Evolution Flashcards
What did Charles Darwin study!?
He studied variation in plants, animals and fossils during a five-year voyage around the world in the 19th century
On his 5 year voyage around the world were did Darwin visit and what was the name of his ship!?
Darwin visited four continents on the ship HMS Beagle.
List some of the organisms Darwin observed…….
finches, tortoises and mocking birds,
Where did Darwin study these examples!?
during his five week visit to the
Galapágos Islands
, near Ecuador in the Pacific Ocean. He continued to work and develop his ideas once he returned from his voyages.
What did Darwin’s Theory of evolution challenge!?
It challenged the idea that God made all the animals and plants that live on Earth, which contradicted the commonly held Christian views of his era
When did Darwin publish his work and ideas!?
Not until 28 years after his voyage
What was Darwin’s world expedition observations backed by!?
They were backed by many years of experimentation
What did Darwin propose after discussing with scientists and using his developing knowledge of geology and fossils!?
1.individual organisms within a particular species show a wide range of variation for a characteristic
2.individuals with characteristics most suited to the environment are more likely to survive and to breed successfully
3.the characteristics that have enabled these individuals to survive are then passed on to the next generation
What is this proposal called!?
Natural selection
Why can bacteria evolve quickly!?
Bacteria
can evolve quickly because they reproduce at a fast rate
What do mutations of bacteria produce!?
They produce new stains
What might some bacteria be resistant to!?
Some bacteria might become resistant to certain
antibiotics
Give an example of a bacteria that is resistant to antibiotics…..
penicillin, and cannot be destroyed by the antibiotic
What are antibiotics!?
Substance that controls the spread of bacteria in the body by killing them or stopping them reproducing.
What is the evolution of bacteria an example of!?
Natural selection and it supports Darwin’s theory of evolution
What is the first main step in the development of resistance!?
random
mutation
occur in the genes of individual bacterial cells
What is the second main step in the development of resistance!?
some mutations protect the bacterial cell from the effects of the antibiotic
What is the third main step in the development of resistance!?
bacteria without the mutation die or cannot reproduce when the antibiotic is present
Why has the number of resistant strains increased!?
partly due to the overuse and misuse ofantibiotics
What has this strain increase resulted in!?
This has resulted in more infections that are difficult to control.
What is MRSA!?
methicillin-resistant staphylococcus aureus
Why is MRSA dangerous!?
it is very dangerous because it is resistant to most antibiotics.
List the 3 things that must be done to reduce the rate of development of antibiotic resistance strains…..
1.doctors should not prescribe antibiotics inappropriately, such as for the treatment of non-serious infections
2.patients should always complete the full course of antibiotics to ensure all bacteria are killed and none survive to mutate and form resistant strains
3.the agricultural use of antibiotics should be restricted
What was the first antibiotic to be produced on a mass scale!?
Penicillin in the 1940s
Where does penicillin derive from!?
It is derived from the Penicillium fungus
When were new types of antibiotics discovered!?
During the 1950s and 1960s
What have recent concerns of increasing resistance created!?
The need for new antibiotics but they are expensive and very slow to develop
What do some scientists fear about resistant bacteria!?
Some scientists fear that we are fighting a losing battle against resistant bacteria, which may ultimately lead to people dying from simple infections, for example following operations.
What is a fossil!?
A fossil is the preserved remains of a dead
organism
from millions of years ago
Where can a fossil be found!?
Fossils are found in rocks
What can fossils be formed from!?
- Hard body parts
- parts of organisms that have not decayed because one or more of the conditions needed for decay are absent for
3.preserved traces of organisms
Give some example of hard body parts…..
such as bones and shells, which do not decay easily or are replaced by minerals as they decay
Give an example of parts of organisms that have not decayed because one or more of the conditions needed for decay are absent for…….
example, dead animals and plants can be preserved in
amber
, peat bogs,
tar
pits or in ice
Give an example of persevered traces of organisms…..
such as footprints, burrows and rootlet traces - these become covered by layers of
sediment
, which eventually become rock
Where are fossils of simplest organisms found!?
Where are fossils of the more complex organisms found!?
fossils of more complex organisms in the newest rocks
How does these fossil placements support Darwin’s theory!?(simple- old rocks, complex-new rocks)
This supports
Darwin’s
theory of
evolution
, which states that simple life forms gradually evolved into more complex ones.
What can scientists tell by studying fossils!?
By studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth.
Why are there gaps in fossil records!?
because many early forms of life were soft-bodied, which means that they have left few traces behind.
How have some traces of fossils been destroyed!?
What traces there were may have been destroyed by geological activity. This is why scientists cannot be certain about how life began.
What are fossils!?
Fossils are the imprints or remains of
organisms
which were alive millions of years ago
What does the fossil record provide!?
The fossil record provides evidence for
evolution
.
What does Darwin’s theory state about organisms alive today!?
Darwin’s theory states that all organisms alive today evolved from more simple life forms
What are the names of the 2 fossils that can provide evidence of human evolution!?
Ardi and Lucy
Where were ardi and Lucy found!?
They were both found in Africa
Describe ardi…
Ardi is a female human-like fossilised skeleton that dates from 4.4 million years ago