each other, it is known as ____________ _______________
BONUS: Give an example of this type of isolation occurring in nature
Mechanical isolation
BONUS: The male and female genitals of specific dragonfly species have to match up like a lock and key for fertilization to occur
________________ refers to the study and practice of naming and classifying organisms into a hierarchical system; _________________ refers to determining the evolutionary relationships among groups of organisms
_______________ _______________ is the naming system used to identify specific organisms by their genus and species
BONUS: On your board, write the properly formatted binomial for the common housecat, felis catus
Binomial nomenclature
BONUS: Felis catus
A ___________________ shows evolutionary relationships based on shared derived characteristics, but branch lengths have no meaning. A ____________ _____________ does the same thing, but the branch lengths signify periods of time since two lineages have diverged from a common ancestor.
Cladogram; phylogenetic tree
In ________________ speciation, a physical barrier (often caused by a natural disaster) separates two groups of organisms long enough for them to accumulate genetic difference that prevents interbreeding; in __________________ speciation, the opening of a new niche within an existing habitat can cause the formation of a new species
Allopatric; sympatric
For the following examples, give the correct type of prezygotic or postzygotic barrier:
A) Apple and hawthorn flies don't interbreed because apples start their growing seasons earlier, so apple flies start their reproductive cycles earlier
B) Male mules and female horses produce a healthy, but sterile, offspring
C) Farmers breed wheat plants of different species. The first generation of hybrids is healthy and fertile, but their offspring are infertile.
A) Prezygotic -- temporal isolation
B) Postzygotic -- reduced hybrid fertility
C) Postzygotic -- hybrid breakdown
________________ evolution, in which organisms develop similar body plans due to similar environmental pressures, generates _____________ structures
Convergent; analogous
When groups of individuals evolve from a recent common ancestor into multiple new species, it is known as __________________ evolution. This type of evolution will lead to the formation of structures in different species that are similar due to sharing a common ancestor, or _______________ structures.
Divergent; homologous
Draw a cladogram that includes a root, a basal taxon, nodes, and a sister taxa. Label each
Answers will vary
_________ ____________ are types of reproductive isolation that occur to prevent fertilization. _________ __________ are types of reproductive isolation that prevent an offspring from being viable after fertilization
________________ ________________ occurs when two different species develop different mating rituals, calls, or displays to prevent interspecies breeding.
______________ ________________ occurs when two different species mate at different times of the day, month, or year.
______________ _______________ occurs when two different species don't occupy the same geographic area, and therefore don't breed with each other
Behavioral isolation; temporal isolation; habitat isolation
Give one example of analogous structures. Give one example of homologous structures.
Analogous structures -- the sleek body shape of sharks and dolphins, due to them both adapting to an aquatic environment
Homologous structures -- the similar arm bones found in humans and bats due to evolving from a common mammalian ancestor
On an cladogram, an ____________________ is used as a reference tool, to compare traits that are derived against traits that are ancestral. Conversely, a _________ __________ is part of the ingroup; it is simply the earliest-diverging member of the ingroup
Outgroup; basal taxon
Give the definition for a monophyletic clade, a paraphyletic clade, and a polyphyletic clade
Monophyletic clade: includes a common ancestor and all of its descendants
Paraphyletic clade: includes a common ancestor and some of its descendants
Polyphyletic clade: includes multiple lineages, but no single common ancestor
Darwin proposed the theory of evolutionary __________________, in which evolution occurs at a steady pace, predictably producing new species. The more likely scenario is _______________ ______________, in which populations experience long periods of little evolutionary change, broken up by rapid speciation
BONUS: Why is the latter theory better supported than the former?
Gradualism; Punctuated Equilibrium
BONUS: The fossil record lacks the abundance of intermediate species that would result from the Gradualism model.
There are three types of postzygotic barriers; identify each and give a brief description
Reduced hybrid virility -- hybrid zygote is generated, but is not viable and doesn't live to maturity
Reduced hybrid fertility -- hybrid zygote is healthy, but sterile
Hybrid breakdown -- first generation of hybrids is fertile, but their offspring are infertile
List the eight taxonomic ranks in order from broadest to most specific
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Scientists look at other homologies besides morphology when determining the relatedness of organisms. List and describe two other homologies that can be used to relate organisms
Embryonic homology: patterns of development or embryonic structures can be compared to determine relatedness
Vestigial structures: structures that remain in an organism but no longer function can be used to establish common ancestors
Molecular homology: similar sequences of DNA or amino acids can be used to establish relatedness
Given the following group of organisms, generate a valid cladogram. You will have to come up with the synapomorphies on your own.
Goldfish, sharks, sponges, mice, birds, crocodiles
Answers will vary, but should go in the general order of:
Sponges, sharks, goldfish, crocodiles, birds, mice or birds/mice