APES
Alec Humphries
Reproductive Isolation and Speciation
1: What happened with Diane Dodd and the fruit flies? How did she create
reproductive isolation?
Diane Dodd took a group of fruit flies and fed them different things. She created
reproductive isolation by splitting the two groups of flies by what they ate until they no
longer interbred.
2: What is the definition a species?
A species is a group of individuals that can interbreed and produce fertile offspring.
3: What are the two main types of barriers in reproductive isolation?
The two main types of barriers in reproductive isolation are geographic, and pre/postzygotic.
4: What is gene flow? What is reproductive isolation?
Gene flow is the mixing of genes in a population. Reproductive isolation is when a
species cannot have gene flow.
5: What is geographic isolation? (Give an example).
Geographic isolation is when there is an isolation in a population due to when they
exist. An example of this is
6: What is allopatric speciation? (give an example)
Allopatric speciation is when two groups live in different lands. An example of this is
meadowlarks.
7: What is sympatric speciation? (give an example)
Sympatric speciation is when two groups share the same land. An example of this is a
mutation in plants.
8: What is peripatric/parapatric speciation? (give an example)
Peripatric/Parapatric speciation is when there is a gradient among two groups. An
example of this is elephants.
9: What are pre-zygotic barriers? Name the types of pre-zygotic barriers (explain
each). (Temporal, Mechanical, Behavioral)
Pre-zygotic barriers are barriers created before the zygote is formed. The three types of
pre-zygotic barriers are temporal; where two groups have different mating systems,
mechanical; where two groups cannot reproduce because of its physical makeup, and
behavioral; where the way two groups search for mates is different.
APES
Alec Humphries
Reproductive Isolation and Speciation
10: What are post-zygotic barriers? Name the types of post-zygotic barriers- give
examples. (Zygote Mortality, Hybrid Sterility)
Post-zygotic barriers are barriers created when the two species interbreed, and their
offspring may either die or cannot reproduce. The two types of post-zygotic barriers are
zygote mortality; when two species create a zygote, which immediately dies (reefs), and
hybrid sterility; where two species create a hybrid of the two species, but it cannot
reproduce (mules).
11: What is polyploidy? What happens? Where is this common?
Polyploidy is very fast speciation. In this, the cells in the species become quadriploid
instead of the regular diploid, making it so they can no longer interbreed. This is
commonly found in plants.
12: What is the theory of Punctuated Equilibrium?
The theory of punctuated equilibrium is the belief that speciation happens very
quickly instead of gradually.