Evidence for evolution
Answers are for parents and teachers.
1
Write one sentence each for the evidence from molecular biology, cytology and embryology.
Molecular: DNA and proteins are similar in close species; cytology: all organisms are made of cells; embryology: embryos are similar at early stages.
2
Mark as homologous or analogous: shark and whale tail fins; cactus spine and hawthorn spine; bird wing and bat wing.
Shark and whale tail fins – analogous (the shark’s is vertical, the whale’s horizontal, with different origins); cactus and hawthorn spines – analogous; bird and bat wings – homologous.
3
Name two vestigial organs in humans and explain their reduction.
The coccyx (a tail remnant) and wisdom teeth: they had a larger function in ancestors and are now reduced.
4
If human–chimpanzee DNA sequences are about 98 % identical, about what percent differ? (Number only.)
2
5
Why is palaeontological evidence linked to the order of strata?
Deeper layers are older; the order of fossils shows the historical sequence of living forms.