Evolution Flashcards Preview

Unit 2 advanced higher biology > Evolution > Flashcards

Flashcards in Evolution Deck (14)
Loading flashcards...
1

what is evolution?

change over time in the proportion of individuals in a population
differing in one or more inherited traits

2

what is an example of a random process

genetic drift
mutations

3

what is an example of a non random process

natural selection
sexual selection

4

what is the disadvantage of a small population?

genetic drift is more important
alleles are more likely to be lost from the gene pool

5

what is a mutation

variations of traits
from new sequence of DNA to form new alleles
beneficial, no change, effect

6

what is genetic drift?

change in populations allele frequency due to chance

7

what can shrink a population

bottleneck effect
founder effect

8

what is the bottleneck effect?

size of initial population reduced eg natural disaster
genetic variation is different from initial population
alleles over represented
alleles under represented

9

what is the founder effect?

few individuals from a large population
colonies another habitat
alleles in new population, not represent original

10

what is natural selection?

environmental conditions determine which individuals in a population produce the most offspring
accumulates favourable genotypes

11

what are the two types of sexual selection?

intersexual
intrasexual

12

what is intrasexual selection?

selection between same sex
compete with each other
warn off competition

13

what us intersexual selection?

females being selective about their choice of male

14

what is sexual dimorphism?

distinct difference in size or appearance between the sexes of animals in addition of sexual organs