Biology - Speciation flashcards

Question	Answer
Speciation	Lets revise!
What are fossils?	Fossils are the preserved remains or traces of dead organisms. They are found in rocks.
What can fossils be formed from?	- Hard body parts, such as bones and shells, which do not decay easily or are replaced by other materials as they decay. - Parts of organisms which have not decayed. For example, dead animals and plants can be preserved in amber (hardened tree resin), peat bogs, tar pits or in ice - Casts or impressions, such as foot prints or burrows. These become covered by layers of sediment, which eventually become rock.
Explain how the horse evolved	One of the few animals for which we have a fairly complete evolutionary record is the horse. All the main stages of the evolution of the horse have been preserved in fossil form. Image: d55ed82d-aece-4944-9eff-8f4123c8feb2 (image/png)
Describe what Darwin investigated in the Galápagos Islands	- He noticed that the finches (songbirds) on the different islands were similar to each other. - The finches showed wide variations in their size, beaks and claws from island to island - for example, their beaks were different depending on the local food source. - Darwin concluded that, because the islands are so distant from the mainland, the finches that had arrived there in the past and had changed over time Image: b9860cb4-77dd-4ef9-b1e6-a4ac35b56b4b (image/jpg)

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	Created by rahateley1 over 9 years ago