5.1 - Evidence For Evolution

Question 1

Define evolution

Answer 1

The cumulative change in the heritable charateristics

Question 2

Contrast preserve remains and traces’ evidence

Answer 2

• Preserved reains provide direct evidence of ancestral forms; bones, teeth, shell, leaves
• Traces provide indirect evidence of ancestral forms and include footprints, tooth marks, burrows and faeces

Question 3

Explain how fossils can be dated by determining the age of the rock layer (strata)

Answer 3

• Sedimentary rock layers develop in a chronological order, such that lower layers are older and newer strata form on top.
• Each strata represents a variable length of time that is classified according to a geological time scale.

Question 4

Use an example to explain how selective breeding has lead to in a species

Answer 4

Over the last 150,000 years many breeds of dogs have been developed by artificial selection from domestication wolves.

Question 5

Explain the process of artificial selection using selective breeding

Answer 5

Humans repeatedly select for and breed the individuals most suited to human uses.

Question 6

Examples of selective breeding and why

Answer 6

Horse breeding - race horses

Cows - increased muscle mass

Dogs - hunting and herding dogs

Question 7

State an example of analogous structures

Answer 7

Similarities between tail fins of whales and fishes

Question 8

State an example of homologous structures

Answer 8

The forelimbs of a human, mole, horse, porpoise and bat have the same bones, in the same relative positions.

Question 9

Contrast analogous structures and homologous structures (4)

Answer 9

Analogous structures are ones that have superficial similarities whereas Homologpus structures appear superficially different.

Homologous structures are structurally similar to each other whereas analogous structures when studied closely are very different to each other.

Analogous structures have had different origins whereas homologous have come from the same origin.

Analogous peform the same function whereas homologous sructures peform different functions.

Question 10

Contrast the meanings of convergent evolution and adaptive radiation

Answer 10

Convergent evolution is when structures have had different origins and have become similar because they peform the same or a similar function.

Adaptive radiation are strucutres that share the same origin and have become different from each other because they peform different functions.

Question 11

Define vestigal structure and example of a vestigal structure

Answer 11

A reduced structure that serves no function

The appendix in humans