Evoloution Flashcards
What is a hypothesis
Suggested explanation that can be tested
What’s a scientific theory
Explanation supposed by scientific evidence, answers question why?
define a scientific law
Describes a natural phenomenon, describes WHAT is happening.
What is a variation
The differences between individuals
The number of possible
Combinations of alleles that an offspring can inherit results in genetic variation
Mutations
Starting point of genetic variation in populations,
they change the dna of a organism
Provide new alleles in a population
Only source of new genetic variation within a species
What happened if a mutation occurs in a somatic cell
The mutation disappears from
The population when the organism dies
What happened if a mutation alters DNA in a gamete
The mutation can be passed on to generations, these mutations are inherited
What is biological evolution
An inherited change that happens within a population, NOT individuals
Change in the allele frequencies within a population
Adaption
Structure, behaviour or physiological process helps an organism survive and reproduce particular environment
Describe adaptations
adaptations make organisms well suited to their habitat,
evolutionary adaptations are not a response to environment but a consequence
What’s another word for reproductive success
Fitness: often described as the relative contribution (number) an organism makes to the next generation by producing offspring that are viable (survive long enough to reproduce)
Does an organism with many viable offsprings have high or low fitness?
High fitness
Does an organism with little to none viable offspring have high or low fitness
Low fitness
What’s the connection between adaptation mutation and variation
An adaptation develops when a specific variation (random, heritable, mutation in DNA) provides a selective advantage (genetic advantage they improved organisms chances of survival)
This advantageous variation will gradually accumulate in population
Change in the allele frequency within a population = evolution
What are the 3 types of adaptions
Structural, physiological, behavioural
What is structural adaptation
Specific part or feature of the organism’s body eg fluffy feathers or an owl allow them to fly in silent
Mimicry
Harmless species physically resemble a harmful species
What is physiological adaptation
Permits an organism to perform a specific function
Eg hibernation allows squirrels to survive harsh winters
What is behavioural adaptation
Ways an organism acts
Eg hunting strategies, migration
Types of evolution
Microevolution, macroevolution
Microevolution
Changes in allele frequencies with a population over successive generations
Allele frequencies: number of copies in an allele compared to the total number of alleles in a population
Macroevoloution
The progression of biodiversity over a long period of time
Descent of many species from a common ancestor
Accumulation of many instances of micro
Invoked speciation (new species) and extinction
What is a fossil, how does it support evoloution?
Fossil: Chronological collection of life’s remains in mostly sedimentary layers, hard tar pits, volcanic ash
Shows the history of life by showing past species that were alive
How does fossil evidence explain how closely related species are?
Fossils found in young layers of rock are much more similar to species alive today then older layers
