Question: There were serious scientific objections to the process of natural selection as the key mechanism of evolution, including Karl von Nageli's insistence that a trivial characteristic with no adaptive advantage could not be developed by selection. Darwin conceded that these could be linked to adaptive characteristics. His estimate that the age of the Earth allowed gradual evolution was disputed by William Thomson (later awarded the title Lord Kelvin), who calculated that it had cooled in less than 100 million years. Darwin accepted blending inheritance, but Fleeming Jenkin calculated that as it mixed traits, natural selection could not accumulate useful traits. Darwin tried to meet these objections in the 5th edition. Mivart supported directed evolution, and compiled scientific and religious objections to natural selection. In response, Darwin made considerable changes to the sixth edition. The problems of the age of the Earth and heredity were only resolved in the 20th century.
Is there an answer to this question: What was Darwin's concession to Karl von Nagel's objections?

Answer: Darwin conceded that these could be linked to adaptive characteristics

Question: Agriculture and horticulture seek to optimize the capture of solar energy in order to optimize the productivity of plants. Techniques such as timed planting cycles, tailored row orientation, staggered heights between rows and the mixing of plant varieties can improve crop yields. While sunlight is generally considered a plentiful resource, the exceptions highlight the importance of solar energy to agriculture. During the short growing seasons of the Little Ice Age, French and English farmers employed fruit walls to maximize the collection of solar energy. These walls acted as thermal masses and accelerated ripening by keeping plants warm. Early fruit walls were built perpendicular to the ground and facing south, but over time, sloping walls were developed to make better use of sunlight. In 1699, Nicolas Fatio de Duillier even suggested using a tracking mechanism which could pivot to follow the Sun. Applications of solar energy in agriculture aside from growing crops include pumping water, drying crops, brooding chicks and drying chicken manure. More recently the technology has been embraced by vinters, who use the energy generated by solar panels to power grape presses.
Is there an answer to this question: What did French and English farmers do during the Little Ice Age to gain more solar energy?

Answer: employed fruit walls

Question: Much of mandolin development revolved around the soundboard (the top). Pre-mandolin instruments were quiet instruments, strung with as many as six courses of gut strings, and were plucked with the fingers or with a quill. However, modern instruments are louderusing four courses of metal strings, which exert more pressure than the gut strings. The modern soundboard is designed to withstand the pressure of metal strings that would break earlier instruments. The soundboard comes in many shapesbut generally round or teardrop-shaped, sometimes with scrolls or other projections. There is usually one or more sound holes in the soundboard, either round, oval, or shaped like a calligraphic F (f-hole). A round or oval sound hole may be covered or bordered with decorative rosettes or purfling.
Is there an answer to this question: What are ancient mandolins' strings made of?

Answer: unanswerable

Question: Weather and climate in the coastal area are dominated by the cold, north-flowing Benguela current of the Atlantic Ocean which accounts for very low precipitation (50 mm per year or less), frequent dense fog, and overall lower temperatures than in the rest of the country. In Winter, occasionally a condition known as Bergwind (German: Mountain breeze) or Oosweer (Afrikaans: East weather) occurs, a hot dry wind blowing from the inland to the coast. As the area behind the coast is a desert, these winds can develop into sand storms with sand deposits in the Atlantic Ocean visible on satellite images.
Is there an answer to this question: What is the wind direction outside of the coastal area?

Answer:
unanswerable