History. Doubt is of satan, and is sin and is death (Rom. 14:23, 6:23, Jhn. 8:44, Gen. 3:1). Genesis is God's inspired (2 Tim. 3:16-17) historical witness of event that the Holy Ghost was there for.
Wood and design given by God Himself.
Gen 6:14 Make thee
an ark of gopher wood; rooms shalt thou make in the ark, and
shalt pitch it within and without with pitch.
Gen 6:15 And
this is the fashion which thou shalt make it of:
The length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits.
Gen 6:16 A window shalt thou make to the ark, and in a cubit shalt thou finish it above; and the door of the ark shalt thou set in the side thereof; with
lower, second, and third stories shalt thou make it.
Gen 6:22 Thus
did Noah; according to all that God commanded him, so did he.
Gen 7:5 And
Noah did according unto all that the LORD commanded him.
Gen 7:17 And the flood was forty days upon the earth; and the waters increased, and bare up the ark, and
it was lift up above the earth.
These men were of
giant intellect, knowing city building [Genesis 4:17], metalurgy [Genesis 4:22], fine craft like musical instruments, arts [Genesis 4:21], tent making [Genesis 4:20], etc.
How many animals were there? Do you have a specific number in mind?
Scripture only says this:
Gen 6:19 And of every living thing of all flesh, two of every sort shalt thou bring into the ark, to keep them alive with thee; they shall be male and female.
Gen 6:20 Of fowls after their kind, and of cattle after their kind, of every creeping thing of the earth after his kind, two of every sort shall come unto thee, to keep them alive.
Gen 7:2 Of every clean beast thou shalt take to thee by sevens, the male and his female: and of beasts that are not clean by two, the male and his female.
Gen 7:3 Of fowls also of the air by sevens, the male and the female; to keep seed alive upon the face of all the earth.
Gen 8:1 And God remembered Noah, and every living thing, and all the cattle that was with him in the ark: and God made a wind to pass over the earth, and the waters asswaged;
Gen 8:17 Bring forth with thee every living thing that is with thee, of all flesh, both of fowl, and of cattle, and of every creeping thing that creepeth upon the earth; that they may breed abundantly in the earth, and be fruitful, and multiply upon the earth.
God brought them to the Ark by angels, and Noah brought them into the Ark:
Gen 6:19 And of every living thing of all flesh, two of every sort shalt thou bring into the ark, to keep them alive with thee; they shall be male and female.
Gen 6:20 Of fowls after their kind, and of cattle after their kind, of every creeping thing of the earth after his kind, two of every sort shall come unto thee, to keep them alive.
Gen 7:9 There went in two and two unto Noah into the ark, the male and the female, as God had commanded Noah.
Gen 7:13 In the selfsame day entered Noah, and Shem, and Ham, and Japheth, the sons of Noah, and Noah's wife, and the three wives of his sons with them, into the ark;
Gen 7:14 They, and every beast after his kind, and all the cattle after their kind, and every creeping thing that creepeth upon the earth after his kind, and every fowl after his kind, every bird of every sort.
Gen 7:15 And they went in unto Noah into the ark, two and two of all flesh, wherein is the breath of life.
Gen 7:16 And they that went in, went in male and female of all flesh, as God had commanded him: and the LORD shut him in.
Gen 8:1 And God remembered Noah, and every living thing, and all the cattle that was with him in the ark: and God made a wind to pass over the earth, and the waters asswaged;
Psa_103:20 Bless the LORD, ye his angels, that excel in strength, that do his commandments, hearkening unto the voice of his word.
Plants/fruits/seeds when required (no evidence says that all the animals were awake and/or ate every day of the year in the Ark):
Gen 1:29 And God said, Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat.
Gen 1:30 And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for meat: and it was so.
Gen 2:16 And the LORD God commanded the man, saying, Of every tree of the garden thou mayest freely eat:
Gen 6:21 And take thou unto thee of all food that is eaten, and thou shalt gather it to thee; and it shall be for food for thee, and for them.
What do you mean by 'niches'?
After the flood there is no 'niches', but a wasteland and debris. They didn't need to go back to anywhere. They left the Ark, and the fear of man was put upon them by God, and went where God directed them to by the same angels that brought them to Noah and the Ark:
Gen 8:19 Every beast, every creeping thing, and every fowl, and whatsoever creepeth upon the earth, after their kinds, went forth out of the ark.
Gen 8:20 And Noah builded an altar unto the LORD; and took of every clean beast, and of every clean fowl, and offered burnt offerings on the altar.
Gen 9:2 And the fear of you and the dread of you shall be upon every beast of the earth, and upon every fowl of the air, upon all that moveth upon the earth, and upon all the fishes of the sea; into your hand are they delivered.
Gen 9:3 Every moving thing that liveth shall be meat for you; even as the green herb have I given you all things.
Gen 9:10 And with every living creature that is with you, of the fowl, of the cattle, and of every beast of the earth with you; from all that go out of the ark, to every beast of the earth.
It is still in the Bible at least.
Assumably, and some evidentially (depending on the sources) its in a mountainous area of Ararat:
Gen 8:4 And the ark rested in the seventh month, on the seventeenth day of the month, upon the mountains of Ararat.
Gen 8:5 And the waters decreased continually until the tenth month: in the tenth month, on the first day of the month, were the tops of the mountains seen.
No, you ought be happy that we are related, even to Jesus.
Gen 3:20 And Adam called his wife's name Eve; because she was the mother of all living.
Act_17:26 And hath made of one blood all nations of men for to dwell on all the face of the earth, and hath determined the times before appointed, and the bounds of their habitation;
1Co_15:21 For since by man came death, by man came also the resurrection of the dead.
Pray that this helps.