Species, natural selection and evolution
On the Galápagos Islands, finches with beaks suited to the seeds available survive dry years better than the rest, and pass that beak shape to their young. Over many generations this natural selection changes a population. Given enough time and separation, it can make new species.
By the end of this page you can
- Define a species, and explain extinction and artificial selection with examples
- Describe how new species form
- Put the steps of natural selection in order
- Define species, speciation, evolution and adaptation
- Explain antibiotic resistance as natural selection
Goals tick themselves off as you try the activities below.
Photo: Johnniewalkerparedes, CC BY 4.0, via Wikimedia Commons. Cropped, JPEG q72.
A Darwin’s finch in the Galápagos. Different species on the islands have beaks shaped for different foods.
How often it shows up in past papers
Paper 1 counts come from our past-paper bank of CSEC Biology Paper 1s. Paper 2 is not included yet.
What a species is, and how it changes
A species can be defined, lost, or shaped by people. Tap each card.
Six ideas about species
Tap each idea to see what it means and an example.
What does it mean?
Tap an idea on the list to see an example.
Caribbean anole lizards are a famous example: on island after island, separate species have evolved with bodies suited to tree trunks, twigs or grass.
Natural selection, step by step
Drag or tap each step into its slot.
What must there be for selection to act on?
Seven terms to know cold
Say what each term means before you flip the card. Then give a Caribbean or textbook example.
Six quick questions, then a real one
Pick an answer to see why it’s right or wrong.
A species is best defined as organisms that
Horses and donkeys are classed as separate species because
An antibiotic is used for a long time, and the bacteria become resistant. This is because
Two populations of lizards on separate islands slowly become different species. This is an example of
Artificial selection differs from natural selection because
The Caribbean monk seal became extinct mainly because of
exam style · 3 marks
Explain how a population of bacteria can become resistant to an antibiotic.
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Practice questions are written by My V.I.P. Academy. They are not official CXC papers.