Evolution - Ch 22 - Evolution by Natural Selection

Question 1

What are the two parts of a scientific theory? (What do each part mean?)

Answer 1

• pattern: a statement summarizing many observations of the natural world
• process: a mechanism that produces this pattern

Question 2

What are the 5 key attributes of life? (not tested probably)

Answer 2

• obtain and use energy
• made up of cells
• process info
• reproduce
• evolve through time

Question 3

What is typological thinking?

Answer 3

species are immutable (unchangeable), and variation in individuals should be ignored

Question 4

What type of thinking was associated with Plato?

Answer 4

typological thinking

Question 5

What two ideas were associated with Aristotle?

Answer 5

• typological thinking

- scale of nature/Great Chain of Being

Question 6

What two ideas were associated with Lamarck?

Answer 6

• species change through time
• scale of nature/Great Chain of Being

[An individual’s phenotype changes as they respond the challenges in the environment, and they pass these modifications onto their offspring. Organisms climb the scale of nature over time.]

Question 7

What type of thinking did Darwin partake in?

Answer 7

-population thinking

Question 8

What is population thinking?

Answer 8

emphasizes the variation that exists among individuals in a population

Question 9

What is the scale of nature?

Answer 9

species are organized based on size and complexity; ex. God then humans at top, rocks at the bottom

Question 10

How does evolution by natural selection work?

Answer 10

(1) heritable variations that exist within a population

(2) leads to differential reproductive success

Question 11

The theory of evolution predicts what two patterns?

Answer 11

• species change through time

- species are related through common ancestry

Question 12

What is fitness?

Answer 12

the measure of how many viable offspring an individual can successfully reproduce, compared to others in the population

Question 13

What evidence supports that species change through time?

Answer 13

• Life on Earth is old (fossil record)
• Law of Succession
• transitional features
• vestigial traits
• variance in populations today and this variance can be observed changing

Question 14

What evidence supports that species are related by common ancestry?

Answer 14

-similar species are found living in the same geographical area
-homologous traits are common
(genetic, developmental, and structural)
-speciation seen today

Question 15

What is an adaptation?

Answer 15

a heritable trait that ameliorates the fitness of an individual in a particular environment (relative to those without this trait)

Question 16

What is an acclimatization?

Answer 16

changes in an individual’s phenotype in response to environmental changes

Question 17

What is internal consistency?

Answer 17

data from many different, independent sources agreeing on predictions made in a theory

Question 18

What is homology, and its three levels?

Answer 18

likeness between species due to common ancestry:

• genetic: similarity in genetic sequences
• developmental: similarities in embryo structures and processes
• structural: similarities in adult structures

Question 19

What is radiometric dating?

Answer 19

observing decay rates of parent -> daughter atoms and their ratios in rocks to give absolute age of fossils

Question 20

What are transitional features?

Answer 20

a trait that seems to be in the middle of change between an older fossil and a younger species

Question 21

What is a vestigial trait?

Answer 21

common structures in extant species that have reduced or no purpose anymore, but are functional in closely related species

Question 22

What are Darwin’s four postulates? Does evolution happen if and only if all four are true?

Answer 22

1. Variance of traits in populations exist
2. These traits are heritable
3. More offspring are born than can survive
4. Certain individuals survive to reproduce more than others

Yes.

Question 23

Is evolution progressive, or goal-orientated?

Answer 23

no

Question 24

Do organisms become perfected with evolution?

Answer 24

no

Question 25

What is a fitness tradeoff?

Answer 25

a compromise between two traits that cannot be optimized at the same time

Question 26

In what three ways are traits limited?

Answer 26

genetic, historical, and environmental constraints

Question 27

What is genetic correlation?

Answer 27

a type of evolutionary constraint where selection in one trait can cause changes in another as well (pleiotropy)

Question 28

How does history constrain traits?

Answer 28

all traits have evolved from previously existing traits, so they depend on past traits

Question 29

How does the environment constrain traits?

Answer 29

the environment, including abiota and biota, is constantly changing over time and over space