evolution pt. 1 (#8) (copy)

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Aristotle, scala naturae

KEY CONTRIBUTORS:

384-322 BCE

believed that species are fixed (____ ____) & organized in a hierarchy based on complexity

(separate answers using comma)

James Hutton, gradualism

KEY CONTRIBUTORS:

1795

principle of ______

• suggesting that geological changes occur slowly over vast timescales

Charles Lyell, uniformitarianism

KEY CONTRIBUTORS:

1795

principle of ________ (built on James Hutton’s ideas)

• emphasizing that current geological processes are the same as those in the past

Thomas Malthus

KEY CONTRIBUTORS:

highlighted the competition for resources, influencing Darwin's ideas on natural selection

Jean Baptiste Lamarck, hypothesis of evolution

KEY CONTRIBUTORS:

1809

_____ of _____

• species evolve over time based on environmental adaptations, proposing an early form of evolutionary theory

Charles Darwin

KEY CONTRIBUTORS:

became Rev. John Henslow’s protege, a botany professor;

wanted to be a clergyman;

independently formulated natural selection theory

Alfred Russell Wallace

KEY CONTRIBUTORS:

naturalist working in the South Pacific Islands of Malay Archipelago;

concluded that species evolve through “survival of the fittest”;

both believed that natural selection acts as driving force behind evolution of life

• diversity of species

• geological observations

• geographic observations

• adaptation & evolution

4 key observations of Darwin

natural selection

3 OF DARWIN’S CONCLUSIONS:

individuals with advantageous traits are more likely to survive & reproduce;

these traits are passed on to future generation;

adaptation

3 OF DARWIN’S CONCLUSIONS:

distinct features of species were adaptations to specific food sources & environment

descent with modification

3 OF DARWIN’S CONCLUSIONS:

unity of life; all organisms share common ancestry

True

TRUE OR FALSE:

Competition for resources drive evolution.

False, Darwin used the phrase “descent with modification”

TRUE OR FALSE:

In the “On the Origin of Species by Means of Natural Selection (1859)”, Darwin used the word “evolution".

True

TRUE OR FALSE:

Darwin imagined the history of life as a tree that has multiple branches coming from common trunk to tips of twigs (diversity of organisms).

On the Origin of Species by Means of Natural Selection

Charles Darwin published this book in 1859

mechanisms of evolution

used to explain the patterns that he observed in evolution

• included artificial & natural selection, mutation, genetic drift, gene flow, & non-random mating

artificial selection

MECHANISMS OF EVOLUTION:

process where humans, not nature, choose which traits they want in plants or animals

mutation

MECHANISMS OF EVOLUTION:

caused DNA changes in an organism’s DNA & introduce new traits that help certain organisms have a survival advantage

• ex. beaks of finches

genetic drift

MECHANISMS OF EVOLUTION:

fluctuations in allele frequencies;

random process that leads to evolutionary change esp. in small populations

bottleneck effect

2 TYPES OF GENETIC DRIFT:

when a large popu. is disrupted by disasters, diseases, or human diversity which can cause a decrease in popu.

founder effect

2 TYPES OF GENETIC DRIFT:

new populations with limited genetic variation from a small group

gene flow

MECHANISMS OF EVOLUTION:

migration introduces new genes, increasing diversity;

movement of genes into or out of a population

non-random mating

MECHANISMS OF EVOLUTION:

selective breeding happens when indivs. choose mates based on their preferred traits like size

homology

EVIDENCE OF EVOLUTION (COMPARATIVE ANATOMY):

similar in structure & physiology among diff. groups due to shared ancestry

• ex. bird’s wing, cat’s leg, human arm

analogy

EVIDENCE OF EVOLUTION (COMPARATIVE ANATOMY):

similar in function, but not in structure or evolutionary origin

• ex. wings of fly, moth, & bird

comparative embryology

EVIDENCE OF EVOLUTION:

similar embryonic stages support common ancestry

vestigial organs

EVIDENCE OF EVOLUTION (COMPARATIVE EMBRYOLOGY):

organs that are no longer functional the way they were in their ancestral origin

• ex. appendix, whale’s pelvic bones

molecular biology

EVIDENCE OF EVOLUTION:

similarity of genes (DNA) & proteins across species (reveal evolutionary relation);

• 98% DNA similarity between humans and chimpanzees

biogeography

EVIDENCE OF EVOLUTION:

geographic distribution of species influenced by historical events

• ex. Pangaea

fossils

EVIDENCE OF EVOLUTION:

show progression of life & changes over time (evolution)

direct observation

EVIDENCE OF EVOLUTION:

natural selection in real-time

• ex. changes in soapberry bug beak lengths due to new food sources