B15.2 - R* Theories of evolution Flashcards Preview

GCSE Biology Triple > B15.2 - R* Theories of evolution > Flashcards

Flashcards in B15.2 - R* Theories of evolution Deck (52):
1

What are humans surrounded by?

Humans are surrounded by an amazing variety of life on planet Earth

2

What have questions such as 'Where has it all come from?' and 'When did life on Earth begin?' done?

Questions such as 'Where has it all come from?' and 'When did life on Earth begin?' have puzzled people for many generations

3

Why is evolution very important?

Evolution is very important, because without it, we wouldn't have the great variety of life we have on Earth today

4

Darwin's theory of evolution by natural selection

Darwin's theory of evolution by natural selection is that all the species of living things alive today have evolved from the first simple life forms that scientists think first started to develop more than 3 billion years ago

5

Darwin's theory of evolution by natural selection tells us that all the species of living things alive today have evolved from the first simple life forms that scientists think first started to develop more than 3 billion years ago.
What do most of us do with these ideas?

Most of us take these ideas for granted, but they are really quite new

6

Up until the 18th century, what did most people in Europe believe?

Up until the 18th century, most people in Europe believed that God had created the world
They thought it was made, as described in the Christian Bible, a few thousand years ago

7

Up until the 18th century, most people in Europe believed that God had created the world.
They thought it was made, as described in the Christian Bible, a few thousand years ago.
However, what were scientists doing by the beginning of the 19th century?

By the beginning of the 19th century, scientists were beginning to come up with new ideas

8

Who was Jean-Baptise Lamarck?

Jean-Baptise Lamarck was a French biologist

9

What did Lamarck think about all organisms?

Lamarck thought that all organisms were linked by what he called a 'fountain of life'

10

Lamarck thought that all organisms were linked by what he called a 'fountain of life.'
What great step forward did he make?

Lamarck made the great step forward of suggesting that individual animals adapted and evolved to suit their environment

11

What was Lamarck's idea in relation to animals and evolution?

Lamarck's idea was that every type of animal evolved from primitive worms

12

Lamarck's idea was that every type of animal evolved from primitive worms.
What was the change from worms to other organisms caused by?

The change from worms to other organisms was caused by the inheritance of acquired characteristics

13

What did Lamarck's theory propose in relation to organisms and their features?

Lamarck's theory proposed that the way organisms behaved affected the features of their body - a case of 'use it or lose it'

14

If animals used something a lot over a lifetime, what did Lamarck think?

If animals used something a lot over a lifetime, Lamarck thought that this feature would grow and develop

15

If animals used something a lot over a lifetime, Lamarck thought this feature would grow and develop.
What would any useful changes that took place in an organism during its lifetime do?

Any useful changes that took place in an organism during its lifetime would be passed from a parent to its offspring

16

If an animals' feature wasn't used, what did Lamarck think happened?

If an animals' feature wasn't used, Lamarck thought it would shrink and be lost

17

In Lamarck's model of evolution, why do giraffes have long necks?

In Lamarck's model of evolution, giraffes have long necks, because each generation stretched up to reach the highest leaves, so each new generation had a slightly longer neck

18

Using Lamarck's theory, what would happen if a rabbit used its legs to run a lot, to escape predators?

Using Lamarck's theory, if a rabbit used its legs to run a lot, to escape predators, its legs would get longer
The offspring of that rabbit would then be born with longer legs

19

What did Lamarck's theory influence?

Lamarck's theory influences the way Charles Darwin thought, but there were several problems with Lamarck's ideas

20

Several problems with Lamarck's ideas

Several problems with Lamarck's ideas were:
1. No evidence for his 'fountain of life'
2. People didn't like the idea of being descended from worms
3. People could see quite clearly that changes in their bodies, such as big muscles, were not passed on to their children

21

How can you see evidence not supporting Lamarck's ideas for yourself?

You can see evidence supporting Lamarck's ideas for yourself:
If you dye a hamster's fur bright pink, its offspring will still be born with the normal fur colour because the new characteristic won't have been passed on

22

What do we now know in the great majority of cases in relation to Lamarck's ideas?

We now know in the great majority of cases, Lamarck's idea of inheritance cannot happen

23

We now know that in the great majority of cases, Lamarck's idea of inheritance cannot happen.
However, what did his ideas do?

However, his ideas paved the way for the scientists such as Darwin who followed him

24

What did our modern ideas about evolution begin with?

Our modern ideas about evolution begin with one of the most famous scientists of all time - Charles Darwin

25

What did Darwin do in 1831?

In 1831, Darwin set out as the captain's companion and ship's geologist and naturalist on HMS Beagle

26

Darwin set out in 1831 as the captain's companion and ship's geologist and naturalist on HMS Beagle.
How old was he?

He was only 22 years old at the start of the round the world voyage to South America and the South Sea Islands

27

Darwin set out in 1831 as the captain's companion and ship's geologist and naturalist on HMS Beagle.
What did Darwin plan to study on the trip?

On the trip, Darwin planned to study mainly geology, developing his knowledge of rocks and fossils

28

Darwin set out in 1831 as the captain's companion and ship's geologist and naturalist on HMS Beagle.
He planned to study mainly geology on the trip, developing his knowledge of rocks and fossils.
Yet, what happened as the voyage went on?

Yet, as the voyage went on, he became as excited by his collection of animals and plants as by his rock samples

29

Rhea

Rhea is an ostrich-like bird

30

In South America, what did Darwin discover?

In South America, Darwin discovered a new form of the common rhea, although he had almost finished eating it before he noticed the differences

31

In South America, Darwin discovered a new form of the common rhea, although he had almost finished eating it before he noticed the differences.
What set Darwin thinking?

Finding two different types of the same bird living in slightly different areas set Darwin thinking

32

On the Galapagos Islands, what was Darwin amazed by?

On the Galapagos Islands, Darwin was amazed by the variety of species

33

On the Galapagos Islands, Darwin was amazed by the variety of species.
What did he notice?

He noticed that they varied from island to island

34

On the Galapagos Islands, Darwin was amazed by the variety of species.
He noticed that they varied from island to island.
What did Darwin find?

Darwin found strong similarities between types of finches on the different islands, yet each was different and adapted to make the most of local conditions

35

Darwin set out in 1831 as the captain's companion and ship's geologist and naturalist on HMS Beagle.
What did Darwin collect during the voyage?

Darwin collected huge numbers of specimens of animals and plants during the voyage

36

Darwin set out in 1831 as the captain's companion and ship's geologist and naturalist on HMS Beagle.
Darwin collected huge numbers of specimens of animals and plants during the voyage.
What did he also make?

He also made detailed drawings and kept written observations

37

Darwin set out in 1831 as the captain's companion and ship's geologist and naturalist on HMS Beagle.
What did the long journey home give him?

The long journey home gave him plenty of time to think about what he had seen

38

Darwin set out in 1831 as the captain's companion and ship's geologist and naturalist on HMS Beagle.
The long journey home gave him plenty of time to think about what he had seen.
When did Charles Darwin return home?

Charles Darwin returned home after 5 years, with some new ideas forming in his mind

39

Darwin set out in 1831 as the captain's companion and ship's geologist and naturalist on HMS Beagle.
The long journey home gave him plenty of time to think about what he had seen.
Charles Darwin returned home after 5 years, with some new ideas forming in his mind.
After returning to England, what did Darwin do?

After returning to England, Darwin spent the next 20 years working on his ideas

40

Darwin set out in 1831 as the captain's companion and ship's geologist and naturalist on HMS Beagle
The long journey home gave him plenty of time to think about what he had seen
Charles Darwin returned home after 5 years, with some new ideas forming in his mind
After returning to England, Darwin spent the next 20 years working on his ideas.
What is Darwin's theory?

Darwin's theory is that all living organisms have evolved from simpler life forms

41

Darwin's theory is that all living organisms have evolved from simpler life forms.
How has this evolution come about?

This evolution has come about by a process of natural selection

42

Phenotypic variation

Phenotypic variation is when the individual organisms in a particular species tend to show a wide range of variation for each characteristic

43

Darwin's 1st main idea:

Darwin's 1st main idea was:
1. The individual organisms in a particular species tend to show a wide range of variation for each characteristic (phenotypic variation)
Organisms also have to compete for limited resources in an ecosystem

44

Darwin's 2nd main idea:

Darwin's 2nd main idea was:
2. Reproduction always gives more offspring than the environment can support
The organisms that have inherited the characteristics most suited to their environment - the 'fittest', are more likely to survive and breed successfully and they would be more successful competitors

45

Darwin's 3rd main idea:

Darwin's 3rd main idea was:
3. When they breed, they pass on the characteristics that have enabled them to survive and be successful to the next generation (their offspring)
The organisms that are less well adapted would be less likely to survive and reproduce, so they are less likely to pass on their genes to the next generation
Over time, beneficial characteristics become more common in the population and the species changes - it evolves

46

Charles Darwin came up with a really important theory about evolution.
What did he use to suggest the really important theory about evolution of evolution by natural selection?

To suggest the really important theory about evolution of evolution by natural selection, Charles Darwin used the observations he made on a huge round-the-world trip, along with experiments, discussions and new knowledge of fossils and geology

47

Phenotype

Phenotype is the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment

48

Genotype

Genotype is the genetic constitution of an individual organism

49

When Darwin suggested how evolution took place by natural selection, what did noone know about?

When Darwin suggested how evolution took place by natural selection, noone knew about genes

50

When Darwin suggested how evolution took place by natural selection, noone knew about genes.
What did he simply observe?

He simply observed that useful inherited characteristics were passed on

51

When Darwin suggested how evolution took place by natural selection, noone knew about genes.
He simply observed that useful inherited characteristics were passed on.
Today, what do we know?

Today, we know it is useful alleles that control the characteristics of the phenotype that are passed from parents to their offspring in natural selection

52

What did Darwin do in relation to iguanas on the Galapagos Islands?

Darwin was impressed by the marine iguanas he found on the Galapagos Islands and he studied them very carefully, comparing them in detail to land-dwelling iguanas