Changes in species over time
Species evolve over time in response to factors such as environmental pressures, genetic mutations, and reproductive isolation. These changes are driven by natural selection and adaptation to new environments or challenges, unfolding gradually over geological time that spans billions of years. The fossil record provides vital evidence in how life has evolved over many millions of years.
These evolutionary changes lead to speciation, the formation of new species. Speciation often occurs when populations become reproductively isolated and evolve independently. This isolation can be geographic or due to other factors.
This topic will explore how the fossil record provides evidence of these evolutionary changes and illustrate how isolation leads to speciation, using the famous examples of the Galapagos finches and Howea palms.
This resource explores change in species over time, focusing on three key concepts:
To determine if this resource will benefit you, start by answering the following questions:
- What are the key differences between relative and absolute dating methods, and how do they help determine the age of fossils?
- What is the difference between allopatric speciation and sympatric speciation?
- What is a transitional fossil, and how does it inform our understanding of evolution?
The answers to these questions are provided on the following pages. Use this resource to refresh your memory, reinforce your understanding of these concepts, and prepare more effectively for university-level learning.