View source for 3. Evolution; CSCG, phylogenetic tree, Convergent evolution -YJ code: 130629

<p><span style="color:#FF0000"><span style="font-family:times new roman,times,serif"><em><span style="font-size:48px">What is the phylogenetic tree?</span></em></span></span></p>

<p><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/7/70/Phylogenetic_tree.svg/450px-Phylogenetic_tree.svg.png" style="height:304px; width:450px" /></p>

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<p><span style="font-size:18px"><span style="font-family:times new roman,times,serif">A&nbsp;phylogenetic tree&nbsp;or&nbsp;evolutionary tree&nbsp;is a branching diagram. I</span><span style="font-family:times new roman,times,serif">t is showing the inferred evolutionary&nbsp;relationships among various biological speciese&nbsp;or other entities based upon similarities and differences in their physical or genetic characteristics.&nbsp;Phylogenetic trees are central to the field of phylogenetics.&nbsp;</span><span style="font-family:times new roman,times,serif">In a&nbsp;rooted&nbsp;phylogenetic tree, each node with descendants represents the inferred most recent common ancestor&nbsp;of the descendants, and the edge lengths in some trees may be interpreted as time&nbsp;estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed.&nbsp;Unrooted&nbsp;trees illustrate only the relatedness of the leaf nodes and do not require the ancestral root to be known or inferred.</span></span></p>

<p><span style="color:#FF0000"><em><span style="font-family:times new roman,times,serif"><span style="font-size:48px">What is the &#39;Convergent evolution&#39;?</span></span></em></span></p>

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<p style="text-align: justify;"><span style="font-size:16px"><span style="font-family:times new roman,times,serif">Convergent evolution&nbsp;is the independent evolution&nbsp;of similar features in species of different lineages. Convergent evolution creates&nbsp;analogous structures&nbsp;that have similar form or function but were not present in the last common ancestor of those groups.&nbsp;The cladistic&nbsp;term for the same phenomenon is&nbsp;homoplasy.&nbsp;The recurrent evolution&nbsp;of flight is a classic example of convergent evolution. Flying insects, birds and bats&nbsp;have all evolved the capacity of flight independently. They have &quot;converged&quot; on this useful trait.&nbsp;Convergent evolution is similar to but different from parallel evolution.&nbsp;Parallel evolution occurs when two independent but similar species evolve in the same direction and thus independently acquire similar characteristics</span></span></p>