Evidence for evolution

Question 1

Why was Darwin’s theory of evolution initially rejected? (3 reasons)

Answer 1

1. Most people at the time believed that humans have been on Earth since the beginning
2. Not enough fossil evidence was found at the time
3. Mechanisms of inheritance (genes/ chromosomes) were undiscovered at the time

Question 2

Why is Darwin’s theory widely accepted today? (3 reasons)

Answer 2

1. Fossils have been discovered that shows changes in characteristics over time and give evidence for older organisms being more simple.
2. Characteristics are known to be passed on to offspring in gene, with the advancement of scientific techniques and technologies.
3. Knowledge of how antibiotic resistance evolves in bacteria.

Question 3

How do fossils serve as evidence for evolution?

Answer 3

Fossils are the remains and impressions of organisms preserved in sedimentary rocks from millions of years ago. Palaeontologists study the fossils, date them and put them in order.
From this we can see the gradual changes in one type of animal or plant to another over time, since life developed on Earth, serving as evidence for natural selection.
Carbon dating can also be used to work out the age of rocks they were found in.

Question 4

Limitations of using fossils as evidence for evolution (4 examples)

Answer 4

1. Many early life forms were soft bodied so they didn’t mineralise to form fossils.
2. Geological activity, like earthquakes, destroyed lots of fossils and any imprints made are easily washed away.
3. Most organisms do not become fossilised- conditions for fossilisation are very rare.
4. Many fossils are undiscovered