Darwin Unit Test

Question 1

Evolution

Answer 1

Changes to an organism overtime through the process of Natural Selection

Question 2

Charles Darwin

Answer 2

The naturalist scientist who created the Theory of Evolution and the many ideas surrounding it.

Question 3

Beliefs about the Earth (Lyell)

Answer 3

Lyell discovered, contrary to belief at the time, the Earth was ancient. Also, the factors which changed Earth’s geography in the past affect Earth today.

Question 3

Darwin’s journey and observations (understand examples)

Galapagos

Answer 3

Finches: Darwin discovered the finches looked eerily similar to mockingbirds on mainland South America. Upon further thought, Darwin developed the idea of Natural Selection, as he used biogeography to discover the finches evolved from the mockingbirds due to geographic isolation, and the finches all varied amongst each other; for example, they all bore adaptations to help them survive in their ‘own’ environments.

Question 4

Lamarck and his hypothesis (acquired traits)

Answer 4

Lamarck hypothesized that organisms could change overtime by selectively using a part(s) of the body, and these acquired traits could be passed on to offspring.

Question 5

Malthus and population growth

Answer 5

Malthus reasoned that if the human population kept on reproducing, there would not be any resources left. This led Darwin to realize there are factors which limit population growth.

Question 6

Alfred Russell Wallace and his impact

Answer 6

The scientist who confirmed the theories Darwin had created, and pushed Darwin to publish his research.

Question 7

Artificial selection (give examples)

Answer 7

Selective breeding which humans use in plants and animals to bring about a desirable trait(s) to reproduce.

• Example: Farmers breed plants with desirable traits, such as bigger fruit, drought resistance, etc., to create offspring with these traits.
• Example: Animal breeders can breed animals with desirable traits, such as two dogs to create a new breed, to create offspring with these traits.

Question 8

Darwin’s Theory of Evolution by Natural Selection – explain it!

Answer 8

The Theory of Evolution explains how all organisms descended from a common ancestor, and how organisms change over time due to Natural Selection. Natural Selection is caused by genetic mutations, which are caused by shifts in the environment, becoming adaptations; that benefit the organisms in its environment. This causes genetic variation among all organisms, and the better suited an adaptation is to its environment, the higher fitness the organism has.

Question 9

Descent with Modification

Answer 9

Traits are which are passed down through generations sometimes change due to DNA mutations from Natural Selection.
- Speciation happens as a result of this process.

Question 10

Fossils

Answer 10

Remains that show organisms which once existed.

Question 11

Natural Selection

Answer 11

The process which drives evolution, as organisims with better adaptations suited to their environment are more likely to survive and reproduce.

Question 12

Darwin’s journey and observations (understand examples)

South America

Answer 12

Fossils: Darwin discovered fossils which looked similar to organsisms living during his time. This led Darwin to develop the idea of a common ancestor from which organisms derive from, and the idea of Descent with Modification. Organisms, from fossils to their modern-day counter parts, have changed overtime from their ancestors—determined through comparative anatomy—giving rise to variation—a result of Descent w/ Modification.

Question 13

Evidence of evolution?

Answer 13

Biogeography, Comparative Anatomy, Fossils, Embryology, and Molecular evidence

Question 14

Biogeography

Answer 14

The study of where organisms lived today, and where their ancestors lived in the past.

• Organisms evolve to have similar traits to each other due to their environment
• Organisms vary locally and globally

Question 15

Comparative Anatomy

Answer 15

Comparing structures of organisms against each other to check for a common ancestor.

• Homologous, Analogous, Vestigial Structures

Question 16

Molecular evidence (DNA and protein sequences)

Answer 16

Descent of an species can be traced back to a common ancestor using genetic similarities and differences.

• Check for similar DNA sequences for a trait (less variations means closely related)
• Amino acid sequences for a protein (less variations means closely related)

Question 16

Embryology

Answer 16

The study and development of embryos, which are checked against each other (by shape, features, etc.) to determine a common ancestor.

Question 17

Types of natural selection

Answer 17

Directional Selection, Stabilizing Selection, Disruptive Selection

Question 17

Directional Selection

Answer 17

When individuals at one end of the curve have higher fitness than those at the middle or end.

• Example: Finches with larger beaks are more fit than finches with smaller beaks, as the latter may not be able to eat the thicker-husked seeds of their environment.

Question 18

Stabilizing Selection

Answer 18

When individuals on both ends of the circle have lower fitness than individuals in the middle.

• Example: Babies that are either too small or big are less fit than babies who are in between such sizes because the latter has a better chance of survival in the womb.

Question 19

Disruptive Selection

Answer 19

When individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle.

• Example: In the coho salmon population, the small and large males are more fit than the medium-sized males. The latter cannot fight for a female, as the large salmon does, nor can it sneak through and mate with a female, as a small salmon can, leaving the medium-sized salmon disadvantaged.

Question 20

Speciation – define term

Answer 20

The creation of new species.

• Arises from Reproductive Isolation

Question 21

Explain the evolution of Darwin’s Finches

Answer 21

All of the finches on the Galapagos Islands have common ancestors to mainland, South American species. However, all finches on the Galapagos evolved adaptations to have bigger beak sizes than their South American counterparts

Question 22

Coevolution

Answer 22

Two organisms evolve together as a result of each other.

• Example: Lynx have to develop better eyesight to see the white snow rabbits, which deeply blend into the snow. But, the snow rabbits have to develop an adaptation to blend in better due to the lynx developing better eyesight. Thus, the cycle repeats ↺.

Question 22

Explain how antibiotic resistance and pesticide resistance are examples of natural selection:

Answer 22

Antibiotic resistance is natural selection because it can cause bacteria to develop an adaptation (genetic mutation) against the antibiotic, to survive, which is spread to the offspring. This causes it to flourish.

Pesticide resistance is natural selection because it causes plants (such as weeds) to develop an adaptation (genetic mutation) against the pesticide, to survive, which is spread to the offspring. This causes it to flourish.

Question 23

Divergent Evolution vs. Convergent Evolution

Answer 23

Divergent evolution is where two new species are created from a common ancestor.

Convergent evolution is where organisms who have similar traits have no common ancestor whatsoever.

Question 24

Reproductive Isolation

Answer 24

When members of two populations cannot interbreed to produce fertile offspring.
- Leads to speciation