TheoryEvol Flashcards
What revolution did Darwin’s ideas challenge?
The traditional views of a young Earth inhabited by unchanging species
This challenge marked the beginning of evolutionary biology.
Define descent with modification.
The process by which species accumulate differences from their ancestors as they adapt to different environments over time.
What does the overwhelming scientific evidence support?
Evolution.
List key topics related to evolution mentioned in the text.
- Descent with modification
- Heritable characteristics
- Natural selection
- Adaptation
- Convergent evolution
- Homology
- Unity of life.
What illustrates the unity of life?
Shared features among organisms, such as three pairs of legs in mantises.
What are Darwin’s three key observations about life?
- Organisms are well suited for their environments
- Shared characteristics (unity) of life
- Rich diversity of life.
What is evolution defined as?
A change in the genetic composition of a population from generation to generation.
What two ways can evolution be viewed?
- As a pattern
- As a process.
What does the pattern of evolutionary change reveal?
Data from many scientific disciplines, including biology, geology, physics, and chemistry.
Who proposed the principle of gradualism?
James Hutton.
What did Charles Lyell contribute to Darwin’s ideas?
He proposed that the same geological processes are operating today as in the past.
What was Lamarck’s hypothesis of evolution?
That life evolves as environments change, through use and disuse and inheritance of acquired characteristics.
True or False: Lamarck’s mechanism of evolution is widely accepted today.
False.
What did Georges Cuvier contribute to the study of fossils?
He noted that older strata have dissimilar fossils compared to current life-forms.
What did Darwin’s observations during his voyage on the HMS Beagle lead him to conclude?
That life evolves over time.
What is the scala naturae?
A ladder or scale of increasing complexity among life forms, proposed by Aristotle.
What naming system did Carolus Linnaeus develop?
The binomial format for naming species.
What did Darwin argue regarding classification of species?
That it should be based on evolutionary relationships.
What is paleontology?
The study of fossils.
How did Darwin’s view of the age of Earth differ from the widely accepted view of his time?
He believed Earth must be much older than a few thousand years.
What was the significance of Darwin’s essay on descent with modification?
It laid the groundwork for his later publication of The Origin of Species.
What is the main idea behind the unity and diversity of life?
That shared ancestry has given rise to diverse characteristics among species.
What did Darwin observe about marine iguanas in the Galápagos Islands?
They illustrated adaptations to their environment.
Who recommended Darwin to Captain Robert FitzRoy?
Henslow
What was the primary mission of the HMS Beagle voyage?
To chart stretches of the South American coast
What did Darwin primarily do during the voyage of the Beagle?
Observed and collected thousands of plants and animals
Which environments did Darwin describe as having organisms well suited to them?
Humid jungles of Brazil, expansive grasslands of Argentina, towering peaks of the Andes
What did Darwin note about the species in temperate regions of South America?
They more closely resembled species in the South American tropics than those in temperate Europe
What geological evidence did Darwin observe during the voyage?
Rocks along the Chile coast were thrust upward by earthquakes
What did Darwin infer from finding fossils of ocean organisms high in the Andes?
The rocks containing the fossils must have been raised by earthquakes
What unique observation did Darwin make about the Galapagos mockingbirds?
They seemed to be different species, some unique to individual islands
What hypothesis did Darwin form regarding the Galapagos species?
They were colonized by organisms from South America that diversified into new species
What are adaptations according to Darwin?
Inherited characteristics of organisms that enhance survival and reproduction
What process did Darwin identify as essential for explaining adaptations?
Natural selection
What significant publication did Darwin complete in 1859?
On the Origin of Species by Means of Natural Selection
What are the three broad observations about nature explained by Darwin?
- Unity of life
- Diversity of life
- Organisms’ suitability for their environments
What term did Darwin use instead of ‘evolution’ in his first edition of The Origin of Species?
Descent with modification
What did Darwin’s tree diagram represent?
The branching pattern of evolution from a common ancestor
What does the term ‘extinction’ refer to in Darwin’s context?
The end of a lineage of organisms
What is artificial selection?
The process by which humans selectively breed organisms for desired traits
What two observations did Darwin base his argument for natural selection on?
- Members of a population vary in inherited traits
- All species can produce more offspring than their environment can support
What inference did Darwin make regarding individuals with favorable traits?
They tend to leave more offspring than others
Which economist’s ideas influenced Darwin’s thoughts on overpopulation?
Thomas Malthus
What is the key feature of natural selection?
Individuals with certain heritable traits survive and reproduce at higher rates
What happens to adaptations over time due to natural selection?
Their frequency increases if they are favorable in a given environment
Fill in the blank: Darwin hypothesized that species could arise from an ancestral form by the gradual accumulation of _______.
adaptations
What is natural selection?
A process in which individuals with certain heritable traits survive and reproduce at a higher rate than others due to those traits.
How does natural selection affect adaptations over time?
It can increase the frequency of favorable adaptations in a given environment.
What happens when an environment changes?
Natural selection may result in adaptation to new conditions, potentially giving rise to new species.
Do individuals evolve in natural selection?
No, it is the population that evolves over time.
What can natural selection amplify or diminish?
Only those heritable traits that differ among individuals in a population.
What is necessary for evolution by natural selection to occur?
Genetic variation among individuals in a population.
How do environmental factors influence natural selection?
They vary from place to place and over time, affecting which traits are favored.
What is homology in the context of evolution?
Similarity resulting from common ancestry.
What is an example of homology?
The forelimbs of mammals, which share the same basic skeletal elements despite different functions.
What evolutionary evidence comes from direct observations?
Documented evolutionary changes in species through scientific studies.
What is a key finding from the soapberry bug study?
Beak lengths are shorter in populations feeding on the introduced golden rain tree compared to those feeding on the native balloon vine.
What is the significance of drug-resistant bacteria in natural selection?
They illustrate rapid evolution due to short generation times and selective pressure from antibiotics.
How did methicillin-resistant S. aureus (MRSA) emerge?
Through individuals that could synthesize cell walls using an enzyme unaffected by methicillin surviving and reproducing.
What is a consequence of antibiotic resistance in bacteria?
Some strains become resistant to multiple antibiotics due to gene exchange among bacteria.
What is the role of time and place in natural selection?
Natural selection favors characteristics that provide an advantage in the current, local environment.
What are homologous structures?
Anatomical features that are similar due to shared ancestry, but may serve different functions.
Fill in the blank: Natural selection is a process of ______, not a creative mechanism.
editing
True or False: Evolution by natural selection can occur rapidly in species with short generation times.
True
What are pharyngeal arches?
Structures in vertebrate embryos that develop into different features in adult organisms.
What does the fossil record provide evidence for?
The pattern of evolution and the origin of new groups of organisms.
What is the concept of descent with modification?
The idea that species change over time, giving rise to diversity while maintaining unity through common ancestry.
What is an example of a direct observation of evolutionary change?
Changes in beak length in soapberry bugs due to differing food sources.
What is the relationship between genotype and phenotype?
Genotype refers to the genetic constitution, while phenotype is the observable characteristics influenced by the genotype.
What anatomical homologies are present in vertebrate embryos?
All vertebrate embryos have a tail located posterior to the anus and structures called pharyngeal arches.
These structures develop into different functions in adult organisms, such as gills in fishes and parts of the ears and throat in mammals.
What are vestigial structures?
Vestigial structures are remnants of features that served a function in the organism’s ancestors.
Examples include the pelvis and leg bones in snakes and eye remnants in blind cave fishes.
What does the genetic code suggest about the relationship among all forms of life?
The genetic code suggests that all species descended from common ancestors that used this code.
What is an example of molecular homology?
Humans and bacteria share genes inherited from a very distant common ancestor.
What is ‘tree thinking’ in evolutionary biology?
‘Tree thinking’ refers to understanding the evolutionary relationships among groups of organisms through a diagram that represents descent from common ancestors.
How are homologous characteristics shared among organisms?
Homologous characteristics are shared because they evolved from a common ancestor.
What distinguishes analogous features from homologous features?
Analogous features share similar function but not common ancestry, while homologous features share common ancestry but not necessarily similar function.
What type of evidence does the fossil record provide for evolution?
The fossil record documents the pattern of evolution, showing differences between past and present organisms and indicating extinctions.
What does the fossil evidence indicate about cetacean origins?
Fossil evidence shows that cetaceans evolved from terrestrial mammals and documents the transition from land to sea.
How does biogeography provide evidence for evolution?
Biogeography studies the geographic distributions of species influenced by factors like continental drift, supporting evolutionary patterns.
What is the significance of the common ancestor in biogeographic studies?
The common ancestor of species helps explain their distributions and adaptations based on evolutionary history.
What is an example of convergent evolution?
The sugar glider and flying squirrels, which evolved similar adaptations independently.
Fill in the blank: The ability to glide through the air evolved independently in the sugar glider and _______.
flying squirrels.
True or False: All homologous structures perform the same function.
False.
What does the evolutionary tree illustrate about the relationships among tetrapods?
The evolutionary tree illustrates that mammals are more closely related to birds than to amphibians.
What does a hatch mark represent in an evolutionary tree?
A hatch mark indicates the origin of a homologous characteristic shared by all groups to the right of the mark.
What evolutionary evidence supports the hypothesis that cetaceans are closely related to even-toed ungulates?
Fossil evidence and DNA sequence data support this hypothesis.
What is the role of natural selection in evolutionary changes observed in fossils?
Natural selection can drive consistent changes over time, such as the reduction in the size of the pelvic bone in stickleback fish.
What is the geographic distribution of Galaxiidae species?
Found in regions separated by wide stretches of open ocean
None of these species can survive in salt water.
What do genetic analyses suggest about the evolutionary lineages of Galaxiidae?
They began to diverge about 55 million years ago.
What does Darwin’s theory of evolution explain?
Natural selection is the primary cause of the observed pattern of evolutionary change.
What is the difference between a scientific theory and a hypothesis?
A theory is much more comprehensive than a hypothesis.
What was Darwin’s primary mechanism for evolution?
Natural selection.
What observation did researchers make about male guppies’ color patterns?
Bright colors attract females but can make males more conspicuous to predators.
What was the control group in the guppy experiment?
Guppies in pools with pike-cichlid fish, predators of adult guppies.
What was the experimental group in the guppy experiment?
Guppies transplanted to pools with only killifish.
What is an observation that supports natural selection?
Species produce more offspring than the environment can support.
What does ‘descent with modification’ refer to?
The process by which new species originate from ancestral forms through natural selection.
What supports the hypothesis that cetaceans descended from land mammals?
Fossils, genetic evidence, and anatomical similarities.
What is the significance of the age of the Earth for Darwin’s ideas?
It suggested that life’s diversity arose over long periods of time.
Fill in the blank: Evolution is supported by an overwhelming amount of ______.
scientific evidence.
True or False: Darwin proposed that evolution occurs rapidly.
False.
What leads to the accumulation of favorable traits in a population?
Natural selection.
What is one key feature of life that the honeypot ant exemplifies?
Adaptation, unity, or diversity.
Explain how anatomical and molecular features fit a nested pattern.
They reflect common ancestry and evolutionary relationships.
What is the main reason for the rapid rise in DDT resistance among mosquitoes?
Natural selection increased the frequency of already present resistant strains.
How does evolution account for the similar mammalian forelimbs with different functions?
Through common descent (homology) or convergent evolution.
