There was a different theory at the same time as Darwin’s theory - AQA - GCSE Biology - Question 10 - 2018 - Paper 1

The formation of the fossil in Figure 14 probably occurred through a series of steps:

1. Covered by Sediment: The snake became covered in sediment or mud shortly after its death.
2. Decay of Soft Parts: Over time, the soft parts of the snake decayed, contributing to the fossil formation process.
3. Mineral Replacement: The bones of the snake remain and may become replaced by minerals from the surrounding environment, leading to the formation of a fossil.

The evolution of the Japanese rat snake into a distinct species from the Texas rat snake can be explained through natural selection driven by environmental factors:

1. Color Variation: There are various colors in snakes; the Japanese rat snake has evolved to have colors that blend more effectively with its environment compared to the Texas rat snake.
2. Survival Advantage: Those snakes that are better camouflaged in their specific environment are less likely to be seen by predators, thus having a better chance of survival.
3. Reproductive Success: Survivors of this selection process will pass on their advantageous traits to their offspring, leading to a population of snakes better suited to their specific environment over generations.

One reason why a species might become extinct is due to changes in the environment, such as habitat destruction, which can lead to a loss of food sources and safe breeding areas.