Biological Evolution (L2)

Do all forms evolve?
No- Some forms remain ancient forms and hardly change (e.g. the coelacanths, unchanged for 200mya), can also happen in plants (e.g. ferns, conifers, flowering plants)
1 of 6
Describe the findings of Westoll (1949)
Scored numerous fossil specimens of lungfish for 21 characteristics, this showed a period of rapid evolution for about 50my then relative stasis until present-- So evolution does not always proceed at a slow constant rate within species or lineages
2 of 6
How can fossil records be used as evidence for evolution?
Complexity of organisms increases throughout Tim, oldest rock strata con only contain simple organisms
3 of 6
How can lineages be used as evidence for evolution?
Fossil forms in chronological order can sometimes form obvious lineages showing cumulative changes, for example horses skulls and hooves
4 of 6
What is an evolutionary arms race?
Where 2 organisms evolved against each other, e.g. grass increases silica deposition in cell walls (tougher) so horses developed larger bodies, longer jaws, increased tooth enamel
5 of 6
How can embryonic development be used as evolutionary evidence?
Mammalian embryos look very similar at early stages, hox genes that control development are widely shared and therefore presumed to be ancient
6 of 6

Other cards in this set

Card 2

Front

Describe the findings of Westoll (1949)

Back

Scored numerous fossil specimens of lungfish for 21 characteristics, this showed a period of rapid evolution for about 50my then relative stasis until present-- So evolution does not always proceed at a slow constant rate within species or lineages

Card 3

Front

How can fossil records be used as evidence for evolution?

Back

Preview of the front of card 3

Card 4

Front

How can lineages be used as evidence for evolution?

Back

Preview of the front of card 4

Card 5

Front

What is an evolutionary arms race?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Evolution resources »