Biology is the best

1. EVOLUTION BY NATURAL
SELECTION
BY MADALANE R.T 216070053

2. OBSERVATIONTS
1.MEMBERS OF THE POPULATION
VARY IN GREAT TRAITS
2. Traits are transferred from
parent to offspring
3. All species are able to produce
offspring
4.If the environment lacks
survival resources such as food,
offspring do not survive.

3. 1. First conclusion:
 Individuals that has good inherited traits of higher probability of surviving they
tend to be at advantage of producing more offsprings than the other individuals.
2. Second conclusion:
 The inequality of survival of individuals and reproduce will result into the
accumulation of favourable traits in the population over generations.

4. Natural Selection
 Individuals with heritable traits survive and reproduce at a
better rate
 Natural selection is capable of increasing the adaptaion of
organisms to their environment overtime
 The new change of the environment results in the
adaptation of these new species giving them suitable
conditions

5. Speciation
 Speciation → the origin of new species
 Two types of speciations Allopatric and Sympatric.

6. Allopatric
 The gene flow is disturbed and reduced when a
population is divided into a geographically isolated
population.
 The barrier is determined by the ability of the population
to disperse
 Mutation, natural selection and genetic drift bring about
the independent evolution of populations(populations),
for an instance the population of snow wolfs and jackals is
different therefore will result in an independent change
 The geographic isolation blocks the gene flow between
population.

7. DIFFERENCES BETWEEN ALLOPATRIC AND
SYMPATRIC SPECIATIONS
ALLOPATRIC SYMPATRIC
The gene flow is disturbed and reduced when a
population is divided into a geographically isolated
population
Speciation occurs in geographically overlapping
populations
The barrier is determined by the ability of the
population to disperse
It can result from the appearance of new ecological
niches
Mutation, natural selection and genetic drift bring
about the independent evolution of populations
It occur due to the following aspects polyploidy,
natural selection, or sexual selection
The geographic isolation blocks the gene flow
between population.
The reproductive barrier isolates a population
without the effect of the geographic separation
Reprodctive isolation between populations is
directly proportional to the distance between them
Reproductive isolation is due the existence of the
biological factors, that can disturb the production

8. Mechanisms
of
production
BREEDING AT DIFFERENT
TIMES OF THE YEAR
SPECIFIC COURTSHIP
BEHAVIOUR
ADAPATATION TO
DIFFEREBT POLLINATORS
INCOMPATILIBILTY OF
EXTERNAL REPRODUCTIVE
ORGANS
PREVENTION OF
EMBRYONIC DEVELOPMENT
PREVENTION OF
FERTILIZATION