B2 Biology - Speciation Flashcards Preview

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Flashcards in B2 Biology - Speciation Deck (9)
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1

what three ways are fossils formed?

gradual replacement from minerals
casts and impressions
preservations in places no decay happens

2

what are casts and impressions?

organism buried in soft mineral like clay, clay hardens and organism decays leaving a cast of itself

3

where can preservation of fossils happen?

glaciers
peat bogs
tar pits

4

what are some reasons why species become extinct? ( 6 reasons)

environment changes
new predators
new disease
cant compete for food
catastrophic event
new species develops

5

what is speciation?

development of new species

6

when does speciation occur?

when populations of the same species become so different that they no longer breed together to produce fertile offspring

7

what is isolation?

where populations of species are separated

8

when does isolation occur?

physical barrier eg. floods, earthquakes
different climates
different characteristcs or change in environment

9

what is natural selection?

organisms better adapted to their surroundings survive and produce more offspring with the change in adaptations
- weaker die