Similarities and Differences
Paleontologists compare __________ to find similarities between species (both living and dead)
Bone structures (or body structures)
What do we call group of organisms of the same type that do not reproduce with any other groups?
Species
WILD SQUARE!!!
What will you get?
Your species branches off with an adaptive trait. Pick another question (worth 300 or less). It is now worth double.
True or False: Life has been very diverse for the entirety of Earth's history.
False. For most of Earth's history (3.5 Billion years) life either didn't exist or consisted of single celled organisms.
Similarities in the body structures of species is possible evidence that the species are ___________.
Related.
How are a Human arm and a cat front limb similar? What does this tell you?
They both share a "one-two-many" bone structure. They share a common ancestor.
a) What is a common ancestor population?
b) What is a descendant species?
a) An older species from which 2 or more different species evolved.
b) A newer species that evolved from an ancestor population
How are species organized onto an evolutionary tree?
Organisms on the same branch have similar traits/body structures
According to fossil evidence, about how long ago did life start on Earth?
About 3.6 billion years ago
What are the 3 things that a scientist will never say?
Not share, impossible, coincidence
Where do organisms get their body structures from? Where do species get their body structures from?
They inherit them (like all traits) from their parents. Species inherit body structures from ancestor populations.
WILD SQUARE!!!
What will you get?
Your species separates into different environments - Choose one of the following:
a) Earn 100 points
b) Try a 200 point question
* How can you tell that these 3 species are related?
Are the three species equally related to each other? How can you tell?
They are all connected on the evolutionary tree.
No, the tiger and the rat are more closely related because they are closer to each other (on the same branch) on the evolutionary tree.
Which of the following changes in traits would take the longest time. Why?
a) A population of tortoises evolves longer necks due to higher location of food sources.
b) A population of fish develop lungs and limbs to survive on land.
c) A population of birds keeps its wings but loses the ability to fly because of little predation.
b) Developing lungs and limbs require very big changes to body structures. The larger the structure change, the longer amount time it takes.
Even though they are different species, a shark and a manta ray both have a skeleton made of cartilage (lighter than bone). Explain why both of these different species have that same characteristic.
Both inherited this structure from a common ancestor population. Because they both live in a similar environment (the water), both species retain this trait over time.
Which of the 3 species are more closely related? How can you tell?
Echidna and toad because they both have neck bones but the fish does not.
Hips are a body structure that is important for carrying the weight of animals that walk on land. Whales live in water, but still have hips. Finding this body part in animals that don’t walk on land is best explained how?
Whales have an ancestor that walked on land. As whales were separated into a new environment, they inherited the hips body structure from their ancestor population but adapted different traits (lost legs - gained tails for swimming) that helped them survive in the aquatic environment.
* Where should Species C go on this evolutionary tree? Which structure did you use to make your decision? Which species is species C most closely related to? Most distantly related?
In spot #1. The tail is evidence. It is most closely related to species B (or the ancestor) and most distantly related to species A.
Put the following events in the correct order to show changes over evolutionary time:
1) A single population gets separated into different environments
2) Two very similar descendant populations have small differences in their structures
3) A single population is living in a stable environment
4) Two descendant populations look very different, though they have many similar structures
3, 1, 2, 4
A tortoise and an eel both have jaws that help them grab food, but they have different jaw structures. The tortoise has a bony beak that helps it bite plants. The eel has sharp teeth that help it eat fish. What most likely explains why both have jaws and why the jaws are different?
They both have jaws because they inherited them from a common ancestor population that also had jaws.
The jaws are different because they separated into different environments that favored different traits. Over millions of years, small changes to the jaws build up and the structures become very different.
* A new species is discovered and you are tasked with figuring out if it is more similar to a hippo or an iguana. (Look at the data table)
a) Why do all 3 share similarities?
b) Why do all 3 have differences?
c) Which species is the fossil more related to? Why?
a) They share a common ancestor
b) They evolved in different environments
c) Hippo, because they share more structures
Describe the process of speciation. Give 2 examples of speciation that we discussed in class.
A population is divided into different environments and evolves separately into 2 different species.
Ex: Tortoises on Galapagos. Polar Bears. Ducks on Hawaiian Islands.
* Which descendant species will probably be most similar to the ancestor population? Most different?How do you know?
Which species will probably be most different from descendant species D? How do you know?
Descendant species 1 or 2 would be more similar because they are closer on the evolutionary tree, while A, B, C, and D would be more different because they are farther.
Species A and B would be most different, because they are the most separated on the evolutionary tree.
WILD SQUARE!!!
What will you get????
Not this (evolutionary) time! Lose a turn.
* Which of these 3 organisms share a common ancestor population? How do you know? Which of the 3 species are more closely related? How do you know?
All 3 share a common ancestor because they are all connected back on the Evolutionary Tree. The locust and spider are more closely related because they are on the same branch of the Evolutionary Tree. The octopus is on a different branch.