Similarities and Differences
This is one shared structure that both our Mystery Fossil and modern-day whales have...
What is a large rib cage?
A group of organisms of the same type that do not reproduce with any other groups....
What is a species?
What is evolutionary time?
the very long time that spans the history of Earth, from the very first cellular life to the present
Similarities in the body structures of species is possible evidence that the species are ___________.
What is related?
This is one way that the human arm and a cat's front limb are similar...
BONUS (100 points): What does this tell us?
What is they both share a "one-two-many" bone structure.
BONUS: They share a common ancestor.
An older species from which 2 or more different species evolved.
What is a common ancestor population?
True or False: Life has been very diverse for the entirety of Earth's history.
What is False? For most of Earth's history (4.6 Billion years) life either didn't exist or consisted of single celled organisms.
This is why our Mystery fossil was not considered to be closely related to crocodiles
Because it was pregnant and crocodiles lay eggs
This is where species get their body structures from...
What is their ancestor populations?
What is an common ancestor population?
an older population from which two or more newer species descended
According to fossil evidence, about how long ago did life start on Earth?
About 3.6 billion years ago
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 moray eel has sharp teeth that helps 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.
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.
This best explains why modern toothed whales and our Mystery Fossil have different teeth....
What is they have different teeth for eating different types of food?
A newer species that evolved from an ancestor population
What is a descendant species?
Which of the following changes in traits would take the longest time.
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 of 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.
Why is having a shared structure evidence that two organisms are related?
A shared structure means they have similar DNA (Genes) which they inherited from a common ancestor
When a population is separated into different environments and evolves into two different species
What is speciation?
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
This is the name of a scientist who studies fossils....
What is a paleontologist?