IB Biology Sub-topic A4.1 Definitions

This page contains our IB Biology definitions for sub-topic A4.1. By learning each one of these definitions, you will fully cover the content for IB Biology 'Further speciation'.

All Topic 4 Sub-topics

A4.1: Evolution & Speciation

(HL)A4.1: Further speciation

A4.2: Conservation Of Biodiversity

B4.1: Adaptations

B4.2: Ecological Niches

C4.1: Populations & Communities

C4.2: Energy & Matter Transfer

D4.1: Natural Selection

(HL)D4.1: Further natural selection

D4.2: Stability & Change

(HL)D4.2: Ecological stability

D4.3: Climate Changes

(HL)D4.3: Further climate change

behavioural isolation

Reproductive isolation due to populations of the same species behaving differently in a way that prevents interbeeding, such as having different mating calls or rituals

geographical isolation

Reproductive isolation due to populations of the same species living in different areas. This can be as extreme as different continents to as close as different parts of a tree

gradualism

The gradual separation with changes over time building up to form a new species

polyploidy

An error in meiosis leading to a doubling of chromosomes

reproductive isolation

When populations of the same species stop interbreeding, a requirement for speciation

speciation

The formation of a new species as a result of evolution

temporal isolation

Reproductive isolation due to populations of the same species breeding at different times, and so they do not interbreed at all