Bio 115 Lecture 2:Evolution, Natural Selection, Biodiversity, and Evidence of Evolution

Comprehensive flashcards covering definition of biological evolution, lines of evidence, history of paleontological thought, fossil proxies, and evolutionary applications based on lecture notes.

How is biological evolution defined in contrast to everyday usages of the word "evolution"?

Biological evolution is defined specifically as biological change across generations in populations, rather than individual growth or non-biological changes over time.

What are four major misconceptions regarding biological evolution?

Biological evolution is NOT ontogeny/growth of an individual, a linear progression toward an ultimate goal, a conscious or intentional process, or a process leading to "perfection" or "superiority."

What mechanism produces the "molecular clock" used to estimate the timing of evolutionary splits?

The accumulation of DNA sequence mutations over time, where lineages that diverged longer ago show greater genetic differences than lineages that diverged recently.

Which Renaissance naturalist published a famous side-by-side skeletal comparison of a human and a bird in 1555?

Pierre Belon (in Belon's Book of Birds, 1555).

What is the biological definition of homology?

Homology is a biological "sameness" or structural similarity across different species, individuals, or their parts inherited from a common ancestor.

What is a vestigial structure?

A genetically determined structure or attribute that has lost some or all of its ancestral function in a given species, frequently appearing reduced in adults.

What set of homologous forelimb bones is conserved across humans, cats, whales, and bats?

The humerus, radius, ulna, carpals, metacarpals, and phalanges.

Which single wild plant species was artificially selected to produce cabbage, Brussels sprouts, kale, kohlrabi, broccoli, and cauliflower?

Wild mustard (Brassica oleracea).

In experimental manipulation studies on Trinidadian guppies, what evolutionary changes were observed in male guppies when predation threat was removed?

Male guppies evolved brighter coloration, attained larger body sizes, and produced fewer offspring.

How did Australian snake populations adapt evolutionary over 80 years following the introduction of toxic cane toads in 1935?

Snakes large enough to eat lethal toads evolved smaller head sizes relative to body length to prevent swallowing fatally large cane toads.

What major ongoing experiment initiated in 1988 has documented evolution over more than $80,000\text{ generations}$ of E. coli?

Richard Lenski's Long Term Evolution Experiment (LTEE).

How did soapberry bug populations in central Florida respond to the introduction of the golden rain tree as a host plant?

They evolved shorter average beak lengths compared to native balloon vine-feeding populations because the seeds were located closer to the fruit surface.

By approximately how many years ago is there archaeological evidence of Neanderthals collecting fossils?

By $46,000\text{ years ago}$.

Who was the 6th-century BC Greek philosopher credited with first using fossil fish and shells to argue that land was once underwater?

Xenophanes of Colophon.

What were belemnite fossils historically interpreted as in various European folklores?

They were believed to be "thunderbolts" dropped during storms, elf-bolts/pixie arrows, gnome candles, or petrified lynx urine (lyngurium).

How did Nicolaus Steno demonstrate the biological nature of "glossopterae" or "tongue stones" in 1667?

He dissected a modern shark head and showed that tongue stones were identical to fossilized ancient shark teeth.

How did nostril location shift during the evolutionary transition from early land artiodactyl relatives to modern baleen whales?

Nostrils migrated from the tip of the snout (Pakicetus, $50\text{ million years ago}$) to the middle of the skull (Aetiocetus, $25\text{ million years ago}$), and finally to the top/back of the skull (Eschrichtius robustus, modern gray whale).

How old are the earliest fossil stromatolites that evidence cyanobacteria and early life on Earth?

Approximately $3.5\text{ billion years old}$.

According to Leaf Margin Analysis, how does leaf edge morphology relate to climate temperature?

Colder climates select for a higher proportion of leaves with toothed (serrated) margins, whereas warmer climates select for a higher proportion of leaves with smooth (entire) margins.

How does the stomatal index of fossil leaves like Ginkgo biloba reflect atmospheric $CO_2$ levels?

As atmospheric $CO_2$ levels increase, plants develop a lower stomatal index (fewer stomata per unit area of the leaf surface).

Which four Permian and Triassic fossil taxa distributed across South America, Africa, India, Antarctica, and Australia helped prove the existence of Gondwana and continental drift?

Glossopteris (fern), Mesosaurus (freshwater reptile), Cynognathus (land reptile), and Lystrosaurus (land reptile).

What is the definition of a "living fossil"?

An extant taxon that phenotypically closely resembles related species known primarily from the fossil record, displaying little morphological change over long geological time periods.

What is conservation paleobiology?

A field of paleontology that applies data from the geological and paleoecological record to inform biodiversity conservation, ecosystem restoration, and environmental management policy.

What unique wing structure was discovered in the scansoriopterygid dinosaur Yi qi?

A membranous, bat-like wing supported by an extra long, rodlike wrist bone rather than elongated feathered digits.

What significant organic building blocks of life were discovered in samples collected from Asteroid Bennu?

All $5$ nucleobases that compose DNA and RNA on Earth, along with $14$ of the $20$ standard amino acids found in biological proteins.