and Variation SBI3U1 Introduction to Evolution Birds are a diverse group of animals They vary in beak colour amp nutrition depending on their environment ADAPTATION Adaptation ID: 285363
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Slide1
7.1-Adaptation and Variation
SBI3U1Slide2
Introduction to Evolution
Birds are a diverse group of animals.
They vary in
beak
,
colour
&
nutrition
depending on their environment Slide3
ADAPTATION
Adaptation:
a structure, behaviour or physiological process that helps an organism survive and reproduce in a particular environment.
The stick insect is able to survive b/c it blends in with the tree (camouflage)
This owl has a specific adaptation of fluffy wings that do not make a lot of noiseSlide4
“Survival of the
Fittest”
Challenges that limit survival:
Severe weather
FamineCompetition (food, space, and mates)Disease If you can
“survive”
to reproduce you pass on the
“fittest”
genes
Extinct: when a species disappears completely from EarthSlide5
3 Main Types of Adaptation:
Structural Adaptation
:
physical features of an organism
E.g. beak on a bird, ability to camouflage, mimicry
Mimicry-
Harmless
species physically resemble a harmful species. Predators avoid the harmless species as much as they do the harmful one
.Slide6
3 Main Types of Adaptation
Behavioural Adaptation:
things organisms do to survive.
E.g. bird calls or migrationSlide7
3 Main Types of Adaptation
Physiological Adaptation
:
changes or chemical reactions that occur within an organism.
E.g. HibernationAllows organisms to survive by slowing down metabolism and preserving their energySlide8
Check your Understanding….
Which of the following is a physiological adaptation?
Bees are attracted to white flowers
Chipmunks have stripes
Monarch butterflies taste bad. Slide9
Check your Understanding….
Which of the following is camouflage?
Peacocks have brightly coloured tails
Chipmunks have stripes
Canada geese fly south for the winterSlide10
Development of Adaptations
How do adaptations develop??
gradual, accumulative changes that help an organism survive and reproduce.
c
hanges
are the result of random, heritable mutations in DNA that accumulate over generations.
Variations
:
structural
, functional, or physiological differences between
individualsSlide11
Development of Adaptations Cont’d
Environmental conditions determine if variation is (+), (-), or neutral
(+) = survival
Pass on to offspring and increase the trait in the
population*Note: not all variations become adaptationsSlide12
Example:Slide13
Case Study:
The English Peppered Moth
3 colour
variations of moths:
Greyish-white flecked with black dotsBlackIntermediate colour
Mid 1800’s black moths were rare in Manchester
50 years later,
95% of moths were black
in Manchester, but less frequent in rural areas
What caused the change?Slide14
The English Peppered Moth
Explanation
In the mid 1800’s light coloured moths were camouflaged in the trees
50 years later, after the Industrial revolution, pollution/soot from factories caused darker
trees
Therefore, dark
coloured moths were then
camouflaged and light moths were unable to survive.
The proportion of flecked and black moths in this population of peppered moths changed in response to changes in
the environment.
What do you think happened when England enacted a clean-air legislation in the 1950s?Slide15
Variation Within Species
-
Variation
-
created
by the different combinations
alleles that are inherited
from
parents
.
-
The
original source of all those different alleles is
mutation
.
-Recall:
mutation
= a
permanent change in the genetic material of an organism and is the only source of new genetic variation.
UNIT 3
Chapter 7: Introducing Evolution
Section 7.1
The kittens in this litter have different fur colour and patterns, partly because each
kitten inherited a different combination of alleles from its parents.Slide16
Variations Within Humans
Humans have lot’s of variation
due to random combinations of alleles from parents.
Different combinations of alleles contribute to different phenotypes. Slide17
What do you think…
In humans, would a mutation be more harmful in a somatic cell or a gamete?
Why?Slide18
Mutations and Selective Advantage
Selective advantage
:
a genetic advantage that improves an organisms’ chance of survival, usually in a changing environment.
Example: Antibiotic ResistanceBacteria reproduce very quicklyA mutation that allows it survive environmental changes (such as introduction of antibiotic) will survive to pass on its mutation to future generationsSlide19
A selective advantage …
Is obvious at birth
Allows an individual to survive in environmental conditions
Is usually a new genetic mutationSlide20
Videos: Antibacterial Resistance
https://www.youtube.com/watch?v=7Q2C0OEvDq0
https://www.youtube.com/watch?v=zjR6L38yReE
Slide21
Video Clips
Mimic Octupus: https://www.youtube.com/watch?v=t-LTWFnGmeg
25 Incredible Camouflaged Animals:
https://www.youtube.com/watch?v=XpdoDBYuHIA
Ultimate Wildlife (long): https://www.youtube.com/watch?v=D1kiCaoIq2M
Slide22
Homework:
Read and make notes 7.1Complete pg 299 Q#1-3,
5,6
Pg.
304 Q# 2-4