4. Small changes in a population's gene pool occurring over a few generations. The accumulation of these changes in allele frequencies over many generations can result in macroevolution.
5. The form of non-random mating in
which individuals who are alike
for particular traits mate and
those who are not alike do not.
The result is a progressive
increase in the frequency of
homozygotes and a decrease in the
heterozygotes for the
6. The mating of closely related
individuals, such as brothers,
sisters, or cousins. Another name
for this mating pattern is
"inbreeding." This is an
extreme form of positive
8. The theoretical model of evolution
in which species remain unchanged
for long periods of time and then
at times rapidly change as a
result of major alterations in the
environment and, subsequently, in
9. The theoretical model of evolution
in which species change slowly at
a more or less constant rate
through time into other species.
12. A term describing mate selection
in which all individuals have an
equal chance of being selected. In
other words, there is no conscious
discrimination for or against any
individual or trait.
13. A severe genetically inherited
fatal degenerative nerve disorder.
The symptoms usually do not appear
until early middle age. There is a
progressive loss of muscle control
that inevitably leads to paralysis
and death. This disease has been
found at an extraordinarily high
frequency among the people in the
Lake Maracaibo region of northwest
14. The exchange of genetic material
between homologous chromosomes at
the beginning of meiosis. This
results in sperm and ova with
greater genetic diversity due to a
recombination of parental genes.
Specifically, a portion of a
chromosome is broken and
reattached on another chromosome.
15. Major evolutionary
changes in a population's gene pool, occurring over many generations, resulting
in the evolution of new species.
1. The form of non-random mating in
which individuals who are not
genetically alike for particular
traits mate and those who are
alike do not. The result is a
progressive increase in the
frequency of heterozygotes and a
decrease in the homozygotes for
the discriminated traits.
2. The general term for the small
population size effect caused by a
dramatic reduction in genetic
diversity of a population or
species due to an ecological
crisis that wipes out most members.
3. Evolution, or change, in gene pool
frequencies resulting from random
chance. This process of evolution
occurs most rapidly in small
7. A term describing mate selection
based on one or more traits that
are discriminated for or against.
9. The transference of genes from one
population to another, usually as
a result of migration, but not
necessarily. The loss or addition
of individuals or their genes can
easily change the gene pool
frequencies of both the recipient
and donor populations.
10. Members of a conservative
Protestant sect related to the
Mennonites. They migrated to
Pennsylvania from Switzerland in
the late 18th century. The “Old
Order” communities of this sect
are relatively closed groups that
shun most modern conveniences in
their farming lifestyle. They use
horse drawn carriages, dress very
simply, and reject those who marry
outsiders. They are similar to the
11. A small population effect in which
the genes of a few people (the
originators of the population) are
inherited over time by a large
number of descendents.