Topic 4: Evolution & Genetic Engineering Flashcards
Who came up with the theory of natural selection?
Darwin
What is evolution?
The slow and continuous change of organisms from one generation to the next
What is natural selection?
The process by which a characteristic gradually becomes more or less common in a population
What is the process of natural selection?
- Species shows a wide genetic variation due to sexual reproduction and mutations
- There is a selection pressure (e.g. competition)
- Organisms that are better adapted to the selection pressures are more likely to survive and reproduce
- This passes on the desired and advantageous gene and they become more popular
- This is called survival of the fittest
What theory does antibiotic resistant bacteria support?
Darwin’s theory of evolution & natural selection
What is the process of how bacteria becomes resistant to antibiotics?
- Random mutations mean some bacteria develop allele for antibiotic resistance
- Resistance bacteria survive the antibiotic and reproduce
- Recessive allele become more common in the population
What are the three fossils that provide evidence for human evolution?
Ardi
Lucy
Turkana boy
How old is the Ardi fossil?
4.4 million years old
What feet does the Ardi fossil have?
Ape like big toe for climbing
What limbs does the Ardi fossil have?
Ape like (long arms, short legs)
What brain size does the Ardi fossil have?
Like chimpanzees
How old is the Lucy fossil?
3.2 million years old
What feet does the Lucy fossil have?
Arched for walking
No ape like big toe
What limbs does the Lucy fossil have?
Between human and apes
What brain size does the Lucy fossil have?
Bit bigger than chimpanzees
How old is the Turkana Boy fossil?
1.6 million years old
What feet does the Turkana Boy fossil have?
Human like (adapted for walking)
What limbs does the Turkana Boy fossil have?
Human like (short arms, long legs)
What brain size does the Turkana Boy fossil have?
Like humans
Where was the Ardi and Lucy fossil found?
In Ethiopia
Where was the Turkana Boy fossil found?
Kenya
What are the three ways to date tools?
- Rock layer - how much sedimentary was built on top of it
- Carbon dating - dates carbon containing material found within a took
- Structural features - if it’s simpler, it’ll most likely be older
What is the trend between how stone tools developed and the human brain size?
As human brain size increased, stone tools developed positively
How have stone tools developed?
- Simple pebble tools used to scrape meat and crack bones open - 2.5 million years ago
- Tools were sculpted from rocks were used to hunt, dig, chop and scrape meat off bones
- Flint tools - pointed to be used as arrowheads, fishhooks, needles etc. - present day
What is the pentadactyl limb?
Limb with five digits