Evidence of Evolution Notes
· Geographic Distribution of Living Things
o a. ________________________is study of distribution of plants and animals throughout the world.
o b. Current ______________________ of organisms reflects evolutionary history; organisms evolve in one location and spread out into other regions; for example, no rabbits are found in South America--they originated elsewhere and did not reach South America.
o c. Physical factors, including location of continents, limit population range.
o d. __________________________________ states that continents have slowly moved over time.
§ i. Explains close puzzle-piece fit of east coast of ____________________ with west coast of _______________, and other continent edges.
§ ii. Explains distribution of seed ferns throughout southern continents.
§ iii. Explains distribution of early reptiles across many continents from time when land was conjoined.
§ iv. Explains divided distribution of mammals that evolved after continents parted.
· Fossil record
o a. ___________________________ are remains, traces or other direct evidence of past life forms.
o b. Most fossils form from burial of plants and animals in ________________________; soft parts are more often consumed or decomposed but may leave imprints if buried rapidly.
o c. Most fossils are embedded in _________________________, weathered particles that provide strata from lower older layers to upper newer layers.
o d. ___________________________________ study the fossil record based on boundaries between strata, where one mix of fossils gives way to another.
o e. Transitional links are intermediate between major groups.
§ i. Archeopteryx has features intermediate between primitive reptiles and birds.
§ ii. Eustheopteron is fish ancestral to amphibians.
§ iii. Seymouria is amphibian ancestral to reptiles.
§ iv. Therapsids are reptiles ancestral to mammals.
fish --> _____________ --> reptile --> ____________
· Body Structures
o Many organisms share a _______________________; for example, vertebrate forelimbs contain same sets of bones used for different functions in bat wings, whale fins, etc.
o __________________________________ that are embryologically similar, but have different _____________________, the wing of a bird and the forearm of a human
o ________________________ structures have similar functions but differ in anatomy and did not derive from the same ancestral structure; for instance, an insect wing and a bird wing.
o ____________________________ structures are reduced and __________________________ anatomical features that are fully developed and functional in other ancestral groups. Vestigial structures are evidence of an organism's evolutionary history.
§ i. Flightless birds have vestigial wings.
§ ii. Snakes have remnants of a pelvic girdle.
§ iii. Humans have a tail bone but no tail.
§ iv. Wale - femur (large bone)
· Biochemistry and DNA
o a. Almost all living organisms use the same basic ____________________: DNA, ATP, many identical enzymes, DNA triplet code, 20 amino acids, and
o b. Similarity of biochemistry is explained by descent from common ancestor.
o c. DNA base sequences: differences in DNA between a number of organisms shows less difference the more closely related they are; for example, 2.5% difference between humans and chimpanzees but 42% difference between humans and lemurs.
o d. Biochemical evidence is generally consistent with anatomical similarity of organisms.
· Embryological development--Embryos of different species develop almost _________________________.
o a. All vertebrates exhibit _____________________ during development.
o b. All vertebrates, including humans, exhibit paired ________________________________________.
§ i. In fishes and amphibians, these become functioning _________.
§ ii. In humans, they become the ____________________ tubes, middle ear cavity, tonsils, and thyroid and parathyroid glands.
o c. Simplest explanation is that fish notochord and pharyngeal pouches are primitive fish features and fish are ancestral to other vertebrates.