Page 11 - Research 1.0

selected an area in the Canadian Arctic, Ellesmere Island, as
having the greatest likelihood of success. It took 4 years of
searching during the short summers of that hostile
environment but succeeded, returning in 2004 with 9 specimens

of the fish they named Tiktaalik. It was exactly what one
would expect a transitional fish-tetrapod to look like and
was found in deposits dated 375 mya. If this was not the
direct ancestor of tetrapods, it was something very much like
it.This is a great example of using evolutionary theory as a
predictive tool.

https://www.biointeractive.org/classroom-resources/great-
transitions-origin-tetrapods

Btw, biointeractive.org is a great source of information for
all of science. If anyone has an interest in expanding their
knowledge of science they should use it.

The genetic variation within a population is referred to as

a gene pool. Organisms can move freely within that population
breeding with each other, perpetuating any new mutations that
work and eliminating those that are less than optimal. Each
offspring will most resemble its parents, yet will vary
slightly genetically because of unique mutations acquired
during meiosis. Thus the genetic makeup of a population will
change ever so slightly with each successive generation.

https://science.howstuffworks.com/life/genetic/gene-
pool2.htm

Populations are not stable, they expand and contract with
changing conditions. So long as there is sufficient genetic
variation within a population there will be some members
capable of surviving those conditions and perpetuating the

species. The alternative is extinction.

When populations expand and migrate to new territories, some
portions of it will become genetically isolated from each
other and no longer share a common gene pool. In such cases,