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Direct Hit

Theme A - Unity & Diversity

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Page Facing Up

Theme B - Form & Function

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Pill

Theme C - Interaction &  Interdependence

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Keycap Digit One

Theme D - Continuity & Change

<ul>
	<li>Speciation refers to the process where a single species diverges into two or more separate species.</li>
	<li>Key condition: reproductive isolation, i.e., when populations of a species are unable to interbreed.</li>
	<li>Analogy: Think of speciation as a branching tree - what was once a single trunk (species) gives rise to multiple branches (new species) over time.</li>
</ul>

<ul>
	<li>Allopatric speciation: Occurs when populations are geographically separated. The word &#39;allopatric&#39; means &quot;different homelands&quot;. It&#39;s like having two siblings living in different countries - they grow up experiencing different cultures, thus developing unique traits over time.</li>
	<li>Sympatric speciation: Occurs within the same geographical area where populations diverge while living together. &#39;Sympatric&#39; means &quot;same homeland&quot;. Think of two roommates who live together but develop different hobbies and routines - eventually they may become so different that they don&#39;t interact much.</li>
</ul>

<ul>
	<li>Sympatric speciation is usually a consequence of behavioural or temporal differences.</li>
	<li>Behavioural differences: Variation in behaviours, often linked to mating, can lead to reproductive isolation.</li>
	<li>Temporal differences: Different timing of life cycle events, such as mating seasons, can separate populations reproductively.</li>
	<li>Real life is a bit messy and it&#39;s hard to tell if species living together are results of sympatric speciation or allopatric speciation followed by migration.</li>
</ul>

<ul>
	<li>Behavioural Isolation: Cichlid fish in Lake Massoko, Tanzania, have developed two forms based on their preferred feeding zones: one near the shore and the other in deeper water. They have adapted to their environments, including variations in body size, shape, jaw structure, teeth, colour, and light sensitivity. Females tend to choose mates similar to themselves, leading to reduced gene mixing and potentially to speciation.
	<ul>
		<li>Fun fact: It&#39;s like choosing friends based on common interests. If you like soccer, you&#39;re likely to hang out with soccer fans, and over time, this group may develop its own inside jokes and traditions, becoming &#39;different&#39; from other groups.</li>
	</ul>
	</li>
	<li>Temporal Isolation: The winter pine processionary moth found around the Mediterranean is an example of temporal separation. A population in Portugal shows a different life cycle timing, with adults emerging in May or June, and larvae feeding through the summer rather than winter. Since these two forms have mating times at different parts of the year, they never interbreed, leading to divergence and potentially, speciation.
	<ul>
		<li>Interesting tidbit: This is similar to people who work different shifts - if one works during the day and the other at night, they may rarely meet and form two distinct social groups with different experiences and customs.</li>
	</ul>
	</li>
</ul>

Remember, understanding speciation isn&#39;t about memorizing terms, but about grasping the beautiful concept of evolution and the diversity it generates in the natural world! Always try to relate these concepts to real-world examples to make your learning fun and relevant.

Explore Speciation: Sympatric vs. Allopatric

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Standard Level

Biology SL

Theme A - Unity & Diversity

Explore Speciation Sympatric Vs Allopatric

Table of content

Concept of speciation

Allopatric vs. sympatric speciation

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Theme A - Unity & Diversity

Explore Speciation Sympatric Vs Allopatric

Table of content

Concept of speciation

Allopatric vs. sympatric speciation

Unlock the Full Content!