Evidence for Evolution

Question 1

5 pieces of evidence for evolution

Answer 1

fossils, geographical distribution (biogeography), comparative anatomy, embryological development, biochemical/molecular

Question 2

How do fossils show evidence for evolution?

Answer 2

Fossil evidence shows how some organisms changed slowly over time

ex) Older rocks contain fossils of simpler organisms

Question 3

How are fossils organized?

Answer 3

by the age of the fossil

(oldest –> youngest)

Question 4

Examples of relationships that fossils can show

Answer 4

dinosaurs and birds
whales and four-legged mammals

Question 5

Fossil record

Answer 5

chronological collection of life’s remains in rock layers recorded during the passage of time

Question 6

What are fossils?

Answer 6

the preserved remains of ancient organisms

Question 7

How do geographical distribution (biogeography) show evidence for evolution?

Answer 7

they show the existence of an a common ancestor

Question 8

Biogeography

Answer 8

the study of where organisms live now and where they and their ancestors lived in the past

Question 9

Two biogeographical patterns of evolution

Answer 9

divergence (closely related species differentiate from different environments)

convergence (distantly related species become similar from similar environments)

Question 10

What happens to an organism when a bunch are spread out over a bunch of islands?

Answer 10

they differentiate because of differing environments

Question 11

Examples of differentiation based on the environment (biogeography)

Answer 11

finches on the Galapagos Islands having different beaks and fur color

Question 12

How does comparative anatomy show evidence of evolution?

Answer 12

Suggests that these organisms developed from a common ancestor

Question 13

Homologous body structures

Answer 13

similar structures found in more than one species that share a common ancestor

Question 14

Vestigial structures

Answer 14

organ/structure that serves no useful function in an organism

Question 15

What do vestigial structures suggest?

Answer 15

organs had a function at one time but as the organism changed over time, it was no longer needed.

Question 16

Examples of vestigial structures

Answer 16

appendix and coccyx in humans; leg bones in whales

Question 17

Examples of homologous structures

Answer 17

forelimbs of mammals

ex) humans, cats, whales, and bats have very similar skeletal parts in the forelimbs

Question 18

Why are homologous structures different?

Answer 18

different functions

ex) humans have metacarpals for dexterity, bats have very long metacarpals to have more tissue -> bigger wingspan

Question 19

How does embryological development show evidence of evolution?

Answer 19

provides visual evidence that organisms descend from a common ancestor, even if their adult forms are different

Question 20

Embryos of closely related organisms have…

Answer 20

similar early stages of development

ex) All vertebrates (animals with backbone) have an embryonic stage in which pouches appear on the sides of the throat

Question 21

The development of embryos adds evidence to evolution. How?

Answer 21

homologous bones and organs developing from the same clumps of embryonic cells in vertebraes

Question 22

Embryo

Answer 22

an unborn or unhatched offspring in the process of development

Question 23

Similarities of embryos of different species

Answer 23

eye placement, vertebrae, head formation, etc.

Question 24

How does biochemical/molecular analysis show evidence of evolution?

Answer 24

“confirmation” of evolution

(can only be applied to existing organisms)

Question 25

If two species have genes and proteins with sequences that match closely…

Answer 25

the sequence was copied from a relatively recent common ancestor

(basically, the two species share a recent common ancestor)

Question 26

What is biochemical/molecular analysis?

Answer 26

Comparison of DNA sequences of genes, amino acids sequences, location of genes on chromosomes, and chromosome structure

Question 27

What three things are compared in biochemical/molecular analysis?

Answer 27

DNA, amino acid sequences, and chromosomes

Question 28

What would the DNA sequence of two closely related species look like?

Answer 28

very similar

Question 29

What would the amino sequences of hemoglobin look like in two species that are vastly different?

Answer 29

more amino acids that differ

Question 30

What gets compared in chromosomes when analyzing them?

Answer 30

size of chromosome, location of genes, location of centromeres

Question 31

What would the chromosomes of similar species look like?

Answer 31

similar

(similar size, similar location of genes, and similar location of centromere)

Question 32

Why is all living things having DNA as a genetic code so important to the idea of evolution?

Answer 32

it is powerful evidence that all organisms evolved from common ancestors that shared this code