A4.1 Evolution - revision quiz
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When members of a species are separated by a physical barrier this can lead to populations which are prevented from reproducing, because individuals from each population never meet.
What is the name given to this situation?
Members of a species may be reproductively isolated in separate populations.
Which of the following statements is not true about Evolution?
Evolution is best defined as "A change in the heritable characteristics of a species".
Most frequently this is a gradual cumulative change.
Changes to individual organisms during their lifetime are not evolution, as the change has to be heritable.
Evolution occurs a the species level because individuals survive or die which changes the genetic composition of the members of the species.
Lake Malawi is the fourth largest lake in the world with a surface area of almost 30 000 km2 and is home to 1000 species of Cichlid fish.
The images of Cichlid fish varieties illustrates great variety in their features across the geographical range of the lake.
It is understood that all but five species are descendants of a single original colonist species.
What is the name of the process which forms this sort of diversity?
Continuous variation across the geographical range of related populations matches the concept of gradual divergence.
The image below shows adaptations in the wings of modern insects.
There is evidence that a common ancestor of all these insects had two pairs of wings.
What is the biological term for structures like these?
All the insects share the feature of having 2 pairs of 'wing-like' structures although there are differences in each animal.
This suggests that they all shared a common ancestor, with 2 pairs of wings.Analogous traits have evolved from different origins but perform the same function.
(due to convergent evolution)
For example, a fly wing and a bat wing.
In the genus Allium, new species have been know to form very rapidly by a special type of speciation.
It is a condition where gametes containing more than one set of chromosomes produce offspring.
What is this condition called?
Speciation can occur in the genus Allium by polyploidy. Diploid, tetraploid, and other types are common.
Which of the following best describes homologous structures?
Homologous structures evolved from a common ancestor and have a similar structure but this structure may be modified to adapted to a different function.
The existence of different breeds of domestic dog is due to which of the following?
Dog breeds are developed by humans artificially selecting certain traits in dogs and breeding only the animals with these desired traits. It is evidence of evolution, even though artificial.
Which of the following best describes evolution?
As evolution occurs, the heritable characteristics (genes) in the gene pool of a species change to those which are the most successful for survival.
Which of the following must happen to allow two new species to be created from a single species?
I Separation of the original species into two groups
II Interbreeding between the groups
III Different mutations in the two groups
IV Reproductive isolation between the two groups
For two groups of one species to form two species, they must be reproductively isolated, so they cannot interbreed and then different mutations will allow different genetic variation in each of the isolated populations, leading to adaptation to their respective environments and phenotypic differences between the groups.
The closeness of an evolutionary relationship between two species can be deduced by comparing which of the following?
Comparing base sequences in areas of DNA and amino acid sequences in specific proteins provide evidence of evolutionary relationships.
What might be expected to happen if two populations of a species of snail are separated by a river which has very different environmental conditions on each bank?
If the are different selection pressures in the two environments, then snails will be affected by different natural selection. This is divergent selection. As they are in different environments (allopatric), they may speciate
What is the term used to describe isolation between populations caused by different breeding times during the year?
Temporal means to do with time - different breeding seasons can isolate two populations.
Adaptive radiation occurs when one species shows slightly different adaptations to the same environment allowing both variants to survive.
How does adaptive radiation allow both variants of the species to survive in the same habitat?
Adaptive radiation occurs when different selection pressures lead to the evolution of a range of different adaptations in a species. This may occur at first in a single species but will eventually be seen in several related species. This allows them to exploit slightly different niches in a single environment, avoiding direct competition.