BIOLOGY: Topic 2

Question 1

Lamarkian theory of evolution proposes:

Answer 1

New, more complex species originated from older and less complex ones. He incorrectly proposed tat this occurred due to the inheritance of acquired characteristics

Question 2

How long did the voyage of ‘The Beagle’ last?

Answer 2

5 years, from 1831 to 1836

Question 3

How many continents did The Beagle visit?

Answer 3

3 continents, including various islands.

Question 4

Define the term ‘Fauna’.

Answer 4

All the animal life that is present in a region at a certain time

Question 5

Define the term ‘flora’.

Answer 5

All the plant life that is present in a region at a certain time.

Question 6

What are examples of the inconsistencies Darwin observed with creationism?

Answer 6

• Species on different islands in similar habitats were distinct
• Species on islands were closely allied to forms on the nearby continents
• The fauna and flora of Africa, Australia, S. America and Europe were different even in regions with very similar habitats.
• Fossil mammals in S. America that no longer exist were similar to present day species.

Question 7

What were Darwins’ two main insights?

Answer 7

• Descent with modification
• Natural selection

Question 8

What is descent with modification?

Answer 8

All species have descended, with modifications, from one or a few common ancestors. (Species don’t pop out of nowhere, they evolve from pre-existing species)

Question 9

Explain the relationship between natural selection and evolution.

Answer 9

Natural selection is the mechanism underlying much of evolution. It explains how the characteristics of organisms change over time and it explains the remarkable fit of an organism to its respective environment.

Question 10

Give three definitions of evolution:

Answer 10

Darwins: A change in traits in a population over time

More modern: A change in heritable characteristics of a population over time.

Most precise: A change in allele frequency of a population over time.

Question 11

What is the main factor that determines natural selection?

Answer 11

The limitation of resources in a population causes individual members of that population to compete, whether they know it or not, over those limited resources. The individuals that win the resources will get a chance to reproduce more often, increasing the frequency of their heritable traits to the next population

Question 12

So what are the three conditions for natural selection to occur?

Answer 12

1) Individuals must vary in a trait
2) The trait is associated to reproductive success
3) The trait is heritable

Question 13

Define fitness

Answer 13

Fitness is a measure of the capability of an individual to contribute to the next generation

Question 14

How are artificial selection and natural selection similar?

Answer 14

Artificial selection is the passing down of heritable traits to offspring to produce a more ‘desirable’ phenotype.

Question 15

Define ‘Batesian mimicry’

Answer 15

Batesian mimicry is a defense mechanism in which a palatable species physically resembles an unpalatable species to gain protection.

Question 16

True or False:

Natural selection is goal driven and progressive

Answer 16

False.

Natural selection makes organisms ‘better’ only in the sense of improving fit to their current environment.