What are adaptations
Characteristics that increase an organisms chance of survival and reproduction in its environment
What are the three type of adaptations?
Anatomical
Behavioural
Physiological
What are physiological adaptations also known as?
Biochemical and cellular traits
What are analogous structures?
Structures that have adapted to perform the same function but are genetically differebt
What is convergent evolution?
Convergent evolution Occurs when unrelated species share similar traits
Because they are in similar environment with similar selection pressures
What’s palaeontology?
The study of fossils and the fossil record
What’s comparative anatomy?
The study of similarities and differences between organisms anatomy
What’s comparative biochemistry?
Similarities and differences between the chemical makeup of organisms
How are fossils formed?
When animal and plant remains are preserved in rocks
What’s the fossil record?
When over a long period of time sediment is deposited and layers of rocks are formed
The different layers correspond to different geological eras
This is known as the fossil record
How can palaeontology help with working out how closely related organisms are?
The similarities in the anatomy of fossil organisms scientists can show how closely related organisms have evolved from the same ancestors
Why is the fossil record incomplete?
Because soft bodied organisms decompose quickly and before they can be fossilised
What’s a homologous structure?
A structure that appeals to he in different in different organisms but has the same underlying structure
What’s divergent evolution?
The function of something have evolved but it’s all from a common ancestor
For example the pentadactyl limbs
In comparative biochemistry which molecules are commonly studied?
Cytochrome C
Ribosomal RNA
Why is ribosomal RNA commonly used in the the fossil record?
Because it has a very slow rate of substitution
How does mitochondrial DNA get passed down?
Mitochondrial dna always gets passed down from the mother
Why does mitochondrial dna have a lot of variation?
It has a higher rate of mutation than nuclear dna so there is a lot of variation in the sequence of mDNA between humans from different parts of the world
What’s the parallel multiregional evolutionary process?
Homo sapiens evolved simultaneously in different parts of the world
What’s inter specific variation?
The variation that exists between different species
What’s intraspecific variation?
Variation that exists within a species
What is continuous variation?
There are two extremes and a full range of intermediate values in between
What are two examples of continuous variation?
Height in humans
Length of leaves on oak trees
What factors impact continuous variation?
Both genes and environmental favtors
