Ch.22: Evolution by Natural Selection

Question 1

Plato

Answer 1

• typological thinking

- species are unchanging types and variation within species is unimportant

Question 2

Aristotle

Answer 2

• Scale of Nature

- linear scheme in which species are fixed types organized into a sequence of increasing size and complexity

Question 3

Lamarckian Evolution

Answer 3

• species are not static but change through time
• Lamarickian evolution is progressive
• inheritance of acquired characterisitics

Question 4

inheritance of acquired characteristics

Answer 4

phenotype changes in response to environmental cues and these phenotypes are passed onto offspring

Question 5

Evolution by Natural Selection

Answer 5

• evolution occurs because traits vary among individuals in a population and some individuals with certain traits produce more offspring than others
• Darwin and Wallace

Question 6

Two predictions of Natural Selection

Answer 6

1. Species change through time

2. Species are related by common ancestry

Question 7

Population Thinking

Answer 7

variation is key to understanding nature of some species

Question 8

Evolutionary turning point

Answer 8

population genetics reconciled Menedialian Genetics and Darwinian Evolution

Question 9

What is descent with modification?

Answer 9

Darwinian descent with modification is that species are related by descent of common ancestry

Question 10

Principle of Uniformitarianism

Answer 10

idea that geological processes occurring today is similar to those that occurred in the past

Question 11

Radioactive decay

Answer 11

steady rate at which unstable parent atoms are converted into more stable daughter atoms

Question 12

Law of Succession

Answer 12

resembles fossils found under rocks in a certain area and living species found in the same geographical area

Question 13

Transitional Feature

Answer 13

trait in a fossil species that is the intermediate between ancestral (older) species and derived (younger species) . It is a link between older and younger species

Question 14

Vestigal Trait

Answer 14

reduced or incompletely developed organ or structure that has no function but resembles a functioning organ or structure in another closely related species

Question 15

Homology

Answer 15

study of likeness that exists due to shared ancestry

Question 16

three types of homology

Answer 16

genetic homology, developmental homology, and structural homology

Question 17

evidence for “species change through time”

Answer 17

• life on Earth is ancient (fossil record)
• fossils (extinct) species resemble living species found in the same area
• vestigial traits
• transitional features
• characteristics of a population vary within species and can be observed today

Question 18

evidence for “species are related”

Answer 18

• similar species often live in same geographic area
• homology (3 levels)
• formation of new species from old species can be observed today

Question 19

Modern Synthesis

Answer 19

• occurring in 1940s
• genetic basis of variation and natural selection is formalized
• all the different types of fields of studies formulate the following: populations are units of evolution, natural selection is the primary mechanism of evolutionary change, and gradualism (large changes result due to the accumulation of small changes)

Question 20

Artificial selection

Answer 20

selective breeding of desirable traits in plants and animals

Question 21

Struggle for existence

Answer 21

more individuals are born than can survive and as a result compete for food and shelter

Question 22

two concepts that lead to Darwin’s finding of natural selection

Answer 22

artificial selection and struggle for existence

Question 23

evolution by natural selection occurs when….

Answer 23

heritable variation leads to differential reproductive success

Question 24

Natural selection

Answer 24

occurs when individuals with certain traits produce more offspring than those without these traits

Question 25

Fitness

Answer 25

ability to produce viable, fertile offspring

Question 26

Adaptation

Answer 26

heritable trait that increases an organism's fitness

Question 27

Homologous structure

Answer 27

have similar structural skeletal elements, but different functions

Question 28

Analogous structures

Answer 28

have similar functions but animals are not closely related their similarity in function is not due to their relations ex. wings of insects and wings of birds

Question 29

three misconceptions of natural selection and adaptation

Answer 29

"Evolutionary change occurs in individuals" (no, natural selection occurs on individuals and evolutionary change occurs in populations) "Evolution is goal-directed" (no) "Evolution perfects organisms" (no)

Question 30

Acclimatization

Answer 30

changes in an individual's phenotype that occurs in response to changes in environmental conditions acclimatization is not adaptation

Question 31

Fitness trade-offs

Answer 31

compromise between two traits that cannot be optimized simultaneously

Question 32

Ontogeny

Answer 32

process of development of an individual organism

Question 33

Phylogeny

Answer 33

evolutionary history of a species

Question 34

Why is the male urinogenital system not a good design?

Answer 34

This is an example of why evolution is not goal-directed. It is not a good design because vas deferens passes over the urethra and that can cause problems in old age.

Question 35

What are the four reasons why evolution does not produce organisms?

Answer 35

- adaptations are often compromises - historical constraints - co-opt existing structures, adapted for new situations - selection only edits previously existing variations