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
What do ardi’s bones show!?
show that she was probably able to walk upright but she had very long arms and long big toes.
Describe Lucy…
Lucy is also a female human-like fossilised skeleton, and dates from 3.2 million years ago
What do Lucy’s bones show!?
Lucy’s bones suggest that she walked in an upright position, like a human, but possessed a relatively small ape-like skull.
What do the bones in ardi’s feet suggest!?
The bones that make up Ardi’s feet suggest that humans and chimpanzees evolved separately.
What do the bones in Lucy’s feet suggest!?
Lucy’s foot bones show that she had similar feet to modern humans but with much more curved toes.
Who found the additional evidence for human evolution!?
were found by the archaeologists Mary and Louis Leakey. Mary was British and her husband, Louis, was Kenyan
How old were the fossils the Leakey couple found!?
The couple discovered fossils that date from 1.6 million years ago
What do the skeletons of the Leakey fossils look like!?
The skeleton looks much more like that of a modern human than either Ardi or Lucy
What does the most recent skeleton suggest!?
This most recent skeleton suggests that humans may have evolved in Africa.
What also provides evidence of human evolution!?
Tools
What are primitive tools!?
Flint and axes
What age are these tools said to be from!?
Palaeolithic Age (10,000 to 2.5 million years ago)
What tools are described as the more advanced tools!?
Arrow heads
What age are arrow heads said to be from!?
Mesolithic Age (6,000 to 10,000 years ago
And what age are the EVEN MORE advanced tools from!?
Neolithic Age (4,000 to 6,000 years ago).
Why are the dates for the tools only approximate!?
These dates are only approximate, as the tools have been dated from the environments they were found in
What environments are fossils usually found in!?
as the tools have been dated from the environments they were found in. This is often the layer of sediment that surrounds the tool.
How can dating fossils be done!?
Dating can be done by radiocarbon dating or other techniques which look at the amounts of elements like iron or potassium.
What is usually assumed about the age of the fossil!?
is the assumed that the tool is approximately as old as the rock which surrounds it.
Living organisms are grouped depending on what 2 factors!?
groups depending on their structure and characteristics
WHO development this classification system!?
This system was developed in the eighteenth century by Carl Linnaeus
What does the classification of species allow!?
The classification of
species
allows the subdivision of living organisms into smaller and more specialised groups.
What is the name for the first division of living things!?
Kingdoms
How many kingdoms are there!?
5
List the kingdoms in order….
1.animals (all multicellular animals)
2.plants (all green plants)
3.fungi (moulds, mushrooms, yeast)
4.protists (Amoeba, Chlorella and Plasmodium)
5.prokaryotes (bacteria, blue-green algae)
What are the names of the father divisions in order….
phylum
class
order
family
genus
species
What is a phylum!?
A taxonomic rank between kingdom and class (the plural is phyla). The arthropods, for example, are a phylum.
What is a genus!?
A rank in classification below family and above species
What is a species!?
A type of organism that is the basic unit of classification. Individuals of different species are not able to interbreed successfully.
What are the categories within the phylum!?
1.chordata, which have backbones
2.arthropod, which have jointed legs and an exoskeleton
3.annelids, which are segmented worms
Class is an additional sub-division meaning that Chordata phylum can be divided Into…..
Mammals
Birds
Amphibians
Fish
Reptiles
Mammals can be further subdivided into a variety of different groups such as…..
Carnivores
Primates
Orders can be broken down into families. List 2 examples
Canidae- dogs
Felidae-cats
What can orders be broken down into!?
Families
Genus, the Felidae family can be further sub-divided into four genus list examples:
acinonyx - cheetah
panthera - lion and tiger
neofelis - clouded leopard
felis - domestic cats
Species is the final classification stage, and the genus panthera can be divided into:
panthera leo (lion)
panthera tigris (tiger)
As an example, what is the complete breakdown of the classification of lions:
kingdom - animal
phylum - vertebrate
class - mammal
order - carnivorous
family - cat
genus - big cat
species - lion
How do you remember the order for the Linnaeus system of classification!?
Kids Prefer Candy Over Fresh Green Salad
What is binomial!?
Having two parts to a name. In the binomial system of classification, each organism is named for its genus then its species. It is named using Latin words
Why is the binomial system important!?
it is important because it allows scientists to accurately identify individual species
Why was the grouping of families added to the system of classification!?
It was added to allow the large number of new species to be included in this system
How have Linnaeus’s Original ideas been adapted!?
Linnaeus’ original ideas have been adapted, but continue to be accepted and as new species are identified they can be fitted into the current classification system.
Originally, what couldn’t Linnaeus distinguish between!?
Linnaeus couldn’t distinguish between different types of organisms such as
algae
,
lichens
and
fungi
What is an algae!?
group of organisms that photosynthesise but lack the complex range of cell types and organs found in land plants. Most algae are aquatic. All have chloroplasts.
What are Lichens!?
A type of fungus that grows on rock.
What is a fungi!?
Non-green plants that obtain their energy by decomposing dead organic remains.
What was made difficult due to the inability to examine such as organisms!?
The inability to examine such organisms in detail made separation of these difficult at the time.
As more scientific methods developed, what did it allow scientists to do!?
it allowed scientists to examine organisms in more detail and note important features, such as the identification of sex organs
As well as being able to note important features what else did developing more scientistic methods allow!?
It allowed more divisions to be created, and with the advancement of technology, this allowed the development of Linnaeus’s classification system.
What does the advanced technology associated with biology allow!?
It has allowed the current classification system to be enhanced by using genetic analysis of DNA sequences.
What did Linnaeus’s system originally rely on!?
It relied purely on human judgement in order to compare the characteristics of various organisms
What have the comparison of DNA sequences allowed!?
have allowed the relationship of organisms to be explored further
What has happened to some species due to comparisons now being made by DNA sequences!?
some cases,
species
that are more closely related may have fewer differences contained within the DNA sequences
How are DNA sequences shown!?
DNA sequences are shown as the order of DNA bases, abbreviated as A, C, G and T.
There has been debate in history over what!?
the classification of the red panda and the giant panda
What do some people argue about the red and giant panda!?
that they should belong to the bear family and others argued that they are more like racoons
What did scientist find when solving this debate!?
Following the development of DNA sequencing technology, it has been shown that the red panda and giant panda are not very closely related genetically
What does DNA analysis of the red and giant panda show!?
DNA analysis showed the giant panda to be a bear, and the red panda to be more closely related to a racoon.
What did Carl woese develop!?
The three-domain system
What is the three-domain system based on!?
This is based on evidence genetic analysis.
What do genes of an organism code for!?
Proteins
What has been demonstrated about some organisms’ genes!?
that some organisms have parts of their genes that are not used in making proteins and other organisms that use entire genes to code for proteins, with no unused portions.
And what has this information about some organism’s coding informed us!?
This information has informed the three-domain system.
What does the updated three-domain system divide into!?
1.Archaea (primitive bacteria)
2. Bacteria ( true bacteria)
3.Eukaryota (including protists!fungi!plants!animals)
Describe Archaea (primitive bacteria)
These cells usually live in extreme environments. They have no nucleus and have unused sections of genes.
Describe bacteria (true bacteria)
Bacteria cells have no nucleus and no unused sections of genes
Describe Eukaryota (including protists, fungi, plants and animals)
These have a nucleus and have unused sections of genes.
List the 2 types of archaea used in the three-domain system …..
Halophiles
Thermophiles
List the 2 types of bacteria used in the three-domain system….
Cyanobacteria
Heterotrophic bacteria
List the 8 types of eukaryota used in the three-domain system…
Animal
Fungi
Plants
Chromists
Alveolates
Rhodophytes
Flagellates
Basal protists
