Speciation

Question 1

Describe disruptive selection

Answer 1

•Selection agains intermediate traits/average
•Both extreme phenotype has increased reproductive success= improved survival/ability to reproduce and find a mate
•Alleles for both extreme phenotype are passed on to future generations in greater numbers
•Over time, frequency of both extreme alleles, coding for extreme phenotypes, increases
•Alleles frequency coding for mean phenotypes decrease

Question 2

Name 3 sources of genetic variation

Answer 2

•Mutation-changes DNA nucleotide sequence forming new alleles
•Meiosis- crossing over and independent segregation in the first meiosis division
•Random fertilisation of gametes during sexual reproduction

Question 3

Define allopatric speciation

Answer 3

Formation of new species from different populations in different areas

Question 4

Define sympatric speciation

Answer 4

Formation of new species from reproductive isolation in a population living in the same area