Transcript Power Point Presentation - Biology Concept Workshop

EVOLUTION
By: Geneva Winterink
Curriculum Expectations


C2.3 analyse, on the basis of research, and
report on the contributions of various scientists
to modern theories of evolution
C3.4 describe some evolutionary
mechanisms(e.g., natural selection, artificial
selection, sexual selection, genetic variation,
genetic drift, biotechnology), and explain
how they affect the evolutionary
development and extinction of various
species (e.g., Darwin’s finches, giraffes,
pandas)
Issues


Religion in schools
Pope John Paul II stated in 1996: “New
scientific knowledge has led us to realize that
the theory of evolution is no longer a mere
hypothesis. It is indeed remarkable that this
theory has been progressively accepted by
researchers, following a series of discoveries in
various fields of knowledge. The
convergence, neither sought nor fabricated,
of the results of work that was conducted
independently is in itself a significant
argument in favor of this theory” (Message to
the Pontifical Academy of Sciences on
Evolution, October 23, 1996).
Changing or Unchanging
 Evolution
– the process in which significant
changes in inheritable traits occur over
time
 Immutable – unchanged and
unchanging, believed to be the
characteristics of life forms
Darwin’s Voyage
In 1831 Darwin began a 5 year
voyage on the HMS Beagle
 Beginning in England and
surveying the coast of South
America
 Studied nature, fossils, collected
several species
 Discovered extinct species such as
the Glyptodon and Megatherium
(share same patterns of distribution
in South America as the modern
day armadillo and sloth)

Galopogos Islands
Darwin’s Finches
 Seed
and tool activity from hooks !
 http://people.rit.edu/rhrsbi/Galapagos
Pages/DarwinFinch.html
 Different beaks allowed finches to
consume different food
Voyage
 Asked
the question… Why
continents separated by large
distances would have entirely
different species occupying
similar niches?
 Did a species transport lands and
reproduce to create similar
species?
UINTATHERIUM
Rhinoceros
Sabre tooth tiger
Modern day tiger
Homologous Features
• Structures that share a common origin or
are similar anatomically but serve different
functions in modern species
Embryos
Analogous Features
 Structures
similar in function but not in
origin or anatomical structure
Vestigial Features
 Rudimentary
and non-functioning
structures that homologous to fully
functioning structures in closely related
species
 Come up with as many examples of
vestigial features and analogous
features relating to either humans,
plants or animals?
 Ex: beetles have wings under fused
covers, humans have muscles behind
their ears, some snakes and whales
have vestigial hips homologous to
mammals with hind limbs
Artificial Selection
 Darwin
began to study artificial selection
in plants and animal done by farmers
 Select offspring with desirable traits and
only allow those to reproduce
 Farmers increased oil content from 6% to
14% in corn kernels
 Artificial selection is done by human
choices
 What are some modern examples of
artificial selection we see today?
Natural Selection
 Just
as humans could chose the traits they
wanted, nature could choose the traits
based on the ability to survive
 Species are different in that their
characteristics will be varied from one
another; through random genetic
mutations
 Some mutations help the species survive
better: if this mutation is dominant it may
be passed on to the next generation
 The environment has an effect on the
survival
Darwin’s Natural Selection
 https://www.youtube.com/watch?v=0SCj
hI86grU
 https://www.youtube.com/watch?v=Me_
041nrRZk
Observations
 “Can
we doubt that individuals having
any advantage, however slight, over
others, would have the best chance of
surviving and procreating their kind?”
 Scenario : Propose an evolutionary scene
in which a lizard who once had a short
tongue would evolve into a species with a
long tongue. What happens over time for
this to occur?
1. Describe the
original crab
population in 4
a
2. Crabs
produce
many offspring
describe what
must be
happening to
the offspring
throughout
each stage?
3. What can
account for
the changes?
Observation 1
Individuals within a species vary
in many ways
Observation 2
Some of this variability can be
inherited
Observation 3
Every generation produces far
more offspring than can survive
and pass on their variations
Observation 4
Populations of species remain
stable in size
Inference 1
Members of the same species
compete with each other for
survival
Inference 2
Individuals with favourable
variations are more likely to
survive. Survival is not random
Inference 3
As these individuals contribute
proportionately more offspring
to succeeding generations, the
favourable variations will
become common (natural
selection)
Examples of Natural Selection
 Within
your group how many examples of
natural selection can you come up with?
 http://www.discovery.com/tvshows/curiosity/topics/10-examplesnatural-selection.htm
Evidence From the Past
 Fossils,
Fossils, Fossils
 At the end of the 15th century Leonardo
da Vinci began examining sea shell
remains in Tuscany mountains (hundreds
of km’s from the Sea)
FOSSIL FORMS
Impressions
 http://www.youtube.com/watch?v=3rkG
u0BItKM
Fossilization
1. Organism dies
2. Organism is buried and compressed under many layers of
sediment
3. Under high pressure deposits harden to form sedimentary
rock and the fossil remains become mineralized
4. Erosion or excavation of sedimentary rock exposes fossil
remains
Ice Baby
Intact Fossils
 Intact/preserved
– fossilized in amber or
ice (woolly mamoth)
Hard Body Parts
 Bones,
teeth, nails, skulls
Early Ideas About Evolution
 Activity
– Create an evolutionary timeline
on a Prezi
 Leonardo da Vinci, Baron Georges Cuvier,
James Hutton, Comte Georges Louis
Leclerc de Buffon, Erasmus Darwin/ Sir
Charles Lyell, Chevalier de Lamarck
 http://prezi.com/luzg8v0_f58d/edit/
Lamarck
Inherited
 Traits
that you are
born with and are
given to you
through genetics
and DNA
Acquired
 Traits that have
been adapted or
learned by an
individual.
 Can be acquired
from environmental
influences
 Can not be
inherited !
Misconceptions
 Genetic
drift is not evolution - Genetic drift
or allelic drift is the change in the
frequency of a gene variant (allele) in a
population due to random sampling. The
alleles in the offspring are a sample of
those in the parents, and chance has a
role in determining whether a given
individual survives and reproduces
 Adaptations are not acquired, they must
occur as a result of a mutation