Evolution-Lecture 1 - Important definitions and concepts

Question 1

Evolution was originally defined as what?

Answer 1

Descent with modfication

Question 2

Darwin based his theory of natural selection on two key observations. These were?

Answer 2

1) Overreproduction

2) Individual variation

Question 3

What does over-reproduction entail?

Answer 3

All species tend to produce excessive numbers. This leads to a struggle for existence.

Question 4

Why is individual variation important?

Answer 4

Variation exists among individuals in a population and, much of this variation is heritable.

Question 5

What was Darwin’s inference?

Answer 5

That natural selection is based on differential reproductive success.

Question 6

What is differential reproductive success?

Answer 6

Those individuals with traits best suited for the local environment leave more fertile offspring.

Question 7

What is the modern synthesis?

Answer 7

Fusion of genetics with evolutionary biology.

Question 8

What are the essentials of evolution via natural selection?

Answer 8

1) All organisms vary genetically within a population and, selection acts upon this variation.
2) Genetically based traits are passed on from one generation to the next. (i.e. traits must be heritable to be selected upon)
3. Organisms with traits that are favourable to their survival (and reproduction) live and pass on their genes to the next generation.
4. Evolution can happen in a few generations, but major changes (speciation) often takes long periods of time.

Question 9

What are some problems with teaching evolution?

Answer 9

• vernacular misconception (certain people believe its more a conjecture or a guess)
• religious issues
• people think they understand evolution
• misconceptions about evolution

Question 10

What is wrong with the misconception that “evolution is a theory about the origin of life”?

Answer 10

Evolution mainly deals with how life changed AFTER its origin and how life “branched and diversified”

Question 11

Evolution focuses on how life _______ and ________.

Answer 11

branched and diversified

Question 12

What is wrong with the misconception that organisms are always getting better?

Answer 12

Evolution does not have a particular target in mind, is is not about marching up a ladder of progress. Natural selection weeds out individuals that are unfit in a particular environment.

Question 13

What is wrong with the misconception that evolution started with Darwin.

Answer 13

The concept of evolution was around long before Charles Darwin.
Georges-Louis Leclerc, Comte de Buffon and Jean Baptiste Lamarck.

Question 14

What was the Comte de Buffon’s contribution to Evolution?

Answer 14

Life changes as a result of environmental influence - no clear mechanism.

Question 15

What was Jean Baptiste’s contribution to Evolution?

Answer 15

Change through use and disuse (Giraffe thing)

Question 16

What is wrong with the evolution = natural selection?

Answer 16

Evolution is actually not the same as natural selection. Evolution is the CONSEQUENCE of the mechanism of natural selection.

Question 17

What is wrong with the misconception that evolution means life changed by chance?

Answer 17

Chance mutations are the ultimate source of genetic variation. Natural selection, the process whereby some variants survive and others do not, is NOT random.

Question 18

What is wrong with the misconception that organisms “try” to adapt?

Answer 18

Natural selection leads to adaptation, but the process does not involve “trying”. Natural involves genetic variation and selection among variants present in a population.

Question 19

What is wrong with the misconception that NS gives organisms what they need?

Answer 19

NS has no intentions or senses; it cannot sense what a species needs. If a population happens to have the genetic variation that allows some individuals to survive better than others, then those individuals will leave behind more kids.

Question 20

What is wrong with the misconception that selection acts for the good of the species?

Answer 20

Natural selection happens to INDIVIDUALS, but what changes is populations.

Question 21

What type of behaviours are a challenge for evolution?

Answer 21

Altruistic behaviours

Question 22

What is selection?

Answer 22

Kin selection is the evolutionary strategy that favours the reproductive success of an organims’s relatives, even at a cost to the organism’s own survival and reproduction.

Question 23

What are implications of Evolution?

Answer 23

• unifying theme for all life-sciences
• medical applications (HIV, antibiotics)
• global warming issues (breeding times)
  Industrial applications (pesticides)

Question 24

What are the different misuses of evolution?

Answer 24

• division between evolution and religion
• evolution leads to immoral behaviour (animal like)
• oppression of people (only the fit should survive)
• social Darwinism (application of survival of the fittest to societal levels)
• Eugenics (sterilizing the unfit)