homologous structures chapter 6_2

 CA
Science Standard- Evolution 7.3
Biological evolution accounts for the
diversity of species developed through
gradual processes over many generations. As
a basis for understanding this concept: c.
Students know how independent lines of
evidence from geology, fossils, and
comparative anatomy provide the bases for
the theory of evolution.
 National
Entrepreneurial StandardsInformation Management K - Understands
the concepts, systems, and tools needed to
access, process, maintain, evaluate, and
disseminate information for business
 Depth
and Complexity- Relate Over TimeWhat are the effects of time on living
 have
characteristics that are shared by
related species because they were inherited
from a common ancestor.
 For example, bones in a human arm are
homologous to the bones in a cat arm, bat
wing, and whale flipper.
 A good way to remember this is that "homo"
means the same.
 Analogous
structures serve the same function
in different species but they evolved
independently rather than from the same
embryological material or from the same
structures in a common ancestor.
 Examples are the wings on birds, bats, and
 Vestigial
structures have marginal or no use
to an organism but once had some function
in its ancestor.
 Examples: Whale pelvic bone, eyes for bats
and moles, snake leg bones, and human
tailbone and appendix.