Evolution & SpeciationFlashcards - AQA Biology

New Day

Current Quiz

You previously generated a quiz from this deck.

Spaced Repetition

This mode helps you retain information by reviewing flashcards at optimal intervals, focusing on what needs the most reinforcement each day.

New Flashcards Per Day

🗂️
Flashcards

The standard way to view your flashcards without any extras

🧠
Exam Mode

Practice active recall and assess your answers with AI

⏳
Spaced Repetition

Memorize your flashcards using a scientifically proven method

🎯
Generate Quiz

Use AI to generate a quiz based on the same content

Evolution & Speciation

A-Level AQA Biology

This pack of flashcards encompasses key concepts in evolutionary biology, including genetic variation, natural selection, speciation, and genetic drift. It covers mechanisms that drive evolution, such as mutations, reproductive success, and selection types (directional, stabilizing, disruptive), along with detailed processes of allopatric and sympatric speciation, and the impact of genetic drift and mutations on population divergence and species diversity.

1 / 13

Combine

All flashcards from the current deck will be added to the deck selected from this list.

Export

This text is tab separated and can be imported into various flashcard apps.

"Describe the first source of genetic variation."	"The first source of genetic variation is mutations. However, meiosis and the random fertilization of gametes during sexual reproduction also result in more genetic variation."
"Define natural selection."	"Natural selection is when individuals within a population show a wide range of variation in phenotype due to genetic and environmental factors. Predation, disease, and competition result in selection pressures. Organisms with phenotypes providing selective advantages are likely to survive, produce more offspring, and pass on their favorable alleles to the next generation. This results in a change in the allele frequency, which is evolution."
"How does differential reproductive success contribute to evolution?"	"Differential reproductive success is when individuals within a population that have a phenotype that makes them more able to survive and pass on their alleles to their offspring. Not all individuals are as likely to reproduce, and this results in changes in allele frequencies within a gene pool. This change in allele frequencies is referred to as evolution."
"What is the impact of directional and stabilizing selection on allele frequency?"	"Directional and stabilizing selection both impact the allele frequency within a population, contributing to evolution. The specifics of their impact would depend on the particular traits and environmental factors involved."
"Define disruptive selection."	"Disruptive selection is a type of natural selection that favors the extremes of a trait within a population, leading to two or more contrasting phenotypes. This can lead to speciation if the populations become sufficiently different."
"Describe the process of disruptive selection."	"Disruptive selection is when individuals that contain the alleles coding for either extreme trait are more likely to survive and pass on their alleles. As a result, the allele frequency changes, and more individuals possess the allele for the extreme trait, and the middling trait allele becomes less frequent. Continued disruptive selection can ultimately lead to speciation."
"Define speciation and explain how it occurs."	"Speciation is the process that results in the creation of new species. This occurs when one original population of the same species becomes reproductively isolated. This isolation means that there are now two populations of the same species, but they cannot breed together. This can result in the accumulation of differences in their gene pools to the extent that the two populations would be unable to reproduce to make fertile offspring, and are therefore classified as two different species."
"Explain the concept of allopatric speciation."	"Allopatric speciation occurs when populations become separated geographically leading to reproductive isolation. A population could become geographically isolated over time by new mountain ranges or new bodies of water separating land masses. This separates the original population into two, which are now unable to reproduce due to the geographical barrier. Both separate populations will continue to accumulate different beneficial mutations over time to help them survive in their environments, which are likely to vary. Due to this accumulation of DNA differences over time, the two populations become so genetically different that they would be unable to reproduce to create fertile offspring."
"How does genetic variation contribute to speciation?"	"Genetic variation contributes to speciation by allowing populations to accumulate different beneficial mutations over time to help them survive in their environments. These mutations can lead to significant differences in the gene pools of separated populations. If these differences become extensive enough, the populations may become so genetically different that they would be unable to reproduce to create fertile offspring, leading to the formation of new species."
"Define sympatric speciation"	"Sympatric speciation is a process where populations become reproductively isolated due to differences in their behavior. Individuals of the same species may not be separated by geographical barriers but are still unable to reproduce. This could be due to a random mutation within the population impacting reproductive behavior, causing individuals to perform different courtship rituals or be fertile at different times of the year. Over time, these reproductively isolated populations accumulate different mutations to the extent that their DNA is so different that they cannot reproduce to create fertile offspring. They are then classified as two different species."
"Describe how genetic drift can lead to evolution"	"Genetic drift is the change in the allele frequency within a population between generations. There will always be genetic drift from one generation to the next, but continual, substantial genetic drift results in evolution. The smaller a population is, the bigger the impact allele frequency changes have proportionally, and this is why evolution often occurs more rapidly in smaller populations."
"Explain the impact of a random mutation on a population's reproductive behavior"	"A random mutation within a population could impact reproductive behavior, for example, it may cause individuals to perform a different courtship ritual or for individuals to be fertile at different times of the year. Due to this, these individuals will not reproduce together, and there will be no gene flow between the two groups within the populations. Over time, these reproductively isolated populations will accumulate different mutations to the extent that their DNA is so different that they cannot reproduce to create fertile offspring."
"How does evolutionary change over a long period of time result in a great diversity of species?"	"Evolutionary change over a long period of time results in a great diversity of species through the process of speciation. This occurs when populations become reproductively isolated due to differences in their behavior or geographical barriers. Over time, these reproductively isolated populations accumulate different mutations to the extent that their DNA is so different that they cannot reproduce to create fertile offspring. They are then classified as two different species."

Click to copy

Image

Front

Describe the first source of genetic variation.

Back

The first source of genetic variation is mutations. However, meiosis and the random fertilization of gametes during sexual reproduction also result in more genetic variation.

Image

Print Flashcards

[{"id":1331918,"front":"Describe the first source of genetic variation.","back":"The first source of genetic variation is mutations. However, meiosis and the random fertilization of gametes during sexual reproduction also result in more genetic variation.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Mutations are the initial source of genetic variation because they introduce new genetic material into a population. Meiosis, a process in sexual reproduction, shuffles and recombines genetic material, further increasing variation. Random fertilization of gametes also contributes to genetic diversity by combining different sets of genes from two individuals. These processes collectively generate the genetic variation observed within a population.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331919,"front":"Define natural selection.","back":"Natural selection is when individuals within a population show a wide range of variation in phenotype due to genetic and environmental factors. Predation, disease, and competition result in selection pressures. Organisms with phenotypes providing selective advantages are likely to survive, produce more offspring, and pass on their favorable alleles to the next generation. This results in a change in the allele frequency, which is evolution.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Natural selection is a fundamental mechanism of evolution proposed by Charles Darwin. It acts on heritable traits, favoring those that enhance survival and reproduction. Over time, this process leads to the adaptation of populations to their environments.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331925,"front":"How does differential reproductive success contribute to evolution?","back":"Differential reproductive success is when individuals within a population that have a phenotype that makes them more able to survive and pass on their alleles to their offspring. Not all individuals are as likely to reproduce, and this results in changes in allele frequencies within a gene pool. This change in allele frequencies is referred to as evolution.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Differential reproductive success drives evolution by favoring traits that enhance survival and reproduction. This process leads to the accumulation of advantageous alleles in a population over generations, shaping its genetic composition and driving evolutionary change.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331926,"front":"What is the impact of directional and stabilizing selection on allele frequency?","back":"Directional and stabilizing selection both impact the allele frequency within a population, contributing to evolution. The specifics of their impact would depend on the particular traits and environmental factors involved.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Directional selection occurs when individuals with a certain phenotype have a higher fitness, causing the allele frequency to shift towards that phenotype. This can lead to the evolution of new traits. Stabilizing selection, on the other hand, favors individuals with intermediate phenotypes, reducing genetic variation and maintaining the status quo. Both types of selection can drive changes in allele frequency over time, shaping the genetic makeup of a population.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331927,"front":"Define disruptive selection.","back":"Disruptive selection is a type of natural selection that favors the extremes of a trait within a population, leading to two or more contrasting phenotypes. This can lead to speciation if the populations become sufficiently different.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Disruptive selection can drive the evolution of distinct traits by favoring extreme variations over intermediate forms. This process can result in the emergence of new species as populations diverge due to the selective pressures acting on different traits.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331933,"front":"Describe the process of disruptive selection.","back":"Disruptive selection is when individuals that contain the alleles coding for either extreme trait are more likely to survive and pass on their alleles. As a result, the allele frequency changes, and more individuals possess the allele for the extreme trait, and the middling trait allele becomes less frequent. Continued disruptive selection can ultimately lead to speciation.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Disruptive selection drives the population towards two distinct phenotypes by favoring extreme traits over intermediate ones. This process can result in the emergence of new species as individuals with extreme traits are selected for, leading to a divergence in characteristics within the population.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331934,"front":"Define speciation and explain how it occurs.","back":"Speciation is the process that results in the creation of new species. This occurs when one original population of the same species becomes reproductively isolated. This isolation means that there are now two populations of the same species, but they cannot breed together. This can result in the accumulation of differences in their gene pools to the extent that the two populations would be unable to reproduce to make fertile offspring, and are therefore classified as two different species.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Speciation is driven by various factors like geographic isolation, genetic mutations, and natural selection. Over time, isolated populations accumulate genetic differences, leading to reproductive barriers. This process is crucial for biodiversity and adaptation to changing environments.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331941,"front":"Explain the concept of allopatric speciation.","back":"Allopatric speciation occurs when populations become separated geographically leading to reproductive isolation. A population could become geographically isolated over time by new mountain ranges or new bodies of water separating land masses. This separates the original population into two, which are now unable to reproduce due to the geographical barrier. Both separate populations will continue to accumulate different beneficial mutations over time to help them survive in their environments, which are likely to vary. Due to this accumulation of DNA differences over time, the two populations become so genetically different that they would be unable to reproduce to create fertile offspring.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Allopatric speciation involves the physical separation of populations, leading to genetic divergence and the eventual inability to interbreed. Geographical barriers prevent gene flow, allowing each population to adapt independently to their environments, accumulating genetic differences over time. This process results in the formation of distinct species.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331942,"front":"How does genetic variation contribute to speciation?","back":"Genetic variation contributes to speciation by allowing populations to accumulate different beneficial mutations over time to help them survive in their environments. These mutations can lead to significant differences in the gene pools of separated populations. If these differences become extensive enough, the populations may become so genetically different that they would be unable to reproduce to create fertile offspring, leading to the formation of new species.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Genetic variation contributes to speciation by enabling populations to accumulate beneficial mutations over time. These mutations can lead to significant differences in gene pools, potentially resulting in reproductive isolation and the formation of new species.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331948,"front":"Define sympatric speciation","back":"Sympatric speciation is a process where populations become reproductively isolated due to differences in their behavior. Individuals of the same species may not be separated by geographical barriers but are still unable to reproduce. This could be due to a random mutation within the population impacting reproductive behavior, causing individuals to perform different courtship rituals or be fertile at different times of the year. Over time, these reproductively isolated populations accumulate different mutations to the extent that their DNA is so different that they cannot reproduce to create fertile offspring. They are then classified as two different species.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Sympatric speciation occurs when a single population becomes reproductively isolated without any physical barriers. This can happen due to changes in behavior or genetic mutations that affect reproductive compatibility. Over time, these differences accumulate, leading to the formation of distinct species.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331949,"front":"Describe how genetic drift can lead to evolution","back":"Genetic drift is the change in the allele frequency within a population between generations. There will always be genetic drift from one generation to the next, but continual, substantial genetic drift results in evolution. The smaller a population is, the bigger the impact allele frequency changes have proportionally, and this is why evolution often occurs more rapidly in smaller populations.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Genetic drift, the random fluctuation of allele frequencies, can lead to evolution due to its cumulative effect over generations. In smaller populations, chance events have a greater impact, driving significant allele frequency changes and accelerating evolutionary processes.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331950,"front":"Explain the impact of a random mutation on a population's reproductive behavior","back":"A random mutation within a population could impact reproductive behavior, for example, it may cause individuals to perform a different courtship ritual or for individuals to be fertile at different times of the year. Due to this, these individuals will not reproduce together, and there will be no gene flow between the two groups within the populations. Over time, these reproductively isolated populations will accumulate different mutations to the extent that their DNA is so different that they cannot reproduce to create fertile offspring.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"A random mutation affecting reproductive behavior can lead to the formation of reproductively isolated groups within a population. This isolation can result in genetic divergence over time, potentially leading to speciation due to the inability to produce viable offspring.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}},{"id":1331956,"front":"How does evolutionary change over a long period of time result in a great diversity of species?","back":"Evolutionary change over a long period of time results in a great diversity of species through the process of speciation. This occurs when populations become reproductively isolated due to differences in their behavior or geographical barriers. Over time, these reproductively isolated populations accumulate different mutations to the extent that their DNA is so different that they cannot reproduce to create fertile offspring. They are then classified as two different species.","front_language":"English","back_language":"English","front_image":"","back_image":"","order":0,"explanation":"Evolutionary change leading to speciation occurs when isolated populations accumulate genetic differences over time, preventing interbreeding. This process, driven by mutations and natural selection, results in the emergence of distinct species, contributing to overall biodiversity.","deleted_at":null,"flashcard_deck_id":"A8LpN","original_id":null,"examMode":{"text":"","correct":"","incorrect":"","info":""}}]

Options

Arrange Cards

Chronological

Random

Card Direction

Front First

Back First

Share this deck

Click to copy

Delete this deck

Are you sure you want to delete this deck? This cannot be undone.

Evolution & Speciation Flashcards

New Day

Current Quiz

Spaced Repetition

New Flashcards Per Day

🗂️
Flashcards

🧠
Exam Mode

⏳
Spaced Repetition

🎯
Generate Quiz

Evolution & Speciation

A-Level AQA Biology

Combine

Export

Front

Back

Print Flashcards

Print Type

Font Size

Rows Per Page

Options

Arrange Cards

Card Direction

Share this deck

Delete this deck

Evolution & Speciation Flashcards

New Day

Current Quiz

Spaced Repetition

New Flashcards Per Day

🗂️ Flashcards

🧠 Exam Mode

⏳ Spaced Repetition

🎯 Generate Quiz

Evolution & Speciation

A-Level AQA Biology

Combine

Export

Front

Back

Print Flashcards

Print Type

Font Size

Rows Per Page

Options

Arrange Cards

Card Direction

Share this deck

Delete this deck

🗂️
Flashcards

🧠
Exam Mode

⏳
Spaced Repetition

🎯
Generate Quiz