Chapter 13 Flashcards
Darwin’s sea voyage lead to
Darwin’s theory of evolution in 1840
Wallace discovered
similar hypothesis to Darwin in 1858
Early greek philosophers suggested that
life might change gradually over time
Lamarck in 1800 used fossils to..
suggest organisms evolved
Darwin’s hypothesis
present-day species arose from a succession of ancestors by accumulating diverse modification that fit to their specific environment
Decent with modification
evolutionary adaptation by natural selection
Darwin’s book
on the origin of species by means of natural selection
Darwin realized that earths surface..
has gradually changed (earthquakes and mountain formations
Environment is the ..
selective force in the process of evolution by natural selection
Artificial selection
humans select individuals with desired traits over generations or selective breeding that modifies species
Natural selection
mechanism to explain how evolution happens in nature, in a particular environment favourable traits are selected for while unfavourable traits are selected against
Darwin recognized the connection between
natural selection and capacity of organisms to over reproduce
Thomas Malthus
argued that human suffering was the consequence of human populations increasing faster than essential resources
2 things darwin observed that organisms
- vary in many traits
- produce more offspring than the environment can support
Camouflage adaptations in insects that evolved in diff environments are examples of..
results of natural selection
Evolution of pesticide resistance is an example of
natural selection in action
Evolution
change in the gene pol of a population over time
Darwin’s ideas of evolution also relied on
the fossil record
The oldest known fossils extending back to __ _____ years ago are prokaryotes
3.9 billion
The oldest eukaryotic fossil are about _ ____ old
2.1 billion
We found multicellular eukaryotic life __ _____ years ago
1.5 billion
Series of fossils show transition of ..
existing groups to new species
Gradual modification example
legs to fins in whales
Biogeography
geographical distribution of species
Organisms more closely resemble..
other organisms that are geographical close than distant organisms
Comparative anatomy
comparison of body structures in different species
Comparative anatomy illustrates that
evolution is a remodelling process
Homology
similarity in characteristics that results from common ancestry
Homologous structures
maybe have diff function but are still structurally similar because of common ancestry
Analogous structures
have similar functions but differ in basic structure; arose independently
Comparative embryology
comparing development in early stages of life
Homologous vestigial stuctures
remnants of features that served important functions in organism’s ancestors
Molecular biology
all life uses same genetic language of DNA and RNA
Genetic code is ______
universal
Molecular biology provides strong evidence that
allele forms are related
Evolutionary trees
represent patterns of descent
Homologous structures are used to determine _____ ____ in evolutionary trees
branching sequences
Evolutionary trees are hypotheses for..
evolutionary descent
Universe “blew apart from one mass __ to __ ____ years ago, eventually forming planets
12; 14
Earth formed from swirling cloud of dust about __ _____ years ago
4.6 billion
What cooled to form oceans
water vapour
Photosynthetic cell found in..
stromatolite
Photosynthesis is a ___ ____ likely evolved __ ___
complex process; over time
Stromatolite fossils indicate
first life
Extra terrestrial experiment that show abiotic synthesis of organic molecules is possible
meteorites as sources of amino acids and other key organic molecules
Some RNA molecules called ribozymes can carry out..
enzyme like functions
Prokaryotes lived alone on Earth for __ ____ from ___ to __ _____ years ago
1.5; 3.5 - 2
Prokaryotic photosynthesis produced
oxygen that enriched the water and atmosphere of Earth
What allowed prokaryotes to flourish
anaerobic and aerobic cellular respiration
The oldest fossils of multicellular eukaryotes are about __ _____ years old
1.2 billion
First multicellular plants and fungi began to colonize land about __ _____ yrs ago
500 million
Humans diverted from other primates about _ to _ ___ years ago
6-7 million
Our species homo sapiens originated about _______ years ago
195 000
If earths history were compressed into an hour humans appeared less than __ ____ ago
0.2 seconds