EVOLUTION EXAM STUDYING

Evolution

2. In what ways does life change over time? - developmental

• We develop (ie. facial structures change because growth and aging) 

3. What are the 3 types of adaptations - be able to explain them and identify or come up with an example of each 

• Structural: ex. Insect camouflage  

• Physiological: ex. Skunk spraying 

• Behavioral: learned - hunting strategies, innate - hibernation

4. What role do mutations play in evolution? 

• Create new genes to increase genetic variation

5. Mutations can be beneficial, harmful or neutral - explain them and how the environment determines which it is 

Beneficial - a positive mutation that allows the organism to thrive, they are favoured and get passed down through generations

Neutral - doesn’t help or harm the organism, will not be eliminated but exists at a low frequency 

Harmful - harms the organisms, makes it harder to succeed, do not accumulate; the environment naturally selects against it 

6. How does change influence generations - i.e. bacteria and antibiotic resistance, plants and insecticide resistance

• When solutions are found to viruses, the viruses are able to quickly evolve

• Through generations we can develop resistance to antibiotics through overuse or misuse of them 

7. Compare selective breeding/artificial selection and natural selection

• Artificial breeding: when we breed for specific traits (e.g. breeding for faster race horses, for a specific dog breed, for a certain type of lettuce)

• Natural selection is based off of VIS (variation, inheritance, selection), nature chooses what traits are beneficial for species to obtain and maintain

8. Dangers of artificial selection? What are monocultures and what risk to biodiversity do they play? 

• Creation of a monoculture - where everyone is genetically the same or very similar, making it harder to survive disease/the environment = can lead to extinction

9. Limits of artificial selection, how does it occur vs natural selection - which is quicker 

• artificial selection can only occur with traits that already exist

  • Breeding selected individuals that contain the preferred traits so they become more prevalent 

• artificial selection can occur within 100s of years while natural selection takes 1000s of years 

10. What does immutable mean?

• A belief by aristotle that we cannot change/evolve 

11. What are fossils - how are they arranged and what do they tell us? 

Fossils: ancient remains, impressions or traces of an organism or their activity that have been preserved in rocks or other mineral deposits in the earth’s crust

• Fossil record: strata are order by most recent at the top and oldest at the bottom, tell us what was happening on earth at that period of time

12. The theory in terms of catastrophism as a evolutionary theory** vs uniformitarianism evolutionary theory - how do they relate to gradualism and punctuated equilibrium (what do they have in common? Different? ) - how does evolution occur in terms of gradualism and/or punctuated equilibrium

• Catastrophism - the world evolves through disasters and new species just come and occupy the area - flawed because the fossil record suggest that species got increasingly complex 

• Uniformitarianism - the world evolves slowly through small changes 

Gradualism - large evolutionary change occurs through the small accumulation of changes over time, not visible in the fossil record because small changes are hard to see over so many years

Punctuated equilibrium - rapid bursts of change followed by little to no change 

Both occur but depends:

• If normal environment, no disease = gradualism

• If disease or changes in environmental conditions = punctuated equilibrium

13. What were Lamarks 2 principles and theory? 

• Use and disuse: structure that are used more become stronger than structures used less 

• Inheritance of acquired traits: traits that an organism inherits throughout its lifetime can be passed down to offspring (FLAWED BECAUSE THINGS LIKE EYESIGHT CANNOT BE PASSED DOWN)

14. List and explain the different types of evidence for evolution. Be able to interpret DNA sequence. 

1. Fossil record

2. Biogeography: species living with similar/same environments in different parts of the world have similar adaptations

3. Comparative anatomy: animals with homologous structures have adapted to use them for their own benefits (e.g. human and whale arms), animals with analogous structures have adapted to have similar function (e.g. wings of a bird and bat), vestigial features: features that barely have a function now because we have evolved (e.g. goosebumps)

4. Embryology: we all evolved from a similar embryo, fish & humans have similar traits as embryos but different as we grow 

5. DNA sequencing: all organisms follow similar genetic codes, the closer we are in genetic sequencing = the more closely related we are 

15. What is adaptive radiation? 

Rapid evolution of species from the same ancestor, usually when the colonise a new environment (e.g. darwin’s finches) 

16. Natural Selection; VIS, Survival of the fittest, Adaptation, environment, selective pressures  - explain Darwin’s theory based on these 

The environment deciding the reproductive success of some individuals over others 

Variation - organisms within a population are different from each other 

Inheritance - The instructions for inheritance of different traits are passed on from parent to offspring

Selection - organisms with different traits (positive) are selected for reproduction

Adaptation - a characteristic that makes an organism well suited to their environment for reproduction

Selective pressures - abiotic/biotic factors that effect reproduction for organisms (e.g. disease, choice of mate, environment)

Darwin’s theory - Over time, a population changes as advantageous heritable characteristics become more common after each generation 

17. What are the 6 mechanisms of evolution? Which one is the primary mechanism? 

• Gene flow: transfer of alleles from one population to another = new genetic material in a population = INITIAL INCREASE OF GENE FLOW AND THEN POPULATIONS WILL GET SIMILAR LEADING TO DECREASE

• Horizontal gene transfer

• Genetic drift: change to allele frequencies as a result of chance 

  • Bottleneck drift: dramatic reduction in population size quickly = loss of genetic diversity

  • Founder’s effect: a small # of individuals separate and form a new population = common alleles might become less common, rare alleles may become more common = POTENTIAL FOR INCREASE IN GENETIC DIVERSITY

• natural selection: environment chooses what is positive for organisms, 

  • Stabilizing selection: average phenotype is preferred in the population = maintaining status quo (e.g. baby weight)

  • Directional selection: one extreme phenotype is preferred over the rest = shift in population over time (e.g. fastest horses, sweetest fruit)

  • Disruptive selection: both extremes are preferred in a population = lead to speciation (e.g. rocket pocket mice)

• Sexual selection: ability to obtain mates can lead to sexual dimorphism (females and males have different features to attract each other 

• Artificial selection: organisms are bred for specific traits

21. Hardy Weinberg said the populations will remain relatively stable unless there are conditions that drive evolution. What are those conditions? 

1. Natural selection: favours passing of some alleles over others 

2. Small populations: increases likelihood of genetic drift 

3. Mutations: introduces new alleles to populations

4. Immigration or emigration: introduces or removes alleles from a population

5. Horizontal gene transfer: gaining of new alleles from a different species 

22. What is microevolution and macroevolution? What is speciation? 

• Microevolution: changes in gene (allele) frequencies and phenotypic traits within a population and species 

• Macroevolution: large-scale changes including formation of new species; happens over longer time period (centuries, millennia

• Speciation: the creation of a new species

23. How do you define a species? 

• Group of organisms that can interbreed and produce fertile offspring and are reproductively isolated from other species

24. Know all the reproductive isolation mechanisms - both prezygotic and postzygotic 

25. What is allopatric speciation vs sympatric speciation? 

Allopatric speciation: when new species are formed because of geographic isolation

Sympatric speciation: when new species are formed even though they are in the same region (disruptive selection could have occurred) 

26. What patterns of evolution are there? Explain = divergent, convergent and coevolution and how they relate to homologous and analogous structures. Give an example for each. 

• Divergent evolution: species that were once similar to an ancestral species become increasingly distinct - homologous features have the same origin but different function (e.g. darwin’s finches evolve from a common ancestor) 

• Convergent evolution: similar traits arise because species adapted independently of each other due to environmental conditions - analogous features have different origin but same function (e.g. bat and butterfly wings)

• Coevolution: one species evolves in response to the evolution of another species (e.g. flowers and bees)

27. What is abiogenesis

Abiogenesis - Origin of life from non-living matter 

28. Concept and connection between extinction events and evolutionary explosion - why? Has there been any others besides cambrian explosion? 

Mass extinctions create space for rapid development to fill in the empty space left by the extinction of other animals 

29. Define phylogenies, cladograms, cladistics, derived traits, synapomorphy 

Phylogenies - classification of species) based on careful evaluation of wide range of evidence including fossil record, genetics and morphology

Cladograms - visual representation of evolutionary relationships

Cladistics - method of determining evolutionary relationships based on presence or absence of recently evolved traits 

Derived traits - trait that has evolved due to adaptations 

Synapomorphy - derived trait shared by 2 or more organisms that makes them more closely related

30. Know how to draw a cladogram based on a chart (simple linear). Also how to interpret it. 

32. What are Transitional forms? Give an example

Fossils that are intermediate in form between 2 other species in a direct line of descent AKA direct line 

• Archaeopteryx fossil – first and most famous transitional species (features of both birds and primitive reptiles – bony jaw with teeth, long bony tail but also feathered wings)