2. Evidence for evolution

Question 1

what’s an advantageous characterstic in guppys

what can be the consequence

Answer 1

• in guppys, males with lots of colourful spots are favoured by females and are able to reproduce
• however some predators prey upon guppys with bright colours (as they are spotted easily)

Question 2

describe John Endlers study on guppys

Answer 2

created artificial pools with guppys and allowed them to breed, then added predators to reflect natural habitat

• at the end of the study, the average guppy had fewer spots than at the beginning of the study
• the species evolved

Question 3

define genetic drifts

Answer 3

the land plates which used to be closer together connecting the continents forming Pangea have drifted over the years, meaning similar species can be found on different continents

Question 4

give an example of a species which are similar on different continents

Answer 4

the ratites- emu, ostrich, cassowary…

Question 5

why are there no native mammals on NZ

Answer 5

new Zealand split with Gondwana before mammals evolved

Question 6

where are fossils found the most

Answer 6

most common in aquatic environments

Question 7

describe the fossilisation process occurs

Answer 7

1) animal dies
2) soft bits rot away
3) sediment washes over bones/shells and then solidifies
4) ground water dissolves bone- leaving a mould
5) minerals deposited in the mould forms a cast
6) erosion or land movement reveals reveals the fossils millions of years later

Question 8

what does stratigraphy do

Answer 8

allows us to identify the age of a fossil using either the layers in a rock

Question 9

what is another method of identifying how old the fossil is

Answer 9

carbon dating

Question 10

what is the burgess shale

Answer 10

a place found to have successfully preserved the sea life from millions of years ago

Question 11

what are homologous characteristics

Answer 11

similar structures from a common ancestor

Question 12

what are vestigial structures

Answer 12

tails/ hairs

these are poorly developed in some organisms but fully functional in others

Question 13

what are homoplastic characters

Answer 13

similar in appearance and functions but are fundamentally different and have separate evolutionary origins

Question 14

give an example of homoplasy

Answer 14

flies and birds

both have the ability to fly yet have different structures that allow this

Question 15

what is embryology

Answer 15

studies the embryos of different species, shows that humans, reptiles, fish and vertebrates all have gill slits at a particular stage of their development

Question 16

discuss the genetic similarities between organims

Answer 16

the closer related they are, the fewer genetic differences, eg haemoglobin, the closer related they are the more similar

Question 17

what is the hierarchical organisation of life

Answer 17

kingdom
phylum
class
order
family
genus
species