Theme 3: Evolution

Question 1

True or false: All species are temporary

Answer 1

• This is true, extinction is as much a part of nature as is the origin of species

Question 2

What was Darwin’s definition of evolution?

Answer 2

• Evolution is descent with modification. Populations change over time

Question 3

What is the current definition of evolution?

Answer 3

• Evolution is a change in allele frequencies in a population over time

Question 4

What were George Cuvier’s contributions to the study of evolution?

Answer 4

• He was a leading and comparative anatomist and palaeontologist of his time
• Found that many species have gone extinct and that the number of species are declining
• Showed that large bones in USA belonged to extinct msatudon, not modern elephants

Question 5

What were Charles Lyell’s contributions to the study of evolution?

Answer 5

• Stated that landforms were not fixed, but changed slowly as a result of geological processes that can be observed today (i.e., not caused by biblical catastrophes)
• Earth was much older than the accepted age at the time since the landforms that existed must have formed over more than a few thousand years

Question 6

What were Jean-Baptiste Lamark’s contributions to the study of evolution?

Answer 6

• Beieved that species changed over time and he called it transmutation
• Lamarckism - acquired traits can be inherited, lost through disuse (epigenetics has somewhat supported this idea)

Question 7

What were Thomas Malthus’s contributions to the study of evolution?

Answer 7

• Human population can increase faster than food supply, leading to competition and survival of the fittest
• The idea of there being limited resources
• Individuals who can’t compete will be unable to produce offspring

Question 8

What were the three big ideas that can be taken from Darwin’s “The Origin of Species”?

Answer 8

• The idea that variation in traits such as size, colouration, etc., influence natural selection which leads to differences in fitness among individuals, and those who are able to produce the most offspring pass on their traits through inheritance
• The struggle for existence due to limited resources causes favorable variations to be preserved and passed on to the next generation while unfavorable ones tend to be destroyed

Question 9

What were Darwin’s 4 postulates?

Answer 9

1) Individuals within a species vary
2) Some variation is inherited
3) More offspring are produced than can survive and reproduce
4) Survival and reproduction is not random, but related to phenotypic variation

Question 10

True or false: Alfred Wallace copied his ideas from Darwin

Answer 10

• This is false
• Wallace came up with ideas similar to Darwin independantly, but it did spur Darwin to publish his own work on the subject

Question 11

In Darwin’s ideas, what is the function of natural selection in evolution?

Answer 11

• Natural selection is the main mechanism in biological evolution
• Natural selection could be considered the driving force of biological diversity in different environments

Question 12

What is the definition of endemic?

Answer 12

• Something that is native and restricted to a certain place
• Ex. The endemic finches of the galapegos islands will share different characteristics between their separate populations

Question 13

What’s adaptive radiation?

Answer 13

• A process in which organisms diversify rapidly from an ancestral species into many new forms
• Increases biological diversity

Question 14

True or false: Natural selection without heritability can occur, but evolution by natural selection cannot

Answer 14

• This is true, you cannot have a species evolve without the future generations inheriting the favoured traits

Question 15

What are vestigial structures?

Answer 15

• Useless body parts that must have functioned in ancestral organisms. Demonstrate that organisms do in fact change.
• Ex. the human appendix

Question 16

What are homologous structures?

Answer 16

• Organisms that appear similar between different species (i.e., they have homology) because they share a common ancestor
• Ex. the limbs of cats and humans have homology
• May or may not have the same structure but have completely different functions

Question 17

True or false: Selective breeding in various types of organisms was an idea that developed during the beginning of the 19th century.

Answer 17

• This is false
• Selective breeding in plants and animals has been around for thousands of years
• Selective breeding = artificial selection

Question 18

True or false: Individuals can evolve within their lifetime

Answer 18

• This is false, individuals cannot evolve within their lifetime

Question 19

What is the role of mutations in evolution?

Answer 19

• Mutations supply the raw material for natural selection to work with
• While mutations are a source of variation, they do not determine the path of evolution

Question 20

What’s the definition of generation time?

Answer 20

• The average difference in age between a parent and its offspring

Question 21

What are analogous structures?

Answer 21

• Physical structures that share similar functions between organisms but aren’t necessarily similar in shape
• Ex. The wings of bats vs. the wings of birds
• They evolve independantly (i.e., not from the same origin)