1. Answer;
They evolved separately as they moved north and became two separate species.
Explanation;
The greenish warblers weren't geographically isolated, but they migrated around the Tibetan Plateau, evolving separately until they were no longer able to interbreed when both species (East and West) contacted in Siberia.
Greenish warblers were thought to have evolved from a single ancestral population that gradually diverged into two new species as it expanded northwards around the Tibetan plateau.
2. Answer;
- Their plumage patterns.
- Genetics and history
Explanation;
West Siberian greenish warblers (P. t. viridanus) and east Siberian greenish warblers (P. t. plumbeitarsus) differ subtly in their plumage patterns, most notably in their wing bars, which are used in communication. While viridanus has a single wing bar, plumbeitarsus has two. Around the southern side of the ring, plumage patterns change gradually.
Additionally, the two northern forms viridanus and plumbeitarsus are highly distinct genetically, but there is a gradient in genetic characteristics through the southern ring of populations. The greenish warblers were once confined to the southern portion of their range and then expanded northward along two pathways, evolving differences as they moved north. When the two expanding fronts met in central Siberia, they were different enough that they do not interbreed.
Answer:
George Washington established precedents for the executive office that have since become customary practice. Washington is responsible for establishing the tradition of the inaugural address and the cabinet system, neither prescribed by the Constitution.
HPOE IT HELPS U..
If the citizens were not required, no one may want to. On jury, you may have a case that may take a long time and you may end up sentencing someone to death. It is likely if citizens were not required that no one would want to volunteer.
Answer:
Détente
Explanation:
Détente is a word of French origin that means to ease hostilities with an adversary.
When Nixon took office in 1969, he promoted a détente policy with the Soviet Union and China, advised by his secretary of the state: Henry Kissinger.
Nixon visited China in 1972, and met personally with Mao Zedong. This event was the start of a new relation between the U.S. and China.
He also met with Soviet leader Leonid Brezhnev in 1972, and reached important agreements like the Anti-Ballistic missile treaty.
Most historians coincide that this policy of détente was successful, and helped Nixon become reelected.
