3 Mechanisms and Evidences of Evolution

Question 1

• process that changes the genes of populations of organisms over time

Answer 1

Evolution

Question 2

Evolution may be used to explain:

Answer 2

• origin of species
• diversity of organisms and their relationships
• similarities and differences among species
• adaptations to the environment

Question 3

one of the alternative forms of the same genes

Answer 3

Alleles

Question 4

– a group of individuals of a single species
inhabiting a certain area

Answer 4

Population

Question 5

• evolutionary process that changes
  anatomy, physiology or behavior, resulting in an
  increased ability to live in a particular environment,
  happens in a POPULATION (not individual)

Answer 5

Adaptation

Question 6

• proposed by a Greek philosopher that life arose in water.
• simpler forms of life preceded complex form.

Answer 6

Anaximander

Question 7

• French naturalist who predicted that the Earth is <6000 years old and suggested that different species may have arisen from common ancestors, though he later argued against it.
• known to be the father of Biogeography

Answer 7

Georges-Louis Leclerc, Comte de Buffon

Question 8

• French naturalist who proposed the inheritance of acquired characteristics.
• though erroneous, his idea provided
  strong advocacy for the concept of
  evolution

Answer 8

Jean Baptiste Lamarck

Question 9

Lamarck’s inheritance of acquired characteristics is also known as…

Answer 9

Use and Disuse Theory

Question 10

• British naturalist who propose together with Alfred Wallace the evolution by natural selection.
• Wrote On the Origin of the Species by
  Means of Natural Selection

Answer 10

Charles Darwin

Question 11

• Organisms beget like organisms
• There are chance variations between individuals in a
  species. Some variations are heritable.
• More offspring are produced each generation that can
  be supported by the environment.
• Some individuals, because of their physical or
  behavioural traits, have a higher chance of surviving and
  reproducing.

Answer 11

Theory of Natural Selection

Question 12

• An Austrian monk that laid down the foundations of heredity.
• Showed that traits can be inherited in a well-defined and predictable manner.
• Darwin could not explain how his traits that lend fitness can be inherited.

Answer 12

Gregor Mendel

Question 13

Laws of Inheritance:

• For each trait, there are two alleles that are
  separated during gamete formation, to be joined
  randomly during fertilization.

Answer 13

Law of Segregation

Question 14

Laws of Inheritance:

• Different genes from different traits are passed
  independently from parent to offspring.

Answer 14

Law of Independent Assortment

Question 15

• Japanese biologist who proposed the neutral theory of evolution.
• The molecular changes represented by majority of molecular differences do not influence the fitness of the individual organism.

Answer 15

Motoo Kimura

Question 16

This theory exempliied by the DEGENERACY of the genetic code.

Answer 16

Neutral Theory

Question 17

Who Elucidated the structure of DNA based on X-ray crystallography data of Rosalind Franklin?

Answer 17

American molecular biologist James Watson and British
physicist Francis Crick

Question 18

He identified DNA as the genetic material.

Answer 18

Oswald Avery

Question 19

Result of differences in survival and reproduction
among phenotypes.

Answer 19

Natural Selection

Question 20

Key challenges to living organisms

Answer 20

• Find appropriate habitat and environmental conditions
• Obtain necessary resources
• Avoid predators
• Find a mate (or mates)
• Produce as many successful offspring as possible

Question 21

Exchange of genes between populations, mostly of the
same species, and regulated by migrations

Answer 21

Gene Flow

Question 22

Change in gene frequencies in a population due to
chance or random events

Answer 22

Genetic Drift (eg. Bottleneck effect, founder effect)

Question 23

Microevolution - _______
Macroevolution - ________

Answer 23

1. below the species level.
2. at or above the species level.

Question 24

• Plant and animal breeding -> led to the emergence of various crop plants and different breeds of farm animals.

Answer 24

Artificial Selection

Question 25

• e.g. sickle-cell anemia
• ss – people with misshapen red blood cells
• Ss – people that are less susceptible to
  malaria
• Presence of malaria in Africa acts as a
  selection pressure to maintain the recessive
  allele in the population
• e.g. British peppered moth Biston
  belutaria
• During the Industrial Revolution,
  white moths were nearly
  decimated, either because they
  were more susceptible to air
  pollution or they were more
  conspicuous to bird predators

Answer 25

Genetic variation maintained by
natural selection

Question 26

• e.g. Archaeopteryx
• Discovered by Von Mayer in Germany
• Missing link between reptiles and birds

e.g. Tiktaalik roseae
* Discovered by Edward B. Daeschler in Canada
* Missing link between non-tetrapod fishes and tetrapod amphibians

Answer 26

Fossil Record

Question 27

• Presence of HOMOLOGOUS STRUCTURES or structures with the same embryonic origin
• Homologous structures must be distinguished from ANALOGOUS STRUCTURES or structures that resemble
  each other physically or functionally but do not have the same embryonic origin

Answer 27

Comparative Anatomy

Question 28

• Closely related organisms have similar stages in their embryonic development

Answer 28

Comparative Embryology

Question 29

Embryonic development in vertebrates

Answer 29

• possess a dorsal, hollow nerve cord
• a notochord (stiffening rod of
  cartilage) in the back
• similar membranes in the embryos
• yolk sac that produces the first blood
  cells and germ cells
• similar development of many organs

Question 30

• Related individuals have greater similarity in their DNA and proteins than do unrelated individuals

Answer 30

Molecular Biology

Question 31

Patterns of Macroevolution:

• When two or more biological characteristics have a common evolutionary origin but have diverged over evolutionary time
• Also known as ADAPTIVE EVOLUTION

Answer 31

Divergent Evolution

Question 32

Patterns of Macroevolution:

• Organisms not closely
  related that
  independently evolve
  similar traits as a result
  of having to adapt to
  similar environments or
  ecological niches
• Exemplified by
  analogous structures

Answer 32

Convergent Evolution

Question 33

Patterns of Macroevolution:

• The independent evolution
  of similar traits, starting from
  a similar ancestral condition
• NOTE: When both
  descendants are similar in a
  particular respect, evolution is
  defined as parallel if the
  ancestors considered were
  also similar, and convergent
  if they were not.

Answer 33

Parallel Evolution

Question 34

Types of Speciation:

• a physical barrier divides a population
• the isolated populations then undergo genotypic and/or phenotypic divergence as they (a) become subjected to dissimilar selective pressures or (b) they independently undergo genetic drift

Answer 34

Allopatric speciation

Question 34

Types of Speciation:

• Small founding population enters isolated niche
• New species are formed in isolated, small peripheral populations
  which are prevented from exchanging genes with the main
  population

Answer 34

Peripatric speciation

Question 34

Types of Speciation:

• New niche found adjacent to original one
• There is no specific extrinsic barrier to gene flow. The population is
  continuous, but nonetheless, the population does not mate randomly.
  Individuals are more likely to mate with their geographic neighbors
  than with individuals in a different part of the population’s range

Answer 34

Parapatric speciation

Question 34

Types of Speciation:

• Speciation occurs without physical separation
• Can be attributed to dependence on different hosts (e.g. plants) or
  increase in chromosome number through polyploidy

Answer 34

Sympatric speciation