Darwin

Question 1

What is a Phylum?

Answer 1

The largest generally accepted groupings of animals with certain evolutionary traits (fundamental aspects of their biology in common and different to other groups)

Question 2

When did Charles Darwin publish his book ‘The Origin of Species’ and what was it focused on?

Answer 2

1859, it focused on the great diversity of organisms.

Question 3

What did Darwin note in his book?

Answer 3

That current species are descendants of ancestral species.

Question 4

What can Evolution be defined as by Darwin, and what can it be viewed as?

Answer 4

Descent with modification. Evolution can be views as both a pattern and process.

Question 5

Who is Linnaeus?

Answer 5

The founder of taxonomy.

Question 6

What did Cuvier advocate and speculate?

Answer 6

Catastrophism. He speculated that each boundary between strata represents a catastrophe.

Question 7

What is Lyell’s principle?

Answer 7

Uniformitarianism. It states that the mechanisms of change are constant over time.

Question 8

What did Lamarck hypothesize?

Answer 8

That species evolve through use and disuse of body parts and the inheritance of acquired characteristics.

Question 9

What did descent with modification by natural selection explain?

Answer 9

The adaptations of organisms and the unity and diversity of life.

Question 10

What were Darwin’s two ideas?

Answer 10

Descent with modification explains life’s unity and diversity.
Natural selection is a cause of adaptive evolution.

Question 11

What were Darwin’s four observations?

Answer 11

1 - Members of a population often vary greatly in their traits.
2 - Traits are inherited from parents to offspring.
3 - All species are capable of producing more offspring than the environment can support.
4 - Owing to lack of food or other resources, many of these offspring do not survive.

Question 12

What were Darwin’s two inferences?

Answer 12

1 - Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than any other individuals.
2 - This unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations.

Question 13

Darwin was influenced by Thomas Malthus, who noted what?

Answer 13

He noted the potential for human population to increase faster than its food supply and other resources.

Question 14

What process explains the match between organisms and their environment?

Answer 14

If some heritable traits are advantageous, these will accumulate in the population, and this will increase the frequency of individuals with adaptations.

Question 15

What are the key features of natural selection?

Answer 15

Individuals with certain heritable characteristics survive and reproduce at a higher rate than other individuals.
This increases the adaptation of organisms to their environment over time.

Question 16

What happens if an environment changes over time?

Answer 16

Natural selection may result in adaptation to these new conditions and this may give rise to a new species.

Question 17

NOTE - Individuals do NOT evolve; populations evolve over time.

Natural selection can only increase or decrease heritable traits in a population.

Adaptations vary with different environments.

Answer 17

Good day!

Question 18

Give two examples that provide evidence for natural selection.

Answer 18

The effect of differential predation on guppy populations.

The evolution of drug-resistant HIV.

Question 19

Explain the effect of differential predation on guppy populations.

Answer 19

Brightly coloured males are more attractive to females but are also more vulnerable to predation.
Guppy populations in pools with fewer predators had more brightly coloured males.
Bright coloured guppies were transferred into a pool with many predators and over time, the population became less brightly coloured.

When the opposite experiment was done, the drab coloured guppies became more brightly coloured once places into a pool with few predators.

Question 20

Why does the evolution of drug-resistant HIV provide evidence for natural selection?

Answer 20

The drugs used to combat HIV selects for viruses resistant to those drugs. HIV uses reverse transcriptase to make a DNA version of its own RNA genome. The drug 3TC is designed to interfere and cause errors in the manufacture of the HIV’s DNA.
However, some HIV viruses have a variation that allows them to produce DNA without errors. These have a greater reproductive success and they have therefore developed resistance to this 3TC drug.

Question 21

Does natural selection create new traits?

Answer 21

No, it edits or selects traits already present in the population.

Question 22

What determines whether traits are selected or not?

Answer 22

The local environment of that population.

Question 23

What does the Darwinian view of life predict about fossils?

Answer 23

That evolutionary transitions should leave signs in the fossil record.

Question 24

What is Homology?

Answer 24

Similarity resulting from common ancestry.

Question 25

What are Homologous structures?

Answer 25

Anatomical resemblances that represent variations on a structural theme present in a common ancestor.
For example, the arm bones of a human, cat, whale and bat. They all contain a humerus, radius, ulna etc.

Question 26

What is comparative embryology?

Answer 26

It reveals anatomical homologies not visible in adult organisms.
Such as the Pharyngeal pouches, which both a human embryo and a chick embryo has.

Question 27

What are vestigial structures?

Answer 27

They are remnants of features that served important functions in the organism’s ancestors.

Question 28

What are examples of homologies at the molecular level?

Answer 28

Genes shared among organisms inherited from a common ancestor.

Question 29

What is biogeography?

Answer 29

The geographic distribution of species.

Question 30

What are endemic species?

Answer 30

Species that are often closely related to species on the nearest mainland or island.t