Which of the following statements best explains the changes in the size and composition of the population of finches?
Which of the following statements best explains the changes in the size and composition of the population of finches after the drought? The total number of finches in the population decreased, and the larger-beaked finches were more successful in the drier environment.
Which of the following is most likely to be the direct result of lack of genetic diversity?
Which of the following is most likely to be the direct result of lack of genetic diversity in a food crop such as corn? Increased susceptibility on plant disease.
Which if the following was the average beak size of finches on the island of Daphne Major in 1976?
In the summer of 1976, there were 751 finches on Daphne Major when the Grants left the island. The 1976 medium ground finch population had an average beak depth of 9.65 mm and an average beak length of 10.71 mm. In 1977 a severe drought began, and only 20 mm of rain fell on the island over the entire year.
What is species richness?
Species richness is simply the number of species in a community. Species diversity is more complex, and includes a measure of the number of species in a community, and a measure of the abundance of each species. Species diversity is usually described by an index, such as Shannon’s Index H’.
Is genetic diversity in a species positive or negative?
Research on the species–genetic diversity correlation (SGDC) suggests that species diversity within a community and intrapopulation genetic diversity are positively correlated, due to the parallel influences of environmental characteristics (area, connectivity, and environmental heterogeneity) on both levels of …
Which of the following best explains why each of the finch species on the Galapagos Islands?
Which of the following best explains why each of the finch species on the Galápagos Islands evolved to be specialists? … Food resources on islands are more plentiful and nutrient rich than on the mainland, leading to specialist behaviors in feeding.
Which community has the highest species diversity?
Species richness is greatest in tropical ecosystems. Tropical rain forests on land and coral reefs in marine systems are among the most biologically diverse ecosystems on Earth and have become the focus of popular attention.
Which region is more rich in species?
Tropical rainforests are the richest habitat of all, tropical grasslands exhibit more diversity than temperate grasslands, and deserts in tropical or subtropical regions are populated by a wider range of species than are temperate deserts.
Which site has the highest species richness?
Brazil is the Earth’s biodiversity champion. Between the Amazon rainforest and Mata Atlantica forest, the woody savanna-like cerrado, the massive inland swamp known as the Pantanal, and a range of other terrestrial and aquatic ecosystems, Brazil leads the world in plant and amphibian species counts.
Why are many species no longer on Earth?
Most species that become extinct are never scientifically documented. … At least 571 species have been lost since 1750, but likely many more. The main cause of the extinctions is the destruction of natural habitats by human activities, such as cutting down forests and converting land into fields for farming.
Which marine zone has greatest biodiversity?
The epipelagic zone stretches from the surface down to 200 m and is home to the greatest biodiversity in the sea, largely because of the availability of sunlight that enables photosynthetic organisms to thrive. Both marine plants and animals are found here.
Why are some animal species disappearing?
All were caused by dramatic events — such as meteor impacts, changes in Earth’s climate, and massive volcanism — that resulted in severe environmental changes. Our planet is now experiencing its sixth major extinction. The current extinction is most likely the result of human activity, especially over the past century.
Will humans go extinct?
Current population predictions vary. But the general consensus is that it’ll top out sometime midcentury and start to fall sharply. As soon as 2100, the global population size could be less than it is now. In most countries—including poorer ones—the birth rate is now well below the death rate.
Is it true that 99.9 of all species are extinct?
Of all species that have existed on Earth, 99.9 percent are now extinct. Many of them perished in five cataclysmic events. According to a recent poll, seven out of ten biologists think we are currently in the throes of a sixth mass extinction.
What animal went extinct in 2021?
The ivory-billed woodpecker is one of 22 species of birds, fish, mussels, and bats (and one species of plant) that were declared extinct in the US in 2021. The announcement contains the largest group of animals and plants to be moved from the endangered to extinct list under the 1973 Endangered Species Act (ESA).
What animal went extinct twice?
Here’s the strange tale of how the Pyrenean ibex became the first extinct species to be cloned and the first species to go extinct twice – and what it means for future conservation efforts.
Can we bring the Dodo back?
“There is no point in bringing the dodo back,” Shapiro says. “Their eggs will be eaten the same way that made them go extinct the first time.” Revived passenger pigeons could also face re-extinction.