86. DARWIN'S THEORIES Flashcards
- What did Charle’s Darwin do in 1859?
- he published his theory on:
The Origin of Species by Natural Selection
- Define Evolution.
- this is the change in the inherited characteristics
- of Biological populations
- ver successive generations
- What is the “Origin of Species” Theory?
- Evolution refers to Descent with Modification
THE MECHANISM OF EVOLUTION:
- is Natural Selection
- What are the 2 main points of the Origin of Species Theory that was coined by Darwin?
- Descent with Modification
- Natural Selection is the mechanism of Evolution
- What is meant by: “Descent with Modification”?
- this is how we define Evolution
- the current species has descended from an Ancestral
Species - modifications have happened to this species along the
way
- What is meant by: “Natural selection is the mechanism of Evolution”?
- this means that it is the mechanism that allows for
descent with modification to take place
INDIVIDUALS WITH FAVOURABLE INHERITED TRAITS:
- are more likely to survive and reproduce
- this is known as survival of the fittest
THESE FAVOURABLE, HERITABLE TRAITS:
- accumulate in a population over time
- this results in a higher proportion of individuals with
traits that are more suited to their environments
- Give an example of one species that underwent a Descent with Modification (Evolution) ?
- Homosapiens
- Define “Natural Selection”.
- this is an evolutionary process
IT OCCURS WHEN:
- a population’s heritable variations
- are exposed to environmental factors
THESE ENVIRONMENTAL FACTORS:
- favour the reproductive success of some individuals
- over that of others
- the environment will define the population
- Give one example of Natural Selection.
- the population of beetles in a specific region
INITIALLY:
- the population of beetles varies greatly
- we have many beetles with different colours
- they range from very light to very dark
BIRDS STARTED TO EASILY SPOT THE LIGHT COLOURED BEETLES:
- these beetles were picked and killed
- the darker coloured beetles had the favourable trait
- they were surviving in their environment
- they started to reproduce more than the lighter
coloured beetles
- the amount of darker coloured beetles increased due
to their survival and reproductive success
- What does Darwin’s Theory of the Evolution of a species explain?
- it explains that the species evolves as descent with
modification - this is caused by Natural Selection
IT ALSO EXPLAINS:
- the unity of adaptations of organisms
- the unity and diversity of life
- What is meant by the “unity of life”?
- this refers to the similarities between living organisms
- it is caused by Evolution
IT ALSO REFERS TO THE IDEA:
- that all of life is connected through its long
evolutionary history
- What is meant by the “diversity of life”?
- this refers to the differences and variations between
living organisms - it is caused by Evolution
- What is an example of “Unity” in life?
- many related organisms will show similar anatomical
features
- Which concepts support the “Unity of life” statement?
- DARWIN’S CONCEPT OF EVOLUTION
- as descent with modification
- Define “Descent with Modification”.
- all living organisms are related
- this is because they are descended from a common
ancestor that lived in the past
- Define the creation of the Tree of Life according to Darwin?
- Darwin proposed that Natural Selection could enable
an ancestral species to split
THIS SPECIES WOULD SPLIT:
- into two or more descendant species
- this is what results in the Tree of Life
- What does this Evolutionary Tree of Elephants represent?
- it represents Descent with Modification
- What does this image represent?
- this shows a Primate evolutionary tree
-it is Phylogenetic - it shows how humans diverged from other apes about
5 million years ago
