Evolution Flashcards
How is the fossil record bias ?
It only shows the remains of; hard body organisms , place of death.
It also is incomplete
Archaeopteryx and tiktaalik are examples of …
Transitional fossils
Name the 4 fossil types
Trace
Impression
Mould
Body
Name and explain the process whereby fossilization occurs
Mineralization.
Soil replaces decaying bone and forms fossil
Name and explain the 2 fossil dating methods
Relative dating - uses strata in rocks to determine age. Lower strata means older fossil
Absolute dating - based on ratio of elements present in fossil
A living fossil is…
A species that has been living on earth for millions of years
How can genetics be evidence for evolution?
All of life shares same nucleotides therefore all have same origin. We can trace ancestry through mutations and DNA changes
Name and explain the 2 ways in which we can “see” genetic evolution
Selective breeding. Choose desirable traits and cross genes.
Antibiotic/pesticide resistance. Evolve resistances over time
How can biochemistry be evidence for evolution?
Similar amino acids shows similar origins
How can geographical distribution be evidence for evolution ?
Pangea meant all animals could roam freely. Continental drift shows their distribution. Extinction of animals shows their ancient living conditions / habitats
Name and explain the 2 styles of evolution
Convergent. Species share similar functions but evolve along different paths
Divergent. Ancestor species gives rise to new diverse descendants that adapt to their environment
Name and explain the 4 methods of comparative anatomy
Homologous structures. Similar structure with different functions.
Analogous structures. Different structures with similar functions.
Vestigial structures. Structures that are no longer functional or necessary.
Divergent/ adaptive radiation. Evolution from common ancestor. Evidence in homologous and vestigial structures
How can comparative embryology be evidence for evolution
Development of embryo across different species is very similar. Therefore all began with one development and changed to suit it’s environment
What did Lamarck believe about evolution ?
Inheritance of acquired traits. Species can change phenotype during its lifetime to suit it’s environment and pass on these changes to offspring.
Also believed “use and disuse” theory whereby structures that are no longer used deteriorate over time
What did Darwin believe ?
Modification by descent or natural selection. Variation of traits caused by mutations , crossing over , RGS, IA. More desirable traits are selected for and non desirable traits are selected against. Traits are inherited through parents to offspring. Over time species adapt to suit their environment
What evidence do we have that evolution has occurred?
Fossil evidence Genetics Biochemistry Geographical distribution Comparative anatomy Comparative embryology
What would one use for a pictorial representation showing relation ?
Cladogram or phylogenic tree
Cladogenesis is…
Branching or adaptive radiation
Anagenesis is…
No branching in a cladogram
The two different types of evolution are
Macro and micro evolution
Explain macro evolution
Evolution at a large scale that results in formation of new species
Evidence is in fossil record.
General trends include increased diversity and size.
Novelties include significant changes in evolutionary history like jaws or lungs.
Rate of change is gradualism and punctuated equilibrium.
Explain the difference between Punctuated equilibrium and Gradualism
PE is periods of stasis interrupted by sudden evolutionary change.
Gradualism is slow evolution
Explain micro evolution
Evolution at a small scale. Evidence is in small genetic changes in species with fast generation time.
Results of macro evolution.
Name the 5 causes of micro evolution
1) Mutation
2) Natural Selection
3) Non-random Mating
4) Gene flow
5) Genetic Drift
Why is gene flow beneficial
Increased variation.
More varied genome.
Why is genetic drift detrimental
Decreases variation.
Can lead to extinction.
Loss allele variation
What can result from genetic drift ?
Founder effect and bottle necking
Explain the founder effect
Small group of individuals in a population becomes isolated. Decrease breeding partners and variation
Define co evolution
The evolution of 2 or more species together for the benefit of all each species
Define convergent evolution
2 unrelated species evolve a function as environment changes. Eg butterfly and birds
