Speciation | 9-1 GCSE Science Biology | OCR, AQA, Edexcel

They key points covered in this video include:
1. Speciation
2. Isolation

Speciation

As we know, a new species develops when populations of the same species become so different that they can no longer reproduce to produce fertile offspring - this is speciation. Alfred Russel Wallace was one of the scientists who heavily influenced our understanding of speciation. We now understand that speciation can occur due to isolation - the separation of individuals within a species.

Isolation

Geographic barriers (e.g. floods, earthquakes) can isolate individuals within a species. As individuals on either side of the separation cannot reproduce, this may eventually lead to speciation. For example, it is thought that the chimpanzee and bonobo species formed because their common ancestors became isolated when the Congo River formed. This is especially true if conditions either side of the barrier are slightly different. This means that different characteristics are beneficial in each environment - so different genes will be naturally selected for in a varied population.

Summary
1. Alfred Wallace did pioneering work on speciation
2. Our current understanding of the theory of speciation is that groups within a species evolve so much so that they can no longer reproduce to produce fertile young
3. This may because groups are isolated by geographic barriers, such as newly formed rivers or mountain ranges
4. If the environments on either side of the barrier are slightly different then different genes will be selected for over time