Transcript Evolutionary Evidence - Northwest ISD Moodle

Evolutionary
Evidence
Part 4: Molecular Homology: Biochemistry and
DNA sequencing
Objectives:
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I can define biochemistry.
I can define a genome map.
I can describe the purpose of a genome map.
I can define an evolutionary tree.
I can describe the purpose of an evolutionary tree.
I can analyze a genome map, evolutionary tree and a
number of DNA sequences to evaluate the likelihood of
common ancestry.
What are the different types of evidence used
to support the evolutionary theory?
There are several places we
can see indirect evidence of
evolution/evolutionary
relationships:
 fossils,
 biogeography
 similarities in
anatomy,
 biochemistry/DNA,
 and embryology.
What is biochemistry?
Biochemistry - a field of both
biology and chemistry focused
on the chemical structures and
processes that occur within
organisms
How does DNA, proteins, and amino
acids demonstrate common ancestry?
Scientists believe that the fact that ALL LIVING
THINGS have A,T,C, and G in their DNA and all use
the same coding for proteins means we are all
related in some way.
How does DNA, proteins, and amino
acids demonstrate common ancestry?
• The metabolism of different organisms is based on the
same complex molecules: DNA, RNA, ATP, and many
enzymes.
• These molecules are similar because the organisms
have a common ancestor.
• The more closely related two organisms are, the more
similar their molecules will be.
– True for DNA, RNA, and amino acid sequences
– Now used to determine evolutionary relationships
between organisms
What is a genome map?
• Genome map - a record of the entire
genome of an organism, consisting of
correctly ordered gene maps.
What is an evolutionary tree?
• Evolutionary tree - a diagram that depicts
the phylogeny between organisms
• Phylogeny is the evolutionary history of a
species.
How are evolutionary trees
read?
• An ancestral character is found in a variety
of groups within the line of descent.
• A derived character is present in one
group within the line of descent, but it is
not found in the common ancestor.
How are evolutionary trees
read?
• Two groups on diverging branches
probably share a more recent ancestor
than those groups farther away.
• The common ancestor at the nodes (place
where branching occurs) is rarely a known
organism, species, or fossil.
How are evolutionary trees
read?
• Divergent evolution occurs when
populations become less alike and form
new species.
• This is easy to determine on an
evolutionary tree by comparing the
number of branches.