Science > Year 9 science Evolution > Flashcards

Year 9 science Evolution Flashcards

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1
Q

By studying the Galapagos finches what did Charles Darwin realise

A

He realised that species must evolve and adapt to their surroundings.

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2
Q

Evolution and natural selection state that

A

organisms that are well-adapted to their environment have a higher likelihood of surviving and reproducing.

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3
Q

What are species?

A

A group of organisms that can produce fertile offspring together

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4
Q

What is evolution?

A

The gradual change in species over time

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5
Q

What is natural selection?

A

The process where better-adapted organisms survive and reproduce.

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6
Q

Evolution is mainly about..

A

The survival and spread of beneficial traits within the entire population over time

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7
Q

When organisms reproduce what do they pass on to their offspring?

A

Beneficial traits

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8
Q

What is the ongoing process described as?

A

Survival of the fittest

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9
Q

Over generations, small differences develop within

A

groups of a species

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10
Q

What can happen to groups of a species over generations?

A

They can begin to branch off from each other, eventually becoming distinct species

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11
Q

What are some resemblances humans and apes share?

A
  1. Opposable thumbs
  2. Facial expressions
  3. Walking upright
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12
Q

What is an ancestor?

A

A species or individual from which later species developed

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13
Q

What is speciation?

A

Evolutionary process that takes us from a common ancestor to a new, distinct species

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14
Q

New species emerge when…

A

populations change so much from one another that they can no longer interbreed to produce viable, fertile offspring.

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15
Q

What does viable and fertile mean?

A

Viable means able to survive and fertile means able to reproduce and produce offspring

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16
Q

Does evolution always take millions of years to occur?

A

No, it can occur rapidly in the case of bacteria

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17
Q

Do new species increase biodiversity?

A

yes, ecosystems experience an increase in biodiversity

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18
Q

This enhanced biodiversity strengthens the ecosystem by

A
  1. Improving stability
  2. Greater nutrient cycling
  3. Increasing its ability to withstand climate change or disease
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19
Q

What is biodiversity?

A

The variety of species in a particular habitat or ecosystem

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20
Q

What is a problem with species?

A

Some species are similar enough that they can interbreed, BUT the offspring they make are NOT FERTILE. often known as a hybrid

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21
Q

What are hybrids?

A

The offspring of two different species

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22
Q

Give me an example of a hybrid

A

A male donkey and a female horse can produce a mule. The mule is unable to reproduce(sterile)

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23
Q

Why isn’t a hybrid able to reproduce?

A

The chromosomes from the two different species are too different, and don’t match well enough

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24
Q

What would happen if there wasn’t a biological boundary?

A

The offspring might have mixed up chromosomes that don’t work well together, making them weak, sick and unable to have babies.
Nature stops this from happening by creating sterile hybrids ro keep species separate and healthy.

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25
The sterility acts as a
Biological boundary which prevents mixing of genes between different species
26
Trade offs are?
Trade-offs are traits that may benefit an organism in one way, like attracting a mate, but also make it more vulnerable in another way, such as attracting predators.
27
Short-term VS Long-term
Organisms that reproduce quickly can pass on beneficial traits and evolve faster, but individuals typically die sooner
28
What is risk of extinction?
If a species cannot adapt quickly enough to changing conditions LIKE sea ice melting it may die out
29
Biodiversity is a function of..
Biodiversity is the variety of species in an ecosystem and is a result of evolution through natural selection, involving processes like changes in populations over time, survival of the fittest, and speciation.
30
What are the limits of evolution?
Trade offs, Short-term VS long-term, Risk of extinction and biodiversity
31
Natural selection favours traits that are
beneficial for survival
32
Traits are guided by
VISTA
33
What does VISTA stand for?
Variation- Exists within a species Inheritance- Traits can be passed onto offspring Selection pressures- Favour certain traits within an environment Time- Allows for favoured traits to increase in a population Adaption- Leads to evolutionary change
34
What does variation mean?
Differences in traits among individuals of the same species.
35
Differences can be in..
Size, Shape, Colour or any innate behaviour for example an octopus mimicking a dangerous predator to avoid being eaten. Innate means present from birth and NOT learned.
36
What would happen without variation
Natural selection cannot occur. It is needed as nature selects options that VARIATION provides for survival. like squid's camouflage
37
The more advantageous traits an individual gets the...
better their chances of surviving and reproducing in their specific environment.
38
Traits can range from
physical to behavioural traits
39
Inheritance and isolation limits what?
Limits interactions between groups, leading to unique traits and potentially new species evolving.
40
What is genetic isolation?
Where one population is cut off from exchanging genes with ither populations because their DNA prevents them from producing viable fertile offspring
41
What is Geographic isolation?
Physical separation of populations by geographical barriers preventing interactions
42
What is Social isolation?
Inherited social, cultural or language traits can lead to separation within a species
43
What are selection pressures?
Environmental factors that influence an organism's ability to survive and reproduce
44
Selection pressures include?
Predation and disease Food availability Climate Mating
45
Predation and disease?
Traits that help an organism survive predation or disease will be favoured
46
Food availability
Organisms best suited to find, consume and digest available food sources will survive.
47
Climate?
Temperature, humidity, and seasonal changes can impact some organisms more
48
Mating?
Organisms with traits that make them more attractive are more likely to reproduce.
49
Why does evolutionary changes usually occur over long periods of time?
As traits are passed onto offspring and beneficial traits gather together in a population.
50
What can accelerate the evolutionary process?
Rapid shifts in the environment depending on the generation time of species
51
What is generation time?
Average time it takes for a species to reach reproductive maturity and produce the next generation
52
What is a example of species with fast generation times and what are they able to do?
Bacteria, is able to adapt to changing selection pressures much faster than those with longer generation times like GRIAFFES
53
Adaptation is the process by which?
Organisms become better suited to their environment through the accumulation of beneficial genetic traits
54
The adaptation can be..
Behavioural- Changes in how an organism acts Physiological- Changes in body functions Morphological- Changes in physical features
55
What is artificial selection?
Where humans intentionally breed plants or animals to emphasise desired traits.
56
What are two strategies used in Artificial Selection?
1. Selecting for the trait you want 2. Selecting against the trait you don't want
57
What is shaping species in plants?
Through repeated selection and breeding, plants with desired traits were isolated and grown by humans
58
Benefits of Artificial selection?
Enhanced traits, Disease resistant, Adapted to human needs
59
Consequences of artificial selection?
Less genetic diversity, unintended traits and Ethical considerations
60
What are some differences between natural and artificial selection
NATURAL - Nature makes selection - Leads to new species - Only favourable characteristics are inherited - Slow process ARTIFICIAL - Humans make the selection - Leads to new breeds - Allows only selected traits to be inherited, favourable or not - Quick process
61
How do fossils form?
Fossils form under special conditions, often involving the preservation of hard parts like bones and shells or other traces like footprints and burrows
62
When does fossilisation occur?
When the elements like specific temperatures, oxygen and moisture needed for decomposition are ABSENT
63
What is the process of fossilisation?
1. When an organism dies a rapid burial by sediments help to preserve the hard remains. 2. The soft tissues decompose and the hard body structures become fossilised 3. Layers gather together and the resultant pressure forms rock. 4. Earth's movements raise the layers of the rocks exposing the fossilised body structures.
64
Fossils
The preserved remains or impressions of ancient organisms
65
Fossilisation
The process by which organic materials become preserved as fossils, often turning into rock over time
66
The location of a fossil can offer what?
clues about evolution
67
How can the age of a fossil be determined?
Through radiometric dating of either the fossil itself or the rock layer where it was found
68
The deeper the rock layer
the older the fossil
69
What can each layer reveal?
Information on past climate, geography and potential life forms that existed during that time
70
What is radiometric dating?
Process to determine the age of the rock or fossils by measuring the rate of decay of radioactive elements
71
What is the fossil record?
Cumulative collection of fossils and their placement in rock formations, documenting the history of life
72
The fossil record has many what
Gaps
73
Why is the fossil record important?
It allows us to understand how species have changed over time
74
Is the fossil record a complete record
No, as it is rare for fossils to form
75
What are some disadvantages of the fossil record.
Dead organisms break down to quickly or are in places where fossils don't easily form and key fossils might not have been found yet or been destroyed by geological events
76
What are transition fossils and what do they do?
The fossilised remains of a life form that has traits common to two ancestral groups. They show links between species
77
What is an example of a transition fossil?
Archaeopteryx is a transition fossil of an animal that lived 150 million years ago, it is important. It is a intermediate specie meaning it has features of both dinosaurs and birds like Feathers, Wings, Teeth and Bonytail
78
What is Biogeography?
Study of why different animals and plants live in certain places and how they arrived at these locations.
79
Biogeography helps us understand evolution by...
Showing that species with the same ancestor often live in similar areas
80
What is Adaptive Radiation?
A single ancestral species evolve into many different species as they adapt to different environments.
81
What does molecular biology allow for?
The comparison of DNA between different species
82
When there are more similarities in two sequences this means?
More recently these species shared a common ancestor
83
What are two limits of Molecular biology?
1. It cannot reveal the complete history of extinct species eg) dinosaurs due to the lack of genetic material in fossils 2. May not capture all aspects of evolution, such as behaviours or ecological interactions.
84
Evidence of evolution is seen in the patterns of
Divergent evolution
85
What is divergent evolution?
Divergent evolution involves species evolving different traits from a common ancestor, evident in homologous structures
86
What is homologous structures
Same structure, different function
87
What is convergent evolution?
When unrelated species independently develop similar traits like both bats and butterflies have developed wings in response to similar selection pressures not shared ancestry.
88
Chicken and dinosaurs share similarities in
embryonic development
89
What is a Vestigial organ
A structure that has lost most or all of its original function through the course of evolution.
90
Evidence for evolution is provided by
ANATOMICAL EVIDENCE Homologous structures Analogous structures Embryonic development CHEMICAL EVIDENCE DNA similarities BIOGEOGRAPHICAL EVIDENCE Fossils Biogeography
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