Homologous and Analogous
Structures
 1. How
does comparative morphology
provide evidence for evolution?
 2. What
can the presence of homologous
structures signify?
 3. What
can the presence of analogous
structures signify?
A study of the configuration or the
structure of animals and plants.
http://www.dallasnews.com/sharedcontent/dws/news/nation/stories/DNbats_09tex.ART.State.Edition2.432418c.html
http://votebits.com/explore-the-world-of-marine-animals/whale/
Similar body parts that reflect shared ancestry.
May be used for different purposes in different groups, but the same genes direct their
development
A body part that appears very different in appearance may
be quite similar in underlying parts.
This indicates a shared ancestry.
Wings
are examples of analogous
structures because they have the
same function, but very different
bone structures (and sometimes, no
bones at all).
 Let’s
think of two animals that have parts
which do the same thing, but have very
different structures.
• What are the two animals?
• What do they do that is similar?
• What structure does each one have that is
different?
 Similar
structures that evolved separately
in different lineages
http://news.nationalgeographic.com/news/2011/04/pictures/110407-science-fossils-insects-bugs-mayflies-mayfly-flying/
http://t2.gstatic.com/images?q=tbn:ANd9GcQWBP7aGyaHzETq76PnDkDbOfbbjpSpl3I5foQjvQTWgOzyIvrJ7A
http://news.nationalgeographic.com/news/2011/04/pictures/11
0407-science-fossils-insects-bugs-mayflies-mayfly-flying/