Evidence For Evolution

Question 1

What is a transitional form and its types?

Answer 1

-lntermediate states between an organism’s ancestral form and that of it’s descendants.
2 types
Gradualism- the concept that evolution occurs as a steady, slow divergence of lineages at an even pace.
Punctuated Equilibrium-states that species remain fairly stable for long periods of time,but may swiftly change into a new species so quickly that they may not be preserved as fossils.

Question 2

Explain electron spin resonance.

Answer 2

• Measures the properties of electrons in the minerals of crystals.
• Electrons become trapped within the crystal lattice and are madly magnetic.
• Radiation increases over time and can be measured.

Question 3

Explain luminescence techniques.

Answer 3

• Properties are measured in minerals in sedimentary rocks.
  Optical Luminescence- measures the light emitted when a mineral is exposed to visible light.
  Thermal Luminescence- measures light emitted from a mineral when heated.

Question 4

Explain divergent evolution and adaptive radiation.

Answer 4

Divergent- the evolution of different species from a common ancestral species.
- isolated species and populations accumulate genetic differences and their homologous features may become more and more different.
Adaptive Radiation- rapid divergence of an evolutionary lineage from a recent common ancestor.
- a cluster of related species is considered evidence of adaptive radiation.

Question 5

Explain convergent and parallel evolution.

Answer 5

Convergent- the development of similar features separately in unrelated groups of organisms.
- natural selection may lead to them evolving one or more similar features, which are analogous.
- the 2 species become more alike, or converge, but still have other differences.
Parallel- occurs when related species evolve similar features independently.
- these organisms are filling similar ecological roles in similar environments but perhaps on the other side of the world, so adaptions were selected.

Question 6

Explain the four types of comparative anatomy.

Answer 6

Embryology of Vertebrates- can establish relationships based on structural similarities and differences of the developing embryo.
-common development pathway depends on closeness of relationships.
Homologous Structures- common physiological structures shared by different organisms that descend from a common evolutionary ancestor.
-have adapted a different purpose for these structures.
Vestigial Structures- evolutionary leftovers, no longer serves a purpose.
- are reduced in size to conserve energy.
- provide evidence of change over time.
Analogous Structures- similar anatomical structures found in unrelated organisms, but still serve the same function.
- they have a different skeletal structure but have experienced similar selection pressure.

Question 7

Explain the three types of molecular evidence for evolution.

Answer 7

Protein Conservation- a protein that is well suited will be conserved, while other traits continue to evolve.
- a point mutation may arise, perhaps causing the loss of an amino acid, usually making it less suited to it’s function, and therefore not conserved.
- protein sequences can be compared across species and conserved amino acids can be identified.
Genetic Comparison- when comparing the genome of 2 species, the mutation rate can be used to estimate at which point in time those species diverged from a common ancestor.
Comparative Genomics- DNA sequences and mutation frequencies, make it possible to trace evolutionary process responsible for divergence of 2 genomes.
bioinformatics- the digital storage, retrieval, organisation and analysis of biological data.