Evidence for Evolution - Video Notes Flashcards

Flashcards covering key concepts from the Evidence for Evolution factsheet notes, including fossils, comparative anatomy, DNA/protein comparisons, embryology, and species distribution.

What types of evidence support the theory of evolution as described in the notes?

Fossils; comparative anatomy (homologous, analogous, and vestigial structures); DNA and protein comparisons; embryology; and patterns of species distribution/isolation.

How are fossils formed and what do sedimentary layers indicate about age?

Organisms become buried in sediments with little decomposition. Over time, sedimentary layers are deposited so that the oldest fossils are at the bottom and the youngest at the top, showing progression through time.

What does comparative anatomy study and what can it reveal about evolution?

The structures of living species and fossils; it reveals evolutionary relationships and phylogeny through similarities and differences in anatomical features.

What are homologous structures and what is their evolutionary origin?

Structures that evolved from a common ancestor; they have the same skeletal elements (e.g., humerus, radius, ulna) but may be modified for different functions; result from divergent evolution.

Provide examples of homologous structures mentioned in the notes.

Forelimbs of humans, cats, whales, and bats—all sharing the same skeletal elements.

What are analogous structures and how do they relate to evolutionary relationships?

Structures that serve the same function but have different internal anatomy; they do not indicate close evolutionary relationships.

Give examples of analogous structures from the notes.

Wings of birds and butterflies; eyes of lobsters and fish; fins of a shark and the flippers of a dolphin or penguin's wing are cited as analogous functions.

What are vestigial structures and what are some examples given?

Structures with little or no function that may be repurposed; examples include the human appendix, tailbone, and wisdom teeth; baleen whale pelvic bone is cited as vestigial.

Why is DNA and protein structure important in studying evolution?

All living cells share the same basic DNA structure and genetic code; comparing DNA sequences shows regions of identity across species; protein amino acid sequences reveal relatedness.

What percentage of genes are identical between humans and chimpanzees, according to the notes?

Approximately 96%.

How can amino acid sequence comparisons inform about relatedness between species?

The number of amino acids in the same positions on a protein chain indicates relatedness; fewer differences mean closer relationships (humans and chimps differ in 1 position; humans and moths differ in about 31).

How do new alleles and genes arise, and what does this imply about the evolution of complexity?

New alleles and genes arise from existing genes by mutation; this supports gradual development of complexity rather than a simple-to-complex reversal.

What trend is observed from early fossils to later fossils regarding organism complexity?

Early fossils are fairly simple; later fossils become increasingly complex, supporting gradual evolutionary change.

What is phylogeny?

The evolutionary history of a group of organisms.

What role does species distribution, especially on isolated islands, play in evolution?

Isolated pockets or islands host unusual species; isolation is a key driver of speciation.

How does plate tectonics relate to the distribution of species, particularly in Australia?

Movement of Earth's tectonic plates explains fossil distributions; Australia’s isolation led to many marsupials and only two living monotremes.

What are the two living monotremes named in the notes and where are they found?

Platypus and echidna; found in Australia.

What does embryology reveal about similarities among vertebrate embryos?

Vertebrate embryos show striking similarities in early development, including transient gill structures and tails that are reabsorbed; supports common ancestry.

Which gene Influences the development of branchial arches into gills, and what happens if it mutates?

Gcm-2; mutation or inhibition can prevent gill development.

How are gill structures used to illustrate homologous traits in evolution?

Gills arise from branchial arches that are homologous across species, illustrating shared ancestry and evolutionary history.