7.6,7,8: Evidence Of Evolution And Comparative Morphology

Question 1

Overwhelming evidence supports the theory of evolution. What are the three primary sources of evidence?

Answer 1

1. The fossil record
2. Comparative morphology
3. Biogeography

Question 2

What are fossils

Answer 2

• remains or traces of past organisms

Question 3

What do fossil records give?

Answer 3

gives a visual of evolutionary change over time

Question 4

How can fossils be dated? (2)

Answer 4

• by examining the rate of carbon 14 decay and age of rocks where the fossils are found
• gives geological data for the organisms found

Question 5

What is the half- life of carbon 14? (2)

Answer 5

• Decay (half-life) every 5730 years

- only good for doing organisms up to 60000 years old

Question 6

What is comparative morphology?

Answer 6

Analysis of the structures of living and extinct organisms

Question 7

Comparative morphology: what is homology?

Answer 7

• characteristics in related species that have similarities even if the structures differ

Question 8

Comparative morphology: What is embryonic homology?

Answer 8

Many species have similar embryonic development

Question 9

What are vestigial structures?

Answer 9

• Structures that are conserved even though they no longer have a use
• tailbones and appendix in humans

Question 10

What is molecular homology?

Answer 10

Many species share similar DNA and amino acid sequences

Question 11

What are homologous structures?

Answer 11

• Characteristics that are similar in two species because they share a common ancestor
  Ex. Arm bones of many species

Question 12

What is convergent evolution?

Answer 12

• similar adaptations that have evolved in distantly related organisms due to similar environments
  Ex. Sharks and dolphins (both have fins)

Question 13

Convergent evolution: what are analogous structures?

Answer 13

Structures that are similar but have separate evolutionary orgins
Ex. Ducks and platypus, turtle and bird beaks

Question 14

How are wings in birds vs bats vs bees examples of analogous structures?

Answer 14

Each species have wings, but the wings did not originate from a common ancestor

Question 15

What indicates common ancestry of all eukaryotes?

Answer 15

Structurak evidence

Question 16

What are conserved across all organisms?

Answer 16

• many fudamental and cellular features and processes

Question 17

What are cellular examples of how many fundamental and cellular features and processes are conserved across organisms? (3)

Answer 17

1. Membrane-bound organelles
2. Linesr chromosomes (recall prokaryotic genomes are circular)
3. Introns in genes (no-coding segments of genome that are removed)

Question 18

In terms of natural selection, how can structures become vestigial (no longer used)? (2)

Answer 18

• A structure may have been useful at one time, but maybe there was a mutation that rendered it useless .
• Therefore it was conserved across generations, neither being selected for or against