Download Phylogeny

Evolution:
Change over time; the process by which modern
organisms have descended from ancient organisms
∆ 𝒄𝒉𝒂𝒏𝒈𝒆
=
𝒕𝒊𝒎𝒆
𝒕
Tiktaalik:
Transitional fossil
DNA:
Take a minute and write down everything you
know about DNA
End
Chromosomes:
Take a minute and write down everything you
know about Chromosomes
End
Inheritance:
Take a minute and write down everything you
know about how traits are inherited
End
Genes & Alleles
Take a minute and write down everything you
know about genes and alleles
End
Phenotype and Genotype
Take a minute and write down everything you
know about phenotype and genotype
End
Phylogeny
And the evolution of plants
Phylogeny
Evolutionary
species
history of a
What is a plant?
All Land Plants
(Embryophytes):
Alternation
of
Generations
Roots & Shoots
Cuticle (prevents water
loss)
Bryophytes: Mosses, Liverworts and
Hornwarts
What
No
makes them special?
vascular tissue
 Can’t
 Need
 No
transport nutrients -> limited size
water to reproduce
seeds
Nonvascular Plants
Time
Mosses,
liverworts,
hornworts
(vascular tissue)
Ancestral
Algae
(Autotroph)
Vascular Plants
Ferns: Seedless Vascular Plants
What
makes them special?
No seeds
Need water to reproduce
Time
Mosses,
liverworts,
hornworts
Seeded Vascular
Plants
Ferns
(Seeds)
(vascular tissue)
Ancestral
Algae
(Autotroph)
Gymnosperm (conifers,
gingkoes, cycads)
What
makes them
special?
Wind pollination, Seeds,
No flowers
Mosses,
liverworts,
hornworts
Ferns Gymnosperm
Angiosperm
Time
Flowers,
(Seeds)
(vascular tissue)
Ancestral
Algae
(Autotroph)
Angiosperm
(Flowering Plants)
What
makes them
special?

Flowers- pollination by animals

Double fertilization
 Seed
doesn't develop w/out pollination
Modeling Phylogenetic Trees
Ferns
Gymnosperm
Time
Mosses,
liverworts,
hornworts
Angiosperm
Look at the Nodes
Ancestral
Algae
Any of the branches can be rotated
at the nodes:
Mosses,
Ferns
Angiosperm
Time
liverworts,
hornworts
Gymnosperm
Look at the Nodes
Ancestral
Algae
Are Angiosperm more closely related to Ferns, or to
mosses/liverworts and hornworts?
Gymnosperm
Time
Ferns
Ferns
Angiosperm
Mosses,
liverworts,
hornworts
Are Ferns more closely related to Angiosperm, or to
Gymosperm?
Angiosperm
Ferns
Time
Gymnosperm
Mosses,
liverworts,
hornworts
Neither: They are equally related
Tree of Life
Tree of Life
Bonus Opportunity
 Fantasy
Phylogeny
Create
a phylogenetic tree of
fantasy creatures
Include at least 5 creatures
Include descriptions of creatures
Describe characteristic that is
associated with each node
(example: seeds, vascular tissue in plants)
Lizard Lab
3 Parts- must be done sequentially.
When you complete part 1,
return that handout and pickup
the next.
Turn in at end of class- we will be
working on them next class also. They are due on _____
Evolution: A more technical
definition
the change in allele
frequency
__________
in a population,
time
over _________.
Mechanisms of Evolution
Mutation
Change in the DNA code
“Instant Evolution”
Almost always harmful. Why?
Mechanisms of Evolution
Migration
Movement of organisms in or out of a population
Changes allele frequency
Mechanisms of Evolution
Drift
Genetic
_________which
is a sampling
_______ error.
Founder Effect
____________in
which a population is
isolated from the parent population.
This
new population is a random
sample of the original, containing
different
Allele frequencies
______________
Mechanisms of Evolution
Drift
Genetic
_________which
Bottleneck Effect
___________
sampling
is a ______
error.
in which a population
declines rapidly, so that only a small
number of members remains. The
remaining members are essentially
a random sample
___________,
and have different
Allele frequencies
______________
than the parent
population.
Mechanisms of Evolution
Bottleneck Effect
___________
Cheetahs
______
underwent this. The
99
population shares ____%
of their
DNA- they are more closely related
than most _____.
siblings
Mechanisms of Evolution

Natural____________
Selection was proposed by
______
Charles Darwin
______
_____ in The Origin of Species.
Conditions:
There
must be variation
_______
heritable
variation
The ________must
be ________
More are born
____ than will
_________.
survive
Some variations
________ survive better
than others.
Mechanisms of Evolution

______
Natural___________
Selection increases __________,
fitness
which is measured in the number of offspring
an individual has, relative to other members
of its species..
Definitions: Genotype vs
Phenotype
Genotype:
What your genes are; 2 alleles
Phenotype:
What you look like; your appearance
Genotype or Phenotype?
The
bunny has brown fur…
Phenotype
Genotype or Phenotype?
Lucy is a carrier for X-linked
color blindness.
Genotype
Genotype or Phenotype?
The
flowers are pink.
Phenotype
Genotype or Phenotype?
The
plants are short
Phenotype
Definitions: Dominant &
Recessive
Dominant:
Represented by a capital letter
Single copy determines the trait
“overrides” other alleles
Recessive:
Represented by a lower-case letter
Can be “masked”
Dominant or Recessive
Recessive
The
It
“O” in blood types
may be helpful to know that
an individual with an AO
genotype has type A, and an
individual with BO has type B,
while an individual with OO has
blood type O
Dominant or Recessive
If
Dominant
an individual inherits even a
single copy of the allele
associated with Huntington’s
disease, the individual will
develop the disease.
Dominant or Recessive
Recessive
Brown-eyed
parents sometimes
have blue-eyed children. Is the
blue eyed allele dominant, or
recessive?
Definitions: Homozygous &
Heterozygous
Homozygous:
Homo- prefix meaning same
Refers to an organism with 2 identical copies
of an allele. Example: AA or aa
Heterozygous
Hetero- prefix meaning different
Refers to an organism with 2 different alleles
Example: Aa
A) homozygous dominant…
B) homozygous recessive…
C) heterozygous…?
AA
Homozygous dominant
A) homozygous dominant…
B) homozygous recessive…
C) heterozygous…?
Aa
Heterozygous
A) homozygous dominant…
B) homozygous recessive…
C) heterozygous…?
An
Heterozygous
individual is a carrier for
sickle cell disease
A) homozygous dominant…
B) homozygous recessive…
C) heterozygous…?
An
individual with O blood
type.
Homozygous recessive
Write the genotype:
Homozygous
 (use
dominant
‘A’ and ‘a’ to represent the alleles)
AA
Write the genotype:

An individual with blue eyes. Use ’B’ and ‘b’ to
represent the alleles
bb
Write the genotype:
Mary
has type A, blood type,
but her father had type O.
AO
Hardy-Weinberg Principle
stating that _______
allele
frequencies do not change
_____
unless there is a factor causing
change
Principle
Hardy-Weinberg Principle
Assumes:





Large population
No Migration
Random Mating
No Mutations
No Selection
Hardy-Weinberg Principle
Equations:
𝑝+𝑞 =1
Where
𝑝 is: frequency of the
dominant allele
Where
𝑞 is: frequency of the
recessive allele
Hardy-Weinberg Principle
Equations:
Where
𝑝
2
2
2
𝑝 + 2𝑝𝑞 + 𝑞 = 1
is: frequency of homozygous
dominant genotype in population
Where
𝑞2 is:
Where
2𝑝𝑞 is:
frequency of homozygous
recessive genotype & phenotype in population
genotype in population
frequency of heterozygous
Hardy-Weinberg Principle
Video
on how to solve HardyWeinberg problems
If
the frequency of the
dominant allele is .3
What
is the frequency of the
recessive allele?
Given:
𝑝 = .3
Equation:
𝑝+𝑞 =1
𝑞 =1−𝑝
𝑞 = 1 − .3
𝑞 = .7
If
the frequency of the
𝑝 = .3
dominant allele is .3 𝑞 = .7
What
percentage of the
population will be heterozygous
Equation:
for the trait?
𝑝2 + 2𝑝𝑞 + 𝑞2 = 1
Calculate 2pq
2𝑝𝑞 = 2 ∙ .3 ∙ (.7)
2𝑝𝑞 = .42
So, 42%
olve:
The frequency of the homozygous
recessive genotype is 0.09. In a
population of 1000, how many
would have the dominant
phenotype ? Find:
Given:
𝑞 = .09
𝑝 = .91
1000 ∗ (2𝑝𝑞 + 𝑝2 ) =
1000 ∗ (2 (.09)(.91) + (.91)2 ) =9938
Solve:
If the frequency of two alleles in
a gene pool is 90% A and 10% a,
what is the frequency of
individuals in the population
Find:
2𝑝𝑞 =
Given:
with
the
genotype
Aa?
2 .9 . 1) = .18
𝑝 = .9
𝑞 = .1
Solve:
In humans, Rh-positive individuals have the Rh antigen
on their red blood cells, while Rh-negative individuals do
not. If the Rh-positive phenotype is produced by a
dominant gene (A), and the Rh-negative phenotype is
due to its recessive allele (a), what is the frequency of
the Rh-positive allele if 84% of a population is Rhpositive?
Given:
Find:
2𝑝𝑞 + 𝑝2 = .84
𝑝2 + 2𝑝𝑞 + 𝑞2 = 1
𝑞2 = 1-(𝑝2 + 2𝑝𝑞)
𝑞2 = 1-.84
𝑞2 = .16
𝑞2 = .16
𝑞 = .4
𝑝=
𝑝=
𝑝+𝑞 =1
Linking HW to Genetic
Drift
Bozeman
Bio:
https://youtu.be/mjQ_y
N5znyk?t=63
Problem 1- first set of
Hardy-Weinberg Problems
Types of Natural Selection

Directional selection


Stabilizing selection


Individuals with intermediate phenotypes are the most fit
Disruptive selection


Individuals with one extreme of the range of variation have
higher fitness
Individuals with extreme phenotypes are the most fit
Sexual Selection
Directional Selection
Stabilizing Selection
Disruptive Selection
Sexual Selection
Any one of the other
three
Increases fitness often at
the cost of longevity
A) Directional
B) Stabilizing
C)Disruptive
Human
birth weight
What is a Species
Biological Species Concept: A
species is…
Members
of a population that can
interbreed,
producing viable and
fertile offspring
Prezygotic vs Postzygotic
Isolation
Bozeman Biology on
Speciation (skip
peri/parapatric- skip to
4:35)
Speciation
Allopatric
Sympatric