Download Evolution Review Answers

Evolution Review Answers
1.
7.
C
2. C
3. C
4. A
5. B
6. C
Lyell: the Earth is very very old (time for small changes to become big) and geological features
are constantly changing (provides a changing environment for life to adapt to)
Malthus: Populations grow faster than their food supply, leading to competition, war and
starvation (nature is the same, so the best adapted survive and pass on their genes)
Lamarke: Animals change according to their environment (basis for natural selection).
8. Artificial selection has lead to the incredible diversity in domestic dogs (Chihuahua to great
dane), horses (miniature pony to Clydesdale), cats (sphinx to Abyssinian), sea cabbage
derivatives (broccoli to cauliflower), cows (all sorts of beef cows to all sorts of dairy cows), etc
9. a) speed in cheetahs, height in horses, human brain complexity: directional
b) birth weight in babies, crocodile anything (but aggressiveness would be a good answer):
stabilizing
c) colour in butterflies (the medium amount of pigment is selected against), size in sticklebacks
(the average size does not reproduce): disruptive
d) Colouration in cardinals (birds), antlers on deer and moose, dance of birds, etc.: sexual
selection.
e) Chickens with huge muscles in their chest, dairy cattle with large udders.
10. No because wildlife has not been exposed to the antibiotics. So, the bacteria that are resistant are
outcompeted, so they are not very common in the population of bacteria that exist in wildlife.
Once you give wildlife antibiotics, the whole population of bacteria will probably be destroyed.
11. Probably, the founding population were shorter than average. Plus, the location must have
selected for the shorter individuals (don’t need to eat as much, maybe there were no predators
threatening the smaller ones). There could not have been any interbreeding with the old
population.
12. Many possible answers, but here’s a sample:
Nest building probably began in birds that didn’t fly and lived on the ground. The ones that dug
out a little spot to lay eggs in the branches and leaves may have done better because the eggs
stayed warmer or were more camouflaged. Then, as the trait became fixed in the population, the
ones that actually moved the sticks from the middle of the hole to the edges were selected for
because the next was more protected. As birds evolved the ability to fly, they had to transport
materials to create nests in trees (there would have been significant pressure to nest in trees due to
predation.
13. a) Tiger populations have been significantly reduced in the last thousand years. The bottleneck
effect reduces the genetic variability of the populations. Breeding tigers from very distant
populations should increase the genetic variability of the resulting generation.
b) It increases the gene pool.
c) It should reduce the bottleneck, but the bottleneck is already present.
d) These, and taking organisms from different populations to put into zoos in the first place. If a
whole family of tigers is sent to different zoos, then putting them back together does not increase
genetic variability. Reduce habitat destruction, pollution, and poaching!
14. True.
15. a) Punctuated equilibrium – many niches have opened up (the species have been eliminated), so
remaining organisms would take over these niches and adapt to them (adaptive radiation).
b) Gradualism – the species on the island would adapt to the new predator, and the predator
would create a niche for itself. It would change, but it probably wouldn’t create many different
species all at once.