Transcript Evolution and Natural Selection

October 16, 2013
1. Please have these
Items on your desk.
AR
Book
Day 2
Agenda Science
Starters
Sheet
Science
fair forms
2- Science Starter: Mr. Parr music video on Evolution.
Write 5 new words that you do not know the meaning of,
from the music video.
http://www.youtube.com/watch?v=r5Y_ILQB-Kg
Guess what day it is ???????
Updating Your Notebook (ToC)
• Page 51 10/16 Environmental Science
(title page)
• Page 52 10/16 Adaptation “I can” goals
• Page 53 10/16 Adaptation Learning goals &
scales.
• Page 54 10/16 Bill Nye video notes-Evolution
• Page 55 10/16 Evolution &Natural Selection
Notes
Evolution and Natural Selection
• What are traits?
• What is DNA and how does is it affect species
traits?
What is Evolution?
• Evolution is the concept
that plants and animals
(species) existing today
came from preexisting
species and that species
change physically
through time.
Founders of Evolution
• Two founders of
evolution were Charles
Darwin and Alfred
Russell Wallace
▫ Charles Darwin is
credited for this theory of
evolution because he
provided massive
evidence for it in a book
he published. (Scott
Freeman, 2003, pg.495)
Darwin
Wallace
Darwin’s Theory
• Darwin published the theory in 1859 in a book
called On the Origin of Species by Means of
Natural Selection.
• He gathered evidence for his theory in the
Galapagos Islands on a voyage in the HMS
Beagle.
• Darwin collected mockingbirds from different
islands were distinct species, based on
differences in coloration, beak size and shape.
Similar mockingbird species on
different Galapagos islands
What does this all mean?
• Each finch were adapted to
particular ways of eating.
▫ Islands had different things
to eat.
▫ Birds with the more adapt
beak were able to survive.
• Originally there was only one
type of finch, but finches
adapted to their environment.
Evidence for Change through Time
• Fossils help support the theory
because rocks and fossils from
rocks underneath other rocks
are older than the fossils found
above them.
• Fossils show species that are
extinct.
▫ Darwin theorized that
extinct forms and living
forms were related.
▫ Transition forms are species
that are in between those of
older and younger species
Evidence for Evolution Continued…
• Development of species
• Many Species have gone
extinct.
• Fossil species frequently
resemble living species
found in the same area
• Earth’s environment is
always changing
• Genetic similarities in
DNA
What is Natural Selection?
• Organisms vary in traits (variations).
• Traits are passed on from parents to offspring.
▫ Example tall parents will have tall parents.
• Only some offspring will reproduce. Those that
don’t reproduce their genetic traits will not be
passed on
• The population that reproduces will most likely
have offspring that will resemble them.
Mutation, Harmful or Beneficial?
• Mutations can be harmful and
some can leave no effect.
• Mutations that harm an
organism will most likely lead
to it dying so it can’t
reproduce.
• Mutations can also give an
organism an advantage over
organisms of its same species.
• Organisms that have a
beneficial mutation will more
likely survive and be able to
reproduce.
Darwinian Fitness
• Ability of an individual to produce offspring
compared to other individuals in the same
population.
▫ Those that are able to adapt to an environment
will be able to reproduce
▫ Those that are dead will not be able to create their
own offspring.
▫ Courtship rituals and status amongst populations
Examples of Darwinian Fitness
• Male stickleback fish swim in a
stereotypical manner as they
court potential mates.
• Male bowerbirds build
elaborate towers of vegetation
to entice females.
• Female moths release
pheromones that attract males
from up to a mile away.
• Male African elephants use
low-frequency sounds to find
females who are sexually
receptive.
Misconceptions on Evolution
• Individuals do not change during the process of
evolution; the population changes
• Evolution does not favor any individuals, it
simply favors individuals that happen to be
better adapted to their environment.
• Not all traits are adaptive
References
• Scott Freeman, S. (2003). Biological science. (2
ed., pp. 494-512). Upper Saddle River, New
Jersey: Pearson Prentice Hall.