Natural Selection And Evolution And Geological Time

Question 1

Adaptation

Answer 1

A process of change so that an organism can survive the environmental changes. Three types of adaptation:

• physical/ structural (camelion)
• behavioural (nocturnal animals)
• psychological (clownfish and anenamies)

Question 2

Biodiversity

Answer 2

The range of organisms within an environment. The greater the diversity, the more likelihood that various species will survive. (Less competition, more detailed food chain, more resources)

Question 3

Species

Answer 3

A group of organisms with similar characteristics within a larger group. Eg: domestic cats are a feline along with tigers and lions

Question 4

Fossils

Answer 4

Permanent records of past organisms

Question 5

Extinction

Answer 5

The permanent loss of a species

Question 6

Five basic principles of evolution via natural Selection

Answer 6

Variation, more are produced than can survive, competition for resources, best adapted survive to reproduce, population changes

Question 7

Variation

Answer 7

There is always slight genetic variation between individuals in a species

Question 8

More are produced than can survive

Answer 8

Organisms can die from many sources - disease, starvation, being eaten - before they reproduce. The environment can’t support every organism that’s born

Question 9

Competition for resources

Answer 9

Organisms must struggle to get resources to survive and to escape predators. For this reason not all organisms survive. Survival of the fittest

Question 10

Best adapted survive to reproduce

Answer 10

If an organism has a trait that helps it to survive, it is more likely that that plant or animal will survive and reproduce

Question 11

Population changes

Answer 11

Organisms that survive and reproduce pass their traits to their offspring. The helpful traits gradually appear in more and more of the population

Question 12

Absolute dating

Answer 12

Provide the actual age of rocks and fossils. Eg. Tree rings and radioactive dating

Question 13

Tree ring dating

Answer 13

Trees grow layers each year which form rings. Cross sections and core drills of trees can be used to compare sizes of rings and count age

Question 14

Radioactive dating

Answer 14

Using radioactive isotopes and their rate of decay, the amount of the isotope (eg: C14 - which is in all living things) can be measured and is directly proportional to the age of the fossil

Question 15

Relative dating

Answer 15

Technique that compares the age of one fossil or rock with another to determine which is older. Relies on two basic factors: sedimentary rocks form layers and fossils are the same age as the rocks in which they are found

Question 16

Index fossils

Answer 16

Some fossils were found in abundance over certain periods of time. Eg trilobites . When fossils are found in similar strata their time frame can be compared and their relative age is determined.

Question 17

Fluorine analysis

Answer 17

Bones absorb fluorine from the water in surrounding rocks. Happens over a long period of time and depends on the amount of fluorine in the water surrounding the bone. Age of the fossil is relative to the fluorine content in both the water and the fossil.

Question 18

Resistance in bacteria - natural selection at work

Answer 18

Bacteria are single celled organisms of which some can cause disease. Antibiotics is the name given to some chemicals which can kill bacteria. However, like in natural selection, some bacteria develop a resistance to the antibiotic and reproduce rapidly and transfer this information to make you ill again and create a new strain of bacteria that cannot be killed.

Question 19

How does bacteria become resistant

Answer 19

Using antibiotics when they’re not needed, using incorrect amounts, not finishing a dose. Bacteria has been exposed to antibiotics in hospitals, treating animals and making its way into soil, food and water making it develop ways to resist antibiotics.

Question 20

How bacteria survive antibiotics

Answer 20

Bacteria, through mutation, become able to destroy antibiotic molecules, alter their cell wall so the antibiotic molecule cannot attach, make it hard for the antibiotic to enter its membrane and pump them out if they do enter.

Question 21

Peppered moth - natural selection at work

Answer 21

Two types: black and white with specks. White ones used to be in abundance because the trees where white and could camouflage easily, occasionally black mutants were born and preyed on so died. Industrial revolution cause the trees to go black and the white moths were eaten. The black moths survived to pass on their mutant gene, changing the population. The selective agents were birds preying on the moths. (Also white in the country, less pollution and black in city)

Question 22

Mosquitoes DDT - natural selection at work

Answer 22

Malaria sickened 225 million in 2009. A chemical insecticide called DDT was used to kill mossies to prevent the spread of malaria. Through natural selection, some mossies developed a resistance to the spray and could break down the poison. They survived to produce offspring who could resist the spray. Became ineffective. DDT also linked to other problems. Killing other wildlife and causing health problems in humans (diabetes, hormonal issues)

Question 23

Evolution definition

Answer 23

Genetic variation over a long period of time

Question 24

Generation definition

Answer 24

A period of time between birth and reproduction of offspring

Question 25

Homologous definition

Answer 25

Structures that are genetically similar, eg: penyadactyl limbs in humans, bats and whales

Question 26

Analogous

Answer 26

Visually similar but no genetic correlation. Eg: sharks and Dolphins

Question 27

Artificial selection

Answer 27

Identifying favourable characteristics in organisms and cross breeding to try and produce offspring that have these characteristics, eg: fast growing, high milk production, multiple births, disease resistance, bacteria - medicine

Question 28

Comparative anatomy

Answer 28

Comparative anatomy is quite literally comparing anatomical features of various organisms in order to investigate and learn about: - their environment - why they mate - why they live the way they do - where they come from - how they evolved - how long each change took - genetic makeup - other organisms they might be closely related to Compares structure of living and dead organisms. Evidence in their similarities and differences, their features evolving that show the species diverged and changed over time.

Question 29

Time line (eras)

Answer 29

1. Precambrian 2. Palaeozoic 3. Mesozoic 4. Cenozoic

Question 30

Precambrian era

Answer 30

3600 Mya - 542 mya Formation of crust, no life Single celled organisms and bacteria form Worms and jellyfish form

Question 31

Palaeozoic era

Answer 31

``` 542 mya- 251 mya - primary periods First fossils. Trilobites, molluscs Primitive Fish and plants Trees, reptiles, insects Dinosaurs ```

Question 32

Mesozoic era

Answer 32

251 mya - 65 mya - secondary periods Dinosaurs and reptiles dominate First birds and mammals Flowering plants

Question 33

Cenozoic Era

Answer 33

65 mya - present - tertiary and quaternary periods Dinosaurs extinct, large reptiles disappear Ancestors of modern apes appear Ice age. Large mammals and primitive humans Warmer climate, modern humans

Question 34

Selective agent - environmental factors

Answer 34

The environmental factor that acts on the population. May be biotic (living) eg, bacterial infection, competition, predator. Or abiotic (non living) eg, temperature, water, soil nutrients, fire. Many selective agents act by killing individuals less suited to their environment. Not all kill, eg, sexual selection - a female bird chooses a male bird with brighter colours.

Question 35

Darwins finches

Answer 35

Darwin studied finches on various islands in different environments and discovered their beaks were different. Their beaks were suited to the foods they ate in their environments. Beaks for sucking nectar, to catch insects or crack seeds. The birds were all related but had evolved to suit the environment they lived in.

Question 36

Study of DNA

Answer 36

Study of DNA can identify similarities in the amino acid arrangement in the proteins they make. Proteins are made by genes. Identical proteins = identical/ similar genes. Fossil DNA and proteins can be analysed to make connections between similar species that have evolved.

Question 37

Speciation

Answer 37

1. Variation in genetics or speciation can't occur 2. Isolation: different groups prevented from interbreeding by barriers that separate them. Eg, mountains, rivers, ocean currents, temperature. Any mutation that arises can't spread because they are isolated 3. Selection: natural selection affects the genotype creating a new species. If they ever come back together again, they will not be able to breed

Question 38

Evidence for evolution - fossils

Answer 38

Early fossils are of simple organisms that get increasingly complex. As evolution does when new alleles and genes are made from mutations. There are increasing numbers of species living on earth (increasing biodiversity) expected if species split and form new species. Fossils also show transitional forms of species in the process of changing between dinosaur and bird.

Question 39

Evidence for evolution - comparative anatomy

Answer 39

The study of similarities and differences in anatomy of different species. Indicates that various organisms share a common ancestor when their anatomical structure is similar. Determines relationship and relatedness between species

Question 40

Evidence for evolution - DNA and protein structure

Answer 40

Organisms that are similar share more of the same genetic code because they have a common ancestor. Humans and chimpanzees share 96% of the same genes. Proteins are made up of amino acids arranged in a sequence controlled by genes. The sequence can be used to compare how closely related organisms are. All living organisms have the cytochrome c protein. Comparing how many amino acids are in the same place on the chain shows how closely two species are related. Humans and rhesus monkeys differ in one place. Humans and bullfrogs differ in 18, therefore we are more closely related to monkeys.

Question 41

Biogeography - evidence for evolution

Answer 41

Distribution: a map of all the places where a species occurs. Unique species of animals are found in different places or isolated islands because isolation is needed to form different species and they then adapt to their unique locations. The location of animals effects their evolution. Eg: Darwins finches, honeycreeper on Hawaiian islands

Question 42

Original fossils

Answer 42

Form when part of the organism is preserved and composition is almost the same as it was when it was alive. Eg: teeth, bones, skeletons

Question 43

Replacement fossils

Answer 43

Form when part of the organism is chemically changed into another mineral. Mostly calcium carbonate is replaced by silicon. Eg bone or she'll to silica or opal, petrified wood

Question 44

Carbon film fossils

Answer 44

Occurs when the dead body of an organism partially decays and leaves a thin black deposit of carbon in the shape of the organism. Eg: plants

Question 45

Indirect fossils

Answer 45

Not part of the organism itself. Preserved remains of imprints of the body. Eg: footprints

Question 46

Fossil formation stage 1

Answer 46

An ammonite dies and falls to the bottom of the sea. It is covered by other animals and sediment. The soft part of the body decays leaving just the shell.

Question 47

Fossil formation stage 2

Answer 47

More and more sediment covers it, squeezing the shell. It may remain or be replaced with minerals such as limestone or Quartz. These minerals seep into it in solution before the origins, shell dissolves

Question 48

Fossil formation stage 3

Answer 48

After millions of years, movement in the earth's crust may thrust the layer of sedimentary rock containing the fossil upwards

Question 49

Fossil formation stage 4

Answer 49

Weathering and erosion wears down the layers of rock to expose the fossil. They're often found in road cuttings or quarries.