Evolution by Natural Selection : Biology

Question 1

Evolution

Answer 1

The change in allele frequencies in a population from generation to generation.

Question 2

Does evolution always refer to one species evolving into another species?

Answer 2

Evolution DOES NOT always lead to more advanced species.

Question 3

How does evolution works at the population level?

Answer 3

Some individuals in population are better able to survive and many of these individuals mate resulting in offspring with greater survival and advantageous traits.

Question 4

Why evolution is considered a fact of nature?

Answer 4

There is a wealth of evidence that supports it and there are no other competing theories or hypotheses that can explain how populations (and species) change over time.

Question 5

How does evolution shape biodiversity?

Answer 5

Organisms will continue to adapt. The diversity of environment that exists promote a diversity of organisms which adapt to them.

Question 6

How does the USA view evolution relative to other westernized countries. How does this pattern of acceptance varying within our country?

Answer 6

The US is one of the few where controversy around the topic still exists. It appears 50/50 on the chart. Coming in at less than 50 is Mississippi.

Question 7

What are the 4 categories of Empirical Evidence for Evolution?

Answer 7

Either the 3 levels of homology or anatomy, molecular biology, biogeography, fossils, & direct observation (steps to conclusion)

Question 8

What are the 3 levels of homology?

Answer 8

1. Developmental Homology
2. Structural Homology
3. Genetic Homology

Question 9

Developmental Homology = embryo, eyes

Answer 9

Similarity in embryonic form or developmental processes due to inheritance from a common ancestor. (The early embryonic stages of a human, chick and cat show strong resemblance/developmental processes)

Question 10

Structural Homology = bones, brains

Answer 10

Similarity in adult organismal structures due to inheritance from a common ancestor. Even though the function varies, all vertebrate limbs are modifications of the same number. (Between humans, horses, birds, bats and seals; along with brains of humans, fish, birds, 98% chimps, and 90% cats.)

Question 11

Genetic Homology = DNA

Answer 11

Similarity in DNA, RNA, or amino acid sequences due to inheritance from a common ancestor. (A human and fruit fly amino acid sequence is very similar. 99.7% Neanderthal (old human) 98% Chimp 92% Mouse)

Question 12

Why are there biases in the fossil record? Know processes that lead to this bias.

Answer 12

• fossils often fragmented
• bones, teeth and shells more abundant than tissue, organs
• Paleontologists tend to focus on best fossil-bearing rocks already discovered
• an organism has to die in right place at right time under good condition, well preserved

Question 13

Endemic Species

Answer 13

Species specific to particular location, found nowhere else. Often higher risk of extinction, unique evolutionary histories.

Question 14

How does endemic species help us understand relatedness?

Answer 14

Geography better predictor of relatedness than habitat. (Pangea)

Question 15

When and where did Darwin’s Beagle voyage take place?

Answer 15

• In 1831-1836
• His mission was to explore the South America coastline because Europeans didn’t know much about it. During his voyage he spent more time studying the animals and specimens on shore, especially the Galapagos.
• Southern Australia, South Africa, West of Europe, East, South and West of South America
• he travelled to these places again with Russel Wallace

Question 16

What did Darwin find at the Galapagos?

Answer 16

Tortoises:
- In the highlands, domed shell
- In the lowlands, saddle-shaped shell
Finches:
- large, ground finch, heavy beak, eat seeds
- Warbler finch, thin beak, eat insects
- Cactus finch, curved beak, split tongue, eat cactus flower nectar

Question 17

What is the name and publication date of his most famous book? And his two proposed hypothesis?

Answer 17

A new era of biology began on 24 November 1859 when Charles Darwin published On the Origin of Species. Organisms have descended with modification from common ancestors = evolution and cause of descent with modification is natural selection.

Question 18

What other influential scientists and the role they played in contributing to Darwin’s theory of evolution by natural selection?

Answer 18

Thomas Paine, Mendel, Alfred Russel Wallace (voyage)

Question 19

The order in which natural selection takes place according to Darwin. !

Answer 19

1. Individuals in a population vary in their heritable characteristics. / Organisms produce more offspring than the environment can support.
2. Individuals that are well suited to their environment tend to leave more offspring than other individuals.
3. Over time, favorable traits accumulate in the population.

Question 20

What are the 3 words that best define evolution by natural selection?

Answer 20

‘Differential Reproductive Success’

Question 21

Postulates of natural selection. !

Answer 21

1 Individuals in a pop are variable in phenotype
2. Some phenotype differences are heritable
3. Species produce more offspring than environment can support (competition)
4. B/c individuals are unique, some have attributes that allow them to exploit resources more efficiently than others (favorable adaptations)
5. These individuals more likely to survive and leave offspring (differential reproductive success)
6. The frequency of traits that confer an advantage will gradually increase over generations

Question 22

Why does selection act on the individual, but it is the population that evolves?

Answer 22

Individuals may mutate, but natural selection acts by shifting the characteristics of the population as a whole.

Question 23

How are peppered moths, camouflage, mimicry, and lactose tolerance are all examples of natural
selection?

Answer 23

• Polluting smog and soot from fossil fuels, the pepper moth adapted to match the tree due to it changing color from being covered in soot. So, the black moths were eaten the most because they stood out.
• Mimicry occurs from the Viceroy butterfly resembling the Monarch butterfly which is poisonous result in less eating of Viceroy.
• When born enzyme called lactase that the body produces to break down lactose.
  By default everyone should be lactose intolerant, but someone’s didn’t shut off so they had the ability to ingest milk so now more people can tolerate it. Recessive mutation allows lactase production to continue on into adulthood.

Question 24

Co-evolutionary race. How can natural selection cause this?

Answer 24

Predators have evolved specialized weapons of attack and prey have evolved specialized defenses. Individuals with the best survival traits face each other in the end.

Question 25

Artificial Selection

Answer 25

Humans choose which individuals to reproduce, based on desired traits. Does not always enhance survival of a species. It is faster, goal-directed and controlled by humans.
First domesticated livestock and dogs 12,000+ years. For flexible diet, fast growth rate, breeding, calm, sociality.

Question 26

Natural Selection (human terms)

Answer 26

Process that occurs naturally without human interference. Increases species’ chance for survival.