Evolution

Question 1

Evolution

Answer 1

Change in genetic makeup of a population of organisms

Question 2

5 Types of Evolutionary Factors

Answer 2

Natural Selection, Mutation, Gene Flow, Genetic Drift, Non-Random Mating or Sexual Selection

Question 3

Natural Selection

Answer 3

Difference in survival and reproduction individuals because of differences in genotypes, acts on individuals but it is the population that evolves

Question 4

Populations

Answer 4

The units of evolution, localized group of individuals belonging to the same species

Question 5

Species (spp)

Answer 5

Group of organisms capable of interbreeding and producing fertile offspring in nature

Question 6

3 Types of Natural Selection

Answer 6

Directional, Stabilizing and Disruptive Selection

Question 7

Directional Selections

Answer 7

Shifts frequency of a trait in a particular direction

Question 8

Examples of Directional Selection

Answer 8

Peppered moth, DDT resistance in flies, and antibiotic resistant bacteria

Question 9

Stabilizing Selection

Answer 9

Selects against extremes in phenotype, maintains well adapted traits, eliminates extremes

Question 10

Example of Stabilizing Selection

Answer 10

Human birth weight is approx. 7.5 lbs, babies at extremes have lower odds of survival

Question 11

Disruptive Selection

Answer 11

Increases frequency of extreme types

Question 12

Example of Disruptive Selection

Answer 12

Members of a spp of African finch have either a large or small beak, adaptive because food consists of either soft or hard seeds

Question 13

Mutation

Answer 13

Change in genetic info of cell, causes evolution, occurs in a gene ~1/mill gametes

Question 14

Point Mutation

Answer 14

Change in one or a few nucleotides

Question 15

Transposition (mutation)

Answer 15

Movement of a gene on a chromosome

Question 16

Chromosome Duplication or Deletion

Answer 16

Type of mutation

Question 17

Polyploidy (mutation)

Answer 17

More than a complete set of chromosomes

Question 18

Inversion (mutation)

Answer 18

Flipped sequence of a section of DNA

Question 19

Mutagens

Answer 19

Agents that cause mutation

Question 20

3 Types of Mutagens

Answer 20

Ionizing radiation, UV Light, and Chemical Mutagens

Question 21

Ionizing Radiation

Answer 21

High energy X and gamma rays knock e-s off atoms, creates free radicals which break DNA

Question 22

UV Light

Answer 22

Absorbed by Cs and Ts of DNA and polymerizes them

Question 23

Xeroderma Pigmentosum

Answer 23

Rare disorder where people can’t repair UV damage, full of skin tumors

Question 24

Chemical Mutagens

Answer 24

Alter DNA nucleotides or are nucleotide mimics that are incorporated into DNA

Question 25

Mutations in Somatic Cells can cause

Answer 25

Cancer, some cancer-causing viruses (oncovirus) have oncogenes as part of their genome

Question 26

Gene Flow

Answer 26

Movement of genes from one population to another

Question 27

Genetic Drift

Answer 27

Genetic makeup of an isolated new group will drift away from its ancestral group, inversely related to size of new group

Question 28

Two Types of Genetic Drift

Answer 28

Founder Effect and Bottleneck

Question 29

Founder Effect

Answer 29

Allele frequency in a small group that becomes isolated is different from the ancestral group, as founder group grows it becomes more and more different from the ancestral group

Question 30

Ellis-van Creveld Syndrome

Answer 30

Causes short limbs and extra fingers, example of founder effect because number of cases in the amish is greater than number of cases in the world

Question 31

Bottleneck

Answer 31

Population undergoes severe decrease in size, population later recovers and grows but retains limited genetic variation, example is cheetahs

Question 32

Non-Random Mating or Sexual Selection

Answer 32

Mates chosen on basis of physical or behavioral characteristics, consists of female choice and male competition

Question 33

Sexual Dimorphism

Answer 33

Caused by female choice and male competition

Question 34

Fisher’s Runaway Selection Theory

Answer 34

Some traits that don’t enhance fitness are selected for because opposite sex finds them more attractive, becomes more extreme over time

Question 35

Examples of Fisher’s Runaway Selections Theory

Answer 35

Blue eyes and peacock’s tail

Question 36

How species form

Answer 36

For speciation to occur, populations must become reproductively isolated by some mechanism

Question 37

Temporal Isolating Mechanism

Answer 37

Populations breed at different times of day, of year or in different years, example is cicadas and skunks

Question 38

Ecological Isolation Mechanism

Answer 38

Lifestyles or habitats of populations differ, example is lions and tigers

Question 39

Behavioral Isolating Mechanism

Answer 39

Mating behavior and courtship rituals become so different that species can’t mate, example is meadowlarks

Question 40

Mechanical Isolation Mechanism

Answer 40

Anatomical incompatibility between body parts or in pollinators

Question 41

Gametic

Answer 41

Gametes become incompatible, gamete recognition molecules allow flowers to distinguish right pollen, fish eggs the right sperm

Question 42

Allopatric Speciation

Answer 42

Occurs when two or more populations diverge because of geographical separation

Question 43

Sympatric Speciation

Answer 43

Speciation occurs without geographical isolation, usually via polyploidy or disruptive selection

Question 44

Cline

Answer 44

Graded change in a trait along a geographic axis, examples are Bergmann’s Rule and Allen’s Rule

Question 45

Bergmann’s Rule

Answer 45

Body size in a species increases as you move north

Question 46

Allen’s Rule

Answer 46

Extremities are shorter as you go north