5. Further Evidence for Evolution Flashcards Preview

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Flashcards in 5. Further Evidence for Evolution Deck (21):

What are domesticated animals (animals reared for human use) related to?

- your mum
- wild species
- in many cases, the domestic and wild animals can still interbreed*

*NB: If the two populations (domesticated and wild) could interbreed, the 'wild species' answer would change to 'wild population'.


How have domesticated breeds been developed?

domesticated developed from wild species:
- selecting individuals with desirable traits, and breeding them


Define selective breeding.

selecting individuals with desirable traits, and breeding them


How does selective breeding contribute (as a piece of evidence) to the theory of evolution?

striking differences between heritable characteristics of domesticated breeds = evidence that species evolve


What else, apart from selective breeding, has given us strong evidence for evolution?

research into fossils


Give some examples of organisms that have been found as fossils.

trilobites and dinosaurs


Can any organisms alive today be found as fossils?



What does the fossil record suggest?

that organisms change over time

- we have found fossils
- they are very old, no fossils have been found of organisms that are alive today
- this shows that organisms change over time (as the theory of evolution states)


What does dating rocks allow us to do?

we can deduce the age of the fossils that lived in the rock
from that we can deduce when they lived on the earth


What does the sequence in which organisms appear in the fossil record match?

the sequence with which organisms appear in the fossil record matches their complexity, going from less to more complex as the fossils get closer to the present day


What appears in the fossil record first? Then? When do land vertebrates begin to appear in the fossil record?

- bacteria and simple algae
- fungi and worms
- recently (relative to bacteria)


So what can we deduce about a particular organism from the fossil record?

their likely ancestors


Give an example of a fossil that has similarities to present day vertebrates.



Give similarities and differences of the Acanthostega to modern day vertebrates?

- four legs like most amphibians, reptiles and mammals

- eight fingers, seven toes (no organism today has this)
- legs + fish like tail + gills = lived in water


What does the Acanthostega example show?

that land vertebrates could have evolved from fish via an aquatic animal with legs


What are dark varieties of light coloured insects called?



What is the most famous example of melanism as evidence for evolution?

Biston betularia (peppered moth)


Which variety of the Biston betularia was rare in England pre 19th Century?

the melanistic variety was rare, the peppered variety was common


What happened to the speckled variety of the peppered moth in industrial areas?

became much less common, the melanistic variety became more common


Why is the Biston betularia example evidence of evolution?

change in heritable characteristic (appearance of wings changing colour from speckled dark bits to fully dark) is an example of evolution


Give the simple* explanation of industrial melanism (in Biston betularia)

*the answer is very long but it is logical so it is a simple explanation

- adult Biston betularia moths fly at night to try and find a mate
- during the day they roost on the branches of trees
- in unpolluted areas tree branches are covered in pale-coloured lichens, so peppered moths are well camouflaged against them
- sulphur dioxide pollution kills lichens on tree branches and soot from coal burning blackens them
- melanic moths are well camouflaged against dark tree branches
- birds and other animals that hunt in daylight predate moths if they find them
- in areas that became industrial the peppered variety were mostly found and eaten and a higher proportion of the melanic variety survived to breed and pass on the dark wing colour, causing Biston betularia populations to eveolve from being peppered to melanic.

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