Evidence Of Evolution

Question 0

Geographic distribution of living species

Answer 0

Animals living on different continents each descended from different ancestors
Animals living under similar ecological conditions on those different continents evolve feature in common

Question 1

What is a fossil record

Answer 1

Any evidence of an organism that lived long ago and by comparing fossils you can see that life has changed over time

Question 2

What are analogous structures

Answer 2

Structures that are different in basic structure but the same in function or form
Does not show evolutionary relationships but provides evidence of natural selection

Question 3

What are homologous structures

Answer 3

Structures that are the same in basic structure but different in form and function
Suggests a common ancestor and strong evolutionary relationships

Question 4

What are vestigial structures

Answer 4

Structure that is so reduced in function or size that they aware just vestiges or traces of the original structure
May have been used in a common ancestor and may be used in another animal alive today

Question 5

What do similarities in embryos suggest

Answer 5

That similar genes are at work in early development
Groups of embryonic cells develop in the same order and in similar patterns
The same set of genes control this development (Hox genes)

Question 6

Biochemical comparisons

Answer 6

The more similar the DNA the more closely related the two organisms are and the more recently they share a common ancestor

Question 7

What are molecular clocks

Answer 7

They use mutation rates in DNA to estimate the time that two species have been evolving independently

Question 8

What mutation do molecular clocks only use

Answer 8

Neutral mutations which have no effect on the phenotype and tend to accumulate in the DNA in different species at the same time
The more neutral mutations, the longer ago two species shared a common ancestor