CB4: Natural Selection and Genetic Modification Flashcards
Define Evolution
the gradual change in the characteristics of a species over time
What is a fossil?
Preserved remains of a dead organism which help scientists to find out more about human evolution
Name the four main fossils we use to prove evolution
- Ardi (Ardipithecus ramidus)
- Lucy (Australopithecus afarensis)
- Homo habilis
- Homo erectus
Describe Ardi
- may have been able to walk upright but had grasping big toes which allowed her to climb trees
Describe Homo habilis
feet adapted to walking upright - feet like ours, becoming smaller, arms shorter
Describe Homo erectus
- body structure adapted to walking and running
- feet getting smaller and spines getting straighter
How are tools used as evidence for human evolution?
Scientists can work out the ages of the layer of rocks the tools are found in and they assume that the layer of rock and the tool are the same age
How do tools show evolution of humans?
The oldest stone tools are the simplest whereas the newer ones are more sophisticated, showing that as species progressed, their work became more sophisticated and they became much smarter
Who came up with the ideas about evolution?
Charles Darwin
State and explain what the acronym GENIE stands for
Genetic variation: the characteristics of individuals vary due to genetic variation + mutations
Environmental change: conditions in an area change which results in competition among organisms
Natural Selection: those better adapted to said environmental change survive…
Inheritance: and reproduce, which results in their offspring inheriting their favourable genes
Evolution: if the environmental conditions remain changed, natural selection occurs over and over again, and a new species evolves with all the individuals having ‘better adapted variations’
What are evolutionary trees?
Charts that show common ancestors between species
Define resistance
How protected something is against another thing
Why were Darwin’s ideas rejected at the time?
- contradicted the idea that God was the creator of all species on Earth
- not enough evidence at the time as few studies had been done on how organisms change over time
- the mechanism of inheritance and variation weren’t known at the time
Describe the process of antibiotic resistance
- Bacteria in a population show variation in the amount of resistance toward a certain antibiotic
- Course of antibiotics begins
- With time, the antibiotic kills more and more bacteria. The most resistant bacteria take the longest to die
- As a result, the bacteria can pass on the advantageous gene to their offspring, creating a whole new strain of resistant bacteria
Describe the classification system created by Carl Linnaeus
Living organisms are classified into groups depending on their structure and characteristics
What are the five kingdoms?
- Plants
- Animals
- Protists
- Fungi
- Prokaryotes