2: Evolution in real time

Question 1

Describe macroevolution

Answer 1

Gradual
Accumulation of small changes

Question 2

Describe microevolution

Answer 2

Can happen quickly
E.g Biston betularia (peppered moths)

Question 3

Define competition and give an example

Answer 3

occurs when 2 species have similar requirements, they cannot coexist
E.g Darwin’s finches
Bill size variation is response to competition for food sources

Question 4

What is explotation of evolution? give some examples

Answer 4

Many species exploited by humans in some way e.g hunt the biggest deer, use of fishing nets
= Rapid evolution in wild populations
E.g Hunting of Bighorn sheep (as trophies) = large rams targeted, genes for big horns become disadvantageous and removed from pop.
Effects of selective hunting on fitness & pop. size

Question 5

define phenology

Answer 5

Timing of life events
→Differs based on environ conditions e.g optimal to flower earlier in poor conditions

Question 6

Give some selection pressures on parasites

Answer 6

Death of hosts stops spread
High virulence of parasite leads to short period of spread
Lower virulence leads to more secondary cases
Hence selection on parasites for less virulence
Higher exposure → resistance

Question 7

Describe what happened to European rabbits and the myxoma virus

Answer 7

• European rabbits (introduced into Aus in 1859)
• Reached pest status, virus released as biological - control
• Coevolution of virulence & resistance
  = Decrease and stabilisation of virulence

Question 8

Why do parasites offer some of the best evidence for evolution in action?

Answer 8

Parasites have a large number of gens in short time
Intense selection pressure on hosts
Hence rapid evolution