Question

Describe palaeontological evidence with an example.

Hint:

Fossils in successive rock layers form a connected sequence; horse evolution is the standard example.

Answer 1

Step 1: Define palaeontological evidence:
Palaeontological evidence for evolution comes from fossils - preserved remains or impressions of organisms from earlier geological periods - which show that life forms have changed progressively over time and that present-day organisms descended from earlier, often simpler, ancestral forms.

Step 2: Explain the age-depth relationship:
Fossils found in deeper, older rock strata are generally simpler in form, while those in more recent (upper) strata more closely resemble modern organisms, showing gradual change over geological time.

Step 3: Give a classic example:
The fossil series showing horse evolution - from the small, multi-toed Eohippus (Hyracotherium) of about 55 million years ago, through several intermediate forms, to the large, single-toed modern Equus - is a classic, well-documented example of palaeontological evidence for evolution.

Final Answer:
Fossils in successive rock strata trace a gradual, connected sequence of change; the horse evolutionary series (Eohippus to Equus) is a classic example of palaeontological evidence for evolution.