Evolutionary Relationships in Nature

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What is the best way to visualize evolutionary relationships according to the text?

A tree - the tree of life

What does tracing the twigs back in the tree of life represent?

Reaching a branching point representing a common ancestor between two different species

What do the leaves at the tip of each twig in the tree of life represent?

Different species

What is Dr. Sammy's profession according to the text?

Entomologist Signup and view all the answers

What is the common feature that connects ravens, rhinoceroses, and every other form of life according to the text?

Evolutionary relationships Signup and view all the answers

How does the text describe the external appearance of a raven and a rhinoceros?

The two may seem very different Signup and view all the answers

What is the main point of the comparison between the tree of life and Six Degrees of Kevin Bacon?

The main point of the comparison is that if you look far enough into the past, you're bound to find a link between two species, similar to finding connections between actors through Kevin Bacon. Signup and view all the answers

Explain why the traditional Linnaean hierarchy may not always match up to the modern branch divisions of the tree of life.

The traditional Linnaean hierarchy is largely based on how organisms look rather than how they're actually related, while the modern branch divisions are based on evolutionary relationships. Signup and view all the answers

Why is it difficult to estimate the number of species alive today?

It's difficult to estimate the number of species alive today because some species live in inaccessible environments, are too small for human perception, or are otherwise outside of our awareness. Signup and view all the answers

What does the addition of a diverse group of 600 species of fungi to the tree of life illustrate?

The addition of 600 species of fungi illustrates that seemingly different species can be better understood as one evolutionary group based on their genes suggesting a common ancestor. Signup and view all the answers

What is the significance of focusing on the main branches rather than each and every twig when understanding the tree of life?

Focusing on the main branches helps in understanding the major groups of living things, with each smaller branch representing a smaller subdivision. Signup and view all the answers

What are prokaryotes and how are they classified?

Prokaryotes are single-celled organisms whose genetic material isn't contained within a nucleus. They are classified into two main groups: bacteria and archaea. Signup and view all the answers

Explain the challenge in differentiating between bacteria and archaea.

It can be challenging to differentiate between bacteria and archaea because both are microscopic and share similarities in appearance. Signup and view all the answers

Why is the tree of life likely to keep growing and changing?

The tree of life is likely to keep growing and changing because as more is learned about different species, the understanding of their evolutionary relationships becomes more detailed and refined. Signup and view all the answers

What does the comparison between the tree of life and Six Degrees of Kevin Bacon illustrate about the interconnectedness of different species?

The comparison illustrates that if one looks far enough into the past, links between different species can be found, demonstrating the interconnectedness of all organisms through common ancestors. Signup and view all the answers

Explain the limitations of the traditional Linnaean hierarchy in representing the relationships between different species.

The traditional Linnaean hierarchy is limited in representing relationships between different species because it is largely based on external characteristics rather than genetic or evolutionary relationships. Signup and view all the answers

Deeper in the past, those dinosaurs descended from an ancestor that they shared with modern ______

reptiles Signup and view all the answers

And before that, the dinosaur-reptile ancestor descended from an ancestor that they shared with modern ______ – like the rhino

mammals Signup and view all the answers

So, the tree of life is kind of like Six Degrees of ______

Kevin Bacon Signup and view all the answers

That system of classification is largely based on how organisms look rather than how they’re actually ______

related Signup and view all the answers

It’s tough to even estimate the number of species alive today because, well, we don’t know what we ______

don’t know Signup and view all the answers

Some species live in the unforgiving deep sea, are too small for human perception, or are otherwise outside of our awareness — so ______.

far Signup and view all the answers

On top of that, the tree of life includes extinct species, and there are billions of those to learn ______.

about Signup and view all the answers

For example, as recently as 2022, a whole new branch of life was added to describe a diverse group of 600 species of ______.

fungi Signup and view all the answers

But for now, let’s zoom ______.

out Signup and view all the answers

Closest to the roots of the tree, you’ll find the branch of ______.

prokaryotes Signup and view all the answers

Each of the different species that currently, or have previously, roamed our world represent a ______ at the tip of each twig. Trace those twigs back, and you reach a branching point, representing a common ancestor between two different species. Trace the limb further and you find more branching points, and more common ancestors among more species.

leaf Signup and view all the answers

Behold the tree of life. Each of the different species that currently, or have previously, roamed our world represent a leaf at the tip of each . Trace those s back, and you reach a branching point, representing a common ancestor between two different species. Trace the limb further and you find more branching points, and more common ancestors among more species.

twig Signup and view all the answers

They’re connected to each other – and every other form of life – by relationships. And if we hope to understand all the connection points between ravens, and rhinoceroses, and everyone else, we need a way to visualize them. Now, the best way we’ve found isn’t a series of steps. Because evolution doesn’t function like a ladder in one direction. Instead, we can visualize relationships with a tree – the tree of life.

evolutionary Signup and view all the answers

They’re connected to each other – and every other form of life – by evolutionary . And if we hope to understand all the connection points between ravens, and rhinoceroses, and everyone else, we need a way to visualize them. Now, the best way we’ve found isn’t a series of steps. Because evolution doesn’t function like a ladder in one direction. Instead, we can visualize evolutionary with a tree – the tree of life.

relationships Signup and view all the answers

And this is ______. Now, might I be able to interest you in some theme music. [THEME MUSIC] Behold the tree of life. Each of the different species that currently, or have previously, roamed our world represent a leaf at the tip of each twig. Trace those twigs back, and you reach a branching point, representing a common ancestor between two different species. Trace the limb further and you find more branching points, and more common ancestors among more species.

Crash Course Biology Signup and view all the answers

Now, might I be able to interest you in some theme music. ______ Behold the tree of life. Each of the different species that currently, or have previously, roamed our world represent a leaf at the tip of each twig. Trace those twigs back, and you reach a branching point, representing a common ancestor between two different species. Trace the limb further and you find more branching points, and more common ancestors among more species.

Theme Music Signup and view all the answers