Chapter 22 - Descent w/ modification: a darwinian view of life Flashcards
1859 Charles Darwin publishes…
…Origin of Species
(1859) Origin of Species
focuses on great diversity of organisms
–Evolution (descent w/ modification)
–Evolution is pattern & process
–Started scientific revolution
–Ideas developed thru influence of other’s works & own travels
(1809) Lamarck publishes his hypothesis of evolution
ok cools. it’s also when Charles Darwin was born
Creek philosopher Aristotle’s view:
species are fixed & arranged them on a scala naturae (increasing complexity)
Carolus Linnaeus was the founder of ______, the branch of bio abt classifying organisms
…taxonomy…
How does taxonomy work?
–groups similar species into categories
–Binomial format (italics + “Genus epithet” SPECIFIC FORMAT)
–still used today
What does Darwin mean by descent w/ modification?
Evolution is the process by which species accumulate difference from their ancestors as they adapt to different environments over time
The pattern & process of evolution:
–PATTERN revealed by scientific data, showing that life has evolved over time
–PROCEsS consists of the mechanisms that cause the pattern of change
The study of ____ helped to lay the groundwork for Darwin’s ideas
…fossils…
Fossils are…
…remains/traces of organisms from the past, usually found in sedimentary rock that appear in layers called strata
Lamarck’s hypothesis of evolution:
Species evolve thru use & disuse of body parts and the inheritance of acquired characteristics. Body parts used extensively become larger & stronger while unused parts deteriorate & disappear.
Inheritance of acquired characteristics:
modifications acquired in one’s lifetime can be passed to offspring
Mechanisms proposed by Lamarck are ______!
…UNSUPPORTED by evidence
General 19th century belief:
species were created & unchanging
Darwin’s trip:
–Traveled on the “Beagle” & collected specimens of S American plants & animals
–Stopped at Galapagos islands & collected many similar but different species of birds, some unique to individual islands, others found on multiple
–hypothesized species from S America colonized Galapagos & speciated on the islands based on what they could find & eat
(1844) Darwin wrote essay on _______ as mechanism of descent w/ modification
…natural selection…
What is natural selection?
A process in which individuals w/ certain inherited traits tend to survive & reproduce at higher rates bc of those traits
Darwin’s observations & inference (1)
members of a population often vary in inherited traits
Individuals whose inherited traits gave them a higher probability of surviving & reproducing in an environment tend to leave more offspring
Darwin’s observations & inference (2)
all species can produce more offspring than the environment can support, which is why most family to survive/reproduce
The unequal ability of individuals to survive & reproduce will lead to the accumulation of favorable traits in the population over generations
Darwin’s observations (general):
bleh
Key features of natural selection:
–Advantageous traits that inc the # of offspring that survive & reproduce will appear in higher frequency in next gen
–Over time, natural selection by predators, lack of food, or adverse conditions can inc the proportion of favorable traits in population
–Individuals don’t evolve; POPULATIONS evolve over time
–If the environment changes, natural selection may drive adaptation to new conditions, making new species
Evolution is supported by…
…a shit ton of scientific evidence
Four types of data document the pattern of evolution:
–direct observations
–homology
–fossil record
–biogeography
Natural selection doesn’t ________ & only edits/selects for traits already present in population
…create new traits…
