好长的一个句子，出自新概念英语第三册第一篇课文，帮忙分析一下这个句子的语法和句型。谢谢~

Question

However, as the evidence began to accumulate, expert from London Zoo felt obliged to investgate, for the description given by people who claimed to have seen the pumar were extraordinarily similar.

Answer 1

However 连词
as the evidence began to accumulate 时间状语从句
as 连词
the evidence 主语
began to accumulate 谓语 begin to do
expert 全句主语 (似乎应该是复数)
from London Zoo 定语 修饰主语
felt 连系动词
obliged 表语
to investgate 补语
for the description given by people who claimed to have seen the pumar were extraordinarily similar 原因状语从句
for 连词
the description 主语
given by people who claimed to have seen the puma 过去分词定语修饰主语
其中 who claimed to have seen the pumar 定语从句修饰people
were 连系动词
extraordinarily similar 表语

Answer 2

expert 主语
felt 系动词
as the evidence began to accumulate，状语从句
for 后面是原因状语从句
the description were extraordinarily similar 是从句中的主谓宾
given by people 是 description的定语
who claimed to have seen the puma 是people的定语从句