1-Charles Darwin
2-Alfred Russel Wallace
Explanation:
are jointly credited with coming up with the theory of evolution by natural selection, having co-published on it in 1858. Darwin has generally overshadowed Wallace since the publication of On the Origin of Species in 1859, however.
Explanation:
Sediment discharge was historically approximately 270 million cubic meters/year of suspended load and 130 million cubic meters/year of bedload. This has decreased 80% since 1850 and can be divided into three periods: historical period (pre 1900), pre-dam period (1932-1952), and post dam (1963-1982). Suspended sediment loads declined 43% between the historical and pre-dam and 51% from pre-dam to post-dam periods. The size of sediment also decreased drastically including a 72% decrease in the sand fraction. Most of this is due to dams on the tributaries acting as sediment traps primarily for the coarser sediments. Large-scale land clearing for agriculture contributed to increased sediment loads in the historic period.
Answer:
They speed up chemical reactions. Without them you wouldn't be alive. They break down macromolecules, and also lower the amount of energy needed for a chemical reaction to happen.
