Evolution Flashcards
Define species
A group of organisms that can interbreed to produce fertile and viable offspring
Define population
A group of individuals of the same species in the same defined geographical area
Define mutation
An alteration in the DNA sequence of an organism
Define gene pool
the complete set of alleles present in a population
Define allele frequency
The proportion of one allele in a gene pool
State four factors that affect genetic diversity
Population size
Inbreeding
Migration
Natural disaster
Define high biological fitness
Individuals are more likely to survive, reproduce and pass on their alleles to offspring
Which levels of classification are used for the binomial name of a species
Genus and species
State the eight levels of classification from most broad to least
Domain
Kingdom
Phylum
Class
Order
Family
Genus
species
Define evolution
A change in allele frequency over time
Give an example of a selection pressure
Competition for resources like food
Predation
Disease
Give an example of a selective advantage
One colour variation is better able to camouflage from predators and escape being eaten
Faster individuals are more successful at hunting
What is the pneumonic to remember the process of Natural Selection
VAST SEINE
What is the scaffold sentence for VA in VAST SEINE when explaining natural selection?
VA – There is variation in the phenotypes of the ……………… population, due to random mutaions, as …………
What is the scaffold sentence for ST in VAST SEINE when explaining natural selection?
ST – All organisms face a daily struggle to survive and reproduce. The ……..…….. struggle because of the……………………………selection pressure
What is the scaffold sentence for SE in VAST SEINE when explaining natural selection?
SE – The …………………………….. have a selective advantage as……………
What is the scaffold sentence for IN in VAST SEINE when explaining natural selection?
IN – The organisms that have a selective advantage (………………..), survive, reproduce and their offspring inherit the alleles for the trait of………………….
What is the scaffold sentence for E in VAST SEINE when explaining natural selection?
E – Evolution occurs by natural selection and there is a change in allele frequency over time and the ………..… population becomes better suited to its environment.
Explain how species arise by allopatric speciation form being isolated from each other
Two populations of ______ are geographically isolated by a permanent geographical barrier of ______.
There are different selection pressures acting on each population of .
Mutations accumulate over many generations in each population.
Eventually they can no longer interbreed to produce fertile and viable offspring and would be considered 2 separate species.
State which order humans are in
Primate
State the features of a primate
Large, forward facing eyes
Opposable thumbs
Large brain volume in comparison to body size
State what you can use to tell two species are more closely related on a phylogentic diagram
They share a more recent common ancestor
Give 2 peices of evidence used to see how closely related species are
D.N.A
Fossils
Structural morphology
Define a fossil
Remains or traces of pre-existing life preserved in ice rock or amber
Outline the environmental conditions for fossilisation
The organisms has hard body parts (as soft tissue decomposes) and is rapdily covered in sediment.
The remains are hidden from scavengers, and undisturbed for a long time
There is no oxygen present so no decay can occur
The temperature is low so no decay occurs
There is high pressure
Outline the steps for fossilisation
A hard bodied organism is rapidly buried in sediment
Soft tissue decomposes
Mineralisation occurs in the hard parts
Pressure turns sediment into rock
Describe how human skeletons differ from earlier hominins
Smaller arg:leg ratio
More bowl like pelvis
Describe how human skulls differ from early hominins
Flatter face
Less brow ridge
Larger brain case
