Evolution

Question 1

For selection to be possible, what must exist?

Answer 1

Natural variation

Question 2

What is biological evolution

Answer 2

Heritable change of a population over time

Question 3

2 types of evolution an explain each of them

Answer 3

1) micro evolution: changes in one or few genes (no new species)
2) macroevolution : formation of new species

Question 4

What does Lamarck state?

Answer 4

-changes in the environment cause organisms to evolve
- patents can pass on acquired traits (phenotype)

Question 5

What is epigenetics?

Answer 5

How environment and behaviour affects gene expression without altering genetic coding of an organism.

Question 6

Artificial selection

Answer 6

To breed desirable, heritable characteristics

Question 7

What does Darwin state?

Answer 7

Natural selection is the driving force of evolution

Question 8

What is natural selection?

Answer 8

An individual with more favourable traits is more likely to survive and reproduce.

Question 9

What are the 4 of Darwin’s observations?

Answer 9

1) in one species there is a great (phenotypic) diversity
2) organisms produce more offsprings that can survive.
3) there is a struggle to survive
4)Differential reproductive success : individuals with favourable traits is more likely to reproduce (more)

Question 10

Theory of evolution does not attempt to….

Answer 10

Explain how life on earth began

Question 11

Natural selection includes:

Answer 11

1) biotic and abiotic pressure
2) sexual selection

Question 12

Adaptations
1) explain
2) when and how does it occur?

Answer 12

1) ability of a specie to survive in a specific environment
2)occurs at population level , can also be behavioural, morphological, or physiological, selected by environment

Question 13

Key points of theory of evolution:

Answer 13

1) species evolve over time
2)new species arise from the evolution of an ancestral species (macro evolution)
3)all living organisms originated from a common ancestor

Question 14

How to know if organisms evolved from each other?

Answer 14

-change in population (genetics)
- formation of new species

Question 15

One example of micro evolution:

Answer 15

Dogs (artificial selection of dogs = same species)

Question 16

Macroevolution

Answer 16

• new species, new genus, new family

Question 17

Limitations of fossils

Answer 17

-Fossil record is incomplete (fossils rarely form)
-info about external, not internal
- evolution can occur without morphological changes (ex: height and diet)

Question 18

Phylogenetic tree

Answer 18

-fossil records
- hypotheses about macroevolution

Question 19

Biogeography

Answer 19

-Study of geographic distribution of organisms
-Examines the patterns where organisms live on earth

Question 20

Continental drift

Answer 20

Similar organisms found on different continents: descend from a common ancestor that lived before the continents drifted.

Question 21

Comparative anatomy:

Answer 21

1) homologous features (divergent evolution): organisms with similar structures but different functions (hypothesized to have a common ancestor)
2) vestigial structures: original function lost as species adapt to different modes of life.

Question 22

What are analogous structures?

Answer 22

Organisms with separate ancestries adapt in similar ways due to environmental demands

Question 23

What is convergent evolution?

Answer 23

Evolution of similar or analogous features in distantly related groups.

Question 24

Post Darwin ideas

Answer 24

• molecular homologies:
  
  • the more recent the common ancestor, the more sequence similarities (DNA and /or amino acid sequence of proteins)
  • leads to a revision of evolutionary trees

Question 25

Limitations of evolutionary trees

Answer 25

-assumption that genes are passed only vertically - conserved sequence - hybridization of species can occur

Question 26

Factors leading to evolution

Answer 26

When one of the five conditions of h-w is not met

Question 27

Adaptive

Answer 27

Natural selection

Question 28

Non-adaptive

Answer 28

-non random mating that is not adaptive (interbreeding=reduce genetic variation) - genetic mutation -genetic drift: bottleneck, founder effect - gene flow

Question 29

Fitness

Answer 29

Ability to produce a surviving offspring

Question 30

Natural selection causes changes in ?

Answer 30

Allele frequency

Question 31

3 modes of selection of phenotypes:

Answer 31

1) stabilizing : favours intermediate variants 2) Directional: favours one phenotypic extreme 3)Disruptive :favours individuals on both extremes

Question 32

Sexual selection: non random mating= natural selection can lead to….

Answer 32

-can lead to stabilizing, directional or disruptive selection

Question 33

According to evolutionary theory, what had to be the source of all original variation?

Answer 33

Mutation (theory hypothesize a single ancestor)

Question 34

Bottle-neck genetic drift:

Answer 34

sudden decrease in population size➡️ reduction in genetic diversity

Question 35

Founder effect genetic drift

Answer 35

Individuals leave the population and starts a new population: founders has less genetic variation that original, population )

Question 36

What kind of population is more susceptible to genetic drift? Why?

Answer 36

Small populations, because allele frequencies are are likely to change by random fluctuations

Question 37

Gene flow

Answer 37

-Transfer of alleles between populations of same or different species -result of mvmt of fertile individual or gamete - if between different species➡️ horizontal gene transfer

Question 38

Geneflow

Question 39

What are the 5 condition of H-W

Answer 39

-no random mating -no natural selection -no mutation -No gene flow - no genetic drift

Question 40

How new species arises? Explain

Answer 40

1) allopathic speciation : -habitat isolation occurs: prezygotic reproductive barrier b/w groups -each population exposed to different selective pressures, genetic drift, +/or mutation that cause macroevolution. -eventually 1/ both populations undergo genetic changes that results in the formation of permanent reproductive barriers 2) sympatric speciation - same place - in geographically overlapping populations - occurs if gene flow is reduced by mutation, habitat differentiation or polyploidy) - result of changes in development 3) hybrid speciation

Question 41

How polypoidy arises in plants

Answer 41

1) Autoploidy (no hybrid formed) 2)Allopolyploidy (hybrids)

Question 42

What is autoploid?

Answer 42

Individual with more than 2 chromosome sets derivespd from a single species

Question 43

How are phylogenetic trees constructed

Answer 43

Presence of common structures Fossils records Molecular analysis

Question 44

What is a gene pool

Answer 44

All alleles present in a population

Question 45

Change in gene pool suggests…

Answer 45

Macroevolution

Question 46

In microevolution…

Answer 46

Selective pressure act on individuals

Question 47

5 conditions that must NOT be met for evolution to occur

Answer 47

1. No natural selection 2. Random mating 3 no net mutations 4.Large populations 5.No migration b/w populations

Question 48

Sexual selection

Answer 48

-non random mating that is an example of Natural selection 1) direct competition 2)indirect competition

Question 49

Genetic mutations are random or not? When can they be passed to offsprings?

Answer 49

Yes, random. When they are in gametes

Question 50

What is quicker : sexual or asexual reproduction? Why?

Answer 50

Sexual. It is a rapid combination of alleles while asexual is dependent on mutation to generate new alleles.