B5.2 - Natural Selection And Evolution

Question 1

What is evolution

Answer 1

The gradual change of a species over time

Question 2

What is natural selection

Answer 2

• change/mutation in genes causing genetic variation
• organism with best suited characteristics will adapt to environment, survive and reproduce. Whereas less well adapted will die out
• the well suited will reproduce and pass the characteristics to offspring and next generation. Whereby the kids will be more likely to possess characteristics that are successful
• cycle repeats and results in new adapted species

Question 3

Examples of evolution É.g. Animals and bacteria

Answer 3

Pepper moths were extinct and black became most common and suited to environment
Bacteria became resistant to antibiotics and reproduce so all became resistant

Question 4

What are fossils

Answer 4

Formed when animals and plants’ remains become preserved in rocks

Question 5

What is a fossil record

Answer 5

The fossils layer with a sequence showing that organisms have gradually changed over time

Question 6

What do fossils show

Answer 6

• that fossils made from old rock - was usually unicellular organisms whereas new at top are more developed
• animal fossils found before plants = animals needed plants to survive
• closely related species have evolved from same ancestors

Question 7

Limitations of fossil records

Answer 7

• some are soft bodied and therefore decompose quickly before they can be fossilised
• some simply have not been found
• some get destroyed due to volcanic activity/eruptions

Question 8

Evidence for evolution

Answer 8

• change in species (through natural selection and survival of fittest)
• extinction (how species that cannot adapt to environmental changes die out)
• molecular comparisons (using DNA and protein structure to find links between species and how evolved over time)

Question 9

What was Darwin’s + Wallace’s experiment and what conclusions did he come to

Answer 9

Researched and learnt about finches, whereby they each have different sizes/ shapes of beaks and claws.
He realised that the design relates directly to the food source available where if you have well suited beak for food source, will survive and if not, die out.
This will be passed on to generations and offspring will have higher chance of having successful mutations
Resulting in new adapted species and survival of fittest in natural selection
Wallace went to Borneo to see the difference in butterfly wing patterns. After they both worked independently, he sent his ideas for peer review to Darwin. As they had similar results, they worked together to make and publish their book

Question 10

Why was theory of evolution not accepted

Answer 10

Many people thought that God created all living things and then conflicted with held beliefs . These were also only theories and didn’t have evidence to support ideas
However, became increasingly accepted with new found technology, and supported through DNA and protein comparisons

Question 11

What is classification

Answer 11

The process of sorting living organisms into groups

Question 12

Classification helps to…

Answer 12

• sort organisms into groups
• predict characteristics
• make links between species

Question 13

Seven taxonomic levels

Answer 13

Kingdom, phylum, class, order, family, genus, species

Question 14

Kingdom consists of…

Answer 14

Plants, animals, fungi, protoctist, prokaryotes

Question 15

What is artificial classification

Answer 15

Sorting out living organisms into groups by their phenotype, appearance and observable characteristics: where people may infer their species even if they are not, less accurate

Question 16

What is natural classification

Answer 16

Sorting out living organisms into groups due to their genotype and DNA sequencing to make evolutionary links: allows links to be inferred

Question 17

What is phylogeny

Answer 17

Study of evolutionary links