NCEA Level 2 Science (90772) 2009 — page 1 of 3
Assessment Schedule – 2009
Science: Describe the factors and processes involved in the evolution of New Zealand’s
plants and animals (90772)
Evidence Statement
ONE
Achievement
Achievement with Merit
Achievement with Excellence
Flight:Lack of predators OR lack of
competition from mammals.
AND
Size: Increased due to competition
between Takahe, retain heat, no
need to remain small for flight,
more energy used for growth or
sexual selection.
Explains flightlessness in terms
of either predation or
competition.
Example: Flightless because of
lack of mammalian predators, so
could browse without fear, and
flying not needed.
OR
Lack of competition for food
meant little need to fly, so
became flightless.
OR
Explains size in terms of
competition, heat retention, lack
of flight or sexual selection
Eg: Takahe increased in size as
larger size became an advantage
when competing with other
takahe for food / mates.
Discusses how becoming
flightless led to increased size.
A
TWO
(a)
(b)
M
Eggs could freeze / live birth keeps
young warm / lack of eggs means
they don’t require incubation. (a)
Described one use of DNA
sequencing or fossil evidence.
DNA sequencing could tell you how
much DNA is in common with
ancestral DNA.
OR
Fossil evidence could tell you what
the ancestral skink looked like.
OR
Either could be used to identify
similarities / differences between
modern and ancestral skinks.
(a)
Explained one use of DNA
sequencing or fossil record. (m)
Eg:
DNA sequencing tells you how
much DNA is in common with
ancestral DNA and so have an
idea of how many generations
ago ancestor existed.
Eg:
Fossils could be used to compare
physical characteristics of the
skinks and estimate when
divergence may have occurred.
Eg:
Strata in rocks containing fossils
can be used to determine the
sequence of evolution / dates
when changes occurred.
Completes following steps:
• why became flightless
• links flightlessness to size
• links size to improved survival
and reproduction.
Eg: Takahē had no need to fly
because of lack of predators /
location of available food, which
led to them becoming flightless
and so takahē able to increase in
size which allowed them to retain
heat more effectively and
therefore more likely to survive
and breed.
E
NCEA Level 2 Science (90772) 2009 — page 2 of 3
(c)
Populations isolated by Gondwana
breakup.
OR
Evolution to different environments.
OR
Selection pressures were different
(such as cold climate).
(a)
Populations isolated by
Gondwana break up
Leads to one of:
Selection pressures were
different (such as cold climate).
OR
Evolution to different
environments such as cold alpine
climate.
(m)
Populations isolated eliminating
gene flow / preventing movement
of genes into or out of the
population.
AND
Different selection pressures
operated.
AND
Populations evolved to suit
special environments like cold.
Links made between isolation,
environment and selection.
Eg: When the populations were
isolated they each may have
encountered different selection
pressures – such as a cold climate
for the Moko Skink. This will
have led to their evolution to suit
different environments or niches.
Question
sufficiency
2a=A
a+m=M
THREE
(a)
The modern southern beech species
arrived in NZ after the split from
Gondwana.
OR
The modern southern beech species
arrived in NZ after a possible
drowning event / after mountain
building.
OR
The modern southern beech species
arrived in NZ during an ice age /
period of glaciation.
Explains that original species
populated NZ when it was part of
Gondwana 85 mya and later, as a
result of chosen geological event,
species evolving separately in
Gondwana populated NZ 30
mya.
m+e=E
NCEA Level 2 Science (90772) 2009 — page 3 of 3
(b)
Describes Natural Selection as the
persistence of an allele as a result of
it aiding survival and / or
reproduction.
AND
Describes at least one bullet point.
• Genetic isolation is when genetic
material cannot be exchanged
between populations.
• Mutations are the source of new
alleles / beneficial mutations
change allele frequencies.
• Genetic isolation is when
genetic material cannot be
exchanged between
populations, so new alleles
from other populations cannot
have an influence on the gene
pool.
• Beneficial mutations enhance
survival / reproduction and are
readily passed on. This
changes the frequency of genes
in the gene pool.
• Founder effect is when colonising
population does not contain a
representative ratio of the parent
gene pool.
• Founder effect is when
colonising population may
evolve in a different direction
to the parent population
because the founder colony did
not contain a representative
ratio of the parent gene pool.
Total of TWO points described. (a)
Explains ONE (m)
• Genetic isolation is when
genetic material cannot be
exchanged between
populations, so new alleles /
changes in allele frequencies in
other populations cannot have
an influence on the gene pool.
The successful genes have an
increased chance of survival,
so there will be more of the
successful genes in the
population.
• Mutations are the source of
new alleles, and so change the
frequency of genes in the gene
pool. If these genes are
successful, they give the
organism an increased chance
of survival and so become
more frequently passed on to
offspring and therefore more
established in the gene pool.
• Founder effect is when
colonising population does not
contain a representative ratio
of the parent gene pool. This
creates the potential for this
population to evolve
differently to the original
population. There is now
decreased variation in the gene
pool meaning more successful
variants will increase in
frequency more rapidly.
Discusses ONE and links back to
natural selection and one of the
other bullet points.
Question
sufficiency
a=A
a+m=M
E
Judgement Statement
Achievement
Achievement with Merit
Achievement with Excellence
2 A or above
2M
1M
1E
Lower case a, m, e may be used throughout the paper to indicate contributing evidence for overall grades for
questions.
Only the circled upper case A, M and E grades shown at the end of each full question are used to make the final
judgement.