Transcript Chapter 26 - Cloudfront.net

Chapter 26
Phylogeny And the Tree of Life
I.____________ is the evolutionary history
of an organism and shows evolutionary
relationship.
>___________ trees depict hypotheses about
______________ relationships.
• A. __________is the study of diversity in the
context of evolution. We use systematics to
construct phylogeny.
– 1.______________ is the naming of organisms.
– 2.Each organism is given a ____________, or 2part name.
• Composed of the genus and species name. (Homo
sapiens)
– 3. The levels of hierarchy in descending order
from largest to smallest group are: _________,
kingdom, phylum, _________, order, family,
genus, and _______________. (each level is a
referred to as a taxon)
– Dumb Kings Play Chess On Fine Green Silk!
• B. __________________________ occurs when 2
organisms become alike because they have similar
environmental challenges. (Streamlined bodies of a
tuna and a dolphin.)
– 1. Results in analogous structures.
• (wings of a bat/wings of an insect.)
Linking Classification and
Phylogeny
• A.The evolutionary
history of a group of
organisms can be
represented by a
branching tree called a
____________ tree.
• B.The tree shows a
series of dichotomies or
___________ that show
the ______________ of
two evolutionary
lineages from a common
ancestor.
• C. ____________________ uses DNA to show
evolutionary connections.
• D. _____________ is the idea that theories
should be kept as simple as possible. (KISS)
• E. Relational diagrams based on phylogeny are
called ___________. Each branch is a ________.
Branches are based on ___________.(similarities)
Important terms in cladistics:
• 1._____________-taxon composed of one ancestral
species and all of its’ descendants.
• 2._____________-taxon composed of an ancestral
species and some (not all) of its’ descendants.
• 3.__________-taxon composed of different ancestors.
• 4. Shared __________
characters originate in
the ancestor.
– The backbone in a
mammal (depending on
how far back you go)
• 5. Shared _________
characters are
evolutionary novelty
shared by one clade.
– Mammalian hair (lizards
don’t have hair!)
• 6.________-a group or species in a
__________ that diverged before the lineage
that includes the species we are studying.
• F. __________________ measure the
time for evolutionary change
– Researchers have recently extracted and sequenced
mitochondrial DNA (mtDNA) from the fossilized bones of
extinct woolly mammoths. The mtDNA, which can be used
as a 'molecular clock' to gauge the time since the mammoths
and present day elephants diverged, has helped to resolve
uncertainty about elephant evolution.
Alas…taxonomy is ever changing…
• G. The ______-kingdom system emerged in the
70’s.
– 1.Monerans were “prokaryotic”, Protists, Fungi, Plants and
Animals were “eukaryotic”.
• H. The _________-Domain system is used
today.
– 1. Domain __________-most bacteria
– 2. Domain ___________-extremophiles and
methanogens
– 3. Domain __________-everything with a nucleus
The Simple Tree of Life
• Based on _______ sequence comparisons,
all life can be grouped into one of three
domains:
Maybe the Tree is really a Ring!
• Some scientist
hypothesize that early
eukaryotes arose from
an endosymbiosis
between a bacteria
and an archaean. If
this is correct, then
eukaryotes are
simultaneously most
closely related to both
groups and not a
branch off the bacteria
lineage.