Evidence For Evolution V2
Biological evolution is defined as ______________________________________________________ .
There is an ______________________ of __________________ from many areas of science to support
the Theory of Evolution. This scientific evidence is gathered by _______________________
_______________________. The 5 main categories of evidence are:
1. Biogeography
2. Fossil Evidence
3. Anatomy
4. Comparative Embryology
5. Molecular Biology (DNA and proteins)
1. Biogeography
In the early 1900’s Alfred Wegner stated that all the
continents had originally been joined together into
_________________________________________ .
The ________________ of the rocks supports the
Here are the continents 300 mya.
theory. We have found fossils from the Pangea era on the _________________________________ of
different continents. Biogeography is the study of the __________ ____________________geographical
distribution of species. Geographically __________ environments are more likely to be
____________________________________________ than geographically separate species. Animals on
___________________ often closely resemble animals on the __________________________ .
2. Fossil Record
Fossils appear in _________________________________________ order in layers of sedimentary rock.
Fossils in ________________________ layers of rock are ______________________ to species alive
today. Usually _____________________________________________ when they are buried under
sediment. Fossils are one of the ___________________ pieces of evidence to support the Theory of
Evolution. Transitional fossils show links between groups of ____________________
_________________ and help scientists better understand relationships between groups of organisms
alive at different times. Vestigial structures are ___________________ ______________ _______
__________________________ but are no longer needed by the organism today. Ex. Pelvic bone in
whales. The Archeopteryx transitional fossil showed the transition from ____________
___________________. This was the first reptilian fossil found with feathers!
3. Anatomy
Homologous structures are
structures that have
_______________________
_________ but have different
functions now.
Ex. Bat ________________
___________________ .
Analogous structures are
structures that perform a similar function now but ____________________ _________________
Ex. _____________ wings and ______________ wings
4. Comparative Embryology
This is the study of ______________________ during embryonic development. Similarities in
development are indicative of ___________ ____________________. Historical note: “Ontogeny
recapitulates phylogeny.” For example, all vertebrate embryos have structures called pharyngeal
pouches in their throat at some stage in their development. These embryonic structures develop into
very different, but still homologous, adult structures, such as __________________________________.
5. Molecular Biology
By comparing the DNA of different organisms, scientists can
determine their _________________ ________. Each DNA gene
controls the _____________________________________.
Proteins control the _______________________________ of an
organism. Here scientists compare the amino acid sequences that
make up the hemoglobin protein in different organisms. The
___________ ______________________ of a protein depends on
the ______________________________________ in the DNA
(GCAT).
In conclusion the major areas of evolutionary evidence are ___________________ to make the best
theory for evolution of a specific organism or to decide on a family tree.
Evidence For Evolution V2
Biological evolution is defined as the genetic change in a population of an organism over time.
Scientific evidence is gathered by observing the world around us. There is an abundance of evidence from
many areas of science to support the Theory of Evolution. The five main categories of evidence are:
1. Biogeography
2. Fossil Evidence
3. Anatomy
4. Comparative Embryology
5. Molecular Biology (DNA and proteins)
1. Biogeography
In the early 1900’s Alfred Wegner stated that all the continents had originally been joined into one super
continent called Pangea. We have found fossils from this era on the corresponding locations of different
continents. The geology of the rocks also supports the theory. Biogeography is the study of the past and
present geographical distribution of species. Geographically close environments are more likely to be
populated by related species than geographically separate species. Animals on islands often closely
resemble animals on the closest continent
2. Fossil Record
Fossils appear in chronological (time) order in layers of sedimentary rock. Fossils in young layers of rock
are more similar to species alive today. Usually only bones form fossils when they are buried under
sediment. Fossils are one of the strongest pieces of evidence to support the Theory of Evolution.
Transitional fossils show links between groups of prehistoric organisms and help scientists better
understand relationships between group of organisms alive at different times. Vestigial structures are
reduced forms of structures that once were useful in ancestors but are no longer needed by the organism
today. Ex. Pelvic bone in whales The Archeopteryx transitional fossil showed the transition from reptile
to bird. This was the first reptilian fossil found with feathers!
3. Anatomy
Homologous structures are structures that have similar parts and a common ancestry or origin but have
different functions now. Ex. Bat wings and human hands
Analogous structures are structures that perform a similar function now but do not have a common
evolutionary origin. Ex. Insect wings and bat wings
4. Comparative Embryology
This is the study of structures that appear during embryonic development. Similarities in development
are indicative of common ancestry. Historical note: “Ontogeny recapitulates phylogeny.” For example,
all vertebrate embryos have structures called pharyngeal pouches in their throat at some stage in their
development. These embryonic structures develop into very different, but still homologous, adult
structures, such as the gills of fish or the Eustachian tubes in mammals.
5. Molecular Biology
By comparing the DNA of different organisms, scientists can determine their degree of relatedness.
Each gene controls the production of a protein from amino acids. Proteins control the structure and
function of an organism. Scientists compare the amino acid sequences that make up the hemoglobin
protein in different organisms. The amino acid sequence of a protein depends on the nitrogen base
sequence in the DNA (ex. GCATTGA).