Scientific Contribution To Theory Of Evolution Flashcards
What years was Lamark present?
1744-1829
What are the points in lamarks theory?
- species increased in (linear) complexity over time, until they achieved a level of perfection
- Inheritance of acquired characteristics- species change in their lifetime to meet their needs and pass their traits on to their offspring
- progressive adaptation-used parts would increase in ability, unused parts would disappear
Give an example of lamarks theory
Short neck giraffe stretched its neck and grew over its lifetime and passed trait to its offspring
When was Darwin alive?
1809-1882
What is the theory of evolution by natural selection
a theory explaining how life has changed, and continues to change,
during Earth’s history
What are 4 of Darwin’s observations for his theory of evolution by natural selection?
Observation 1
Individuals within a species vary in many ways.
Observation 2
Some of this variability can be inherited.
Observation 3
Every generation produces far more offspring than can survive and pass
on their variations.
Observation 4
Populations of species tend to remain stable in size.
Inference
What are 3 inferences of Darwin’s theory of evolution by natural selection?
Inference 1
Members of the same species compete with each other for survival.
Inference 2 Individuals with more favourable variations are more likely to survive
and pass them on. Survival is not random.
Inference 3 all these individuals contribute proportionately more offspring to succeeding generations the favourable variations will become more common
What is survival of the fittest?
the idea that the organisms that are the fittest leave the most offspring, so those organisms win the struggle for survival;
“fittest” refers to best adapted
What is the theory of natural selection?
Organisms produce more offspring than can survive. Therefore, organisms compete
for limited resources.
• Individuals of a population vary extensively, and much of this variation is heritable.
• Individuals that are better suited to local conditions survive to produce more offspring.
• Processes for change are slow and gradual.
What is the mechanism of natural selection?
- Individuals have traits.
2 Variation exists in a population.
3.Environment causes “pressure”.
4.Adaptations are passed on.
5.Traits become more common in a population —>evolution
Give an example of Darwin’s theory of natural selection
Finches on Galapagos with different beak structures
What are the differences between Lamark and Darwin’s theories? Compare
Acquired Traits
- change within lifetime of individual
- change as a result of environmental conditions
Natural Selection
- change is seen over many generations
- change is based on survival of the fittest, influenced by various factors including the envir
What is descent with modification?
Darwin’s theory that natural selection does not demonstrate progress, but merely results from a species’ ability to survive local conditions at a specific time
Eg arms and wings homologous structures
