Evolution Of Species Flashcards
What is a mutation
A mutation is a random change to genetic material DNA
What are environmental factors of mutation
They speed up the rate at which mutations occur
What are examples of environmental causes of mutations
Radiation- UV light, x-rays, gamma rays
Chemicals- mustard gas, colchicine, caffeine and cigarettes
Types of mutation
Neutral- no change to survival or ability to reproduce
Advantageous- increase “”
Disadvantageous- decrease “”
What is an adaptation
An inherited characteristic that makes an organism well suited to survival in it’s environment/ niche.
What are two types of adaptation
Behavioural
Physical
What is variation
The new alleles that cause adaptation result in variation in a population. This variation allows the population to evolve to deal with changing environmental conditions
What is natural selection
The process of natural selection allows only the best adapted individuals in a population to survive and reproduce. Survival of the fittest
What is speciation
New species are formed when a population is separated by an isolation barrier
What are the three types of isolation barrier
Geographical- mountain range/ ocean
Ecological- pH/ salt concentration
Behavioural- mating call / active time of day
What are the four steps of speciation
- Population becomes separated by an isolation barrier
- Mutations occurs in each subpopulation
- Natural selection selects for different mutations due to selection pressures
- Each sub-population evolves until they become two new species
What is the acronym for speciation
Iguanas Must Not Steal
