rbp; Flashcards
full name of darwins famous book
on the origin of species by means of natural selection
date darwin published origin of species
november 24, 1859
the origin of species focused biologists’ attention on _______
the great diversity of organisms
darwin’s 2 major points in the origin of species
- he presented evidence that the many species of organisms presently inhabiting earth are descendants of ancestral species that were different from the modern species
- he proposed a mechanism for this evolutionary process – natural selection
the basic idea of natural selection is that ________
a population can change over generations if individuls that possess certain heritable traits leave more offspring than other individuals
the result of natural selection is _______
evolutionary adaptation – an accumulation of inherited characteristics that enhance organisms’ ability to survive and reproduce in specific environments
we can define evolution as
a change over time in the genetic composition of a population
we can also use the tem evolution on a grand scale to mean ________
the gradual appearance of all biological diversity
aristotle’s views in evolution
he views species as unchanging. through his observations, he recognized certain “affinities” among living things. he concluded that life-forms could be arranged on a ladder, or cale, of increasing complexity, later called the scala naturae
scala naturae
“scale of nature”
each form of life, perfect and permanent, had its allotted rung on this ladder.
it was a ladder of increasing complexity
carolus linnaeus
swedish physician and botanist who sought to classify life’s diversity “for the greater glory of god”
linnaeus founded ______ and developed ______
taxonomy;
binomial system of naming organisms according to genus and species
taxonomy
the branch of biology concerned with naming and classifying organisms
the scalar naturae system was a ______ ______
linear hierarchy
to linnaeus, the observation that some species resemble each other
didn’t imply evolutionary kinship, but rather the pattern of their creation
_____ helped to lay the groundwork for darwin’s ideas
the study of fossils
fossils
remains or traces of organisms from the past, found in sedimentary rocks
sedimantary rocks
formed from the sand and mud that settle to the bottom of seas, lakes, and marshes. new layers of sediment cover older ones and compress them into superimposed layers of rock called strata
paleontology
study of fossils; largely developed by french scientist Georges Cuvier
in examining rock layers in the paris region, cuvier noted that
the deeper the strata, the more dissimilar the fossils are from current life. also, from one stratum to the next, some new species appear while others disappear
cuvier staunchly opposed
the idea of gradual evolutionary change
cuvier advocated
catastrophism, speculating that each boundary between strata represents a catastrophe, such as a flood or drought, that destroyed many of the species living at the time
cuvier proposed that periodic catastrophes
were usually confined to local geographic regions, which were repopulated by species immigrating from other areas
gradualism
the idea that profound change can take place through the cumulative effect of slow but continuous processes
james hutton
scottish geologist who proposed that earth’s geologic feature could be explained by gradual mechanisms CURRENTLY operating in the world. he suggested that valleys were formed by rivers wearing thru rocks and that sedimentary rocks containing marine fossils were formed from particles that had eroded from the land and been carried by rivers to the sea
charles lyell
leading geologist of darwin’s time. he incorporated hutton’s thinking into a more comprehensive theory known as uniformitarianism – the same geologic processes are operating today as in the past, and at the same rate
darwin agreed that if geologic change results from slow, continuous actions rather than sudden events, then
earth must be much older than the 6,000 years that theologians estimated. he later reasoned that similarly slow and subtle prcesses could act on living organisms
during the 18th century, several naturalists suggested that
life evolves as environments change
Jean-Baptiste de Lamarck
french biologist who developed a comprehensive model for how life evolves. he is primarily remembered today not for his visionary recognition that evolutionary chnage explains the fossil record and organisms’ adaptations to their environments, but for the incorrect mechanism he proposed to explain how evolution occurs
lamarck published his theory in
1809, the year darwin was born
by comparing current species with fossil forms, lamarck had found what appeared to be
several lines of descent, each a chronological series of older to younger fossils leading to a living species
lamarck’s 2 big principles
use and disuse; inheritance of acquired characteristics
both were commonly accepted at that time
use and disuse
the idea that parts of the body that are use extensively become larger and stronger, while those that are not used deteriorate
inheritance of acquired characteristics
stated that an organism could pass use and disuse modifications to its offspring
lamarck also thought that evolution happens because
organisms have an innate drive to become more complex
darwin thought that variation was introduced into the evolutionary process through
inheritance of acquired characteristics
lamarck was vilified in his own time, esp. by
cuvier, who denied that species ever evolve
darwin was born in
1809, ,shrewsbury in western england
darwin’s father sent darwin to
univ. of edinburgh to study medicine
at cambridge, darwin became the protege of
reverend john henslow, a professor of botany
john henslow
recommended darwin to captain robert fitzroy, who was preparing the survey ship HMS Beagle for a voyage around the world
the primary mission of the Beagle voyage was to
chart poorly known stretches of the south american coastline
darwin noted that the plants and animals in temperate regions of south america more closely resembled
species living in the south american tropics than species in temperate regions of europe
the south american fossils darwin found, though clearly different from living species, were
distinctly south american in their resemblance to the living organisms of the continent
lyell’s book
principles of geology
darwin experienced geologic chance firsthand when
a violent earthquake rocked the coast of chile, and he observed afterward that the coastline had risen by several feet
finding fossils of organisms high in the andes mountains, darwin inferred that
the rocks containing fossils must have been raised there by a long series of similar earthquakes
darwin learned from lyell that
the traditional view of a static earth only a few thousand years old was not valid
galapagos
a group of geologically young volcanic islands located near the equator about 900 km west of south america
darwin found that although the galapagos animals resembled species living on the south american mainland, most of the lived nowhere else in the world. he hypothesized that
the galapagos had been colonized by organisms that had strayed from south america and had then diversified on the various islands
darwin perceived _____ and ______ as closely related processes
adaptation to the environment; the origin of new species
in the year ____, darwin wrote a long essay on _____ but ____
1844; the origin of species and natural selection; was reluctant to introduce his theory publicly, apparently b/c he anticipated the uproar it would cause
lyell, not yet hiself convinced of evolution, nevertheless urged darwin to
publish on the subject before someone else came to the same conclusions and published first
alfred russel wallace
young british naturalist working in the east indies who had developed a theory of natural selection similar to darwin’s. in june 1858, wallace asked darwin to evaluate his paper and forward it to lyell if it merited publication
lyell and a colleague presented wallace’s paper + extracts of darwin’s unpublished 1844 essay to the
linnean society of london
within a decade, darwin’s book and its proponents had
convinced most biologists that biological diversity was the product of evolution
darwin followed up his 1st book w/ other pioneering work, in particular
an exploration of the type of natural selection known as sexual selection
in publishing his theory, darwin developed 2 main ideas:
that evolution explains life’s unity and diversity and that natural selection is a cause of adaptive evolution
in the 1st edition of the origin of species,
darwin didn’t use the word evolution until the very end
descent w/ modification
a phrase that summarized darwin’s view of life. he perceived unity of life, w/ all organisms related thru descent from an ancestor that lived in the remote past. as the descendants of that ancestral organism spilled into various habitats over millions of years, they accumulated diverse modifications, or adaptations, that fit them to specific ways of life
most branches of evolutions
are dead ends. about 99% of all species that have ever lived are now extinct
who are the elephants’ nearest relatives
manatees and hyraxes
linaeus had realized that ____, but ____
some organisms resemble each other more closely than others, but he hadn’t linked these resemblances to evolution
to darwin, the linnaean hierarchy reflected
the branching history of the tree of life, with organisms at the various taxonomic levels related through descent from common ancestors
for any species population sizes would
increase exponentially if all individuals that are born reproduced succssfully
populations tend to
remain stable in size, except for seasonal fluctations
production of more individiuals than the environment can support leads to
a struggle for existence among individuals of a population, w/ only a fraction of their offspring surviving each generation
darwin perceived an important connection between
natural selection, which results from what he called the struggle for existence, ad the capacity of organisms to “overreproduce”
thomas malthus
contended that much of human suffering – disease, famine, homelessness, and war – was the inescapable consequence of the human population’s potential to increase faster than food and other resources.
increases in the frequencies of favored traits in a population,
which are always taking place regardless of whether the environment is changing, are an important source of evolutionary modification
darwin derived another piece of his theory from
the many familiar examples of selective breeding of domesticated plants and animals
artificial selection
process by which humans have modified other species over many generations by selecting and breeding individuals that possess derived traits
natural selection
is the differential success in reproduction among individuals that vary in their heritable traits. these reproductive differences emerge as each individual interacts w/ its environment
over time, natural selection
can increase the adaptation of organisms to their environment
if an environment changes over time, or if individuals of a particular species move to a new enviornment,
natural selection may result in adaptation to these new conditions, sometimes giving rise to new species in the process
smallest unit that can evolve
population
evolution can be measured only as
changes in relative proportions of heritable variations in a population over a succession of generations
although natural selection occurs thru interactions btwn individual organisms and their enviornment,
individuals DO NOT evolve
natural selection can amplify or diminish ONLY
heritable traits
environmental factors vary from place to place and from time to time. therefore,
a trait that is favorable in one situation may be useless, or even detrimental, in different circumstances
natural selection is more a ____ than a ______
process of editing; creative mechanism
homology
similarity resulting from common ancestry
homologous structures
represent varations on a structural theme that was present in their common ancestor.
similar structure, different function
comparative embryology
comparison of early stages of animal development
vestigial organs
type of homologous structures. vestigial organs are remnants of structures that served important functions in the organism’s ancestors
b/c evolution can modify only existing structures and functions, it often
produces less than perfect results
biogeography
the geographic distribution of species
closely related species tend to
be found in the same geographic region
the same ecological niches in distant regions are
occupied by very different, though sometimes similar-looking, species
eutherians
mammals that complete their embryonic development in the uterus
marsupials
are born as embryos and complete their development in an external pouch
analogous/convergent structures
that they serve the same function in different species but they evolved independently rather than from the same embryological material or from the same structures in a common ancestor.
endemic
found nowhere else in the world
most island species are
closely related to species from the nearest mainland or neighboring island
2 islands with similar environments in different parts of the world are populated
not by closely related species but rather by species that resemble those of the nearest mainland, where the environment is often quite different
comparative data from biochem, molecular bio, and cell bio suggest that ______ are the ancestors of all life and _____ should precede ______
prokaryotes
prokaryotes; all eukaryotic life
the darwinian view of life predicts that evolutionary transitions should
leave signs in the fossil record
