Biology SL
Biology SL
4
Chapters
553
Notes
Theme A - Unity & Diversity
Theme A - Unity & Diversity
Theme B - Form & Function
Theme B - Form & Function
Theme C - Interaction &  Interdependence
Theme C - Interaction & Interdependence
Theme D - Continuity & Change
Theme D - Continuity & Change
IB Resources
Theme A - Unity & Diversity
Biology SL
Biology SL

Theme A - Unity & Diversity

Understanding Clades Evolution's Family Trees

Word Count Emoji
444 words
Reading Time Emoji
3 mins read
Updated at Emoji
Last edited on 14th Jun 2024

Table of content

Clades - a family tree

Imagine your own family tree - with your parents, grandparents, and so on. Now, picture that on a much bigger scale: a family tree for all life on earth. That's essentially what a clade is! A clade is a group of organisms that all descended from a common ancestor, like a family tree branch.

 

Real-World Example: The bird kingdom is a big, feathery clade - all of its 10,000 species evolved from a shared ancestor! In contrast, the lone survivor of an ancient clade is the Ginkgo biloba tree - all its "siblings" from its clade are extinct, making it a very unique plant!

DNA - the clues in our genes

How do we know who belongs to which clade? The answer lies in our DNA! Genes or proteins' amino acid sequences are excellent tell-tale signs of shared ancestry. In cases where extinct species are involved, fossils and morphological traits come into play, as DNA is unavailable.

 

Real-World Example: Imagine you and your cousins share a similar trait, like the same nose shape - this is your "morphological trait". Now, if someone wanted to trace your shared ancestry but couldn't do a DNA test, they'd use these shared traits as a clue - just like we do with fossils!

Clades within clades - nesting dolls of life

Species aren't limited to just one clade, they belong to multiple! Smaller clades are nested within larger ones, like a Russian Matryoshka doll.

 

Real-World Example: Araucaria araucana (the monkey puzzle tree) and Podocarpus totara are in the same clade (doll), which is nested in a bigger clade (bigger doll) with other species, and so on. It's like you belong to your immediate family, then your extended family, and even a larger family tree.

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IB Resources
Theme A - Unity & Diversity
Biology SL
Biology SL

Theme A - Unity & Diversity

Understanding Clades Evolution's Family Trees

Word Count Emoji
444 words
Reading Time Emoji
3 mins read
Updated at Emoji
Last edited on 14th Jun 2024

Table of content

Clades - a family tree

Imagine your own family tree - with your parents, grandparents, and so on. Now, picture that on a much bigger scale: a family tree for all life on earth. That's essentially what a clade is! A clade is a group of organisms that all descended from a common ancestor, like a family tree branch.

 

Real-World Example: The bird kingdom is a big, feathery clade - all of its 10,000 species evolved from a shared ancestor! In contrast, the lone survivor of an ancient clade is the Ginkgo biloba tree - all its "siblings" from its clade are extinct, making it a very unique plant!

DNA - the clues in our genes

How do we know who belongs to which clade? The answer lies in our DNA! Genes or proteins' amino acid sequences are excellent tell-tale signs of shared ancestry. In cases where extinct species are involved, fossils and morphological traits come into play, as DNA is unavailable.

 

Real-World Example: Imagine you and your cousins share a similar trait, like the same nose shape - this is your "morphological trait". Now, if someone wanted to trace your shared ancestry but couldn't do a DNA test, they'd use these shared traits as a clue - just like we do with fossils!

Clades within clades - nesting dolls of life

Species aren't limited to just one clade, they belong to multiple! Smaller clades are nested within larger ones, like a Russian Matryoshka doll.

 

Real-World Example: Araucaria araucana (the monkey puzzle tree) and Podocarpus totara are in the same clade (doll), which is nested in a bigger clade (bigger doll) with other species, and so on. It's like you belong to your immediate family, then your extended family, and even a larger family tree.

Unlock the Full Content! File Is Locked Emoji

Dive deeper and gain exclusive access to premium files of Biology SL. Subscribe now and get closer to that 45 🌟