1. Unit 3 Evolution Chapters 7, 8, 9
Evolution
Chapters 7, 8, 9

2. Learning Goal
To become familiar with the ideas and concepts of adaptation and variation, as well as natural selection and artificial selection

3. Chapter 7 – Introducing Evolution
Section 7.1 ~ Adaptation and Variation

4. Introduction
Evolution can be defined as the way in which organisms changed because they had to adapt to the changing earth

5. 7.1 – Adaptation and Variation
Organisms constantly face environmental changes that limit their ability to survive
Severe weather, famine, and competition for food, space, and mates are challenges that not all organisms can survive
Those that live long enough and reproduce have the opportunity to pass along their genes

6. Adaptation and Variation
The diversity within species and the interactions of organisms with their environment help explain
How populations can change over time &
Why some survive, while others become extinct
Extinction – when a species has completely disappeared from Earth

7. Adaptations and Survival
Adaptation is a structure, behaviour, or physiological process that helps an organism survive and reproduce in a particular environment
There are many examples of adaptation found around the world

8. Examples of Adaptations
Structural Adaptation
Behavioural Adaptation
Physiological Adaptation
Include physical features like an animals shape
Colouring / structure to camouflage seen in insects, birds, etc.
Owl’s Needle sharp talons: Help them catch their prey more easily
Can be inherited or learnt and include tool use, language and swarming behaviour
Arboreal animals, for example, live in trees and nocturnal animals are active at night.
 Ability to make venom
Temperature regulation
Animal Hibernation
Allows organism's to survive in environments that would normally kill them
Bears, Squirrels, birds, etc.

9. Mimicry: Structural Adaptation
Many harmless species resemble a harmful species in colouring / structure
When this happens = Mimicry
Why do you think harmless species do this?
Complete the LAB on pg. 312 – Investigating Mimicry

10. Development of Adaptations
Adaptations are the result of gradual and accumulative changes that help an organism survive and reproduce
Often these changes occur at random due to changes (mutations) in an organism’s DNA

11. Development of Adaptations
Variations are structural, functional, of physiological differences between individuals
Not all variations become adaptations
Environmental conditions determine whether a variation in an individual has a (+) or (-) effect on the organism’s ability to survive and reproduce
Those with helpful variation survive and pass along this positively mutated DNA to their offspring

12. Development of Adaptations
Interactions with environments is important to adaptation and variation because environment's change continuously
Human activities also change and environment, like deforestation to build communities, etc.
So you see, a characteristic that may not give an organism an advantage at the present, may be useful later based on changes in the environment

13. Case Study: English Peppered Moth
Use pgs. 298 – 299 to learn about how the proportions of some inherited characteristics in a population change in response to changes in their environment, as seen with the English peppered moth

14. Variation within Species
Through sexual reproduction, parents pass on genes to their offspring
The number of possible genetic combinations offspring can inherit from their parents gives us huge variation as a population
For example – kittens! Are very different from one another, even in the same litter

15. Take Time!
Complete the given worksheet on characteristics of heredity and genetic variation

16. Mutations = Genetic Variation
Mutations = changes in genetic material (DNA)
Can take place spontaneously when DNA is copied before a cell divides
When there is a mutation in the DNA, a cell can have new characteristics, which can cause it to die, malfunction, or multiply more than it should (like cancer cells)
But not all mutations are bad, some can have no effect at all, or in fact be helpful to the organism

17. Mutations & Selective Advantage
With changes in an environment, a mutation that at one point may have had no effect or no benefit, could provide and advantage later on
A selective advantage – is the genetic advantage of one organism over its competition
Over time, selective advantage helps an organism survive in a changing environment and reproduce successfully

18. Gizmo Activity User name: AlexB617 | wind423

19. Rapid Reproduction & Selective Advantage
Some organisms, like bacteria, reproduce quickly, while others, like elephants, take longer
In populations that reproduce quickly, a new allele that resulted from a random mutation, may allow for selective advantage to benefit the newly reproduced organism vs. earlier organisms when the environment changes
With time, the gene that provided the selective advantage becomes more common in the population

20. Example: Antibiotic-Resistant Bacteria
Staphylococcus aureus is a type of bacteria that can have lasting effects on human health
They reproduce asexually and quickly (almost every 30 mins) via binary fission
This rapid reproduction helps adaptation to take place just as quickly – where only those that survive in an environment will reproduce
For humans, this constant adaptation of the bacteria make it difficult to treat, where some new species of the bacteria have alleles that make them resistant to antibiotics .. Making them “super bugs”

21. Section 7.2
Natural Selection &
Artificial Selection

22. Vocabulary
Natural Selection - is the process that happens when characteristics of a population change over many generations as organisms with heritable traits survive and reproduce, passing their traits to their offspring

23. Gizmo Activity AlexB617 | wind423

24. Selective Pressure
Abiotic (non-living) environmental conditions select certain characteristics in some individuals, and then select against different characteristics in other individuals
This allows for the environment to have selective pressure on a population
Selective pressure can also be affected by biotic (living) factors too, like predators / parasites

25. Natural Selection is Situational
Natural selection doesn’t anticipate changes in the environment – thus, it is situational ... “of the moment”
Example – a trait that at one time is useless, can become helpful in a different time / environment
It will always be the organisms that survived in an environment that produce offspring, thus the further generations reproduce, the more successful alleles will be inherited

26. Natural Selection is Situational
When discussing natural selection, words like “fitness” or “fit” … like survival of the fittest – tend to be used
Fitness – describes the contribution an individual makes to the gene pool of the next generation by producing offspring that will survive, live long, and reproduce

28. Artificial Selection
In the English Peppered Moth example, change occurred naturally in the population because of changes in the environment
But people have been artificially selecting organisms for particular traits for a1000 years
Recall from Unit 2: Genetics – Selective breeding … is a form of artificial selection

29. Artificial Selection
Selective breeding and artificial selection are a form of biotechnology, where:
Artificial Selection – the selective pressure exerted by humans on populations in order to improve or modify desired traits
Biotechnology – the use of technology and organisms to produce useful products

30. Artificial Selection
We see a huge impact on human survival based on the use of artificial selection
The food we eat is genetically modified (GMO) for desirable traits
For example, humans have places a gene from artic fish into tomatoes to keep them from freezing during transport

31. The Selection Processes
The key difference between Natural selection and Artificial selection is that:
In Natural Selection – it’s the environment that determines which organisms survive and reproduce in certain conditions
In Artificial Selection – it’s up to humans to determine which genes are favourable and would be inherited through generations

32. Artificial Selection- Pros / Cons
Some artificial selection methods like genetic engineering have been used to introduce a new gene into a domestic organism
But if 1 main goal of domestication is to produce organisms that are all similar – this reduces genetic diversity
While beneficial to manage, like a monoculture of corn in Alberta, that exists over acers of land
Can also put these organisms at risk of being affected by disease / pests because of the lack of diversity

33. GMO’s – Bill Nye Video

34. GNO’s – Research Assignment
After watching the video and reading about GMO’s from the textbook
Complete the following research project provided to you

35. “Is the use of genetically modified corn beneficial to feed our world or are they a disaster in disguise?”
Prepare an argumentation as:
A representatives of the world who intend on planting a genetically modified corn crop
Or as an environmentalists who oppose the sale of genetically modified seeds to countries based upon population growth and available land usage
Both sides of the argument must be carefully prepared with claims, data researched, and positions represented

36. Population (estimated) Available Land for Agriculture
Year
Population (estimated)
Available Land for Agriculture
1959
3 billion
12.16 acres per person
2006
6.68 billion
5.46 acres per person
2039
8-13 billion
2.81 acres per person
FACT! Arable land is being lost at the rate of 38,610 square miles per year and in 2039 there will only be 0.53 acres of arable land per person worldwide.

37. World Population / Time

38. With the world’s population approaching 8 billion, the amount of land required to feed this growing population is becoming scarcer.
Is the use of genetically modified corn beneficial to feed our world or could they be a disaster waiting to happen?
Use the table below as a guide to develop your claim to answer the question stated above.
You must support your claim with evidence that will be collected through online research.
Use your computer to collect evidence that supports or opposes the use of GMOs such as corn
You will also need to justify your claim with the use of the evidence that you have collected