Speciation and Extinctions – Chapter 14 Terms
Terms:
• Macroevolution – The term used to
describe large changes over periods of
time due to accumulations of changes
• Biological Species – Species are the basic
unit of organisms in an evolutionary
sense
Share the same gene pool
• Speciation – The separation of a species
based upon reproductive isolation
• Results in each group accumulating
their own unique mutations
• Gene Pool – all the genes and alleles
present within a population
• Reproductive Isolation – There are many
different ways that organisms avoid
mating with one another
• Pre-Zygotic Barriers – is in reference to
barrier which keep organisms from
being able to fertilize one another
o Hybrid inviability – an hybrid
either dies during early
development or sometime
before reaching reproductive
maturity
o Hybrid infertility – animal
develops and becomes an adult,
but is infertile.
Mules
Ligers
o Hybrid breakdown – hybrids
which are capable of
reproducing, but offspring have
major genetic problems.
• Allopatric = A result of a complete
separation of a species into two
populations and kept physically apart
from one another. Examples: Island
formation
