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What does the Biological Species Concept (BSC) define species as?
What does the Biological Species Concept (BSC) use as an objective criterion for defining species?
Who formalized the taxonomic rank of species and devised the binomial nomenclature system?
Who offered an explanation of how species evolve over time in the book 'On the Origin of Species'?
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Who proposed the Biological Species Concept (BSC), which defines a species as populations of organisms that can reproduce with one another and are reproductively isolated from other populations?
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What did Carolus Linnaeus introduce to classify species?
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What did Theodosius Dobzhansky and Ernst Mayr focus on when further developing ideas on species?
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What is neoteny?
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What features in humans are potentially brought about by neoteny?
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What is homoplasy in biology and phylogenetics?
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What is the difference between homoplasy and homology?
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What does the term 'homoplasy' derive from?
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What makes phylogenetic analysis more challenging, especially in closely related groups?
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What is a homology in biology?
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What is a homoplasy in phylogenetics?
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What is an analogy in biology?
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What gives rise to homoplasies and analogies in organisms?
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What is the term for a shared trait due to common ancestry?
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What did Linnaeus attempt to classify plants based on in his book, Systema Naturae?
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What is the reason for the ability of bird wings and the wings of flies to fly?
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What are the structures that armadillos, anteaters, pangolins, and spiny anteaters share?
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What did biologists use to inform their analysis of morphological data to determine whether a given trait is a homology or an analogy?
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What did Carolus Linnaeus base his classifications of plants on in Systema Naturae?
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What is the term for traits that are similar in function and appearance but have different evolutionary origins?
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In phylogenetics, we want to avoid classifying organisims together based on homoplasies or analogies.
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If homoplasies and analogies are similarities in structure and function between animals that aren't closely related, then how do these similarities arise?
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A key difference between convergent (parallel) evolution and divergent evolution is that convergent deals with UNCOMMON ancestry and divergent deals with COMMON ancestry.
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Species experiencing convergent evolution do not share a close genetic relationship.
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Convergent evolution often leads to different species from separate evolutionary lineages developing similar adaptations.
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In divergent evolution, two or more related species become more similar over time.
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Which of the following statements best describes the difference between homologous and analogous traits in evolutionary biology?
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Homologous traits result from a common evolutionary ancestry, while analogous traits arise independently in different lineages due to similar environmental pressures.
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Homologous traits and analogous traits both arise independently in different lineages due to similar environmental pressures.
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Homologous traits and analogous traits can both result from independent evolution in different lineages, with no shared common ancestry.
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In phylogenetics, you should avoid classifying organisms based on homoplasies or analogous traits.
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The biological species concept defines a species as a population or group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring, BUT CAN'T produce viable, fertile offspring with members of OTHER populations.
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2 Tigers of the same population mating in a zoo and producing fertile, viable offspring is an example of the Biological Species Concept.
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The key difference between microevolution and macroevolution is:
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Which best describes microevolution?
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Gene flow refers to genetic additions or subtractions from a population resulting from the movement of fertile individuals or gametes.
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Gene flow is the exchange of genetic material from one population to another.
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Gene flow usually doesn't result in the reduction of differences between 2 populations.
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The ease of modern travel makes gene flow between human populations easier to happen than in the past.
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Gene flow introduces new alleles to the population, increasing the rate of microevolution.
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Genetic Drift refers to predictable fluctuation in allele frequencies from one generation to the next due to planned events.
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Genetic drift has a significant impact on small populations
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What are the 2 categories of genetic drift?
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Gene flow and genetic migration mean the same thing.
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A way to remember that genetic drift deals with random, unpredictable changes in allele frequencies between generations is to think of someone who's just "drifting" through life & doesn't plan anything- everything in their life is unpredictable/ by chance/ random.
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Is microevolution sometimes referred to as "population genetics"?
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Study Notes
The Evolution of the Species Concept
- The distinction between species and varieties has been vague and arbitrary throughout history.
- The idea of species as stable entities goes back to early farming, with the term species being used to refer to a sort or kind of organism.
- John Ray introduced the biological concept that species were distinguished by always producing the same species, but considerable variation was possible within a species.
- Carolus Linnaeus formalized the taxonomic rank of species and devised the binomial nomenclature system.
- Charles Darwin's book "On the Origin of Species" offered an explanation of how species evolve over time.
- Darwin's theory suggested that the recognition of distinct species could be subjective.
- The modern synthesis in the 1920s and 1930s combined Mendel's theory of inheritance and Darwin's theory of evolution by natural selection.
- Theodosius Dobzhansky and Ernst Mayr further developed ideas on species, focusing on reproductive isolation.
- Ernst Mayr's 1942 book proposed the Biological Species Concept (BSC), which defines a species as populations of organisms that can reproduce with one another and are reproductively isolated from other populations.
- Many other species concepts have been introduced, with some being designed to be more useful than the BSC for describing species.
- The philosophical position of realism, advocated by Mayr, posits that species are real, mind-independent entities, and natural kinds.
- Mayr's argument for realism has been criticized, with the fact that independently observing humans see the same species not necessarily proving the reality of species.
Neoteny in Humans, Domestic Animals, and Other Species
- Neoteny, the opposite of "gerontomorphic" or "peramorphic", refers to the retention of youth into adulthood, and was described as the major process in humanization by Louis Bolk in 1926.
- Neoteny in humans results in features such as a large head, flat face, and short arms, potentially brought about by sexual selection in human evolution.
- Some evolutionary theorists propose that neoteny was a key feature in human evolution, leading to a greater prolongation of childhood and retardation of maturity.
- Neoteny is observed in domesticated animals like dogs and mice due to more resources, less competition, and selective breeding for behavioral characteristics, leading to physical traits such as floppy ears and large eyes.
- Selective breeding for neoteny in dogs has strengthened the human-canine bond, with some breeds exhibiting juvenile physical traits as adults, such as short snouts and wide-set eyes.
- A 2004 study using wolf and dog skulls concluded that dog skulls generally cannot be described by neoteny, although some pedomorphic dog breeds have skulls resembling those of juvenile wolves.
- Neoteny has been observed in many other species, with partial neoteny seen in the frog Lithobates clamitans, which delays maturation during resource-scarce periods, and full neoteny observed in Ambystoma mexicanum and some populations of Ambystoma tigrinum, remaining in larval form throughout their lives.
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Description
Test your knowledge of the evolution of the species concept with this quiz. Explore the historical development of species definition from early farming to modern biological and philosophical concepts. Learn about the contributions of key figures such as John Ray, Carolus Linnaeus, Charles Darwin, Theodosius Dobzhansky, and Ernst Mayr, and the different species concepts that have emerged over time.
