The impact of small populations

Question 1

What does the gene pool of larger population ensures?

Answer 1

• lots of genetic diversity
• presence of many different genes and alleles

Question 2

What does genetic diversity lead to? How is this useful?

Answer 2

• leads to variation within a population
• essential in the process of natural selction
• the population can adapt and change over time

Question 3

What are some selection pressures?

Answer 3

• change sin the environment
• new diseases
• new pray
• new competitors
• human influence

Question 4

What is the problem with small populations?

Answer 4

• limited genetic diversity
• cannot adapt to change as easily
• more likely to become extinct

Question 5

What are limiting factors

Answer 5

factors which limit or decrease the size of a population

Question 6

What are the two types of limiting factors?

Answer 6

• density-dependant facotrs
  
  • dependant on population size
  • include competition, predation, parasitism, and communicable disease
• density-independant factors
  
  • affect populations of all siozes in the same way
  • including: climate change, natural diseasters, seasonal change, and human activities

Question 7

Whhat are population bottlenecks?

Answer 7

• large reductions in population size which last for at least one generation

Question 8

What are the effects of a population bottleneck?

Answer 8

• gene pool, along with genetic diversity, is greatly reduced
• effects will be seen in future generation
  
  • it takes thousands of years for genetic diversity to develop in a population through the slow accumulation of mutations

Question 9

What is the advantage of a genetic bottleneck?

Answer 9

• a beneficial mutation will have a much greater impact
  
  • lead to the quicker development of a new species
• this is though to have played a role in the evolution of early humans

Question 10

What is the founder effect began?

Answer 10

• small populations can arise due to the establishment of new colonies by a few isolated individuals, leading to the founder effect

Question 11

What is the founder effect?

Answer 11

an extreme example of genetic drift

Question 12

What are the characteristics of the new population (FE)?

Answer 12

• much smal;ler gene pools than the original population
• display less genetic vairation
• if carried to the new population
  
  • the frequency of any alleles that were rare in the original population iwll be much higher in the new, smaller population
  • will have a much bigger impact during natural selection