Environmental Effects on Organisms

Selection pressure is a factor that influences an organism's ability to survive, thereby affecting the evolution of a species.

An example of a biotic factor is predation, which can limit the population size of prey species and influence their adaptations.

Selecting agents are specific environmental factors that create selection pressures for particular phenotypes.

<p>Cane toads at the invasion front have evolved longer legs, faster movement, and a metabolism that supports more energy for movement.</p> Signup and view all the answers

<p>The introduction of cane toads has led to their overpopulation, disrupting local ecosystems and posing threats to native species.</p> Signup and view all the answers

<p>Organisms with selective advantages are more likely to survive and reproduce compared to others in the population.</p> Signup and view all the answers

<p>Abiotic factors, such as temperature and soil pH, can severely limit the range and health of organisms in their environments.</p> Signup and view all the answers

<p>Cane toads lay up to 30,000 eggs at a time, significantly more than the 1,000-2,000 eggs laid by native frogs.</p> Signup and view all the answers

<p>Cane toads can poison larger predators, leading to their death after consumption.</p> Signup and view all the answers

<p>The Cactoblastis moth larvae significantly reduced the prickly pear population by consuming the plants.</p> Signup and view all the answers

<p>A structural adaptation is a physical change to an organism's body that aids in survival, such as blubber in blue whales.</p> Signup and view all the answers

<p>Koalas possess a low metabolic rate, allowing them to digest food slowly and effectively.</p> Signup and view all the answers

<p>'Survival of the fittest' refers to the idea that individuals with traits best suited to their environment are more likely to survive and reproduce.</p> Signup and view all the answers

<p>Phenotypic variations allow certain individuals to adapt better to their environment, influencing survival and reproduction.</p> Signup and view all the answers

<p>Possums are nocturnal, allowing them to hunt for food at night while avoiding daytime heat.</p> Signup and view all the answers

<p>Darwin observed varying beak shapes in finches, which corresponded to the different food sources available on each island.</p> Signup and view all the answers

<p>Adaptations are changes that enable organisms to better survive and thrive in their specific habitat conditions.</p> Signup and view all the answers

<p>Natural selection favors individuals with advantageous traits, leading to those traits becoming more common in subsequent generations.</p> Signup and view all the answers

<p>Cane toads compete with native species for food and shelter, negatively impacting native populations.</p> Signup and view all the answers

<p>Fruit bats have long fingers that support the thin layer of skin stretching over them.</p> Signup and view all the answers

<p>Cactoblastis caterpillars specifically target prickly pear plants, effectively reducing their invasive numbers.</p> Signup and view all the answers

<p>Adaptations improve individuals' chances of survival, thus increasing their opportunities to reproduce and pass on beneficial traits.</p> Signup and view all the answers

<p>Natural selection is the mechanism whereby organisms better adapted to their environment tend to survive and reproduce more successfully.</p> Signup and view all the answers

<p>Variation among individuals in a population allows for differential survival and reproduction, as some traits may provide better adaptation to the environment.</p> Signup and view all the answers

<p>Microevolution refers to small, gradual changes in gene frequency within a population, while macroevolution involves larger-scale changes that occur over long periods and can lead to the emergence of new species.</p> Signup and view all the answers

<p>Mutations introduce new genetic variation into a population, which can be acted upon by natural selection and contribute to evolutionary change.</p> Signup and view all the answers

<p>'Survival of the fittest' means that individuals best suited to their environment are more likely to survive and reproduce, passing on their advantageous traits.</p> Signup and view all the answers

<p>Speciation is the formation of new species from a common ancestor, often driven by natural selection acting on different populations exposed to varying environmental pressures.</p> Signup and view all the answers

<p>Divergent evolution occurs when two species with a common ancestor evolve different traits, while convergent evolution happens when unrelated species develop similar traits due to similar selection pressures.</p> Signup and view all the answers

<p>Evidence includes biochemical similarities, comparative anatomy, fossil records, and biogeography that demonstrate relationships among species.</p> Signup and view all the answers

<p>Punctuated equilibrium suggests that species evolve during short bursts of rapid change followed by long periods of stability, in contrast to gradualism which posits slow, continuous changes over time.</p> Signup and view all the answers

<p>Genetic drift can lead to random changes in allele frequencies, potentially resulting in the loss of genetic diversity and making populations more susceptible to extinction.</p> Signup and view all the answers

<p>An example is the development of pesticide resistance in a population of insects, where individuals with genetic variation survive and reproduce, passing on the resistant trait.</p> Signup and view all the answers

<p>Adaptive radiation refers to the rapid evolution of diversely adapted species from a common ancestor in response to different environmental challenges.</p> Signup and view all the answers

<p>Migration can bring in individuals from different populations, introducing new alleles that can affect the gene pool and create additional variation.</p> Signup and view all the answers

<p>The fossil record provides evidence of past life forms, illustrating transitional species, the timeline of evolution, and patterns of macroevolution.</p> Signup and view all the answers

<p>It measures the temperature at which hybrid DNA strands separate, indicating the degree of mismatches in their base sequences.</p> Signup and view all the answers

<p>Homologous structures share a common ancestor, while analogous structures evolved independently to serve similar functions.</p> Signup and view all the answers

<p>They are remnants of features that served a function in ancestral species but no longer have a purpose in the current form.</p> Signup and view all the answers

<p>It studies the geographic distribution of species that share common ancestors, correlating with the historical configuration of continents.</p> Signup and view all the answers

<p>Rapid burial of an organism under sediment is essential to impede decomposition and allow fossilization.</p> Signup and view all the answers

<p>Relative dating determines the chronological order of fossils, while absolute dating calculates their actual age using radioactive elements.</p> Signup and view all the answers

<p>Index fossils represent specific time periods and are used to correlate the age of rock layers where they are found.</p> Signup and view all the answers

<p>Cane toads have evolved to be faster travelers, allowing them to spread more efficiently across the landscape.</p> Signup and view all the answers

<p>They illustrate natural selection, where bacteria with resistance genes survive antibiotic treatment and reproduce, leading to a resistant population.</p> Signup and view all the answers

<p>They indicate a common ancestry, as these structures in mammal embryos are homologous to gill slits in fish.</p> Signup and view all the answers

<p>It indicates the degree of genetic similarity between two species, with higher temperatures reflecting closer genetic relationships.</p> Signup and view all the answers

<p>These structures are remnants from ancestors that had functional features, but they may have lost their purpose over time due to evolutionary changes.</p> Signup and view all the answers

<p>They reveal structural similarities among different species that suggest modifications of a common ancestral design.</p> Signup and view all the answers

<p>Single-stranded DNA absorbs UV light, whereas double-stranded DNA does not, allowing for the measurement of hybridization success.</p> Signup and view all the answers