Chapter 4

Question 1

Coevolution

Answer 1

the joint evolution of two or more systems that interact with each other.

Question 2

Microevolution

Answer 2

variation within a species, allows species to adapt

Question 3

Speciation

Answer 3

Long-term microevolution due to population isolation, creation of sister species

Question 4

Microbial evolution

Answer 4

viruses, bacteria and single-celled organisms, same species/large population

Question 5

Macroevolution

Answer 5

species changing form

Question 6

Chemical Evolution

Answer 6

origin of life; Abiogenesis, life from chemical process alone

Question 7

Divergent evolution

Answer 7

Divergent Evolution: newly developed species becoming different over time (from a common ancestor)

Question 8

Convergent Evolution

Answer 8

the evolutions of two different groups of organisms so that they come to closely resemble one another. (NOT from a common ancestor)

Question 9

Adaptation

Answer 9

is a physical feature, behaviour, or physiological process that helps an organism survive and reproduce in a particular environment.

Question 10

Physical Adaptation

Answer 10

structural differences (sharp talons, large ears for heat loss)

Question 11

Behavioural Adaptation

Answer 11

differences in how an organism acts (hibernation, mating dance)

Question 12

Physiological adaptation

Answer 12

refers to the inner workings of an organism (plant toxins, blood clotting mechanism)

Question 13

Variation

Answer 13

is a visible o invisible difference that helps an individual or population to survive

Question 14

Biological species

Answer 14

is a group of reproductively compatible populations

• Through sexual reproduction, hereditary information is passed from parents to their offspring
• This allows for genetic variation

Question 15

Mutations

Answer 15

are changes in the genetic material (DNA) of an organism

• Mutations cause variations among individuals in a population.
• A mutation may provide an individual with an advantage or a disadvantage, or neither (neutral).

Question 16

How do mutations happen?

Answer 16

• errors made during DNA replication
• a physical or chemical agent (mutagen) damages the physical structure of DNA

Question 17

Beneficial Mutation

Answer 17

can provide a selective advantage for an organism

Ex.
- Houseflies becoming resistant to DDT allowing these insects to survive after being exposed to the insecticide

• Certain types of bacteria become resistant to antibiotics

Question 18

Natural Selection

Answer 18

is the process by which a population of organisms changes because individuals with certain traits can better survive the local environmental conditions (selection pressures) and pass on these traits to their offspring

Question 19

Buffon

Answer 19

• Challenged the accepted idea (for over 2000 years) that life forms are unchanging and perfect
• noted similarities between humans and apes - suggested that they could have a common ancestor but did not have a mechanism for how changes occurred
• suggested that the earth was older than 6000 years old

Question 20

Cuvier

Answer 20

• developed the science of Paleontology (study of ancient life through fossils)
• found unique organisms in each rock layer
• lower layers had older layers and organisms very different than modern ones
• new species appeared in layers and others disappeared (extinct)
• proposed natural events - (like floods, volcanic eruptions, etc) shaped the Earth and explained extinctions (Catastrophism)

Question 21

Lyell

Answer 21

• rejected Cuvier’s ideas
• suggested that the earth was slowly and continuously changing (not due to catastrophes)
• “slow changes could therefore
  result in big changes (inspired
  Darwin)”

Question 22

Lamarck

Answer 22

• observed species changing over time in the fossil record, increasing in complexity
• he suggested species changed based on the use or disuse of a feature
• believed that characteristics acquired through an organism’s lifetime would be passed onto the next generation (inheritance of acquired characteristics)

Question 23

Malthus

Answer 23

• noted that populations produce more offspring than can survive
• Darwin read Malthus and realized that this premise meant members of a population must compete to survive

Question 24

Darwin and Wallace

Answer 24

• both traveled and collected specimens
• reached similar conclusions that populations changed over time
• beneficial traits are more likely to allow an organism to survive and therefore pass on these traits
• competition for limited resources among individuals of the same species would select for individuals with favorable traits (increasing chances of surviving to reproduce)
• co-developed the theory of evolution by natural selection

Question 25

Burgess Shale

Answer 25

Fossil bed of the soft body tissues (very rare) of ancient sea creatures preserved from the Cambrian Explosion - explosion of biodiversity located in Yoho National Park (near Field, BC)

Question 26

Evidence provided by Fossils

Answer 26

1. Fossils in younger rock are similar to today’s species. 2. Fossils are in chronological order (older layers have older fossils) 3. Not all organisms are found in the fossil record at the same time 4. Fossils can't tell us everything 5. Fossils are very rare 6. The Fossil record is like a big jigsaw puzzle, with most of the pieces missing

Question 27

Transitional Fossils

Answer 27

New discoveries of fossils, help fill in the gaps in the fossil record.

Question 28

What is Biogeography?

Answer 28

the study of the geographical distribution of organisms, provides information about how and when species may have evolved.

Question 29

Biogeography

Answer 29

1. geographically close environments are most likely to contain related organisms 2. animals on islands are similar to animals on the closet continent 3. fossils of similar species are found on coastlines of neighbouring continents 4. closely related species are almost never found in exactly the same location/habitat

Question 30

Homologous structures

Answer 30

have similar structural elements and origin but may have a different function. (homo means same; used as evidence for same ancestor)

Question 31

Analogous structures

Answer 31

perform similar functions, even though the organisms do not have a common evolutionary origin.

Question 32

Embryology

Answer 32

Closely related organisms go through similar stages in their embryonic development

Question 33

How species form?

Answer 33

- A species consists of a reproductively compatible population.

Question 34

What are 2 ways species form?

Answer 34

Transformation or divergence

Question 35

Transformation

Answer 35

- new species may result from accumulated changes in the population over a long period of time - A new species gradually develops as a result of mutation and adaptation to changing environmental conditions, and the old species is gradually replaced.

Question 36

Divergence

Answer 36

one or more species arises from one parent which continues to exist

Question 37

Geographical Barriers

Answer 37

mountains, rivers or lava flows that physically separate populations from interbreeding

Question 38

Biological Barriers

Answer 38

behaviors like bird calls, frog mating calls or pheromones that prevent populations from interbreeding

Question 39

Reproductive Isolation

Answer 39

ex. Cichlids in Lake Victoria, Africa

Question 40

Adaptive radiation

Answer 40

is the diversification of a common ancestral species into a variety of species, all of which are differently adapted

Question 41

Two models scientists proposed for the pace of evolution

Answer 41

Gradualism and Punctuated equilibrium

Question 42

Gradualism

Answer 42

slow, steady, linear change over time

Question 43

Punctuated Equilibrium

Answer 43

long periods of equilibrium interrupted by periods of speciation

Question 44

Four Main Points of Natural Selection

Answer 44

1. Life forms have developed from ancestral species 2. All living things are related to one another by varying degrees through common descent 3. All living things on Earth have a common origin(share a common ancestor)